Acta Mineralogica-Petrographica

ACTA MINERALOGICA-PETROGRAPHICA ABSTRACT SERIES

HU ISSN 1589-4835 HU ISSN 0324-6523

Editor-In-Chief Tibor Szederkényi

University of Szeged, Szeged, Hungary E-mail: [email protected]

Associate Editor Elemér Pál-Molnár

University of Szeged, Szeged, Hungary E-mail: [email protected]

EDITORIAL BOARD

Magdolna Hetényi University of Szeged, Szeged, Hungary

Gábor Papp Hungarian Natural History Museum, Budapest,

Hungary

Péter Árkai Laboratory for Geochemical Research, Hungarian

Academy of Sciences, Budapest, Hungary

Dr. Csaba Szabó Eötvös Loránd University, Budapest, Hungary

György Buda

Eötvös Loránd University, Budapest, Hungary Gyula Szöőr

University of Debrecen, Debrecen, Hungary

Imre Kubovics Eötvös Loránd University, Budapest, Hungary

István Viczián Hungarian Institute of Geology, Budapest, Hungary

Tibor Zelenka

Hungarian Geological Survey, Budapest, Hungary

Abbreviated title:

Acta Mineral. Petrogr. Abstr. Ser., Szeged

The Acta Mineralogica-Petrographica is published by the Department of Mineralogy, Geochemistry and Petrology, University of Szeged

On the cover: Lamellar limestone, Létrás-tető, Bükk Mountains, Hungary. Photo: Attila Kovács.

Designed by: Elemér Pál Molnár & György Sipos

A forum for giving an insight in the state of the art of Mineral Sciences in the Carpathian–Pannonian Region…

MCC2 2nd MINERAL SCIENCES IN THE CARPATHIANS

INTERNATIONAL CONFERENCE Miskolc, Hungary, 6–7 March 2003

ABSTRACTS

Edited by

Béla Fehér and Sándor Szakáll

English text was revised for major grammatical problems by

Erzsébet Tóth, Tamás Váczi and Tamás G. Weiszburg

Sponsored by

Koch Sándor Foundation (Miskolc) Mineralholding Ltd. (Budapest)

Foundation for Hungarian Minerals (Miskolc) Socrates/Erasmus Curriculum Development Programme (CDA) on

a Co-ordinated European Curriculum in Mineral Sciences

Szeged, Hungary

2003

Organizers

Herman Ottó Museum, Miskolc University of Miskolc

Co-organizers

Austrian Mineralogical Society Hungarian Geological Society

Mineralogical Society of Poland Mineralogical Society of Romania

Slovak Geological Society Ukrainian Mineralogical Society

CBGA Commission on Mineralogy and Geochemistry

INTERNATIONAL SCIENTIFIC BOARD Martin Chovan Comenius University, Bratislava, Slovakia Aleksandra Gawęda University of Silesia, Sosnowiec, Poland Friedrich Koller University of Vienna, Vienna, Austria Victor M. Kvasnytsya Institute of Geochemistry, Mineralogy and Ore Formation, National Academy of Sciences, Kyiv, Ukraine Milan Novák Masaryk University, Brno, Czech Republic Gábor Papp Hungarian Natural History Museum, Budapest, Hungary Gheorghe Udubaşa Geological Institute of Romania, Bucharest, Romania LOCAL ORGANIZING COMMITTEE Sándor Szakáll (Chairman) University of Miskolc, Miskolc, Hungary Béla Fehér Herman Ottó Museum, Miskolc, Hungary Ferenc Mádai University of Miskolc, Miskolc, Hungary Timea Tóth-Szabó Herman Ottó Museum, Miskolc, Hungary

Acta Mineralogica-Petrographica, Abstract Series 1, Szeged, 2003

3

INCORPORATION OF “INVISIBLE GOLD” TO THE SULPHIDE MINERALS FROMTATRIC UNIT (WESTERN CARPATHIANS, SLOVAK REPUBLIC)

ANDRÁŠ, P.1, CHOVAN, M.2 & OZDÍN, D.21 Geological Institute, Slovak Academy of Sciences, Severná 5, SK-974 01 Banská Bystrica, Slovak Republic.E-mail: [email protected] Deparment of Mineralogy and Petrology, Comenius University, Mlynská dolina G, SK-842 15 Bratislava, Slovak Republic.

The main gold carriers among the sulphide minerals ofthe Tatric Unit are arsenopyrite and pyrite. They are usuallyenriched in Sb and their characteristic feature is the stronginhomogeneity caused preferentially by negative As-Au vs.S-(Sb, Fe) correlation. The Au contents in arsenopyrite reachup to 6700 ppm (point analyses from the Trojárová deposit)and in pyrite vary from 0 to 62 ppm (from the Pezinok de-posit). Mössbauer spectroscopy proved that the dominantpart of the Au content in gold-bearing sulphide minerals is(with the exception of the Jasenie deposit) represented byinvisible gold.

The incorporation of Au into the crystals show many ir-regularities. We cannot define any definite scheme but wecan present several relatively expressive trends:

It is possible to distinguish three types of gold-bearingsulphide crystals: with more or less homogeneous distribu-tion of Au, with Au-enriched crystal cores and Au enrichedcrystal rims. The Au-enrichment shows an important positivecorrelation with As contents. This correlation is usually ab-sent in homogeneous sulphide crystals. Au-As enrichment ofcrystal rims was described from the Malé Karpaty Mts. re-gion (Pezinok, Trojárová deposits) and from some occur-rences of Nízke Tatry Mts. (Mlynná dolina Valley). Oppositetrend was observed at the Dúbrava, Vyšná Boca and NižnáBoca deposits (Nízke Tatry Mts.).

Incorporation of Au into the sulphide minerals dependson various factors: stoichiometry, stability of the aqueouscomplexes, presence of a suitable bonding-relations. Impor-tant supposition of gold incorporation to the sulphides is thehigh arsenic concentration. The presented process is usuallyaccompanied by Sb, S and Fe content decrease in connectionwith the acidification of the ore-forming fluids. Critical valueof this decrease is different at various deposits but is usuallyapproximately constant within one single deposit.

Au enters into the crystals during favourable conditionsfrom CO2 containing aqueous solution of low salinities (from1 to 11 weight equiv. % NaCl). Homogenization tempera-tures vary from 230 to 325 °C and the crystallization tem-peratures are about 330-450 °C. The coprecipitation of Fe,

As, S, Sb with Au usually follow the temporary increase ofthe As-content during the dynamic varying crystallizationconditions, the suitable temperature and pH conditions. Thequiet stable crystallization conditions seems to be not verysuitable for Au-incorporation.

After some common assumptions the submicroscopicgold is situated in lattice deformations. WAGNER et al.(1988) and CATHELINEAU et al. (1989) published opinionthat Au is incorporated to the sulpides in “non-metallic”anion form. BOYLE (1979) and COOK & CHRYSSOULIS(1990) suggested that Au substitutes for As in arsenopyrite.This hypothesis is based on comparison of ionic radii ofcovalently bonded As and Au. JOHAN et al. (1989) usedelectron-probe data from gold-rich arsenopyrite and stoichi-ometric calculations to propose that Au is substituting for theexcess As, which actually is present in Fe sites. SCHOONENet al. (1992) and FLEET et al. (1993) show the great impor-tance of adsorption-redox reactions on surface of the sul-phides growth zones in the gold-bearing sulphide ores form-ing process. The Au transport is possible in form of miscel-laneous fluids (by diffusion too) and Au is not incorporatedto sulphide structure but to pores, vacancies and on surfaceof mineral growth-zones. According to this assumption py-rite and arsenopyrite contain in aqueous fluids at the growthplain surfaces oxidizable S-H and Sx-H surface groups (≡SSH), so they can reduce AuOH(H2O)0 ligands and createAu-S complexes on surface of arsenopyrite and pyritecrystals (SCHOONEN et al. 1992).

The last mentioned mechanism is the most probable onefor the investigated Western Carpathian deposits. Such as-sumption could explain nearly any As:Au correlation inICP/MS-laser ablation and microprobe point analyses and onthe other hand an important As:Au correlation in AAS bulk-analyses of distinct growth zones of gold-bearing sulphideminerals (there were realised parallel analyses of separatelydissolved crystal rims and crystal cores).


4

WESTERN CARPATHIAN AND SELECTED EUROPEAN Sb-MINERALIZATIONS;Pb -ISOTOPE STUDY

ANDRÁŠ, P.1, CHOVAN, M.2, SCHROLL, E.3, NEIVA, A. M. R.4, KRÁL, J.5 & ZACHARIÁŠ, J.61 Geological Institute, Slovak Academy of Sciences, Severná 5, SK-974 01 Banská Bystrica, Slovak Republic.E-mail: [email protected] Deparment of Mineralogy and Petrology, Comenius University, Mlynská dolina G, SK-842 15 Bratislava, Slovak Republic.3, Institute of Mineralogy and Crystallography, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.4 Departamento de Ciencias da Terra, Universidade de Coimbra, P-3000 Coimbra, Portugal.

5 Slovak Geological Office - Geological Survey of Slovak Republic, Mlynská dolina 1, SK-817 04 Bratislava, Slovak Rep.

6 Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University, Albertov 6,CZ-128 43 Praha 2, Czech Republic.

The Pb-isotope study of Sb-mineralizations from theWestern Carpathians show a polycyclic character of the oreforming process.

Tatric Unit - the oldest model ages (corresponding touranogenic lead) were determined in samples from the NízkeTatry Mts (about 400 Ma). The second group of the datafrom this region vary between 300-330 Ma and the third oneabout 200 Ma (ANDRÁŠ et al., 1998). The main field of theresults from the Malé Karpaty Mts. is clustered round time-linea at 200-250 Ma (Pezinok deposit). The second group ofthe model ages is about 110-120 Ma (Pezinok and Pernekdeposits). Kriváň occurrence (Vysoké Tatry Mts.) belongs tothe last group (155-160 Ma). The Sb-mineralization from theHelcmanovce, Poproč and Grexa deposits (Gemeric Unit) isconnected with some younger events (110-140 Ma), includ-ing Permian volcanism. The special position (negative modelage) have the samples from Zlatá Baňa neovolcanic deposit.The source of the lead from Sb-deposits of the Western Car-pathians is not homogeneous and could be connected withthe wall rocks. The lead is derived from crustal rocks, orrelated material.

Eastern Alps. The model ages calculated from the leadisotopes of stibnite from Schlaining (Penninic Rechnitz Win-dow) deposit correspond with the young Alpidic age. Themodel ages of the other mineralizations can be interpreted aspre-Alpidic. The oldest model ages give stibnite from Draurange: Obertilliach (440 Ma), Radlbergalm (up to 385 Ma)and Rabant (360 Ma). The most important part of the resultsindicate model ages around 250 Ma. Data from Guginock(Drau range) and Brückl (Gurktal thrust system) indicateinfluences of younger events and ore-mobilization processes.The large spread of the data is partly due to the presence ofyoung upper crustal Pb enriched in 206Pb and 208Pb in Varis-can vein type deposits, partly also due to the addition ofradiogenic Pb during remobilization of ores under metamor-phic conditions of the Alpine orogenic process. The leadisotope data show the importance of the fluid mixing in theorigin of the veins and suggest that the lead was leachedfrom the wall rocks (ANDRÁŠ et al., 1998).

The Pb model ages for the Sb-mineralizations of the Bo-hemian Massif coincide by and large with the assumed time

of ore formation during Variscan orogeny. The oldest modelages determined from Krásna Hora deposit (510–435 Ma).Pb-isotope data from Hynčice deposit correspond with De-vonian age – 380 Ma and the sample from Příbram withCarboniferous (or Lower Permian?) age – 295 Ma. With theexception of the data from Krásna Hora deposit the samplesindicate average crust origin of lead (µ1 < 9.80).

The oldest 206Pb/204Pb model ages both from Dúrico –Beirão district and from Trás-os-Montés (Galicia-Trás-os-Montés zone, Northern Portugal) correspond with Devo-nian age. They range from 405 (Alto do Subrido, Dúrico –Beirão district and Coitadinha-Grijó, Trás-os-Montés) up to320 Ma (Alto do Subrido and Medas, Dúrico – Beirão dis-trict). The majority of the data is concentrated to the fieldbordered by values from 390 to 320 Ma (Alto do Subrido,Aguiar de Sousa-Abelheira, Moinho do Picão, Dúrico –Beirão district). Two samples: from Pinheirinhos and fromBorralhal (both from Dúrico – Beirão district) show someyounger mineralization formation about 245 Ma. One an-other sample from Borralhal gives model age at about 120Ma (Cretaceous?) which represent the result of partialremobilization of the original mineralization .

The Pb in stibnite mineralizations is derived from ho-mogenous crustal source. The lead gives µ1 values between9.66 and 10.04 which is higher than the average crust value(9.74). Only the µ1 values from 2 samples (from Grijó andfrom Medas) are close to the upper crustal lead (µ1 > 10). Inthe Dúrico-Beirão district were the metals mobilized frommetamorphic complexes during the regional metamorphosisand during the intrusion of granitoides (304–280 Ma).

Data from Northern Portugal and from Bohemian Massif(in contradiction to Western Carpathian and Eastern Alpinearea) present the features of the old Variscan terrains withoutsignificant younger Alpine overprint.

ReferenceANDRÁŠ, P., CHOVAN, M. & SCHROLL, E. (1998). Car-

pathian - Balkan Geological Association XVI Congress(Vienna), 4.


5

EVOLUTION OF ORE-FORMING FLUIDS AT PEZINOK-KOLÁRSKY VRCHSb-Au DEPOSIT (WESTERN CARPATHIANS, SLOVAKIA)

ANDRÁŠ, P.1, LUPTÁKOVÁ, J.1 & KOTULOVÁ, J.21 Geological Institute, Slovak Academy of Sciences, Severná 5, SK-974 01 Banská Bystrica, Slovak Republic.E-mail: [email protected] Slovak Geological Institute of Dionýz Štúr, Mlynská dolina 1, SK-817 04 Bratislava, Slovak Republic.

Pezinok-Kolársky vrch Sb-Au deposit belongs to thegroup of Sb-Au-FeS2 ore deposits of Malé Karpaty Mts.associated with basic volcanism. The deposit is situated inabout 3500 m long tectonic zone of NW-SE direction. Themineralised structure is 25-70 m thick and about 430 m longat the surface. Two types of ore mineralisations have beendistinguished: 1 – metamorphosed, primarily volcano-sedimentary pyrite mineralisation, genetically related toDevonian basic submarine volcanism, and 2 – epigenetichydrothermal Sb (Au-As) mineralisation located mostly intectonically deformed black shales. Metallic elements couldhave been mobilised from the black shales by the circulationof fluids released during regional and periplutonic metamor-phism caused by granitoid rock intrusion (CHOVAN et al.,1992).

Four stages of epigenetic mineralisation have been rec-ognised: 1. - gold-bearing quartz-arsenopyrite-pyrite, 2. -quartz-pyrite-arsenopyrite±löllingite, tetrahedrite, chalcopy-rite, 3. - quartz-carbonate-stibnite± gudmundite, pyrrhotite,pyrite, sphalerite, Pb-Sb sulphosalts, berthierite, 4. - stibnite-kermesite±antimony, valentinite, bismuth, Bi-Sb sulphosalts(CAMBEL, 1959; ANDRÁŠ, 1983).

Lead in stibnites is of upper crustal origin. The youngmodel ages (220-230 and 110-130 Ma) are caused by theyounger metamorphic processes and rejuvenation of Sb (-Au) ores. Isotope distribution shows at least two sources ofsulphur. Biogenic sulphur had an important role predomi-nantly in metamorphosed, primarily volcano-sedimentarypyrite mineralisation and in Sb hydrothermal minerals withFe content (gudmundite, berthierite). Sulphur isotopes ingold-bearing sulphide mineralisation are differentiated: thelight biogenic sulphur is incorporated into pyrite while sul-phur from deep lying source into arsenopyrite. Hydrothermalfluids (mainly 3rd and 4th stage) were probably meteoric inorigin but they incorporated predominantly magmatic sul-phur that could have been derived from the older plutonicrocks or of juvenile origin. Distribution of carbon and oxy-gen isotopes in carbonates and distribution of oxygen iso-topes in quartz of Sb mineralisation is inhomogeneous. Thevalues show a relatively wide range and indicate predomi-nantly meteoric origin of fluids (ANDRÁŠ et al., 1999).

The character of ore-forming fluids was specified bymeans of fluid inclusion study. Quartz of 1st stage contained

secondary two-phase fluid inclusions. Salinity of includedfluid is between 6 and 11 wt. % NaCl equiv. Nevertheless,eutectic temperature values (-45 to -55°C) suggest the pres-ence of divalent cations such as Ca2+. Inclusions homoge-nised to the liquid in the temperature range of 140-275°C.Calculated fluid density is around 0,88 g/cm3. The estimatedpressure is about 3 kbar. Fluids were probably endogenous-metamorphogenous in origin. Quartz coexisting with stib-nite-sulphosalts mineralisation of 2nd and 3rd stage containedprimary two-phase fluid inclusions. These inclusions en-closed NaCl-H2O±CaCl2 solutions with moderate to highsalinity (7 – 25 wt. % NaCl equiv.) as resulted from lowtemperature measurements. Presence of bivalent cations(Ca2+) is indicated by eutectic temperatures below -45°C.Homogenisation to liquid phase occurred between 145-200°C. According to various independent thermometers,temperature of crystallisation ranges from 350 to 390°C.Two-phase aqueous fluid inclusions from 4th stage quartzcontained CaCl2-NaCl-H2O solutions with salinity of 8-25wt. % CaCl2 equiv. Inclusions homogenised to the liquid inthe temperature range from 89 to 199°C. Density of includedfluid varied between 0,96 and 1,16 g/cm3. Obtained resultsshow that of hydrothermal fluids were similar in characterduring whole ore-forming process. However, decrease inhomogenisation temperatures indicates apparent cooling ofthe hydrothermal system.

The investigations Pezinok-Kolársky vrch deposit sup-ported the increasing role of meteoric water and its intensivemixing with endogenous fluids while penetrating wall rocksduring the metamorphic process.

ReferencesANDRÁŠ, P. (1983). Thesis. Manuscript, 159 p.ANDRÁŠ, P., KOTULOVÁ, J., HAŠKOVÁ, A & DUBAJ,

D. (1999). Uhlí-Rudy-Geologický průzkum, 11, 6: 24-30.CAMBEL, B. (1959). Acta geol. geogr. Univ. Comen.,

Geogr., 3, 338 p.CHOVAN, M., ROJKOVIČ, I., ANDRÁŠ, P. & HANAS, P.

(l992). Geol. Carpath., 43/5: 275-286.


6

APPLICATION OF THE SURFACE ENERGIES OF A CRYSTAL FOR THE CALCULATIONOF THE RELATIVE FORMATION TEMPERATURE

BABIĆ, D.Faculty of Mining and Geology, University of Belgrade, Djušina 7, YU-11000 Belgrade, Yugoslavia.E-mail: [email protected]

In this paper the results of the application of the Gibbs-Wulff’s theorem upon some crystal morphological types andthe dependence of the surface energies on temperature arepresented. We obtained an expression that enables us tocalculate the relative formation temperature of the{100}{111} crystal form combination for pyrite, fluorite andgalena. The results for pyrite and galena crystals are pre-sented in details.

Applying the Gibbs-Wulff’s theorem on the {100}{111}crystal form combination in the cubic system we obtained thefollowing expression:

( ) YTT.X nk

−−=

2

351

In this expression X is the size of the (111) planes (mm, cm);Y is the size of the (100)-planes (mm, cm); Tk is the criticaltemperature of the crystal formation (K); T is the unknownrelative temperature of formation (K) and n is an exponentthat has different values for different minerals (n = 0.062 forpyrite and galena etc.). The relative temperature of formationcan be calculated from the above mentioned expression if wemeasure the values X and Y on the real crystal and if weknow Tk.

The calculated values for the relative formation tempera-ture of pyrite {100}{111} crystal form combinations fromLipe (copper deposit, East Serbia) are given in Table 1. Forpyrite, Tk is 1014 K in the Fe-S system.

Table 1: Calculated relative formation temperature for pyrite{100}{111} crystal form combinations, Lipe deposit, East

Serbia.

Ymeas.(mm) X meas.(mm) T (ºC) Number ofcrystals

1.8 0.43 315 211.8 0.42 270 152.0 0.47 260 182.2 0.53 316 123.0 0.40 316 23.0 0.70 331 6

Table 2: Calculated relative formation temperature for ga-lena {100}{111} crystal form combinations, Ravnaja de-

posit, West Serbia.

Ymeas.(mm) X meas.(mm) T oC Number ofcrystal

2.62 0.62 276 151.45 0.36 262 231.36 0.31 223 27

For galena, the {100}{111} crystal form combination ex-pression is the same as for pyrite, but Tk is different. Forgalena, Tk is 989 K in the Fe-Pb-S and Pb-S systems. Table 2presents the calculated values for the relative formation tem-perature of galena {100}{111} crystal form combinationsfrom the Ravnaja Pb-Zn-deposit (West Serbia).


7

THE MORPHOLOGICAL STABILITY OF GROWING CRYSTALS

BABIĆ, D.Faculty of Mining and Geology, University of Belgrade, Djušina 7, YU-11000 Belgrade, Yugoslavia.E-mail: [email protected]

The morphological stability of growing crystals is a veryold problem preoccupying many scientists. The primaryproblem of the morphological stability of growing crystals isthe recovery of the mathematical expression that depictscrystal growth. To solve this problem, we start in this paperfrom the perturbation of field concentration in the interphasesborder that is represented by a Laplace equation. The fieldconcentration at the interphase border is a real physical field,upon which mathematical physics can be applied. By partialsolution of the Laplace equation, and the presentation of thatsolution as Legendre polynomial, we can get a complexfunction that describes the growth of several crystal forms inthe cubic system.

Growth of the {100} and {100}{111} crystal formsGrowth of the {100} crystal form can be described by the

following function (perturbation of field concentration) at the

interphase border: ( )4 0d aidt

dd

= Y - =l

l

l ; ψ = (Ck-C0),

where Ck is the density of a crystal, C0 is the density at the

interphase border; ( 00)la

RTdg

= , where γ(100) is the interphase

surface energy at the (100)-plane (erg/cm2),R = 8.314·107erg/mol K, T is the temperature in K and d isthe thickness of an interphase border; l is the fundamental

number of lamina growth. If we solve the above function,we get four symmetrical solutions for l =1, 2 that are pre-sented in Fig. 1a.

The growth of the {100}{111} combination can be de-

scribed by the function ( )24 0

dai

dtdd

= Y - =l

l

l . If we

solve this function, we get eight symmetrical solutions forl =1, 2 that are presented in Fig. 1b.

Growth of the {111} and {111}{100} crystal formsThe growth of the {111} crystal form can be described by

the function ( )3 0d

bidt

dd

= Y - =l

l

l , (111)b

RTdg

= ; the

growth of the {111}{100} crystal form can be described by

the function ( )23 0

dbi

dtdd

= Y - =l

l

l . If we solve these

functions, we get adequate solutions for l =1, 2. The solu-tions for the growth of the {111} and {111}{100} crystalforms are presented in Fig. 1c and Fig. 1d, respectively.

Fig. 1a Fig. 1b Fig. 1c Fig. 1d


8

PHOSPHATE-BEARING MINERALS IN EPITHERMAL SYSTEMS – A FEW EXAMPLESFROM THE CARPATHIAN-PANNONIAN REGION

BAJNÓCZI, B.1, SERES-HARTAI, É.2 & SZAKÁLL, S.31 Laboratory for Geochemical Research, Hungarian Academy of Sciences, Budaörsi út 45, H-1112 Budapest, Hungary.E-mail: [email protected] Department of Geology and Mineral Resources, University of Miskolc, H-3515 Miskolc-Egyetemváros, Hungary.3 Department of Mineralogy and Petrology, University of Miskolc, H-3515 Miskolc-Egyetemváros, Hungary.

Sulphate minerals have a significant role in the alterationzones of epithermal systems, as sulphate-containing solutionsof different origin are present in both HS and LS systems.The most typical sulphate mineral in these systems is alunite.

It is not widely known that during these processes phos-phate-bearing minerals are also formed - though in a lessamount. The phosphate-bearing minerals in the alterationzones of epithermal mineralizations appear in a wide rangeof genetic environment, from hydrothermal to supergeneprocesses.

While the sulphur is abundant in the hydrothermal solu-tions of epithermal systems, the phosphor is subordinate.Thus, the main source of phosphor can be the apatite ofmagmatic rocks, which is dissolved in strongly acidic fluidsat high temperature (STOFFREGEN & ALPERS, 1987).

An early-formed mineral is the woodhouseite (alumin-ium-phosphate-sulphate or APS mineral), which is isostruc-tural with alunite. Two new occurrences of woodhouseitewere found in the Carpathian–Pannonian region (BAJNÓCZIet al., 2003). One of these occurrences is at the eastern partof the Velence Mountains (Hungary), in the quartz-alunitezone of the HS system related to Paleogene volcanites. Theother occurrence is at Podpolom, Javorie Mountains (Slova-kia), in the siliceous breccias of the HS system, which isdeveloped in a Neogene volcanic complex. In both areas thewoodhouseite occurs in the core of the magmatic-hydrothermal alunite or in the siliceous matrix, which meansthat it was formed prior to alunite. Beside woodhouseite, two

other phosphate minerals, augelite and crandallite were alsofound.

Near Legyesbénye, Tokaj Mountains, Hungary, aluniteappears in strongly silicified rocks, filling fissures and closedvugs. Electron microprobe studies proved the enrichment ofPb, Al, and P in the core of the alunite crystals (SZAKÁLLet al., 1986). The elongated forms of minerals suggest thatthe alunites are pseudomorphs of apatite. The chemical com-position indicates a transition for hinsdalite (a mineral inrelation with woodhouseite). It seems that the formation ofthe APS minerals took place before the crystallization ofalunite.

However, we suppose that the APS minerals occurringalong the opened fractures in spherical or radial, needle-likeclusters are of supergene origin. These are crandallite (Pod-polom, Slovakia and Recsk-Parádfürdő, Hungary), wavellite,faustite and variscite (Parádfürdő) and plumbogummite(Pátka and Nadap, Hungary). In association with these min-erals jarosite and clay minerals are common.

ReferencesBAJNÓCZI, B., SERES-HARTAI, É. & NAGY, G. (2003).

Acta Geol. Hung. (in press)STOFFREGEN, R. E. & ALPERS, C. N. (1987). Can. Min-

eral., 25: 201-211.SZAKÁLL, S., TAKÁCS, J. & WEISZBURG, T. (1986).

Natura Borsodiensis, 1: 20-34


9

SOURCE MINERALS OF RADON ANOMALIES – HUNGARIAN CASE STUDIES

BARABÁS, A.1, BURJÁN, Zs.1, BREITNER, D.1, SZABÓ, Cs.1, NAGY-BALOGH, J.1, GÁL-SÓLYMOS, K.1 &MOLNÁR, Zs.21 Department of Petrology and Geochemistry, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest,Hungary.E-mail: [email protected] Institute of Nuclear Techniques, Budapest University of Technology and Economics, Hungary.

IntroductionRadon, a radioactive noble gas, has three isotopes found

in natural environments, which originate from decay series ofuranium or thorium. The 222Rn radioisotope, having a halflife of 3.8 days, enter the atmosphere of ground-level bed-rooms and living rooms of houses and may cause, in a longterm scale, serious health problem as snipped into lung thenattacking the tissues by emitting alpha particles. In Hungary,due to extended measurement of indoor radon level has beencarrying out by the RAD Lauder Lab (Budapest), now sev-eral villages and towns are known characterized with ele-vated radon activity concentration. Three of these settlementsand an additional one have been taken under a serious studyin order to determine the potential sources of radon enteringthe houses. For this reason, detailed sedimentological, pet-rographical and geochemical study was performed on differ-ent materials (e.g. granite, soils) collected from the settle-ments chosen.

Geological backgroundThe areas studied were as follows: villages of Sukoró (S)

in the Velence Mountains, Nézsa (N) at the foot of one of theMesozoic blocks on the left bank of the Danube (CserhátMountains), Sajóhídvég (SH) (along Sajó River, North EastHungary), and Tápiószentmárton in the Great HungarianPlain (T). All of them represent significantly different geo-logical environments such as Paleozoic (carboniferous)granite (S), Mesozoic limestones and dolomites surroundedand partly covered by Oligocene and young sediments (N)and alluvial fan of River Sajó (SH), which consists mostly ofsand, loess, silt and gravel, and in the case of locality T, loessand running sand cover the surface.

MethodsWe have collected samples from both the surface (S, N,

SH, T) and from shallow drills (N, SH). The samples in allcases were sieved and subsequently sorted and subjected to awide range of examinations as follows: heavy mineralogy,gamma-spectrometry, trace element analysis (by instrumentof neutron activation and optical emission spectrometry),electron microprobe and Roentgen diffraction analysis.Furthermore, at the N locality outdoor radon measurementswere carried out in soil gas and in groundwater.

Results and conclusionsNeutron activation analysis showed no elevated amounts

of radioactive elements (basically U and Th) in the bulksamples such as granite and granite rubble (up to 5.37 ppmU, 23.26 ppm Th), different kinds of soils (up to 3.2 ppm U,12.8 ppm Th) and loess (up to 2.4 ppm U, 9.5 ppm Th) com-pared to the Clarke values of these rock types. Electronmicroprobe analysis show in micrometer scale, potentialsource minerals such as monazite, xenotime, allanite, zirconand zirkelite, which contain the parental elements (U and Th)of radon. Among these minerals the monazite occurs mostfrequently and believed to be the most important radonemitter in the rocks and soils studied. Our petrographical andgeochemical results suggest that monazites could haveformed by near-surface alteration from allanite. This indi-cates that these physical and chemical processes, which pro-duce monazites may act recently, too. However, mineralsfound at the T locality show no alterations which can berelated to the low radon activity concentration at that loca-tion.


10

USING WOLLASTONITE FROM BĂIŢA BIHOR (APUSENI MOUNTAINS, ROMANIA) FORFAST-FIRING CERAMIC GLAZES

BENEA, M. & GOREA, M.Department of Mineralogy, Babes-Bolyai University, 1 Kogalniceanu St., RO-3400 Cluj-Napoca, Romania.E-mail: [email protected]

Wollastonite (CaSiO3) with a theoretical chemical com-position 48.25% CaO and 51.75% SiO2 is particularly suit-able for reducing shrinkage and increasing strength duringfast-firing as well as for improving gloss and reducing sur-face defects in glazes. During firing, a minimum volume ofgas is generated as compared to other traditional materials,resulting in a smooth surface with diminished pinholing.Wollastonite is the main source of CaO flux in glazes (andbodies) instead of lime. Since wollastonite contains silica aswell, glaze recipes employing it do not need as much rawsilica powder. In fast-fired glazes wollastonite smooths outrapidly and completely, and the SiO2 and CaO react morereadily to form silicates.

The polymetallic skarn ores from Băiţa Bihor, BihorMts., developed in fractures cutting carbonate-rich Triassic

deposits, contain about 100 various mineral species. Amongthem, wollastonite aggregates (up to 20 cm in diameter)locally form nearly monomineralic bodies.

Fibrous white wollastonite aggregates were characterizedby means of X-ray diffraction (XRD) and optical micros-copy.

In order to test the wall tiles ceramic glazes, 5, 10 and15% wollastonite were introduced into the recipe. The ther-mal treatment was conducted for 45 minutes between 1130-1140 °C.

The obtained ceramic glazes showed an increased me-chanical strength, a better resistance again acid corrosion andan improved gloss.


11

STRUCTURAL CONTROLS OF FLUID MOBILIZATION PROCESSES CONNECTED TOTHE VARISCAN AND ALPINE IGNEOUS ACTIVITY IN THE VELENCE MTS. (WESTERNHUNGARY) ON THE BASIS OF STUDIES OF FLUID INCLUSION PLANES

BENKÓ, Zs. & MOLNÁR, F.Department of Mineralogy, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected]

The Velence Mts. is a part of a largely covered NE–SWoriented belt that consists of Variscan granitoid intrusionsand Palaeogene andesitic-dioritic intrusive and volcaniccomplexes (among other sedimentary and metamorphicrocks) along the southern margin of a crustal unit that hasbeen escaped from the Alpean collision zone due to north-east-oriented lateral movements of Neogene age. In the areaof the Velence Mts., both Variscan and Alpine igneous rocksare strongly mineralized and there are field, mineralogical-geochemical, as well as fluid inclusion evidences of the in-teraction of the Palaeogene hydrothermal system with thegranitoid intrusion that has already been mineralised duringthe Variscan post-magmatic activity. Fluid inclusion studieson granite-related pegmatite, quartz-molybdenite stockworkand base-metal bearing vein-filling mineralization as well ason the porphyry-copper and high-sulphidation type epither-mal mineralization connected to the emplacement of intru-sions and volcanic rocks of Palaeogene age revealed signifi-cant differences in chemical and phase compositions of fluidsof these various hydrothermal systems (MOLNÁR et al.,1995; MOLNÁR, 1996, 1997). In the eastern part of theVelence Mts., there are small intrusions and dikes of Palaeo-gene age that intrude into the old granite, and outcrops andquarries excellently expose their tectonised and hydrother-mally altered zones. Fracturation of granitic rocks and typeof fluids that circulated along fractures can be reconstructedon the basis of orientation (dip direction and dip angle)measurements and microthermometric analyses of secondaryplanes of fluid inclusion assemblages in rock-forming quartztogether with the evaluation of field observations on jointsand faults.

The tectonic regime at the time of the emplacement of theVariscan intrusion is characterized by the orientation apliteand granite-porphyry dikes which is NE–SW in the recentposition of the granite. Analyses of field data and data offluid inclusion planes revealed that the high temperature(400–600°C at 2 kbar pressure) and relatively dilute earlymagmatic fluids of the Variscan system circulated along

fractures that have N–S strike-direction and were developeddue to a N–S oriented compression. The late Variscan fluidswith carbonic-aqueous composition (300–400 °C at 1.5–2.5kbars pressure) were channelled by NW–SE oriented frac-tures.

The Palaeogene fluids circulated under low pressureconditions (20–300 bars) that resulted in their boiling. Twostages of Palaeogene hydrothermal fluid circulation thataffected the Variscan granite have been recognised. Theolder Palaeogene fluid circulation event took place mostlyalong E-W oriented fractures and it was associated withintense illitic alteration of granite. These fluids are charac-terized by about 250°C temperature and low salinities. Thesecond phase of Palaeogene fluid mobilization may be con-nected to a second generation of intermediate intrusions. Thisphase of fluid circulation was connected to a NW–SE ori-ented shear-zone and is characterised by the occurrence ofhigh temperature (around 400°C) and low salinity, as well aslow-temperature (around 250–300°C) and low and high sa-linity hydrothermal solutions.

The post-Palaeogene fracturation of granite is character-ized by NE–SW orientation of joints and can be connected tothe NE-oriented large scale lateral movements of Neogeneage. A second generation of young open fractures is NW–SEoriented and they can be connected to the recent-subrecentstress field of the Pannonian Basin.

This work was supported by the OTKA (HNSF) T035095 research grant to F. Molnár.

ReferencesMOLNÁR, F. (1996). Plate tectonic aspects of the metal-

logeny in the Carpatho-Balkan region (Popov et al. Eds).UNESCO-IGCP project No. 356, vol. 2.: 29-44.

MOLNÁR, F. (1997). Földt. Közl., 127: 1-17.MOLNÁR, F., TÖRÖK, K. & JONES, P. (1995). Acta Geol.

Hung., 31: 57-80


12

SOME FEATURES OF NEOGENE VOLCANIC STRUCTURES AND METALLOGENICPRODUCTS FROM VOIA AREA, METALIFERI MOUNTAINS, ROMANIA

BERBELEAC, I.Institute of Geodynamics, Romanian Academy, Jean-Louis Calderon Str. 19-21, RO-70201 Bucharest, Romania.E-mail: [email protected], [email protected]

Voia area is situated in the central part of the Brad-Sacaramb Tertiary Basin, Metaliferi Mountains (MM),South Apuseni Mountains. This basin is coupled with open-ing of the Pannonian Basin. It is the result of an extensionalprevail period (17–14 Ma) followed by a period (14–11 Ma)of strike-slip faulting with accommodation of extension pull-apart structures (DREW & BERGER, 2001). The subvol-canic intrusions and volcanic rocks form Voia area, as wellas in other parts of MM, are preferentially localized in theextensional stepovers relate with this younger deformationperiod (14–11 Ma).

Voia area represents a region of about 20 km2. It is builtup of Jurassic ophiolites – calc-alkaline volcanics and theircovers represented by Upper Jurassic-Paleogene sedimen-tary formations, by Badenian-Sarmatian sedimentary andvolcano-sedimentary formations and by Sarmatian-Pannonian volcanic rocks. At the surface only small patchesof Lower Miocene sedimentary and volcano-sedimentaryrocks are present. The Pre-Tertiary E–W and NE–SW (reac-tivated) faults and the Tertiary NW–SE normal and strike-slip faults controlled the Neogene volcanic structures.

Concerning Voia Neogene volcanic activity it is impor-tant to note the followings: 1) the Neogene magmatic rocks(11.7-11.54 ± 0.5 Ma, ROSU, 2001) are calc-alkaline incomposition and consist of quartz amphibole ± biotite ande-sites, quartz amphibole biotite ± pyroxene andesites, por-phyry microdiorites and amphibole-quartz ± pyroxene ande-sites; 2) the volcanic structures show a great diversity offorms such as simple volcanoes (Buha, Momeasa, Geamana)and stratovolcanoes (Cetras, Macris) with extrusive domes,lava flows ± talus and avalanche deposits; 3) the volcanicnecks describe a circle with some subvolcanic bodies withinit like in the Sacaramb area and 4) a multi-stage Voia ande-sitic-dioritic subvolcanic body (VADSB) and other andesiticdikes have been recognized in some boreholes. The metallo-genic processes are dominantly related with high fluid con-tent of Neogene calc-alkaline magmas; the mineral reactionsin extensive fluid-rock interactions with basement and coverformations must be taken into account. In spite of the verysmall area great varieties of the mineralization and alteration

types are known in Voia area, such as: 1) pyrite-calcium andcalcium-magnesian skarns and hornfelses have been foundin some boreholes and formed through heat and pyro- andhydrometamorphism processes, probably close to Eo-Cretaceous intrusions and VADSB; 2) the porphyry copper–gold ore body with a side like porphyry iron ± copper-goldore (BERBELEAC et al., 1985) and the argillic, propyliticand potassic alteration types genetically related withVADSB; 3) the Mo-base metal brecciated structure presentson the north-western contact of Macris-Cetras andesitic dyke(borehole no. 24); 4) the epithermal HS mineralization andalteration types such as Cu-As-Au quartz-clay minerals-barite veins (Paraul lui Avram) and marcasite-pyrite-clayminerals-gypsum (anhydrite)-alunite-diaspore dissemina-tions and veins in magmatic and sedimentary rocks and 5)the epithermal LS mineralization and alteration types as Au-pyrite disseminations in magmatic and sedimentary rocks,probably Au-base metal veins (borehole no. 17) and pyrite-marcasite breccia body from Lazuri stream. In the Voia areasome particular features are emphasized: 1) the abundanceof the gypsum-clay minerals-marcasite-pyrite assemblage inargillic alteration zone from the upper part of Voia subvol-canic body and anhydrite-pyrite±base metal sulfides towardsthe depth of this structure; 2) within VADSB there is a zonewith very chloritized rocks, richer in iron oxides and likeiron porphyry±Cu-Au ore and 3) there is a genetic link andpartial spatial superposition between the skarn occurrences,porphyry Cu-Au and hydrothermal mineralizations.

ReferencesBERBELEAC, I., ZAMARCA, A., DAVID, M.,

TANASESCU, I., BERINDE, N. (1985). D. S. Inst.Geol. Geofiz., LXIXL/2: 8-26.

DREW, J. I. & BERGER, R. B. (2001). Min. Deposits at thebeginning of the 21st Century, Pietrzynski et al (eds),Swets & Zeitlinger Publishers, 519-522.

ROSU, E. (2001). ABCD-GEODE 2001 Workshop VataBai, Romanian J. Mineral Deposits, 79,/Suppl. 2: 19-22.


13

GEOPHYSICAL SETTING OF THE DEEP WELL 6042 DELENI IN CENTRALTRANSYLVANIA, ROMANIA

BESUTIU, L.1, GORIE, J.2 & DORDEA, D.21 Institute of Geodynamics, Romanian Academy, Jean-Louis Calderon Str. 19-21, RO-70201 Bucharest, Romania.E-mail: [email protected] SC “Prospectiuni” SA, Caransebes Str. 1, Bucharest-32, Romania.

Deep well 6042 Deleni was drilled for hydrocarbon ex-ploration in the central part of Transylvanian Depression(TD). It penetrated at a depth of about 4700 m and wentthrough for more than 350 m, some basic rocks (basalts,basaltic-andesites, etc.), located beneath Tithonian carbonateseries (dolomites). The mafic sequence was considered byseveral authors as the ophiolite suture of the Transylvanianbranch of the Tethys Ocean.

The paper is intended to present airborne/surface geo-physical data related to the area in correlation with well-logging data (caliper logs, electric, gamma-ray, and neutronlogs) and previous regional geotectonic framework. It wasaimed at adding geophysical and tectonic setting to the thor-ough mineralogical studies dedicated to the mafic rocksencountered by this well (HOECK & IONESCU, 2003).

Gravity, magnetics (both ground and airborne), geother-mal gradient (heat flow), as well as seismics were taken intoaccount in this analysis. Various filtering techniques (matrixsmoothing, polynomial regression, etc.) were extensivelyused in order to improve the signal/noise ratio in separatingeffects made by sources of different extent and/or located atvarious depths.

Airborne data (CRISTESCU & STEFANCIUC, 1968)clearly outlined a large regional geomagnetic anomaly overthe whole central part of the TD. Later on, it has been fullyconfirmed in the images provided by the ground verticalcomponent geomagnetic map of Romania (AIRINEI et al.,1983, 1985).

Several previous geological interpretation (BESUTIU,1984) considered this regional geomagnetic effect as a com-posite anomaly mainly due to sources located at least at threelevels: (i) Dej tuffs, located in the upper part of the section;(ii) basic to intermediate igneous rocks located at the level ofthe TD basement; (iii) a large wavelength component due tothe basaltic layer geomagnetic expression in the “colder” partof TD.

It should be noted that analyses made on core samplesfrom the 6042 Deleni borehole clearly exhibited high mag-netic susceptibility for the above mentioned basalts, but rela-

tively low densities. The fact was attributed to the presenceof some deep fracture zones located at the basement level,hidden beneath the TD Mesozoic and Cenozoic cover. Grav-ity and geomagnetic data processing allowed outlining sev-eral regional deep faults striking eastward and north–north-eastward in the borehole area. The presence of the fracturezone is confirmed in the well logging data reflected in thecombined γ-ray highs, low resistivity, and larger neutronporosity values, which are completely unusual for basaltrocks.

Based on gravity and geomagnetic data, under the con-straint of seismics and rock physics laboratory determina-tions, attempts were made to model the borehole environ-ment.

Finally, some concluding remarks and speculations aremade on the regional geotectonic framework of the 6042Deleni deep well.

ReferencesAIRINEI, ST., STOENESCU, SC., VELCESCU G., RO-

MANESCU, D., VISARION, M., RADAN, S., ROTH,M., BESUTIU, L., BESUTIU, G. (1983). An. Inst. Geol.Geofiz. (ser. Geofizică, Hidrogeologie şi Geologie in-ginerească), LXIII: 5-11.

AIRINEI, ST., STOENESCU, SC., VELCESCU G., RO-MANESCU, D., VISARION, M., RADAN, S., ROTH,M., BESUTIU, L., BESUTIU, G. (1985). St. Cerc. Geol.Geofiz. Geogr., Geofizica, 23: 12-19.

BESUTIU, L. (1984). An. Inst. Geol. Geofiz., LXIV: 361-368.

CRISTESCU, T. & STEFANCIUC, A. (1968). The aero-magnetic map of the Romanian territory: The 5th Na-tional Symposium of Applied Geophysics and Physics ofthe Earth, Bucharest.

HÖCK, V. & IONESCU, C. (2003). Acta Mineralogica-Petrographica, Abstract Series 1 (this volume).


14

LEONITE IN PRE-CARPATHIAN EVAPORITES AND ITS TRANSFORMATION UNDERINCREASED TEMPERATURES

BILONIZHKA, P.National University of Lviv, Hrushevskogo 4, UA-79005 Lviv, Ukraine.E-mail: [email protected]

Leonite is a rare mineral in Precarpathian evaporites. Ithas been discovered as small admixture in the kainite andpolymineral rocks and as fibrous streaks in the clayey salif-erous breccia near and among potassium salt deposits.

Leonite is a light yellow, transparent, bitter-tasting min-eral with high solubility in water. Its lustre is waxy to vitre-ous. The mineral is firm in dry air. Under the microscopeleonite grains are colourless with low interferential colours(grey). Polysynthetic twins are sometimes visible. Someleonite grains have wavy extinction. The refractive indices ofleonite are: Nx=1.479; Ny=1.482; Nz=1.487; Nz-Nx=0.008.

On the X-ray powder diffraction patterns of the fibrousleonite from Stebnyk potassium mine the following reflec-tions appear: 6.1; 5.9; 5.25; 4.93; 4.77; 4.21; 3.97; 3.71; 3.52;3.49; 3.42; 3.30; 3.04; 2.87; 2.75; 2.62; 2.50; 2.46; 2.38;2.29; 2.21; 2.17 Å. They are similar to the reflections of thestandard X-ray powder diffraction pattern (JCPDS № 21-995).

The chemical composition of the studied leonite isK2O=25.30; MgO=11.01; SO3=43.75; H2O=19.66;Na2O=0.36; Cl=0.06 (wt%). Chlorine is connected withhalite admixture. The crystallochemical formula of leonite(after subtraction of halite) is K1.96Na0.04Mg1.00[SO4]2.00 •4H2O. The sodium in the formula may be connected to thepresence of blödite (Na2Mg(SO4)2 • 4H2O), that is in closeparagenetic association with leonite. Leonite and blödite arevery similar because their refractive indices are close to eachother. It is important to note that potassium may also substi-tute in blödite. Domain isomorphism (inclusions of blöditemicrolayers in the leonite structure and vice versa) is quitepossible between them, too.

Based on the TG data, the loss of structural water of thestudied leonite starts around 130°C. A bump on the dehydra-tion curve around 200°C testifies some delay in the process.About 10% of water is lost under that temperature. Dehydra-tion of the mineral is completed at about 240°С. The DTAcurve shows two endothermic effects at 167 and 212 °С,respectively.

Experimental investigations were run to study the natureof these thermal reactions. Samples of the fibrous leonitefrom Stebnyk mine were heated in a regulated oven at tem-peratures of 100, 150, 200, 250, 300 and 400°С, respectively.

Heating time was 30 minutes. Heating products were studiedby X-ray powder diffraction.

On the X-ray powder diffraction patterns of leoniteheated to 100 and 150°С all the reflections typical of naturalleonite were present, but peak intensities became smaller.

At 200°С the crystal structure collapses. The new phaseis most probably K2Mg[SO4]2 • 2H2O (dhkl: 6.7; 5.6; 3.56;3.36; 3.33; … Å). That crystalline phase exists only in anarrow temperature range and we do not know it from na-ture. Some admixtures of langbeinite (K2Mg2(SO4)3; 3.15;3.91; 2.67; 2.43; … Å) and arcanite (K2SO4; 3.36; 3.01; 2.91;2.87; … Å) phases appear as well.

Further heating to 250°С leads to the complete loss of thestructural water and to the formation of langbeinite (5.7;4.05; 3.15; 3.01; 2.76; 2.66; 2.41; 2.28; 2.17; … Å) and ar-canite (5.0; 4.18; 3.76; 3.51; 3.39; 3.15; 3.01; 2.91 (100);2.85; 2.66; 2.51; 2.43; … Å). These two phases remain stablealso at 300 and 400°С.

The transformation process of leonite can be representedwith the help of the following equation:

2K2Mg[SO4]2 • 4H2O = K2Mg2[SO4]3 +733.37 419.99100% 56.59%

K2[SO4] + 8H2O174.25 144.1323.76% 19.65%

Leonite admixtures in potassium salts are primary whileits interlayers in the clayey saliferous breccia are secondaryformations.

On the basis of these investigations we may assume thatduring catagenesis, under increasing pressure and tempera-ture, leonite decomposes and transforms through an unstable,intermediate dihydrate phase into langbeinite and arcanite.

Considering also geological time, this process may takeplace in evaporites at temperatures even lower than the tem-peratures suggested by the above experiments.


15

REE ACCESSORY MINERALS IN THE FELSIC SILICIC ROCKS OF THE WEST-CARPATHIANS: THEIR DISTRIBUTION, COMPOSITION AND STABILITY

BROSKA, I.Geological Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, P.O. Box 106, SK-840 05 Bratislava 45,Slovak Republic.E-mail: [email protected]

The paragenesis of the accessory minerals in the graniticrocks depends on the water or volatile content, and verystrongly on aluminosity and alkalinity of the primary melt.From among the different accessory minerals, the typomor-phic REE-bearing accessory minerals currently help to dis-criminate (by their presence or absence or physico-chemicalcharacter) following granite genetic suites in the WesternCarpathians: Palaeozoic orogenic I- and S- type and anoro-genic A- and S-type. Generally, the REE-rich accessorymineral assemblages typical for the I-type granites is formedby allanite, apatite, and sphene on the other hand the par-agenesis characteristic for the S-type granites containsmainly monazite, apatite, xenotime and garnet.

The allanite / monazite antagonism, which is importantfor the recognition of the S / I-type granite suites is verydistinctly developed in the West-Carpathian granites. Therelationships between monazite and allanite are explained bydifferent solubilities of these minerals when the solubility ofallanite in peraluminous granites is higher than monazite.Generally, allanite precipitated rather in metaluminous (orslightly peraluminous) than peraluminous granitic rocks, soallanite is typical for the I-type granitic rocks, on the otherhand, monazite for the S-types. The highest content of allan-ite is observed in the Lower Carboniferous Sihla I-typegranitoids, which is known in the Slovak Ore Mts, TribečMts. and Čierna Hora Mts. In comparison with the I-typegranitic rocks, total Al in allanite increases with whole rockperaluminosity, usually being above 2.0 Al pfu in allanitesfrom S-type granites. Monazite is characteristic for the S-type granites, only more evolved I-type or late differentiatedI-type granitic rocks contain beside allanite also monazite.The monazite composition, as solid solution of the monazites.s. component, brabantite and huttonite, show some depend-ency on the primary melt composition and physicochemicalconditions. The proportion of brabantite increases with per-aluminosity and peralkalinity as can be demonstrated on theexample of the Spiš-Gemer granites, while huttonite contentin the monazite increases with temperature. Apatites from theS-type granites show pronounced Eu-negative anomaly, incontrary to I-type granites, where higher redox conditions inthe melt caused the presence of Eu mainly in the trivalentform. The S-type granites contain more Eu in divalent formdue to the reduction regime, state this valence being easierincorporated into plagioclase. Except REEs, apatite is typo-morphic mineral also due to the presence of other elementswhich discriminate the granite rocks between the S or I-types. More peraluminous granites, like orogenic West-Carpathian S-type granites produce apatites with highercontent of Mn and Fe compared to the I-type of granites.

Stability of the principal REE-bearing accessory miner-als, as monazite or allanite, is in the fluid regime restricted.The alteration of monazite is possible already by subsolidusmagmatic fluids in the low temperature conditions. In suchconditions monazite breaks down and newly-formed LREE-enriched apatite occurs on the monazite grains. It is knownfrom the S-type granitic rocks presented e.g. in Suchý. Thenew apatite usually forms only very tiny rims on monazite,but sometimes the alteration is much less complete. Otheralteration also on the rim of monazite grains is the result atformation of huttonite. This is accompanied by the increasedmobility of the actinides as U and Th, and this was describedin the Western Carpathians e.g. in the Tribeč Mts. within theS-type granite suites. Formation of rhabdophane on monazitesurface is also possible. Monazite from the felsic silicic rocksoverprinted in the amphibolite facies breaks down to allaniteoften with formation of an intermediate zone of apatite(FINGER et al., 1998, BROSKA & SIMAN, 1998). Thisassemblage is associated with the reaction between biotite,anorthite and monazite-(Ce) with high activity of Ca. Theapatite in such transition zone in monazite-allanite-epidotecoronas or grains contains usually low amount of the REEs.Similar to monazite, xenotime is also unstable during over-printing under the amphibolite metamorphic conditions.Xenotime alteration is resulted in formation of REE-richepidote in the form of coronas around the xenotime grains.Such alteration of xenotime is known from the orthogneissesin the Western Tatra Mts., during retrogression events(JANÁK et al., 1999). Allanite breakdown is also commonand usually REE-rich epidote is the product of such disinte-gration. Titanite shows interesting alteration, because allaniteand REE epidote represents the breakdown products. Usuallythese minerals form small patches within the titanite grainsand this effect reflects the mobility of the REEs or REE-leaching processes.

The stability of the REE-bearing accessory minerals is inmost aspects still unknown phenomenon, although theirdistribution is crucial for the understanding of the REE mo-bility in the granitic rocks.

ReferencesBROSKA, I. & SIMAN, P. (1998). Geol. Carpath., 49: 161-

167.FINGER, F., BROSKA, I., ROBERTS, M. P & SCHER-

MAIER, A. (1998). American Mineralogist, 83: 248-258.JANÁK, M., HURAI, V., LUDHOVÁ, P., O’BRIEN, P. I. &

HORN, E. E. (1999). J. Metamorphic Geol., 17: 179-195.


16

ANOMALOUS GRANDITE GARNET FROM BĂIŢA BIHOR, ROMANIA

BÜKÖS, M. CS.1 & DÓDONY, I.21 Babeş-Bolyai University, Kogalniceanu 1, RO-3400 Cluj-Napoca, Romania.E-mail: [email protected] Department of Mineralogy, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.

Garnets are expected to crystallize in the cubic Ia3d spacegroup. Many of the calcium garnets formed during contactmetamorphism or in hydrothermal environments proved tobe optically anisotropic. Mostly the intermediate members ofthe andradite-grossular series reveal anomalous birefrin-gence, meanwhile the end-members are expected to be opti-cally isotropic (SHTUKENBERG et al., 2002).

The analysed samples are postmagmatic products of alamprophyric intrusion from Băiţa Bihor. Compositionallythey are close to the pure andradite member of grandite solidsolutions. The optical anisotropy is mostly related to zona-tion with oscillatory zoning of the Fe3+/Al3+ ratio. Addition-ally, there are minor anisotropic areas in pure andradite, too.

Although the anisotropy seems to be proportional to the Alcontent, the microprobe did not reveal an exact relationship.

Beside the expected cubic structure (Ia3d) X-ray powderdiffraction showed also a triclinic (I1) component in thestudied samples.

TEM studies also proved a lower than Ia3d symmetry. Inaccordance with the published interpretations, the origin ofbirefringence is explained by the Fe3+/Al3+ ordering in theoctahedral position.

SHTUKENBERG, A. G., POPOV, D. Yu. & PUNIN, Yu. O.(2002). Mineral. Mag., 66: 275-286.


17

MORPHOLOGY AND GEOCHEMISTRY OF ZIRCON FROM THE METAMORPHIC ROCKSOF THE WESTERN TATRA MTS. (S-POLAND)

BURDA, J.Department of Paleogeography and Paleoecology of Quaternary, Faculty of Earth Sciences, University of Silesia,Będzińska st. 60, PL-41-200 Sosnowiec, Poland.E-mail: [email protected]

In the Polish part of the Western Tatra Mts. metamorphiccomplex, migmatites predominate forming the northern en-velope of the Rohace granite. They are both heterophanic(mainly stromatitic) and homophanic (schliere-type) ones.The P-T evolution of the metamorphic complex shifted fromthe medium pressures (7.5–9 kbar) and temperatures in therange of 700–730oC (Ky + St stability field) to the stabilityof sillimanite (750–780oC) and than to andalusite(GAWĘDA et al., 1999). Among the migmatites two gen-erations were distinguished: the first generation was formedduring differentiation in the Ky+St stability field and thesecond one due to the partial melting in the sillimanite sta-bility field (BURDA & GAWĘDA, 1999).

Zircons, being accessory minerals in migmatites, havebeen affected by the metamorphic events, occurring in thisarea and they may be considered as good petrogenetic indi-cators of the rock evolution. To observe the zircon responsefor the partial melting of the host metasedimentary rocks, thezircon crystals from both leucosome and mesosome from thestromatitic migmatite were investigated.

The population of zircons from mesosome is dominatedby the normal prismatic crystals, differing in colours (col-ourless, grayish, yellowish-grayish and abundant brown anddark grey crystals). The length of single crystals varies in therange of 20 to 60 µm and the aspect ratio (length : width)ranges from 1:1 to 2:1. The degree of crystal roundnesschanges in the large scale, but in general subhedral crystalspredominate. The percentage of anhedral zircons withrounded edges and tops is difficult to determine because ofthe transitional stages from euhedral to anhedral forms. Eu-hedral zircons can be both short and prismatic and elongatedones. In the population of short, isometric crystals therounded, subhedral to anhedral forms are more popular.Different forms of zircon corrosion are observed in the ana-lysed grain population. Fine-grained zircon aggregates areabundant in mesosome but rare in leucosome. The morphol-ogy of zircons from mesosome is dominated by the {110}

prism and {211} pyramid. The most common types are S1,S2, S6, S7, L1, L2, with a distinguished maximum at S1.

In CL images of the mesosome zircons inner cores, sur-rounded by the outer magmatic rims are commonly observed.The outer rims represent the magmatic recrystallization eventin the metamorphic complex. Many rounded zircons arecompletely diffuse in the CL images, with neither an old corenor the outer magmatic zoning observed.

Among the zircons from leucosome euhedral, transparent,light-coloured crystals predominate, with elongation 2:1 to4:1. They are mostly S1, S2, S21, S22 forms according to Pu-pin’s classification (PUPIN, 1980). In the typological distri-bution two maxims can be observed, suggesting the occur-rence of two generations of zircons.

CL investigations often revealed subtle oscillatory zon-ing, due to heterogeneous distribution of trace elements dur-ing the crystal growth (HOSKIN & BLACK, 2000). Theintensity of CL signal shows no major variations. It is possi-ble that the chemical environment during crystallizationremained fairly stable. These zircons grew during a singlemagmatic event. Some zircons exhibit inner cores, which arerelics from the protolith.

Chemical analyses of zircons from mesosome revealedthat Zr/Hf ratio varies in a wide range: from 24 to 110,2.However, about 50% of the analysed zircons show the Zr/Hfratio in the range of 24–39. There are no major changes inmajor element distribution in the zircon crystals.

ReferencesBURDA, J. & GAWĘDA, A. (1999). Arch. Miner., LII/2:

163-194.GAWĘDA, A., DEDITIUS, A. & PAWLIK, A. (1999).

Miner. Pol., 30/2: 63-82.HOSKIN, P. W. O. & BLACK, L. P. (2000). J. Metamorphic

Geol., 18: 423-439.PUPIN, J. P. (1980). Contr. Miner. Petr., 73: 207-220.


18

LOST MINERALS?

BURKE, E. A. J.Chairman of the IMA-CNMMN, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085,1081 HV Amsterdam, The Netherlands.E-mail: [email protected]

The Commission on New Minerals and MineralNames (CNMMN) of the International MineralogicalAssociation (IMA) was established in 1959 for the purposeof controlling the introduction of new minerals and mineralnames, and of rationalising mineral nomenclature. TheCNMMN consists of representatives appointed by nationalmineralogical bodies (currently 30 voting members) and anexecutive committee consisting of chairman, vice-chairmanand secretary. The CNMMN repartitions its workloadamongst the three officers: the chairman prepares the new-mineral proposals, the vice-chairman handles the proposedchanges to existing nomenclature (discreditations and redefi-nitions), and the secretary coordinates the subcommitteescreated to examine the nomenclature of mineral groups. The30 members of the CNMMN evaluate all nomenclature pro-posals (new minerals, changes in existing minerals, mineralgroups), and cast their votes on these, on a monthly basis forthe new-mineral proposals, and as they come for the otherproposals. About 70-80% of the members participate activelyin the monthly new-mineral proposals, and about 60% in theothers. The work of the CNMMN has gained since 1959overwhelming support from the international mineralogicalcommunity.

The CNMMN handles about 50-60 new-mineral propos-als per year (52 proposals in 2000, 70 in 2001, 57 in the firstten months of 2003). The CNMMN has voted on 300 new-mineral proposals in the period from January 1998 to Octo-ber 2002. Approximately 80% of these were approved, theremainder being either rejected, or suspended pending furtherinformation. The CNMMN has also adjudicated in the sameperiod 22 proposals to discredit, redefine or revalidate min-eral species or to amend nomenclature in mineral groups(e.g., amphiboles, micas, zeolites). About 50% of these wereapproved, with the remainder being rejected, withdrawn orpending. Since 1959 the IMA-CNMMN has officially takena decision on 3,500 or so minerals and mineral names ontheir approval, discreditation and/or redefinition. The listwith these 3,500 or so decisions is available as a PDF filefrom the recently established IMA-CNMMN web site(www.geo.vu.nl/users/ima-cnmmn). This official IMA listonly gives name, formula and one reference for each species;the reference supplied is for the published announcement ofthe CNMMN decision regarding the mineral’s status, for newminerals usually the publication by their authors.

And here we have a first problem. According to theCNMMN procedures and guidelines (NICKEL & GRICE,1998) authors of approved proposals (new minerals or

changes in existing nomenclature) should publish descrip-tions of the minerals covered by these proposals within twoyears of being notified of the approval by the chairman orthe vice-chairman. This period of two years is probably tooshort, it is well known that it takes on average about one yearfrom the submission of a manuscript to the appearance of thehard copy of a journal, a considerable delay due to the timeneeded for the peer review and the printing process. Of the48 new minerals approved in 2000, only 24 have been pub-lished until November 2002.

But we have also much older new minerals that have notbeen published yet. According to several databases kept byCNMMN officials, we lack the publication of 30 or so min-erals approved between 1988 and 1999. One of the CNMMNmembers (Michel Deliens of Belgium) regularly contacts the‘slow’ authors by proxy of the chairman, and these actionssometimes result in the ‘rescue’ of these new minerals, whichwould otherwise be lost to our science.

A completely different case is represented by the phaseson which research has been carried out, but that for somereason or other have never reached the stadium of submis-sion to the CNMMN for approval, e.g., by lack of data askedfor by the CNMMN. In many cases these phases are pub-lished as ‘unnamed minerals’, giving partial descriptions.The CNMMN has an active subcommittee working on anannotated list of these unnamed minerals published since1960. Most of these published unnamed minerals, however,will never be fully characterised.

The present author has been involved between 1969 and1977 in a cooperation with Slovak and Russian colleagues onan interesting phase on which the work has remained incom-plete. It concerns a sulphosalt with a particular composition(Pb-Hg-Sb-S) from the locality Zenderling near Gelnica(Slovakia). Almost all work was ready, even X-ray work wascarried out on the specially made synthetic equivalent of themineral, but the final description was never submitted to theCNMMN, and only fragmentary descriptions have beenpublished, although even recently with a name (HÁBER etal., 1999) not approved by the CNMMN.

ReferencesHÁBER, M., JELEN, S., KRIZÁNI, I., SOTÁK, J. &

SPISIAK, J. (1999). Exkurzný sprievodca II, BanskáBystrica 21.-22.mája 1999.

NICKEL, E. H. & GRICE, J. D. (1998). Canadian Mineralo-gist, 36: 1-14.


19

CHEMICAL COMPOSITION OF Ni, Co AND Fe SULPHOARSENIDES AND ARSENIDES INTHE HYDROTHERMAL SIDERITE VEINS IN THE WESTERN CARPATHIANS(SLOVAKIA)

CHOVAN, M. & OZDÍN, D.Department of Mineralogy and Petrology, Faculty of Natural Sciences, Comenius University, Mlynská dolina G,SK-842 15 Bratislava, Slovak Republic.E-mail: [email protected]

There are Ni-Co minerals occurring mainly in the hy-drothermal siderite veins of Alpine age in the Western Car-pathians. The mineral succession scheme is the following:alteration → siderite → alpine paragenesis → Ni-Co-Fe-Asminerals → quartz with Cu-Bi-Fe-Sb-Hg sulphides. Themost abundant are in the sulphide (sulphoarsenide, arsenide)stage with less contents of carbonates and silicates. Thereare often occurred with the Cu minerals – tetrahedrite, ten-nantite, chalcopyrite and with the others sulphides mainlypyrite and galena. Those were described on numerous de-posits and occurrences in the Slovak Republic. Ni-Co-Fe-Cu-As minerals are represented by gersdorffite, cobaltite, arse-nopyrite, rammelsbergite, pararammelsbergite, krutovite,ullmannite, skutterudite, nickeline and carrollite which werestudied in details at the following localities: Vyšná Boca,Dobšiná and Častá.

Optical zoning is a characteristic feature of all the men-tioned Ni-Co minerals, but mainly of the sulphoarsenides anddiarsenides. It may be oscillatory, concentric or sector zon-ing. The typical oscillatory zoning was developed probablyin a non-steady system under the influence of locally chang-ing physico-chemical conditions or by diffusion in solidstate. The dominant components in the chemical zoning inthe sulphoarsenides are As and S over the also varying Ni,Co and Fe.

The most abundant minerals are sulphoarsenides repre-sented mainly by arsenopyrite and gersdorffite. Based onchemical composition of sulphoarsenides we described 3basic types of gersdorffite. The 1st type is represented byeuhedral, homogenous gersdorffite from Vyšná Boca, withtypical strong isomorphism of Ni vs. Co (± Fe) and a lesspronounced variation of As vs. S. That type forms rimsaround arsenopyrite crystals and was crystallized close to thetemperature of the arsenopyrite formation. Higher tempera-ture sulphoarsenides, including cubic gersdorffites and co-baltites with strongly disordered structure and space groupPa3, were formed at a temperature of 500–550 °C (KLEMM,1965). The 2nd type from Dobšiná deposit is characterized bysmooth transition from arsenopyrite to gersdorffite. Gers-dorffite formed by metasomatic replacement of arsenopyrite,thus both minerals might have crystallized in the triclinicspace group P1 (ČVILEVA et al., 1988), at temperature of550–650 °C (KLEMM, 1965). During that replacement theprimary crystal shape of arsenopyrite is preserved. The inten-sive zonal (but smooth) arsenopyrite-cobaltite transitionsamples may also belong to this type. The 3rd type is repre-

sented by gersdorffites from Vyšná Boca and Dobšiná. Inthese samples a smooth transition to krutovite is observed,with strong variation of As vs. S and a less characteristicisomorphic substitution of Fe vs. Co. Both minerals crystal-lized in the space group P213, a space group of gersdorffiteof temperature lower then 300 °C (KLEMM, 1965). In theeuhedral crystals intensive oscillatory zoning is typical. Thecores of the crystals are formed by krutovite and the rims bygersdorffite. Krutovite was identified by X-ray diffraction.Gersdorffites from Častá belong also to that type. They wereformed together with ullmannite by solid solution decompo-sition. They show strong isomorphous substitution of Sb, Asand S. Space group is P213. Their formation temperature wasrelatively low, probably under 300 °C.

Most arsenopyrites contain no isomorphous substitutionand are close to stoichiometric formula. Isomorphous sub-stitution of Fe vs. Co or Ni respectively indicated a highertemperature of formation (KLEMM, 1965). Antimony rarelysubstitute in the arsenopyrite crystal lattice. Arsenopyrite-gudmundite smooth transition was not observed (VyšnáBoca), but zonal arsenopyrite contains zones, mainly in thecrystal core, enormously enriched in Sb (up to 11.81 wt.%Sb; (=5.59 at.% Sb)). This is the maximum Sb substitution inarsenopyrite reported from the Western Carpathians. Sbreplaces As in the lattice. These Sb substituted arsenopyritesmight formed at a lower temperature.

Based on this chemical variation, (successive precipita-tion from solid solution; substitution of cations (Ni, Co, Fe)and anions (As, Sb, S)), we can say, that with increasingtemperature arsenopyrite began to precipitate; later gers-dorffite and cobaltite, with strong substitution of cations. Onthe reverse path ullmannite and gersdorffite was crystallizedby solid solution decomposition. Fluid inclusion studies ofthese hydrothermal veins (HURAI et al., 2002) confirmed atemperature increase during the crystallization of quartz andsiderite from the core to the rim.

ReferencesČVILEVA, T. N., BEZSMERTNAYA, M. S. & SPIRI-

DONOV, E. M. (eds.) (1988). Nedra, Moskva, 1-504.HURAI, V., HARČOVÁ, E., HURAIOVÁ, M., OZDÍN, D.,

PROCHASKA, W. & WIEGEROVÁ, V. (2002). OreGeology Reviews, 21/1-2, 67-101.

KLEMM, D. D. (1965). Neues Jahr. für Miner., Abh., 103,205-255.


20

VESUVIANITE AND GROSSULAR FROM THE SKARN NEAR SUSULA, EAST SERBIA

COCIĆ, S.1, ERIĆ, S.2 & SRECKOVIĆ-BATOCANIN, D.21 Institute for Copper-Bor, Zeleni Boulevard 33-35, Bor, Yugoslavia.2 Faculty of Mining and Geology, University of Belgrade, Djušina 7, YU-11000 Belgrade, Yugoslavia.E-mail: [email protected]

Intrusive rocks are common in the Timok Eruptive Com-plex (TEC). They are usually intruded into the andesites ofthe TEC, or in the sedimentary rocks (Jurassic and Creta-ceous limestones) of the TEC or in the marginal parts of theTEC. They mostly form small bodies that are present all overthis complex between Majdanpek, on the north, and Bucje,on the south.

In the contact zones between the intrusive bodies and thesedimentary formations skarns were formed. They are pre-dominantly built up of vesuvianite and garnet. Subordinatelyquartz, epidote, wollastonite, magnetite and pyrite can alsobe found. Very rarely chalcopyrite, bornite and chalcociteoccur. The Susula Skarn, one of these skarn formations, wasdiscovered in the western part of the TEC, in the mountainarea between the Crni Vrh and Kucaj. At that locality euhe-dral vesuvianite crystals (tetragonal prisms + bipyramid) upto 5 cm in size, and euhedral grossular-andradite type gar-nets, up to 1 cm in size can be found. Morphology of thevesuvianite crystals (Fig. 1) is the same as in the skarn of thePotoj Cuka locality.

Fig. 1: Vesuvianite crystal.

Chemical analyses of vesuvianite show that FeO-contentranges between 2.49–3.57%, while TiO2-content is in the0.14–0.95% range. Contents of the same oxides in garnetrange from 3.93 to 5.76% for FeO, and from 0.06 to 1.58%for TiO2.

Mineral chemistry coefficient activity (Kd), i.e. molarfraction rate of Ti and Al was also determined. The Kd valueranges from 0.310 to 0.330, suggesting that these mineralswere formed in a system poor in CO2, and at temperaturesaround 400 °C (LOBOTKA et al., 1988).

As the Susula Skarn has a more complex compositioncompared to the association of a simple “wollastonite zone”,with Al being present in both vesuvianite and grossular, theprimary rock was probably not a pure limestone. Consideringthe low mobility of aluminium, it is assumed that it wasalready present in the clay fraction of the original sedimen-tary rock, rather than being brought by the intruding magma.

ReferenceLOBOTKA et al. (1988). Amer. Mineral., 73: 1302–1324.


21

BRIEF OVERVIEW ON THE SiO2 VARIETIES OF GEM-QUALITY FROM SOUTHERNAPUSENI MOUNTAINS (ROMANIA)

CONSTANTINA, C.1 & POP, D.21 Department of Mineralogy, Institute of Gemology, Babeş-Bolyai University, 1, Kogălniceanu St., RO-3400 Cluj-Napoca,Romania.E-mail: [email protected] Mineralogical Museum, Babeş-Bolyai University, 1, Kogălniceanu St., RO-3400 Cluj-Napoca, Romania.

The Southern Apuseni Mts. were known as hosting gem-quality SiO2 varieties since the second half of the XIXth cen-tury (KOCH, 1885; PRIMICS, 1886). Several occurrences inthe region provide some of the most beautiful chalcedonies,even agates in Romania. The present study provides a briefoverview of the main areas where such materials were identi-fied, arranged chronologically according to the genetic typesof the host- (and generating-) rocks. In each case new geo-logical and microscopic data on the gem materials are given,based on recent results of one of the authors (CC).

1. Gem materials associated to the “ophiolitic” volcanism“Ophiolitic” complexes containing gem materials (mainly

represented by coloured chalcedonies, jaspers and rarelyagates) consist of basalts, spilites, microgabbros, andesites,latiandesites, alkaline trachites, dacites, and rhyolites. Theformation of the SiO2 varieties was mainly related to pyro-clastic deposits that provided relatively more porous andpermeable substrates for the circulating solutions.

The most representative occurrence of this type is Rachiş(Alba district) (GHIURCĂ, 2000). The chalcedony is ofvein-type, rarely nodular - in this case mainly consisting ofthe agate variety. The typical colour is white, and reddish-grey; gem-quality materials are usually translucent. Micro-scopically, a nucleus of microgranular quartz (grey and/orwhite in colour) is surrounded by concentric reddish bands offibrous quartz; the intensity of the red colour depending onthe concentration of iron oxy-hydroxides. Gem-quality mate-rials can be collected from the host-rock or from alluvia.

2. Gem materials associated to the banatitic volcanismPyroclastic agglomerates and tuffs represent mainly the

volcanic rocks of a Paleocene age. The SiO2-type gem mate-rials are very diverse and abundant: chalcedony, agate, opal,jasper, silicified wood. The type locality is Gurasada (Hun-edoara district), and materials can be typically collected fromalluvia. The chalcedony shows a massive texture and hasusually lighter colours (white-bluish) than the chalcedonyfrom the “ophiolitic” complex.

3. Gem materials associated to the Neogene volcanismThe generating rocks are represented by andesitic pyro-

clastics in Brad area and pyroxenic andesites in Hărţăganiarea, both complexes having a Sarmatian age. The white todark-grey chalcedonies from Hărţăgani (Hunedoara district)

usually formed as veins, but currently they can be collectedfrom the alluvia. Under the optical microscope, the presenceof calcite and epidote in contact with chalcedony indicatestransformation processes due to the circulation of hy-drothermal solutions (MÂRZA & CONSTANTINA, 2000).

Măgura Bradului Hill (Brad, Hunedoara district) is wellknown for its jaspers mentioned in early papers on the re-gion. Coarse andesitic pyroclastic agglomerates host sili-ceous sinters (geyserites). The generating epithermal silica-rich solutions were deposited within small lakes, as provedby the fossil fauna and flora. The local prevalence of variousimpurities (Fe oxy-hydroxides, Mn oxy-hydroxides etc.) leadto the local formation of variously coloured jaspers, domi-nated by the brown-reddish varieties. Mineralogical data onthese jaspers were given by GHERGARI & IONESCU(1999). Silicified woods from Prăvăleni (Hunedoara district)are hosted by Sarmatian cinerites; they show a reducedgemological value.

4. The gemological-field Techereu (Hunedoara district)On a relatively small area five genetic types of gems are

present: chalcedonies associated to the Mesozoic “ophiolitic”complex, polychromatic jaspers in Cretaceous conglomer-ates, variously-coloured chalcedonies in Paleogene rhyolites,siliceous nodules, jaspers and silicified wood within theAlmaşu Mare Gravel (Badenian), as well as reworked chal-cedonies and jaspers in Quaternary deposits (MÂRZA,1999). This complex geology confers a unique positionamong the above-mentioned locations to the Techereu occur-rence.

ReferencesGHERGARI, L. & IONESCU C. (1999). Anal. Univ. Bu-

cureşti, Min. Petr. (Abstract volume), 48: 32.GHIURCĂ, V. (2000). Studii si Cercet. (Geol.-Geogr.), 5: 9-

17. Muz. Jud. Bistriţa-Năsăud, Bistriţa.KOCH, A. (1885): Erdély ásványainak kritikai átnézete.

Orv.-Term. Társ., Kolozsvár, p. 211.MÂRZA, I. (1999). Studia Univ. Babeş-Bolyai, Geol. 44/1:

78-86, Cluj-Napoca.MÂRZA, I. & CONSTANTINA, C. (2000). Studia Univ.

Babeş-Bolyai, Geol., 45/1: 91-104, Cluj-Napoca.PRIMICS, Gy. (1886). Földt. Közl., 16: 308-313, Budapest.


22

SHALLOW SUBVOLCANIC ANDESITIC MAGMATISM IN THE EAST BORSOD BASIN,HUNGARY: AN EXAMPLE OF MAGMA/WET SEDIMENT INTERACTION

CSÁMER, Á.Department of Mineralogy and Geology, University of Debrecen, P. O. Box 4, H-4010 Debrecen, Hungary.E-mail: [email protected]

Already from the 1970s but mainly from the 1990s manyauthors published examples where magma comes in contactwith wet sediment, generating hyaloclastites, peperites, in-situ breccias, etc. (LYDON, 1968; YAMAGISHI, 1991;HANSON & HARGROVE, 1999). These works make itclear that phenomena of magma/wet sediment interactionsare common in geological environments where thick sedi-ment sequences accumulate during active volcanism. Mio-cene palaeogeographic environment (HÁMOR, 2001) andneutral volcanism of the East Borsod Basin allowed the for-mation of different types of these rocks.

The East Borsod Basin (EBB) is mainly built up fromCenozoic sequences. Paleo-Mesozoic rocks, representedmostly by limestones, siliceous shales and derived volcano-clastics, cover small areas. The greater part of EBB is cov-ered by Cenozoic clastic sediments, volcanic-subvolcanicrocks, pyroclastic and volcaniclastic deposits, and the Paleo-Mesozoic basement is situated within a few hundred metersbelow the surface.

The Lower and Middle Miocene (Ottnangian-Karpatian)sequences (Salgótarján Lignite Formation – SLF) are repre-sented by sandstones, aleurolitic sandstones, argilliferousaleurolites, clays and redeposited acidic tuffs with interca-lated coal seams. These sediments were deposited in shallowmarine and near-shore environments.

The Upper Badenian–Sarmatian–Pannonian sequencesbuilding up the Sajóvölgy Formation (SF) are deposited withunconformity on the SLF. These sediments were deposited influvial, deltaic or near-shore environments. The upper part ofthe formation consists mainly of cross-bedded medium- orcoarse-grained sands, polymict gravels or conglomerates; thelower part contains shallow marine–offshore tuffites andsands. Sediments of the SF are unconsolidated or poorlyconsolidated, therefore, erosional valleys and canyons arebarely found, while derasional and erosional-derasional val-leys are more abundant.

Interbedded Sarmatian–Pannonian andesitic pyroclastsand volcanic-subvolcanic rocks are present in patches on thesurface, because most of them are covered by younger de-posits. Their characteristics, habits and facies could be inter-preted as a separate volcanic formation (Dubicsány AndesiteFormation – DAF) formed by pyroclastic tuff-breccias, lap-illi-tuffs, and shallow subvolcanic intrusions, dikes, in situbreccias and hyaloclasts. The age of the neutral volcanicactivity in the EBB ranges from 9.5 ± 0.8 to 13.73 ± 0.76 Ma(Upper Badenian–Sarmatian–Pannonian) according to K/Arradiometric data.

Epiclastic tuff-breccias and lapilli-tuffs are drab or grey,poorly bedded or unbedded, with tuffaceous matrix, andconsist of andesite blocks, fragments and epiclasts of varioussize. By the major element composition of the andesiteblocks, they belong to the calc-alcaline series; the range ofcontents of SiO2 and K2O varies between 56.85–58.22 wt%and 1.86–2.10 wt%, respectively. These rocks are highlyporphyritic with phenocrysts mainly consisting of plagio-clase, orthopyroxene (ferrosilite), clinopyroxene (augite).The groundmass of andesite blocks is felsitic containingmineral assemblage of plagioclase, orthopyroxene, clinopy-roxene, magnetite and titanomagnetite. The texture is micro-holocrystalline-porphyritic or pilotaxitic.

Andesite intrusions and dykes are small (max. 15 m indiameter), and often show columnar, slab jointing or coarseblocked structure (CSÁMER & NÉMETH, 2000). Theirchemical and mineralogical composition is similar to that ofthe pyroclastic andesite blocks. Andesite intrusions wereemplaced into wet unconsolidated sediments during orshortly after their deposition. The host sediment is domi-nantly lapilli-tuff, tuff-breccia. On the margins of the intru-sions aureole and hyaloclastite occur containing angular orpartly rounded andesite fragments of varying quantity in atuffaceous matrix. Beside the regular chaotic texture (clusterof angular andesite fragments), jigsaw-fit texture can be alsorecognized recording in situ fragmentation.

AcknowledgementThis work was supported by the Hungarian National Sci-

ence Research Foundation (OTKA) under Res. Contracts NoT-029058.

ReferencesCSÁMER, Á. & NÉMETH, G. (2000). Földtudományi

Szemle, 1: 85–90.HÁMOR, G. (2001): Explanation to the Miocene palaeo-

geographic and facies maps of Carpathian Basin. Geo-logical Institute of Hungary, Budapest, p. 66. (in Hun-garian)

HANSON, R. E. & HARGROVE, U.S. (1999). Bull. Vol-canol., 60: 610–626.

LYDON, P. A. (1968): Geology and lahars of the TuscanFormation, Northern California. In: Studies in Volcanol-ogy, The Geological Society of America Inc., Boulder,Colorado: 441–473.

YAMAGISHI, H. (1991). Sediment. Geol., 74: 5–23.


23

BOURNONITE FROM HYDROTHERMAL ORE DEPOSITS IN THE BAIA MARE AREA,ROMANIA

DAMIAN, F. & DAMIAN, Gh.Department of Geology, North University of Baia Mare, 62/A Dr. Victor Babes Street, RO-4800 Baia Mare, Romania.E-mail: [email protected]

The most frequent occurrences of bournonite in Romaniaare related with the Neogene hydrothermal mineralizations.In the hydrothermal mineralizations associated with the Neo-gene subduction type magmatism at the Baia Mare area,bournonite was identified at Ilba-Alunis, Dealul Crucii,Herja, Baia Sprie, Cavnic, Băiuţ and Toroiaga-Borşa. In thebase metal mineralizations bournonite appears as inter-growths with galena and less frequently with chalcopyrite,sphalerite and pyrite. Among the sulphosalts the mineralfrequently associated with bournonite is tetrahedrite. Bour-nonite is present as prismatic crystals of 2–3 mm size withvertical striations. These crystals are disposed on galena andsphalerite. Bournonite forms crystal aggregates with differentspatial arrangements, of several centimetres in diameter. Inreflected light they show fine characteristic lamellar twins(0.05-0.10 mm) in one or two directions. The value of Vick-ers microhardness determined for a standard print of 20 µ is150–190 kg/mm2. The bournonites from the Baia Mare areawere studied by electron microprobe analyses. The formulaeof the studied bournonites have been recalculated on thebasis of 3 sulphur (Table 1).

Besides the major elements Cu, Pb, Sb, S small quantitiesof As, Fe, Bi, Ag, Sn and Te also appear. Arsenic appears assubstitute for Sb. This shows the existence of a solid solutionbetween CuPbSbS3 (bournonite) and CuPbAsS3 (seligman-nite). Fe, Ag and Sn appear as substitutes for metallic cationsCu and Pb. The presence of Sn can indicate a high formationtemperature of the paragenesis. Bi and Te appear as substi-tutes for Sb.

Table 1: Atomic proportions based on 3 atoms of sulphurfor the Baia Mare bournonites.

No Atomic proportions Sample1 Pb1.03Cu1.1Ag0.003Sb0.98S3 Ţiganul vein,

Toroiaga2 Pb1.02Cu0.95Bi0.004Sb1.11S3 Caterina vein,

Toroiaga3 Pb0.98Cu0.99Sb1.05S3 Caterina vein,

Toroiaga4 Pb1.02Cu0.98Sb1.03S3 Caterina vein,

Toroiaga5 Pb092Cu1.17 Ag0.0005Fe0.004-

Sb1.09S3

Baia Sprie

6 Pb0.86Cu1.12 Fe0.002Sb1.02S3 Baia Sprie7 Pb1.004Cu1.02Bi0.002Sb1.02As0.01-

Te0.001S3

Ignaţiu vein,Herja

8 Pb0.96Cu0.95Sb0.95S3 Dealul Crucii9 Pb0.933-0.96Cu0.95-0.98Fe0.02-0.034-

Sb0.92-0.99As0.013-0.085Sn0.004-0.01S3

Băiuţ 101

10 Pb0.97-0.99Cu0.96-0.98Fe0.011-0.05-Sb0.723-0.98As0.08-0.3Sn0.003-0.005S3

Băiuţ 602

11 Pb099Cu0.98Fe0.018Sb0.95S3 Baia Sprie12 Pb0.98Cu1.15Fe0.072Sb0.91As0.027S3 Cavnic

1–4 after GÖTZ & DAMIAN (1990); 9–10 after DAMIAN& COSTIN (1999); 11 after SIPŐCZ (1886); 12 afterHIDEGH (1881).

ReferencesDAMIAN, Gh. & COSTIN, D. (1999). Studia Universitatis

Babeş-Bolyai, Geologia, XLIV/1: 138-149.GÖTZ , A. & DAMIAN, Gh. (1990). Revista Minelor, 41/9:

467-471.HIDEGH, K. (1881). Akad. Közlem., 8: 17, Ref. Z.K., 8.SIPŐCZ, L. (1886). Tschermak’s Mineral. Petrol. Mitt., 7,

Z.K., 11.


24

Mn-RICH TETRAHEDRITES IN THE ROMANIAN TERRITORY

DAMIAN, Gh. & DAMIAN, F.Department of Geology, North University of Baia Mare, 62/A Dr. Victor Babes Street, RO-4800 Baia Mare, Romania.E-mail: [email protected]

Tetrahedrite–tennantite is the most common sulphosaltpresent in the majority of hydrothermal ore deposits. Man-ganoan tetrahedrites appear in some hydrothermal ore de-posits from South Apuseni Mts. MAKOVICKY & KARUP-MØLLER (1994) showed that Mn can be incorporated in thesynthetic tetrahedrite structure. The stoichiometric formulaof tetrahedrite is Cu10Me2

2+(Sb,As)4S13. Incorporation of Mnin tetrahedrites is possible by substituting cations in thestructure. Mn can substitute Cu2+ in the structure. Manganesewas indicated in all publications, but not exceeding 0.5 wt %.

BASU et al. (1984) described an occurrence of man-ganoan tetrahedrite with 1.5–1.7 Mn atoms per formula unit.These tetrahedrites are As varieties containing between 0.7and 2.2 atoms, alongside with 0.1–0.2 Pb, 0.1–0.3 Fe, andminor amount of Zn and Hg. BURKHART-BAUMAN(1984) described at Quiruvilca (Peru) two intimately inter-grown tennantites. One variety had Pb-bearing manganoantennantite, and the other had tennantites rich in Mn with 1.48atoms per formula unit. Another occurrence of manganoantetrahedrite was described by DOBRE (1992) from theskarns of the Tunaberg Cu-Co deposit, Bergslagen, CentralSweden, and had 0.61 to 0.86 Mn per formula unit.

In Romanian territory the richest analyses in Mn werecommunicated by HIDEGH (1881) at Săcărâmb (SouthApuseni Mts) with 1.23 wt % Mn. This tetrahedrite is inter-mediary between tetrahedrite-tennantite with 1.77 wt % Fe,and 5.55 wt % Zn. Other manganoan tetrahedrite occurrenceswere described at Boteş-Bucium, Arama vein by LOCZKA(1901) with 0.69 wt % Mn and KRETSCHMER (1911) with0.26 wt % Mn.

We have identified new occurrences of manganoan tetra-hedrites in the South Apuseni Mts. Two occurrences arecertain at Gura Barza (Brad) and Coranda Hondol. The GuraBarza tetrahedrites contain 3.04–4.16 wt % Mn, and theCoranda-Hondol ones, between 0.74–6.31 wt % Mn. Micro-scopically, some varieties have been identified. At Coranda-Hondol the intergrowings between different varieties arehighly evident and UDUBAŞA et al. (1982) signalled them.These intergrowings are more evident when they are built upof varieties with manganoan tetrahedrites and non-manganese varieties.

Formulae units for Gura Barza tetrahedrites are Cu6.82-

7.45Zn0.98-1.65Fe0.33-1.01Mn0.95-1.31Ag1.56-1.9Sb3.89-3.93S13 and forCoranda-Hondol are Cu8.32-9.58Zn1.45-1.74Fe0.21-0.2721Mn0.22-1.87

Ag0.19-0.24Sb2.73-3.15As0.8-1.40S13. The tetrahedrites from GuraBarza contain Sb and especially large quantities of Ag, whichinclude them in the argentian tetrahedrites group. Thesetetrahedrites contain more Me2

2+ than would normally resultfrom the substitution of Cu2

2+ by Fe and Zn. The tetrahedritesfrom Coranda-Hondol contain As and Sb and a very smallamount of Ag. In these tetrahedrites Cu2

2+ is almost totallysubstituted by Fe and Zn. Under these circumstances weassume that Mn substitutes Cu+ together with Ag. BASU etal. (1984) claims that once the Me3+ content increases theMe+ content lowers. This statement is not applied to sometetrahedrites from South Apuseni Mts. Because Fe and Znsubstitute most of Me2

2+, we assume that Mn together withAg+ substitutes Cu10

+ in the formula unit. According toMAKOVICKY & KARUP-MØLLER (1994), the presenceof Mn in synthetic tetrahedrites contributes to the increase ofthe unit cell parameter a. This increase is due to the muchhigher value of Mn2+ (0.67 Å) cationic radius compared tothat of Fe2+ (0.64 Å) and Zn2+ (0.637 Å). The presence of Agin tetrahedrites also determines the increase of the a pa-rameter (RILEY 1974). The high amount of Mn and Ag,present in the studied tetrahedrites, can determine essentialchanges in the tetrahedrite structure. As the structure is verymuch modified, we do not exclude the possibility of having anew mineral, a tetrahedrite with manganese. Further investi-gation of these tetrahedrites will either confirm or reject oursuppositions.

ReferencesBASU, K., BORTNIKOV, N., & MOOKHERJEE, A.

(1984). N. Jb. Miner. Abh., 141: 280-289.BURKHART-BAUMAN (1984). N. Jb. Miner. Abh., 150:

37.DOBRE, R. T. M. (1992). Miner. Mag., 56: 113-115.HIDEGH, K. (1879). Tschermak’s Mineral. Petrol. Mitt., 2,

Ref. Z.K., 1881, 5.KRETSCHMER, A. (1911). Zeits. Kryst., 9.LOCZKA, J. (1901). Zeits. Kryst., 34.MAKOVICKY, E. & KARUP-MØLLER, S. (1994). N. Jb.

Miner. Abh., 167: 89-123.RILEY, J. F. (1974). Mineral. Deposita, 9: 117-124.UDUBAŞA, G. et al. (1982). D. S. Instit. geol. geofiz., Bu-

cureşti, LXVII/2: 197–232.


25

THE USE OF THE ZEOLITIC TUFFS IN THE DETOXIFICATION OF HEAVY METALCONTAMINATED SOILS

DAMIAN, Gh. & DAMIAN, F.Department of Geology, North University of Baia Mare, 62/A Dr. Victor Babes Street, RO-4800 Baia Mare, Romania.E-mail: [email protected]

Zeolitic tuffs are used in a various range of activities.MUMPTON (1973) has drawn attention upon their greatpotential regarding industrial applications. During the last 40years, many research studies were carried out concerning theuse of natural zeolites in many areas including environmentalprotection (MUMPTON, 1999). The excellent ion-exchangeselectivity of clinoptilolite for ammonium has beenemphasized recently (LEGGO, 2000). Zeolitic tuffs can beused at large scale in the detoxification of the heavy metalcontaminated soils produced by mining and metallurgicalindustry. These contaminated soils are a serious problem atan international scale. For the remediation of these soils insuch a way that pollution is avoided, research with naturalzeolites has been carried out in the last few years. Heavymetal contaminated soils have been treated with a mixture oforganic substance and zeolite (organo-zeolitic materials).

Organo-zeolitic material has been obtained by fermenta-tion of 2/3 fresh organic substance with 1/3 zeolitic tuffs.The tuffs were prevailed from Bârsana and Ocna Şugatagareas (Maramureş Basin). They are vitroclastic tuffs con-taining 1–5% crystalloclasts (quartz, plagioclase, biotite),glass and volcanic ash that are strongly vitrified and substi-tuted by: clinoptilolite, heulandite, mordenite, montmorillo-nite, celadonite and silica. Clinoptilolite is the predominantzeolite and appears as compact masses of tabular and pris-matic micron-sized crystals that are evident in SEM images.The medium ion exchange capacity ranges between 125 and142 mvals/g. The contact surface is 15–18 m2/g.

Zeolitic tuffs were roll crushed and ground in smallgrains with dimensions between 0.08 and 2.5 mm, thensieved to obtain 0.5–2 mm-sized fraction. This material washomogeneously mixed with two parts of organic material andthe mixture was put in a plastic container for fermentation.Ammonia that results from bacterial discomposition changesthe zeolitic structure. In this way, Ca2+ and K+ got incorpo-rated in the organic substance. This final product is excellentfor inhibiting heavy metal cations from soils and promotesvegetation growth.

The experiments were made in pots, each containing 2 kgof polluted soil with organo-zeolitic material. In the mixture,the polluted soil represents 83% and the organo-zeoliticmaterial represents 17%. The soil used in the experimentcontains 4% Pb and a pH = 3.77–4.44. The original soil and

the treated soil have been planted with Lolium perenne. Thegermination was accomplished in proportion of 90% in thetreated soil and approximately 40% in the original soil. Thegrowth of the plants has demonstrated that the soil treatedwith organo-zeolitic material allows the growth of vegetationmuch faster than the original soil.

Growth has been possible because the organo-zeoliticmaterial supplies all the necessary substances for the plants(nitrogen, humus, potassium, and calcium). During growth,the plants take up NH4

+ and some cations from the soil solu-tion. Cations and NH4

+ taken up by the plants emerge intothe soil solution from the structure of the organo-zeoliticmaterial. The same way, cations and NH4

+ ions included inthe zeolitic structure are exchanged with the heavy metalcations, which are fixed in the zeolitic structure. All thiscationic exchange is adjusted by the growing plants, whichcreate a permanent NH4

+ cation deficiency in the soil solu-tion. The experiment was carried out in the laboratory andthe plant growth was observed for 4 months. We noticed apH increase in the treated soil, in comparison with the origi-nal soil, which indicates that the organo-zeolitic material alsohas a pH correction role, improving its value from 4.4 to 5.9and from 4.1 to 5.4.

Considering the results obtained during the experimentwe can conclude that the maximum plant growth was ac-complished in the cases when the soil was treated with or-gano-zeolitic material. This growth was possible because theorgano-zeolitic material mixed with soil provides the sub-stances necessary for the plants to develop (ammonium,humus, potassium, calcium). At the same time heavy metalsthat inhibit the plant development are blocked through thecationic exchange mechanism that makes them enter thezeolite structure and they no longer have direct access to theplant roots.

ReferencesLEGGO, P. J. (2000). Plant and soil, 219, p. 135–146, Klu-

wer Academic Publishers.MUMPTON, F. A. (1973). Industrial Minerals, 73/2: 30-45.MUMPTON, F. A. (1999). Proc. Natl. Acad. Sci. USA, 96:

3463-3470.


26

CRYSTALCHEMISTRY OF CLAY-MINERALS AROUND THE BORDER OF AN OVER-PRESSURE ZONE IN ONE OF THE DEEP SUB-BASINS OF THE SOUTHERN PART OF THEGREAT HUNGARIAN PLAIN

DÓDONY, I. & LOVAS, Gy. A.Department of Mineralogy, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected]

In this contribution the smectite to illite transition and thematuration of organic matter have been studied with in-creasing temperature and pressure, i. e. with increasing depthin one of the sub-basins of the Pannonian Basin (Hungary)called Hódmezővásárhely-Makó trench. Hódmezővásárhely-Iis the deepest borehole (5842.5 m) in Hungary traversingonly Pannonian (s. l.) sedimentary formations built upmainly of marls, marly shales, shales and sandstone. Clayfractions extracted from the core samples were studied byXPD using method given by Reynolds and Moore (1997) inorder to estimate the smectite content of mixed-layered il-lite/smectite. Orientated air-dried ethylene-glycolated andglycerolated, Mg-saturated air-dried ethylene-glycolated andglycerolated, and heated to 350 and 550ºC <2 µm fractionmounts were measured in order to determine the mineralassemblages, the smectite % (S %) and the order of the I/Sphases. In the course of diagenesis the regular pattern of thesmectite content of I/S is diminishing with increasing depth.In the present case, however, an anomalous change – in-creasing, than stagnating S% – in this sequence was detectedin the depth of 4500-5800 m, where dominantly pelagicmarls and marly shales occur. In the same zone, the corre-

sponding vitrinite reflectance values showed also a sharpchange. The estimated pore pressure data for this depth rangeindicated an overpressure zone between 4500 and 6000 m,that could result in interrupting the continuos dehydration ofsmectites and could be responsible for the stagnation of thesmectite content of the I/S in this zone. The increase ofsmectite content, however, could certainly not be explainedby the pressure conditions. A possible explanation lay in theactual crystalchemistry, that is the real structure, the in situinterlayer and/or octahedral, tetrahedral co-ordinated cationdistribution, that is the individualism of this clay mineralassemblage, resulting in a decreased reactivity. Anotherpossible approach is the supposition of an abrupt change ofthe source (containing smectite-like clay of a different kind)of the sedimentary rock. A nanometer scale crystalchemicalstudy has been carried out on the undisturbed in situ smec-titic material using analytical TEM technique the revealedseveral interesting facts that will be discussed.

This research project is financially supported by the Hun-garian National Research Fund (OTKA) under contract no.T032450, which is greatly acknowledged.


27

SLOVAKIAN MINERALS – THE CURRENT STAGE OF KNOWLEDGE

ĎUĎA, R.Eastern Slovakian Museum, Hviezdoslavova 3, SK-041 36 Košice, Slovak Republic.E-mail: [email protected]

From the beginning of the evolution of mineralogy, thearea of Slovakia had an important position. Many minerals ofhistorical names were described from the area of BanskáŠtiavnica, Smolník, Špania Dolina etc. already in the timesof AGRICOLA (1556). A more complex review of the min-erals of Slovakia can be found in the works of ZIPSER(1817), JONAS (1820), ZEPHAROVICH (1859, 1873,1893), TÓTH (1882) and others.

Throughout the 19th century and in the beginning of the20th. century many new minerals were first described fromSlovakian localities (evansite, euchroite, libethenite, szomol-nokite etc.). The Mining Academy in Banská Štiavnica(Schemnitz, Selmecbánya) was a rather important scientificcentre of mineralogy of that time, many world-famous min-eralogists worked there.

During the 20th century, the mineralogical studies wereconcentrated at universities and in research institutes in Slo-vakia and in the Czech Republic. The results of an almost100-year-old continuous research activity were summarizedin the 1980’s, in the three volumes of the book by KODĚRAet al., (1986, 1990): Topografická mineralógia Slovenska(Topographical mineralogy of Slovakia). Since that timethere has been an intense progress in mineralogical research,thanks to the development of laboratory methods applied inmineralogy (microprobe techniques, electron microscopy,infrared spectroscopy, chemical analytical methods etc.).That development is also proved by the intense increase ofthe number of mineral species described from Slovak locali-ties: from the 430 species in 1980 (KODĚRA et al., 1986)we arrived to 661 species by the end of 2002. That increaseof more than 50% in average shows a more or less homoge-nous distribution over the mineral classes (Table 1).

Table 1

Class 1980 2002 Increase %Elements 17 26 34.6Sulfides etc. 94 175 46.3Halides 7 11 36.4Oxides etc. 63 94 33.0Carbonates etc. 23 32 28.1Sulfates etc. 52 69 24.6Phosphates etc. 41 69 40.6Silicates 129 180 28.3Organic minerals 4 5 20.0Summary 430 661 35.0

ReferencesAGRICOLA, G. (1556). De re metallica libri XII. Froben,

Basileae.JONAS, J. (1820). Ungerns Mineralreich orycto-

geognostisch und topographisch dargestellt. Hartleben,Pesth.

KODĚRA et al. (1986, 1990). Topografická mineralógiaSlovenska I-III. SAV Veda, Bratislava.

TÓTH, M. (1882). Magyarország ásványai. Hunyadi MátyásInt., Budapest.

ZEPHAROVICH, V. VON (1859, 1873, 1893). Mineralogis-ches Lexicon für das Kaiserthum Oesterreich. Braumüller(1859, 1873), Tempsky (1893), Wien.

ZIPSER, CH. A. (1817). Versuch eines topographisch-mineralogischen Handbuches von Ungern. Wigand,Oedenburg.


28

CALCIUM PHOSPHATES IN THE BAT GUANO DEPOSIT FROM PEŞTERA MARE DE LAMEREŞTI, PERŞANI MOUNTAINS, ROMANIA

DUMITRAS, D.-G.1, MARINCEA, Ş.1, DIACONU, G.2 & BILAL, E.31 Geological Institute of Romania, Caransebeş 1, RO-78344 Bucharest, Romania.E-mail: [email protected] “Emil Racoviţă” Institute of Speleology, Bucharest, Romania.3 Ecole Nationale Supérieure des Mines, Saint-Étienne, France.

The cave from Mereşti (Peştera Mare de la Mereşti) is lo-cated at the northern margin of Perşani Mountains, in theVârghiş Gorges, at about 18 km north–northwest of Baraolt,Covasna County, Romania. The cave, which has, includingthe divergent galleries, 1527 m in length, is developed inTithonian-Neocomian algal micritic limestones with cal-carenite levels. A bat guano deposit, with limited extension,was identified inside the cave.

Calcium phosphates (i.e., hydroxylapatite, carbonate-hydroxylapatite, brushite and ardealite) are the most repre-sentative mineral species in the bat guano pile, but the asso-ciated minerals also include calcite, gypsum, alpha (low)quartz, illite and interstratified kaolinite-illite.

Hydroxylapatite, or more precisely carbonate-hydroxylapatite, is the most common mineral species in thelower part of the guano pile. It occurs as creamy white crustscomposed of fine platy crystals up to 15 µm in diameter and1 µm in thickness.

An inductively coupled plasma - atomic emission spec-trometry (ICP-AES) analysis of a carefully handpicked sepa-rate, recalculated to 100% after the deduction of water inorder to assess the charge balance, gave (in wt.%) the fol-lowing results: K2O = 0.01, Na2O = 0.01, CaO = 54.87, MnO= 0.03, MgO = 0.27, FeO = 0.39, P2O5 = 42.03, SO3 = 0.53,H2O = 1.86. This composition, normalized on the basis of 6(P + S) and 26 (O,OH) per formula unit (pfu), leads to thechemical-structural formula:[K0.002Na0.003Ca9.804Mn0.004Mg0.067Fe2+

0.054](P5.934S0.066)O23.929(OH)2.071.

Note that the presence of carbonate substituting for phos-phate groups was ignored, because CO2 was not checked for.The infrared spectrum of the same sample gave, however, apattern typical for carbonate-hydroxylapatite, characterizedby OH stretching (3570 cm-1) and librational (635 cm-1)bands, CO3 (ν3 1466 cm-1, ν3’ ~1430 cm-1, ν2 872 cm-1)bands, and PO4 (ν3 1086 cm-1, ν3’ 1042 cm-1, ν1 955 cm-1, ν4

604 cm-1, ν4’ 564 cm-1, ν2 472 cm-1) bands.The cell parameters obtained by least-squares refinement

of 59 X-ray powder (XRD) reflections obtained for a repre-sentative sample are a = 9.438(3) Å, c = 6.868(3) Å and V =529.8(3) Å3.

Brushite occurs as snow white powdery coating on hy-droxylapatite or as nodular earthy masses (several mm to 2cm in diameter) in the bat guano mass, in which case themineral is generally surrounded by hydroxylapatite. In terms

of the composition and stoichiometry, the Mereşti materialclosely matches the CaHPO4·2H2O end-member. Its meancomposition, taken as an average of five ICP-AES analysesof samples whose purity was proved by XRD analysis is (inwt.%): K2O = 0.02, Na2O = 0.02, CaO = 32.09, MnO = 0.07,MgO = 0.21, FeO = 0.16, P2O5 = 40.26, SO3 = 1.11, H2O (ascalculated for the charge balance) = 26.05. This composition,normalized on the basis of 2 (P+S) and 8 (O) in the anhy-drous part of the compound, leads to the chemical-structuralformula:[K0.001Na0.002Ca1.969Mn0.003Mg0.018Fe2+

0.008](HPO4)1.952

(SO4)0.048 • 4H2O.The average unit-cell parameters, taken as mean of the

values obtained by least-squares refinements from 7 sets ofX-ray powder data including 51-93 reflections unequivocallyattributable to brushite are a = 5.812(5) Å, b = 15.169(5) Å, c= 6.239(4) Å and β = 116.35(13)°.

Ardealite occurs as cream white, thin and porous cruststhat overcoat hydroxylapatite or as small nodules, up to 0.5cm in diameter, surrounded by a mass composed of hy-droxylapatite and brushite.

The average ICP-AES composition, obtained as mean ofthree individual analyses of representative samples yielded(in wt.%): K2O = 0.01, Na2O = 0.01, CaO = 32.45, MnO =0.02, FeO = 0.05, MgO = 0.04, P2O5 = 21.05, SO3 = 22.76,H2O (calculated in order to assess the charge balance) =23.60. The resulting chemical-structural formula, calculatedon the basis of basis of 2 (S+P) and 8 (O) in the anhydrouspart of the compound, is:[K0.001Na0.001Ca1.992Mg0.004Fe2+

0.002](HPO4)1.021(SO4)0.979 •4H2O.

The cell parameters, taken as mean of least-squares re-finements on 6 different sets of X-ray powder reflections, area = 5.718(3) Å, b = 30.998(24) Å, c = 6.248(5) Å and β =117.17(5)°.

The textural relationships between the three calciumphosphates, observed by scanning electron microscopy andenergy-dispersive electron microprobe analysis suggests thattheir sequence of crystallization was from (carbonate-) hy-droxylapatite to brushite and finally ardealite. All the threespecies clearly resulted from the reaction between thestrongly acidic solutions derived from the guano mass andthe cave floor or moonmilk flows.


29

MINICOLLECTIONS OF MINERALS – A CONTRIBUTION TO EDUCATING THE YOUNGGENERATION

EDELSTEIN, O.V. Babes 30A, RO-4800 Baia Mare, Romania.E-mail: [email protected]

Due to many reasons, the collections of minerals have animportant role in the education of the young generation.These collections contribute greatly to increasing the knowl-edge in various fields:

• In chemistry, due to the fact that all minerals repre-sent chemical compounds,

• In geography, due to the fact that a collection in-volves a clear specification of the location of thesample,

• In history of civilization, because some minerals arepart of ore deposits and they have influenced theevolution of people, geographic regions and periodsin human history.

Collection of the minerals also involves collecting trips,which lead to new knowledge, better understanding of newareas, and requires spending more time outdoors.

The poster presents several mineral collections as fol-lows:

• No. 1 Volcanic rocks and minerals from the BaiaMare region - Romania

• No. 2 Minerals from Baia Mare – Romania andAtacama – Chile

• No. 3 Copper minerals• No. 4 Semiprecious and ornamental gems from

around the world I• No. 5 Semiprecious and ornamental gems from

around the world II• No. 6 Native elements• No. 7 Ore minerals from Romania• No. 8 Minerals from Romania – A field guide• No. 9 Aesthetic mineral samples from the Baia

Mare region – Romania• No. 11 Natural and synthetic gemstones.


30

KAMPHAUGITE-(Y), A RARE HYDROUS Ca-Y-CARBONATE MINERAL FROMSZARVASKŐ, BÜKK MOUNTAINS, HUNGARY

FEHÉR, B.1, SZAKÁLL, S.2 & NAGY, G.31 Department of Mineralogy, Herman Ottó Museum, Kossuth u. 13, H-3525 Miskolc, Hungary.E-mail: [email protected] Department of Mineralogy and Petrology, University of Miskolc, H-3515 Miskolc-Egyetemváros, Hungary.3 Laboratory for Geochemical Research, Hungarian Academy of Sciences, Budaörsi út 45, H-1112 Budapest, Hungary.

Known localities of kamphaugite-(Y)Kamphaugite-(Y) – ideally Ca2Y2(CO3)4(OH)2 • 3H2O –

was first described by RAADE & BRASTAD (1993) fromHørtekollen, Oslo region, Norway. The Hørtekollen depositis a contact metamorphic skarn deposit, where kamphaugite-(Y) is a late-stage phase in cavities of the rock. There are twoother occurrences of the mineral in Norway: a) Høydalengranite pegmatite, Tørdal (RAADE et al., 1993); b) Tangenpegmatite quarry, Kragerø.

Outside Norway some additional localities of kamphau-gite-(Y) are known: 1) A Ca-Y-carbonate mineral was re-corded and identified as “tengerite” by STEPANOV (1961)from an undefined locality in Kazakhstan. 2) An unnamedCa-Y-carbonate was discovered in a quartz-barite vein withinthe carbonatized Goudini volcano, Transvaal, South Africa(VERWOERD, 1963). 3) The next locality is in the Evans-Lou pegmatite, Quebec, Canada (HOGARTH, 1972), whereit was designated as UN-21. According to RAADE & BRA-STAD (1993) the Ca-Y-carbonate minerals from the threelocalities given above represent kamphaugite-(Y). Recentlykamphaugite-(Y) was recorded by GAMBONI & GAM-BONI (1998) from Cala Francese, La Maddalena Island,Italy. There are some other unpublished localities of kam-phaugite-(Y) without any additional data, e. g. Paratoo cop-per mine, Yunta, Olary Province, South Australia; Mt. Plo-skaya, Keyvy, Kola Peninsula, Russia.

Kamphaugite-(Y) from SzarvaskőIn Hungary kamphaugite-(Y) was found in the Tóbérc

quarry (formerly Forgalmi mine) at Szarvaskő, Bükk Moun-tains. It forms white globular aggregates up to 0.5 mm indiameter and white coatings on the walls of fissures of gran-ite. Globular aggregates consist of 10–20 µm sized thicktabular crystals on {001}.

Kamphaugite-(Y) is tetragonal with space group P41212(RØMMING et al., 1993). Observed reflections on the X-raypowder pattern of Szarvaskő specimen are [d in Å (int., hkl)]:6.344 (s, 102), 5.438 (w, 004), 5.126 (w, 111), 4.405 (m,104), 3.534 (m, 202), 3.295 (w, 211), 3.198 (w, 212), 2.906(m, 107), 2.835 (m, 214), 2.742 (m, 008), 2.637 (s, 220),2.449 (w, 216), 2.033 (mw, 322), 1.926 (w, 324) and 1.890(ms, 228). The experimental pattern was obtained with a114.6 mm Gandolfi camera using CuKα radiation. Unit celldata are a = 7.515 Å, c = 21.898 Å, V = 1236.5 Å3.

Six chemical analyses were carried out with JEOL JXA-733 electron microprobe operated at 20 kV and 40 nA. H2Oand CO2 couldn’t be directly determined because the amountof available material was very limited. A representative ana-lytical result is the following (in weight per cent): CaO20.07, Y2O3 29.72, La2O3 0.10, Ce2O3 0.93, Pr2O3 0.33,Nd2O3 2.13, Sm2O3 1.55, Eu2O3 0.53, Gd2O3 3.26, Tb2O3

0.63, Dy2O3 4.91, Ho2O3 0.99, Er2O3 2.74, Tm2O3 0.50,Yb2O3 1.65, Lu2O3 0.43, Σ 70.47, which corresponds toCa1.94(Y1.43Dy0.14Gd0.10Er0.08Nd0.07Sm0.05Yb0.05Ce0.03Ho0.03

Eu0.02Tb0.02Pr0.01 Tm0.01Lu0.01)Σ=2.05 (CO3)4.03 (OH)1.97 • xH2O,where x = –1.94. CO3 and OH were calculated from chargebalance and H2O was calculated from the difference.

We can’t determine the degree of hydration of the Szar-vaskő kamphaugite-(Y) from the electron microprobe analy-ses, because ca. 10 wt% CO2 and H2O eliminated from thesample when it decomposed under the electron beam. Fromthe chemical analyses a formula with 3H2O per 4CO3 hasbeen proposed by RAADE & BRASTAD (1993), but only2H2O is implied from the structural investigation (RØM-MING et al., 1993). The 004 and 008 reflections of the XRDpowder diagrams may have strongly variable intensitiesprobably depending on water content. For the kamphaugite-(Y) with a lower water content the 004 reflection is alwaysclearly visible and 008 is strongly enhanced, whereas the 004reflection may or may not visible on X-ray films for water-rich kamphaugite-(Y) (RØMMING et al., 1993). Because onthe X-ray film of kamphaugite-(Y) from Szarvaskő the 004reflection is visible and 008 is rather strong, this mineralcontains probably less than 3H2O per formula unit.

In Szarvaskő kamphaugite-(Y) is a low temperature latestage mineral formed in the fissures of metagranite. There arenot any other members of this low temperature paragenesisexcept for calcite, however, it is never associated with kam-phaugite-(Y). The only primary REE-mineral of metagraniteis an REE-bearing epidote group mineral (allanite?), whichcould be the source of yttrium in the hydrothermal system.

Investigated kamphaugite-(Y) sample from Szarvaskő ispreserved in the mineral collection of Herman Ottó Museum(Miskolc, Hungary) under catalogue number 25257.

ReferencesGAMBONI, A. & GAMBONI, T. (1998). Rivista Miner-

alogica Italiana, 1998/2: 27-28.HOGARTH, D. D. (1972). Mineral. Record, 3: 69-77.RAADE, G. & BRASTAD, K. (1993). Eur. J. Mineral., 5:

679-683.RAADE, G., SÆBØ, P. C., AUSTRHEIM, H. & KRIS-

TIANSEN, R. (1993). Eur. J. Mineral., 5: 691-698.RØMMING, C., KOCHARIAN, A. K. & RAADE, G.

(1993). Eur. J. Mineral., 5: 685-690.STEPANOV, A. V. (1961). Trudy Kazakhskogo Nauchno-

Issledovatel. Instituta Mineralnogo Syrya, 5: 147-161.VERWOERD, W. J. (1963). Ann. Geol. Surv. S. Africa, 2:

119-129.


31

TRACING GLAUCONITE FORMATION IN OLIGOCENE–MIOCENE SANDSTONESIN HUNGARY

FEKETE, J., WEISZBURG, T. G. & TÓTH, E.Department of Mineralogy, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected]

Glauconite formation has been a subject of lively debatefor many decades. The results of recent seafloor studies(ODIN, 1988) demonstrated the complexity of this process.In the frame of a larger research project on celadonite-glauconite minerals the process of glauconite formation onclastic substrate was studied in details.

Two glauconite-bearing clastic sedimentary formationswere selected for detailed study: the Upper Oligocene EgerFormation (south-western foreland of the Bükk Mountains,North Hungary; two samples from different locations) andthe Lower Miocene Pétervására Sandstone Formation (north-ern foreland of the Mátra Mountains, North Hungary; onesample). The current presentation is to report the final resultsof the separation process and the preliminary results of thestudy of these separated mineral fractions.

The studied rocks are mostly cemented by calcite, thusthe first step of separation was acetic acid treatment (10%solution). Each studied sample weighed approximately 1 kg.After the treatment acetic acid was washed out of the sam-ples.

The second step was the separation upon grain size. Thefollowing grain size fractions were obtained by wet sieving:>800 µm, 800–400 µm, 400–250 µm, 250–125 µm, 125–63 µm, <63 µm. To enhance the disintegration of the grains,the obtained fractions were gently shaken in an ultrasoniccleaner (for 5 minutes), then wet sieving was repeated. Afterdrying the samples, dry sieving was also applied. The frac-tions >800 µm and <63 µm were not subjected to furtherseparation due to their reduced importance concerning glau-conitization.

The third separation step was magnetic separation. Eachgrain size fraction was separated at (0.5), 0.6, 0.7 and(0.8) A, depending on the magnetic behaviour of the sam-ples. Magnetic behaviour was different in the different grainsize fractions of the different samples.

The fourth separation step was the separation upon den-sity. For this purpose, bromoform (tribromomethane) dilutedby different amounts of ethyl alcohol was applied, resultingin the following density fractions in each formerly separatedfraction: (>2.83 g/cm3), 2.83–2.78 g/cm3, 2.78–2.73 g/cm3,2.73–2.68 g/cm3, 2.68–2.63 g/cm3, 2.63–2.58 g/cm3, 2.58–2.53 g/cm3, 2.53–2.48 g/cm3, 2.48–2.43 g/cm3 and<2.43 g/cm3.

The fifth, last, step was the purification of samples byhand picking under the binocular.

This minute and rather time-consuming procedure en-abled us to (1) get an overview on the mineral composition

of the clastic sedimentary rocks; (2) study the relationshipbetween the iron content, density, magnetic behaviour, grainsize, structure and maturity of the glauconitic grains.

The results confirmed the complexity of glauconitization.The green grains, formerly handled as single phase“glauconite” (characterized by one chemical and XPD dataset in one geological horizon) of the profiles showed highvariability in their physical, chemical and structural proper-ties.

For example in one of the Oligocene samples (Nyárjas-1)the green grains were distributed over a density range of2.83–2.53 g/cm3. Their colour, even if it has faded a bit, wasstill characteristically green around the 2.53 g/cm3 densityfraction. Even the lowest density fraction (<2.43 g/cm3) got alight green tint.

The data indicate a density-grain size correlation, in thelarger grain size fractions the population of the larger densityglauconitic grains is higher.

While the morphology of the different colour grains inthe different size fractions is very similar, the XPD patternsshow a clear separation of the lowest density fraction (poorlycrystallized, smectite-like pattern) and the fractions above2.53 g/cm3 (mica-like, still not very well crystallized struc-ture).

In some of the studied samples glauconitic grains repre-senting a complete series of the stages of the glauconitizationprocess could be found, while in others glauconite grainswere present in only one dominant density/size fraction.Based on these differences autochthonous and allochthonouspositions of glauconite could be assumed.

With the help of that systematic and complex separationprocedure it has become possible to study glauconitic grainsof different size, density and magnetic property separately.We suppose that glauconitic grains of different size, densityand magnetic character from the same glauconite populationrepresent different stages of glauconitization. By this highlydifferentiated study of a single glauconite population wehope to get a deeper insight into the formation process ofglauconites.

This work was supported by the OTKA (Hungarian Sci-ence Foundation) grant #T25873.

ReferenceODIN, G. S. (ed., 1988). Green marine clays. Development

in sedimentology, 45. Elsevier, Amsterdam.


32

MORPHOLOGY OF QUARTZ FROM PALEOGENE SEDIMENTS AT THE LOCALITYVEĽKÝ LIPNÍK, SLOVAKIA

FULÍN, M.Eastern Slovakian Museum, Hviezdoslavova 3, SK-041 36 Košice, Slovak Republic.E-mail: [email protected]

Marmarosh diamond (originally described as quartzcrystals of pseudocubic shape) is one of the genetic types ofquartz. In the north-eastern part of Slovakia, in the Inner-Carpathian Klippen Belt Zone several occurrences of Mar-marosh diamond have been described. The region of VeľkýLipník is one of the registered Marmarosh diamond locali-ties. The clear crystals of quartz occur here in joints in grey-black slates and in sandstones. The occurrence of Marmaroshdiamond is here the result of a low-temperature (140–190 °C) mineralization. An important condition for themineral growth was the diagenesis of flysch. Water andmethane, products of diagenesis, influenced the crystalmorphology. The variability of quartz crystals depends onchanges at the joints during the growth. By the opening ofthe joints the pressure and the chemical character of thesolutions changed. The andesite volcanism in Poland nearSzczawnica played an important role, too (BAJOVÁ, 1987).

At Veľký Lipník quartz crystals of the range 0.5–5.0 mmpredominate. Centimeter-size crystals are common here, too.The largest crystal from this locality was 6.0 cm long and 4.0cm wide. With the increasing crystal size, the typical mor-phological characteristics of Marmarosh diamonds (shortditrigonal resp. pseudohexagonal prism, two sides closedwith area of positive and negative rhomboedra) change, theirlustre and clarity decreases. The larger crystals show parallelintergrowths and also skeleton habit. Very frequent are inclu-sions of methane and carbon dioxide. According to the mor-

phology of crystals the following types are distinguished(BAJOVÁ & FULÍN, 1989):

- Crystals with short prisms (length of prisms smallerthan 1/3 of the whole length of the crystals)

- Crystals with long prisms- Crystals with subordinate prisms- Skeleton crystals

With the study of crystal faces we tried to find out,whether all the four morphological types described can beregarded as Marmarosh diamonds (in genetical sense) or theyrepresent other genetical types of quartz (ZACICHA et al.,1984). We studied 52 crystals above the size of 1.0 cm. Wecalculated the reciprocal ratio of the crystal faces and com-pared these data between the crystals, so that we obtained thecharacter of the dominant crystal form. The results confirmthat the big crystals have the character of Marmarosh dia-monds, too.

ReferencesBAJOVÁ, Ľ. (1987). Diploma thesis, KGaM BF VŠT

Košice.BAJOVÁ, Ľ. & FULÍN, M. (1989). Zborník Výcho-

doslovenského múzea v Košiciach, XXX: 11–15.ZACICHA, B. V. et al. (1984). Naukova dumka, Kiev/Lviv:

83–100.


33

POLISHED BASALT STONE TOOLS FROM HUNGARY

FÜRI, J.1, SZAKMÁNY, Gy.1, KASZTOVSZKY, Zs.2 & T. BÍRÓ, K.31 Department of Petrology and Geochemistry, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest,Hungary.E-mail: [email protected] Institute of Isotope and Surface Chemistry, Chemical Research Centre, Hungarian Academy of Sciences, P. O. Box 77,H-1525 Budapest, Hungary.3 Hungarian National Museum, Múzeum krt. 14-16, H-1088 Budapest, Hungary.

Volcanic rocks were very popular as raw materials forstone tools in the Neolithic Age in the Carpathian Basin andits environs. Basalt and andesite were considered very goodfor polished stone tools due to the good mechanical qualitiesand the common occurrence of the raw material in the Car-pathian Basin. The main aim of our study was to determineand characterise the different types of basalt polished stonetools and localise the source region of the different types ofbasalt in Hungary by Prompt Gamma Activation Analysis(PGAA). Macroscopical, petrographic microscopical andgeochemical studies were made on archaeological as well asgeological samples. Geochemical studies were made usingPGAA which is a relatively new, sensitive and non-destructive analytical method, therefore it may be useful onarchaeological finds.

We have investigated 30 samples (17 archaeologicalsamples; 14 basalt and 3 andesite, moreover 13 basalt sam-ples from outcrops). The samples are from different geologi-cal and archaeological age and locality.

Basalt stone tools from several archaeological collectionswere selected from different parts of Hungary. All sampleswere studied by PGAA and petrographic investigation. Theexamined samples originated from the Miháldy collection,Laczkó Dezső Museum (Veszprém), some pieces from Wo-sinszky Museum (Szekszárd), from Tápé-Lebő, Szolnok andSzentgál (Hungarian National Museum, Budapest; Dam-janich Museum, Szolnok and Laczkó Dezső Museum, Vesz-prém) and from a private collection from Mórágy. We col-lected basalt from outcrops of the 4 main areas in Hungary,where significant basalt occurrences suitable for tool-makingcan be found: notably, in the Mecsek Mts., the BalatonHighlands, the Little Hungarian Plain and in the Nógrád-Gömör Unit.

The archaeological basalt samples are macroscopicallygrey or dark-grey, black in their colour, the cut surface isusually darker, almost black. They are massive, fine-grained,and homogenous. The surface is sometimes heavily altered;therefore it has a lot of tiny holes because of the dissolutionof olivine and pyroxene. We can see small black (pyroxene)and dark green (olivine) phenocrysts in the grey matrix. Ingeneral, the smaller finds have more elaborate surface thanthe larger pieces. We have investigated 3 fine grained darkandesite archaeological samples too, which were macro-scopically very similar to the geological samples.

The mineral composition of basalt can be characterisedby plagioclases and clinopyroxenes, olivine, amphibole, andore minerals also present. On the basis of microscopicalfeatures, we could distinguish three groups among the basalt

samples. The first and second group has fluidal texture.There were clinopyroxene and sometimes a few olivine phe-nocrysts, too, in the first group. The second group is similarto the first group, but with smaller pyroxene phenocrysts. Inthe third group there were a lot of olivine phenocrysts, buttheir size and quantity were smaller than the clinopyroxenes.In both cases the plagioclase formed the skeleton in thegroundmass, and there were small-size opaque minerals,clinopyroxene, apatite, chlorite and a variable quantity ofglass among the plagioclase laths.

The Prompt Gamma Activation Analysis measurementswere carried out at the Budapest Research Reactor, Hungary.This measurement technique is based on the detection ofprompt gamma rays originating from neutron radiative cap-ture or (n, γ) reaction. The method is suitable for determina-tion of all the elements at the same time, however, with dif-ferent sensitivity. PGAA measurements gave reliable data forthe main components of basalt (SiO2, TiO2, Al2O3, Fe2O3,MnO, MgO, CaO, Na2O, and K2O) and some trace elements(B, Sc, V, Cr, Sm, Eu, Gd and Dy). Moreover, we coulddetect Cl, too. The advantages of the method are: it is abso-lutely non-destructive and the measurement requires no sam-ple preparation. 7 samples were measured in powder andmassive form too, to check reproducibility and we got muchmore consistent data on the main element composition thanfor the trace elements.

Macroscopical investigation did not show a significantdifference between the samples. Moreover, the archaeologi-cal implements are typically heavily altered on the surface,because of being buried for a long time. The differences intexture and mineral composition observed in the microscopi-cal studies did not show any connection with the previousmacroscopical grouping. Seemingly meaningful groupscould be made on the basis of microscopical observation andPGAA.

We could form three groups of basalt by geochemistryand petrography. Two of them are clearly distinct and corre-spond, on one hand, to Mecsek Cretaceous basalt (Group 1),on the other hand, to young alkaline basalt (Group 3). Group2 shares more features of the former, its interpretation, how-ever, needs further studies. Another question raised wasseparating macroscopically similar andesite polished stonetools from basalt. It was possible by microscopical investi-gations and PGAA too, but the unbroken polished stone toolscan be studied preferentially by non-destructive methods,like PGAA.


34

MINERAL ASSEMBLAGES AND CRYSTALLIZATION OF THE KOSMAJ GRANITOIDSAND ITS ENCLAVES (SERBIA)

GAJIĆ, B.1 & VASKOVIĆ, N.21 Faculty of Forestry, University of Belgrade, Kneza Viseslava 1, YU-11000 Belgrade, Yugoslavia.E-mail: [email protected] Faculty of Mining and Geology, University of Belgrade, Djušina 7, YU-11000 Belgrade, Yugoslavia.

On the southwestern slopes of the Mt. Kosmaj (North Su-madija, Serbia) in an area of about 2.5 km2 a few smaller orlarger outcrops of granitic rocks are discovered. These occur-rences expose a part of a granitoid pluton that intruded duringOligocene (29–30 Ma) into Upper Cretaceous flysch sediments.The pluton occurs in the Vardar Zone Composite Terrane(KARAMATA & KRSTIC, 1996). Its intrusion caused a 400–550 oC thermal contact aureole over an area of about 11 km2 at apressure of 0.5–1.5 kbar. Among the mentioned granitoid occur-rences the most interesting one is outcropping in the Radovaccreek and its tributaries and can be traced for about 1 km. It ischaracterized by a number of mafic igneous enclaves and frag-ments of contact metamorphosed flysch sediments.

The granitoid rocks are medium- to fine-grained withmegacrysts of K-feldspar (1–6 cm in length). The main min-eral constituents are K-feldspar (Or70.5-92.8), rarely microper-thite and mirmekite, plagioclase (An39.7-14.8), quartz, amphi-boles (magnesio-hornblende, edenite, actinolitic hornblende,actinolite, XMg = 0.63–0.75), biotite (XMg = 0.53–0.57), andaccessories are zircon, apatite, titanite and magnetite. Ac-cording to major element composition these rocks corre-spond to granodiorite (GRD) and tonalite (TON).

The mostly elliptic mafic igneous enclaves are irregularlydistributed throughout the exposed mass. The enclaves usu-ally have a size of 1–10 cm. Their structure is quite differentfrom that of the incorporating granitoids: fine-grained orporphyritic. They are composed of plagioclase (An51.8-21,8),K-feldspar (Or79-85), quartz, amphibole (magnesio-hornblende, actinolitic hornblende; XMg = 0.65–0.76), biotite(XMg = 0.53–0.59); accessories are titanite, apatite and mag-netite. Major element composition exhibits monzodioritic(MD) and dioritic (D) character.

Pressure of 0.5 to 1.5 kbar and temperatures from 668 to 529oC were calculated for GRD and TON and 740–620 oC for theMD enclaves, using hornblende and co-existing hornblende andplagioclase compositions, respectively. The two feldspar geo-thermometer was calculated applying an average pressure of 0.5to 1.5 kbar. The calculated temperatures range between 583 and565oC (± 50oC) for GDR and 648–573oC (± 50oC) for MDenclaves. These temperatures are lower than those calculated forthe equilibrium of the amphibole–plagioclase assemblage and

can be considered as the temperature at which GRD and MDmagmas were completely crystallized or as a temperature of re-equilibration.

The thermo-sensitive cation content in amphiboles (Tiand AlIV) projected on the empirical temperature scale ofNABELEK & LINDSEY (1985) showed that temperaturesare not significantly different from those calculated from theamphibole–plagioclase geothermometer.

In order to place thermal constraints on the late-magmaticcrystallization at excess fluid composition CIPW normative ofthe Ab, Or, Qtz components of the Kosmaj granitoid rocks wereprojected via an into the ternary residual system for PH2O = 3kbar (JOHANNES, 1985). MD and D enclaves plot above thebinary Ab-Or minimum (765 °C) and close to M2, indicatinglower water pressure (1–2 kbar). However, plotting these dataon to haplogranite diagram of PH2O = 2 kbar and aH2O = 1(HOLTZ et al., 1992) results in a little bit different tempera-tures, suggesting plagioclase fractionation joined by alkali-feldspar in the porphyritic types. Cotectic near minimum com-position in rocks with An < 28% indicates water-excess crystal-lization which probably did not exceed 3 vol. % at temperaturesbetween 720 and 680 °C.

The obtained results suggest that the main rock type (grano-diorite) of the Kosmaj pluton crystallized in the temperaturerange of 640 ± 70 °C, and enclaves in the temperature range of760 ± 20 °C, under the pressure range of 0.5 to 1.5 kbar, indi-cating shallow-level emplacement (cca. 1.5 to 3 km) and con-solidation under H2O-saturated conditions.

ReferencesHOLLAND, T. & BLUNDY, J. (1994). Contrib. Mineral.

Petrol., 116: 433-447.HOLTZ et al. (1992). Amer. Mineral., 72: 321-239.JOHANNES, W. (1985): In”Migmatites” (Ed. Ashwort,

J.R.), Blackie, 36-85.KARAMATA, S. & KRSTIC, B. (1996): In “Terranes of

Serbia and neighbouring areas” 25-40.NABELEK, C. R. & LINDSEY, D. H. (1985). Geol. Soc Am.

Prog. Abst. 68384, 673.


35

MIGRABITUMENS – THE LINK BETWEEN THE PODHALE TROUGH AND THECRYSTALLINE BASEMENT OF THE WESTERN TATRA MTS.

GAWĘDA, A.1, MARYNOWSKI, L.1 & KĘPIŃSKA, B.21 Faculty of Earth Sciences, University of Silesia, ul. Bedzińska 60, PL-41-200 Sosnowiec, Poland.E-mail: [email protected] Mineral & Energy Economy Research Institute, Polish Academy of Sciences, ul. Wybickiego 7, PL-30-950 Cracow, Poland.

The Tatra Mts. form one of the uplifted crystalline corespresent in the Inner Western Carpathians. The allochtonouscrystalline basement is overthrusted by folded Mesozoicunmetamorphosed sedimentary sequences. From the northblock of the Tatra Mts. is bordered by the Podhale Trough.That structure is built up of Mesozoic basement (adequate tothe Tatra Mesozic cover) and Tertiary filling: Podhale Flyschand nummulitic Eocene limestones (KĘPIŃSKA, 1997).Several boreholes drilled the structure of the PodhaleTrough. Apart from gas and oil manifestations sulphidethermal waters were stated here, too. Both the Tatra Mts.block and Podhale Trough are cut by the NE-SW trendingtectonic zones. Some of the boreholes, cutting PodhaleTrough, are located roughly on/near the tectonic lineaments(Zakopane IG-1, Poronin PAN-1, Biały Dunajec PAN-1).

In the crystalline basement the presence of bitumens, en-trapped in the quartz-sealed tectonic zones, were stated.Bitumens are at oil window stage of transformation (RCS =0.75–0.82) and contain biomarkers (steranes and hopanes),conventionally used for the oil-source rocks correlation.Possible source rocks for the bitumens were Upper Triassic –Lower Jurassic sedimentary rocks, deposited in the marine,oxic to suboxic environments (MARYNOWSKI et al.,2001).

Rock-Eval analyses showed that rock samples from thePodhale Flysch have the total organic carbon (TOC) contentin the range 0.6–1.4 wt% and Tmax varying in the range from430 °C to 445 °C. All investigated Tertiary samples representthe usually non-generative, III type of kerogen. Additionally,extractable bitumens from the Tertiary Podhale Flysch con-tain significant amounts of oleanes, which are absent in themigrabitumens as well as in the extractable organic matterfrom the Tatra Mesozoic cover and Podhale Mesozoic base-ment.

The Mesozoic basement rocks reached the transformationof dry gas window stage, with Ro changing from 1.1% (northof Podhale) to 1.51% and 2.3% (south of Podhale). Organicmatter from the Mesozoic rocks of the Tatra block covershowed the mean Ro = 1.23%.

GC-MS investigations revealed that thermally stable iso-mers of phenantrenes, terphenyls and phenylonaftalenes aswell as the aromatic sulphur compounds concentrations are

the lowest in the bitumens from the crystalline rocks andmuch higher in the Mesozoic and Tertiary rocks. That fact,together with vitrinite reflectance measurements, point outthe differences in maturity between bitumens and organicmatter from the Podhale and Tatra sedimentary rocks. Thehigh level of organic matter maturity in the Podhale Troughcaused the decomposition of biomarkers, so it is not possibleto compare the characteristics of source rocks for migrabitu-mens and Mesozoic and Tertiary rocks of Podhale. The pres-ence of n-alk-1-enes was stated in both Mesozoic rocks and,in lower concentrations, in bitumens from the tectonic zones.The n-alk-1-enes are important markers of rock-oil migrationand secondary expulsion, especially in the rocks which un-derwent the maturation processes to the level higher than Ro

= 1.2 %. They are usually enriched during the last stages ofcrude oil expulsion.

Both Mesozoic basement rocks and Tertiary fill of thePodhale Trough underwent the intensive maturation (level oflate catagenesis to early metagenesis) after the hydrocarbonsexpulsion. In this complex situation the correlation of themigrabitumen and source rocks was enabled only by theoccurrence of n-alk-1-enes and δ13C isotope data. The simi-larity of isotope data and consequent changes of n-alk-1-enesalong the NE-SW-trending tectonic lineaments, together withthe characteristics of Mesozoic sedimentary rocks led to theconclusion that Mesozoic (T, J) sedimentary rocks were thesource of the investigated bitumens.

The migrabitumens from the tectonic zone of the crystal-line basement of the Tatra Mts. are much less mature than thedispersed organic matter in the Mesozoic source rocks. Thepreservation of primary molecular constitution was possibledue to quartz sealing of the tectonic fractures and/or due tothe differences in heat flow in the western part of the Tatraand Podhale complex.

ReferencesKĘPIŃSKA, B. (1997). Polish Academy of Sciences –

Monographs, CPPGSMiE, 48, Cracow.MARYNOWSKI, L., GAWĘDA, A., CEBULAK, S. &

JĘDRYSEK, M. (2001). Geol. Carpathica, 52: 3-14.


36

TOURMALINES FROM THE CRYSTALLINE BASEMENT OF THE WESTERN TATRAMOUNTAINS (POLAND) – INDICATORS OF PARTIAL MELTING PROCESSES

GAWĘDA, A.1 & PIECZKA, A.21 Faculty of Earth Sciences, University of Silesia, ul. Bedzińska 60, PL-41-200 Sosnowiec, Poland.E-mail: [email protected] Department of Mineralogy, Petrography and Geochemistry, University of Mining and Metallurgy, al. Mickiewicza 30,PL-30-059 Cracow, Poland.

Tourmaline is the most important mafic mineral in thepegmatites and leucogranites present in the crystalline base-ment of the Western Tatra Mts. Tourmalines are very ir-regularly distributed, spatially bound to the leucogranites(alaskites) and their pegmatites (GAWĘDA, 1993). They areusual component of leucogranite pegmatites – as idiomorphicand/or xenomorphic crystals, ranging from 0.3 cm to 8 cm inlength. Tourmaline-rich lenses at the contact between leu-cogranite and mica schists can be also found. Tourmalinesare rarely present as small (up to 3 mm) dispersed crystals infolded mica schists, defining L2 lineation. Both leucogranitesand associated tourmaline occurrences are located in theshear zones, cutting the metamorphic complex of the West-ern Tatra Mts. which acted as a migration path both for theescaped melt and fluids.

All tourmalines, found in the Western Tatra Mts., belongto the schorl-dravite solid solution. They are saturated withrespect to Al (Al in Y sites = 0.182–0.631 a.p.f.u.), poor in Li(0.001-0.003 wt.%), with X-sites occupied mainly by Na(0.564–0.801 a.p.f.u.), relatively poor in F (0.18–0.19a.p.f.u.). The crystal zoning, typical of tourmaline group, isvery poor. Some crystals are nearly homogeneous. But thechemistry and Fe+3/Fetotal ratio differ in different localities.

Fm parameter, defined as FeT/(FeT + Mg), of the investi-gated tourmalines varies in the range 0.362–0.652. The low-est values are typical of the internal zone of tourmaline-richlenses, while tourmalines from the outer part of the same lensare characterized by the Fm values in the range of 0.427 to0.508. The highest Fm values (0.513–0.652) are reportedfrom tourmaline-bearing pegmatites.

The origin of tourmalines is interpreted, in general, ascrystallization of B-rich portions of fluid, separated from theanatectic leucogranite magma, formed by partial melting(dehydration-melting of muscovite) of metasediments(GAWĘDA, 2001). The main factor was the reaction be-tween the B-rich fluid/melt and (Fe, Mg)-rich host rocks:Bt + AS + 0.5 Pl + V(BO3, H2O, Na2O

+) = 0.7 Tr + K+ +0.1 Ilm + 1.2 Qtz + Fe2O3.

The speculations about the source of boron resulted intwo conclusions:1. the source of boron can be the decomposition of primary

B-bearing minerals (i.e. muscovite),2. introduction of B-rich fluid could have occurred along the

shear zone.The temperature of crystallization, calculated according

to tourmaline-biotite geothermometer (COLOPIETRO &FREIBERG, 1987) ranged from 490 to 515 °C. TheFe3+/Fetotal ratio varies in all investigated samples. The possi-ble explanation for the different Fe-oxidation states can bepresented in two ways:1. Oxygen fugacity differed from place to place in the source

rocks due to their inhomogeneity and presence or lack ofgraphite. Because separate magma batches had no contactwith each other, and there was no equilibrium in themetamorphic complex the original differences in oxygenfugacity could have been preserved.

2. The magmatic/post-magmatic fluid interacted with thehost rocks, forming a chemical gradient. Such gradientproduced the internal zoning in the tourmaline nest andthe differences in the Fe3+/Fetotal ratio in the tourmalines.

Both possibilities are applicable for different localities.The irregular distribution of tourmalines is interpreted as

a result of limited boron and water availability in the meltedmetasedimentary rocks and restricted mobilization of mafic(Fe, Mg) components. The escape of (B, H2O)-rich fluidphase along a zone of shearing was an additional factor,controlling the occurrences of tourmaline-bearing rocks.

ReferencesCOLOPIETRO, M. R. & FREIBERG, L. M. (1987). Geol.

Soc. Amer. Abstr. Progr. 19: 264.GAWĘDA, A. (1993). Arch. Miner. XLIX/2: 113-144.GAWĘDA, A. (2001). Monographs of the University of

Silesia, No. 1997, Katowice.


37

NOTE ON THE RECORD OF AN UNKNOWN METEORITE FALL NEAR THE ORADEAFORTRESS (TRANSYLVANIA, ROMANIA) AT THE END OF THE 17TH CENTURY

GEORGIŢĂ, M.The National Archives of Romania, Cluj Branch, 10, Kogălniceanu St., RO-3400 Cluj-Napoca, Romania.

During the preparatives for a new siege of the Oradeafortress by the Austrian imperial army, an astronomical eventwas noticed by the upper-rank officers, who soon after thatofficially reported it to the emperor Leopold II.

At the end of a long report on the current evolution of thewar from Transylvania and on the requirements of suppliesand equipment forwarded by general Veterani to the emperoron 20th April, 1692, a brief version of a note by general Au-ersperg on a meteorite fall near Oradea was also included.Count Auersperg was in that time the leader of the blockadeagainst the fortress, still occupied by the Turks. There hementioned about a „fire ball” that was noticed in the skies onApril 8th around 10 p.m., that went beyond the blockade,fortress and the army forefront, and finally landed in thewoods in the neighborhood (…“Übrigens hat der Graff vonAuersperg berichtet, dass den 8th dieses nachts um 10 Uhr beiWaradein ein feurige Kugel an dem Himmel gesehen worde,welche sodann über unsere Schantz, die Festung und unsereFeldwachte in dem aldortige Wald gefallen seye”…)1.

Attached to the report there is a sketch showing the tra-jectory of the meteorite until the impact with the soil where,according to the drawing it was fragmented into severalpieces. The meteorite in flames occurred from the clouds, itstrajectory being marked by „a fire tail” consisting of a multi-colored bright path. By comparing the sketch with a militarymap realized in May 1692, it can be concluded that the di-rection of the fall was probably NW-SE. Presumably Auer-sperg and his officers did the sketch.

The size of the meteorite was compared to that of a 200kg bomb. It may be assumed that the original size was larger,keeping into account the distance from where it was ob-served and the fact that the meteorite could not be recon-structed from its pieces after the landing.

One can expect that supplementary data could be foundin the military archives from Austria. Little chance exists tofind geological evidence in the field, the place of the fallbeen now probably within the area covered by the present-day town of Oradea. Our note is also intended to be a signalfor museums in the region that posses meteorite collections,where in a fortunate case, fragments of this meteorite couldbe identified.

The importance of this information consists of the rarityand value of a meteoritic fall itself, but more than that, itcould be the first mention of this type on the present-dayterritory of Romania. There are two reference papers con-cerning the meteorite falls in the Romanian territory:STANCIU & STOICOVICI (1943) give, besides the list offalls known at that time, a detailed description on the featuresrecorded by eye-witnesses during the fall of six meteorites(Mădăraş, Cacova, Ohaba, Jădani, Mociu, Şopot) as well aspetrographical and geochemical data. MAXIM (1968) addsto the previous list of falls four additional ones: Buzău, Târ-govişte, Târgu-Jiu – Câmpina, Tăuţi) and indicates the mu-

1 The National Archives, Bucharest (microfilms)

seums and other collections that host fragments of some ofthese meteorites.

Until now, the oldest record of a meteorite fall in Roma-nia concerns the meteorite from Buzău (Magnus meteoriticusBozaianus), January 1714, that was mentioned by S. Kölesériin his work “Auraria Romano-Dacica” but of which no sam-ple was preserved (MAXIM, 1968). The Catalogue of Mete-orites (GRAHAM et al., 1985) indicates a meteorite fall nearOradea, at Tăuţi, but the date of the fall is 1937 (p. 343);Oradea refers in that case to the former district at the time ofthe fall, the present-day administrative affiliation of Tăuţivillage being Arad district.

If the information presented above is confirmed, the fallfrom Oradea (1692) would represent the 11th and at the sametime the oldest record on meteorite falls in Romania.

ReferencesGRAHAM, A. L., BEVAN, A. W. & HUTCHISON, R.

(1985). Catalogue of Meteorites. British Museum, Lon-don.

MAXIM, I. A. (1968). Studia Univ. Babeş-Bolyai, Ser.Geol.-Geogr., 13/1: 3-6.

STANCIU, V. & STOICOVICI, E. (1943). Revista MuzeuluiMineralogic-Geologic Univ. Cluj, 7/1-2: 121-152.


38

THE MINERALOGY OF THE NEOLITHIC CERAMICS FROM UNGURULUI CAVE(SUNCUIUS, ROMANIA)

GHERGARI, L., IONESCU, C. & LAZAR, C.Department of Mineralogy, Babes-Bolyai University, 1, Kogalniceanu Str, RO-3400 Cluj-Napoca, Romania.E-mail: [email protected]

The paper presents the mineralogical features of the rem-nants of Neolithic pottery found in clayish deposits coveringthe floor of the Ungurului Cave, located on the left side ofCrisului Gorge (Apuseni Mts.). From archaeological andmineralogical points of view, the ceramics from UnguruluiCave is similar to the ceramics of same age, also found in thewestern part of Transylvania, at Salca-Oradea, Piscolt-Carei,Zauan-Zalau (the archaeological characterization belongs toC. Ghemis from Oradea Museum).

The colour of the ceramic body varies from reddish-yellow to red, brown or reddish-brown. Granulometrically,the ceramics is mainly of semifine, rarely coarse and finetype.

The fabric of the ceramic body (observed in thin sections)is microcrystalline-amorphous, reflected by a highly trans-formed clay matrix, which contains different clasts. Theclasts belong either to the raw materials or were added astemper (sands).

The clasts are represented by:• lithoclasts (fragments of andesites, quartzites, quartzitic

schists, granodiorites, garnet mica schists, rhyolites andvolcanic glass);

• crystalloclasts (quartz, feldspars, biotite, muscovite aswell as epidote-zoisite, calcite, zircon, garnet, titanite,tourmaline and amphiboles);

• ceramoclasts (potsherds).Vegetal remnants (transformed into carbon) were also

identified.The changes of the mineral compounds during the firing

are mainly of middle-to-high temperature type, as: sinteriz-ing, partial melting, recrystallizations, and changes of theoptical features. The clay minerals melted partially and gen-erated amorphous material or even supported some recrys-tallizations. The iron oxides and hydroxides formed magnet-ite and hematite. The birefringence of clay minerals changedas a function of the temperature of firing.

In cross section, the ceramic wall presents in general a bi-layered texture, marked by an outer layer (lighter colour;oxidizing firing) and an inner layer (darker colour; reducingfiring).

The arrangement of the lamellar minerals (micas, clayminerals) inside the ceramic wall gives the structure, whichcan be:• oriented, with the minerals arranged in rows parallel to

the ceramic body surface;• non-oriented, with the minerals randomly arranged.

The surface of the pottery was smoothed and coveredwith a coloured slip, prepared from clay and calcite. SEMstudies identified the presence of kaolinite, illite and il-lite/montmorillonite.

X-ray diffractometry reveals the presence of clay miner-als, quartz, calcite, feldspar, micas, magnetite (see figure).The changes noticed in the X-ray pattern for clay minerals,as well as microscopic studies, allow us to conclude that thefiring temperature for the Neolithic ceramics was around800oC (half-opened pits).

At least three sources of raw materials were used:• a Jurassic kaolinitic clay from Suncuius deposits;• a Neogene kaolinitic-illitic clay with tuffs fragments

(from Borod Basin);• soil formed on metamorphic rocks (Piatra Craiului area).


39

GEOARCHAEOLOGICAL STUDY ON LOCAL FINE CERAMICS FROM II-III CENTURY(NAPOCA SITE, ROMANIA)

GHERGARI, L.1, IONESCU, C.1 & RUSU-BOLINDET, V.21 Department of Mineralogy, Babes-Bolyai University, 1, Kogalniceanu Str, RO-3400 Cluj-Napoca, Romania.E-mail: [email protected] National History Museum of Transylvania, 2, Daicoviciu Str, RO-3400 Cluj-Napoca, Romania.

Ceramic pottery made in Roman times and found in theNapoca archaeological site (Transylvania, Romania) is ana-lyzed to establish a real classification as well as sources ofraw materials.

The colours of the ceramic body are quite homogenous:red to yellowish-red or gray. The surface of the pottery issmoothed and in general is not decorated, rarely vegetalmotifs being carved or pressed. The pottery is covered with ablack or white, glassy slip.

Granulometrically, the ceramics is lutitic-siltic, themaximum diameter of the particles being less than 0.1 mm.The porosity of the ceramic body is low.

The microscopic studies, performed on thin sections,identified a microcrystalline-vitreous fabric, as well as themain compounds: various clasts in a clayish matrix. Theclayish matrix present sinterizing or vitrification processes,in various degrees, function of the firing temperatures andthe composition of the raw materials (SHEPARD, 1976).

The lithoclasts (magmatic and metamorphic rocks),crystalloclasts (quartz, plagioclase feldspars, orthoclase,biotite, muscovite, heavy minerals), bioclasts (fragments ofglobigerinid forams, echinid plates, nannoplankton) andceramoclasts (potsherds) indicate both the composition ofraw materials and the temper used for ceramic paste.

The fabric (the arrangement of lamellar minerals) is ingeneral oriented, as the ceramics is a wheel-made one.

The changes in the microscopic characteristics of theminerals, the diffraction spectra and the SEM analyses indi-cate the temperatures of firing, which reached various do-mains, between 850 and 1000oC for the red ceramics andabout 1100 oC for the gray one. With few exceptions, thecalcite is partly or totally decomposed. The feldspars andclay minerals show changes of their optical properties. Theceramics fired over 950oC contains high amounts of glass asthe result of melting processes. In the gray ceramics, fired athigher temperatures, around 1100 oC, mullite crystals are alsopresent.

The provenance studies, based on the comparison of themineralogical–petrographical compounds (as temper, litho-clasts, bioclasts) and the features of the clayish rocks foundnearby the location of the ancient city suggest the using of akaolinitic-illitic clay, with calcite content. Similar rocks ofBadenian age occur to the north of the archaeological site.

ReferenceSHEPARD, O. A. (1976): Ceramics for the archaeologist.

9th ed. Carnegie Inst. of Washington, 414 p.


40

TECHNOGENIC GEOLOGY – A NEW BRANCH OF EARTH SCIENCES

GOROVOY, A., DOROFEEV, V. & GOROVAYA, N.Donbass Mine-Metallurgical Institute, Lenin prospect 16, UA-94204 Alchevsk, Ukraine.E-mail: [email protected]

Huge quantities of industrial wastes have been accumu-lated in many countries of the world. Up to now, 2–3 x 1012 tof industrial wastes have accumulated all over the world.Wastes cover an area of approximately 16 x 106 hectares. Itsquantity increases by 1010 t every year, 106 t every hour.

The wastes are objects of geological study, because geo-logical processes (mainly weathering; in coal mine wastedumps also reduction) take place in them. The study ofwastes must form a new branch of earth sciences, which weoffer to call technogenic geology. General task of this sci-ence is the studying of geological processes in wastes. In thatframe we can list several processes, among others thosewhich depend on the composition (wastes of coal, ore, met-allurgical and other industry) and on climate (humid, aridetc), those which provoke the generation of mobile chemicalcompounds. The new branch can be further subdivided fore.g. technogenic geochemistry (studying migration and ac-cumulation laws), technogenic mineralogy (formation of newminerals as it takes place e.g. in burning coal mine wastedumps), technogenic economic geology and metallogeny(studying the concentration of elements etc. of industrialimportance), technogenic geoecology (studying the concen-tration of toxic elements).

Wastes may be the “technological” deposits of elementsof major economic importance (e.g. workable concentrationsof scandium, germanium, lithium, silver and other elementshave been discovered in coal ashes), but may also be sourcesof environment pollution (by arsenic, lead, molybdenum andother toxic elements).

We worked out methods for the evaluation of wastes(usefulness/toxicity).

The offered estimation methods are based on the estab-lishment of useful and toxic indices and the determination ofseveral parameters. The useful and toxic indices are the gen-eral number, composition, quantity, sum and mean of spe-cific frequencies of occurrence, sum and mean of the excessmultiple of limiting-allowable concentration for toxic ele-ments (industrial concentration for useful elements), rangesof useful and toxic indices, mean combined index (rating).The general number of toxic (useful) elements is the sum ofthose chemical elements the contents of which exceed thelimiting-allowable concentration (minimum industrial con-centration). The specific frequency of occurrence shows howfrequently the element is present in the analyses. The sum ofspecific frequencies of occurrence is obtained by summingthe specific occurrence frequencies of all elements in theanalyses, while the average is the result of the division of thesum by the number of toxic (useful) elements. The excess

multiple of limiting-allowable concentration (industrial con-centration) shows how many times the content of the toxic(useful) element exceeds the limiting-allowable concentra-tion (industrial concentration). The sum is the result of sum-ming the excess multiples of all toxic (useful) elements in theanalysis, average is obtained by the division of the sum bythe number of the toxic (useful) elements. The chemical typeof toxicity is defined by the most widespread element fol-lowed by its prevalence to a class and then subclass. Toxity(usefulness) can be presented as the formula of the threemost widespread elements among toxic (useful) elements.The chemical symbol is surrounded by some parameters: thecoefficient showing specific frequency of occurrence theelement is disposed in front of the chemical symbol; behind,in subscript the excess multiple of limiting-allowable con-centration (industrial concentration); behind, in superscriptthe element role among others. The graphical plot consists ofthe general number of elements on the vertical axis and theexcess multiples on the horizontal axis. The received indicesallow to determine the typomorphism, model, metallogenicspeciation of useful elements and the chemical composition(type, class and subclass) of toxic elements, quantities, com-parison maps, chemical formulae and diagrams.

We studied the chemical composition of industrial wastes(containing rocks, rock-coal mixture, pure coal and coalashes of Donbass mines, dumps, slags, slimes, soils aroundDonbass metallurgical plants and slags of some power sta-tions). We found very high concentrations of useful and toxicelements (scandium up to 700 g/t, germanium up to 2000 g/t,lithium over 10000 g/t, arsenic up to 5000 g/t in coal ashesand others). In the Northern Donbass mines coal ashes“reserves” of antimony, beryllium, yttrium, cadmium, nio-bium and silver are estimated to be around thousands of tons;bismuth, zinc, copper, cobalt, molybdenum, vanadium, ger-manium, strontium, zirconium, scandium, gallium and ytter-bium around tens of thousands of tons; titanium and lithiumaround hundreds of thousands of tons. In reality the stockscan be even higher (by 25–30%).

It is possible to recover some metals simultaneously byone technology. In some coal mine fields up to 10 metalshave been revealed. Economic profit is obvious. If we as-sume that 1 t of coal contains 20–30% coal ashes, in whichscandium content is 300 g/t, we can extract 60–90 g of scan-dium from the ashes of 1t coal. The minimum price of 1 g ofscandium is 10 USD. The price of 1 t coal is 20–25 USD,while that of the extracted scandium is 600–900 USD.


41

THE PARTICIPATION OF MICRO-ORGANISMS AT THE FORMATION OF TODOROKITEFROM OXIDATION ZONE (TERÉZIA VEIN, BANSKÁ ŠTIAVNICA DEPOSIT, SLOVAKREPUBLIC)

HÁBER, M.1, JELEŇ, S.1, SHKOLNIK, E. L.2, GORSHKOV, A. A.3 & ZHEGALLO, E. A.41 Geological Institute, Slovak Academy of Sciences, Severná 5, SK-97401 Banská Bystrica, Slovak Republic.E-mail: [email protected] East Geological Institute, Russian Academy of Sciences, Vladivostok, Russia.3 Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry, Russian Academy of Sciences, Moscow,Russia.4 Institute of Palaeontology, Russian Academy of Sciences, Moscow, Russia.

Todorokite has been identified at the Terézia vein in theBanská Štiavnica ore field. Todorokite belongs to the young-est minerals of the vein filling, confirmed by its position inthe central part of the cluster cavities, often formed by per-fect crystals of quartz. The grey-brown coloured, fine-grained aggregates of todorokite, having a characteristicmetallic lustre, frequently fill the space among the crystals ofquartz and often form crusts up to 4 cm thickness. Some-times they form also spheroidal and reniform aggregates withradial to fibrous texture, built up of very small needle-likecrystals.

The SEM images from reflected (back-scattered) elec-trons, obtained from various parts of sample under relativelygreat magnification, show that the sample is formed byplates, needles and tables of various length and width, andalso by fibres and spheroidal aggregates of todorokite.

By scanning electron microscope (CAM SCAN-4) thetypical gradual stratifying of the aggregate of todorokite wasobserved, which corresponds to the gradual natural formingof more layers within the aggregate.

Some layers are characterised by vertically curved basalt-shaped crystals and among them are situated the cohesionlessinterwoven mass of very thin fibres (probably mineralisedbasidia). Their presence is confirmed by their carbon content(Corg = 0.10–0.22%). Vertical structures with variable posi-tion of bacteria-like structures are often also present and/orfungus-like structure clusters at upper parts of the layers. Thethickness of the fungus-like structures is several tenths of µmand the length several hundred µm.

Other layers form remicated, strongly cellular and porousfungus-like structures (thalluses) with marginal feathered andglobular termination, which probably correspond to basidia.The thickness of these bacteria-like and/or fungus-likestructures is up to 40–50 µm, the length of individual uni-cellular bodies is up to 200–300 µm. The terminal basidiareach the size of 15 to 30 µm.

Typically, there are also relatively large (20 to 40 µm)spheroidal forms (clusters of identical, partly disturbed)spheroidal remainders of micro-organisms or bacteria-likeand/or fungus-like structures. Here the bacterial mucilage

(probably glycokalyx, i.e. recrystallized microbial liquid)was probably partially preserved, metasomatised by todoro-kite. The well-preserved spheroidal remainders have an aver-age size of 3 to 10 µm. The various maculose clusters(probably septa), cumulates, or the vertical off shoots can beobserved on some fungus-like structures.

Closely vertical layers with systems of oval cavities–gal-leries, with fungus-like structures at the upper part of thal-luses and strongly cellular structures with the fungi (probablybasidia) of spheroidal shape, with a size up to 15 µm, werealso observed. The cohesion’s knitting-through is observedamong the relatively compact thalluses, where the fibrousstructure is clearly seen. The thin fibres of the fungus-likestructures are not always totally mineralised.

Up to now not exactly identified euhedral rhombohedralcrystals (probably Ca-Mn carbonates) were been formed atthe cavities of the cellular structures of the above describedaggregates.

The quantitative analyses of the sample were converted tothe following empirical formula of todorokite:(Na0.25K0.15Ca0.45Zn0.16)1.01(Mn4+

5.20Mn2+0.45Mg2+

0.34)5.99O12·3H2O. The quantity of water in the given formula and thedistribution of cations within the formula is analogous withthe formula given by STRACZEK et al. (1960). The basicdiffraction lines are 9.58 Å (100), 4.82 Å (50), 2.45 Å (40),2.360 Å (30), 1.971 Å (20), 1.422 Å (40). The structure isnearest to the orthorhombic lattice with parameters: a = 9.75Å, b = 2.84 Å and c = 9.6 Å (Z = 1). Nevertheless, at basicmasses this todorokite is characterised by the disorderedstructure. It appears, that in the oxidised zone micro-organisms participate also in the creation of todorokite (pres-ence of todorokite pseudomorphs of various parts of fungi,seldom a woodruffite mass).

ReferenceSTRACZEK, J. A., HORER, A., ROSS, M. & WAR-

SHAWCH, M. (1960). Amer. Mineral. 45: 1174-1184.


42

PETROGRAPHIC EVIDENCE TO EXTENSION OF THE PANNONIAN BASIN

HIDAS, K., FALUS, Gy. & SZABÓ, Cs.Lithosphere Fluid Research Lab, Department of Petrology and Geochemistry, Eötvös Loránd University,Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected]

IntroductionThe Pannonian Basin is thought to have formed as a re-

sult of a complex deformation history in the Middle-LateMiocene. Two major tectonic events have been recognizedwhich determined the evolution of the basin: 1/ a rollbackeffect of subduction in the Early-Middle Miocene (thinningfactor was nearly the same for both the lithospheric mantleand the crust: β = δ = 1.4-1.6); and 2/ an asthenosphericmantle upwelling in the Late Miocene which caused a large-sized extension in the lithospheric mantle (thinning factor:δ = 4-8) at the central portion of the basin (HUISMANS etal., 2001). Subcontinental lithospheric mantle xenoliths col-lected from the Bakony-Balaton Highland Volcanic Field(central part of the Pannonian Basin) have been studied pet-rographically to trace textural evidence of the large-scalemantle deformation events described.

Sample and techniquesAfter looking at more than 300 mantle xenoliths from the

Bakony-Balaton Highland Volcanic Field, one spinel lher-zolite xenolith from Szentbékkálla with a unique, specialtabular texture was chosen for a detailed microscopic studyusing universal stage. We measured lattice-preferred orienta-tion (LPO) of orthopyroxenes and olivines on more than 100grains, respectively and our data have been projected andevaluated on a stereographic projection.

Results and conclusionsLPO patterns of orthopyroxene show a (001) maximum

parallel to the lineation in the foliation plain and anothermaximum perpendicular to the lineation and the foliation.The pattern of the (010) plains also displays a double maxi-

mum similar to that of (001). The pattern of the (100) plainsdisplays a single maximum perpendicular to the lineation inthe foliation plain. Only very few orthopyroxenes display“normal” LPO pattern: (001) parallel to the lineation and thefoliation and (010) perpendicular to both plans. OlivineLPO’s are normal, (100) plains are in the foliation parallel tothe lineation, whereas (010) is perpendicular to the lineationand foliation, both show single maximum.

The orthopyroxenes are more resistant to recrystallizationthan olivines (PASSCHIER & TROUW, 1998; MERCIER,1985) and may preserve earlier deformation states of themantle. Our results suggest that the observed orthopyroxenepatterns might be due to a deformation predating the defor-mation that recrystallized the olivines in the mantle. Theorientations of the stress fields of the two deformations weresignificantly different, almost perpendicular.

These results correspond to geophysical modeling offormation of the Pannonian Basin, as summarized HUIS-MANS et al. (2001), and might provide the first petrographicevidence that a two-stage deformation process formed thebasin.

ReferencesHUISMANS, R. S., PODLADCHIKOV, Y. Y. &

CLOETINGH, S. (2001). Tectonics, 20: 1021-1039.MERCIER, J-C. C. (1985). Deformed Metals and Rocks: An

Introduction to Modern Texture Analysis, AcademicPress, Inc., p. 471.

PASSCHIER, C. W. & TROUW, R. A. J. (1998).Microtectonics, Springer-Verlag, p. 251.


43

MINERALS AND MINERAL VARIETIES FROM METAMORPHOSED Mn DEPOSITS OFBISTRITA MOUNTAINS, ROMANIA

HÎRTOPANU, P.1 & SCOTT, P.21 Geological Institute of Romania, Caransebeş 1, RO-78344 Bucharest, Romania.E-mail: [email protected] Camborne School of Mines, Redruth, Cornwall, United Kingdom.

The Bistrita Mountains belong to the Crystalline Meso-zoic Zone of the East Carpathians, which consists of super-posed Variscan and Alpine Nappes, overthrusted eastwardsover the Flysch Zone. The manganese ore is contained byTulghes Group (Tg2 level) of the Variscan Putna Nappe,situated over the Pietrosu Bistritei Nappe and supporting thethrusting of the Rebra Nappe. All these Variscan nappesconstitute the Alpine Sub-Bucovinian Nappe localised be-tween Alpine Infrabucovinian Nappe in the East and theAlpine Bucovinian Nappe in the West.

The mineralogy of Mn metamorphosed deposits fromBistrita Mts. includes 328 minerals and mineral varieties.They may count among the mineralogically the most com-plex deposits of the world. Prior to 1970 there were knownca. 50 minerals. The mineral number grew in 1970-1976period to 70 minerals and in very recent period (1994-2002)the mineral number reached 328. Minerals and mineral va-rieties from almost all mineral classes have been identified:carbonates 17, silicates 157, oxides 47, sulphides 48, sul-phates 5, phosphates 11, wolframates 2, borates 1, arsenates5, vanadates 1, native elements 1 and 33 minerals from oxi-dised zone.

The minerals and mineral varieties were determined bycombined methods: X-ray, IR, AAS, SEM analysis and opti-cal microscopy. Several of them are very rare species (nam-bulite, natronambulite, norrishite, bannisterite, parsettensite,manganpyrosmalite, friedelite, schallerite, nelenite, minne-sotaite, kellyite, etc.). A lot of determined minerals have Mnas major constituent: tephroite, manganese humite group(manganhumite, sonolite, alleghanyite), leucophoenicitegroup (ribbeite, leucophoenicite, jerrygibbsite), some of theoxide group, manganiferous phyllosilicates group, etc. Manyare secondary, as they occur in veins or are product of retro-gressive transformation from the granulite to amphibolitefacies, from the amphibolite to blueschist or greenschistfacies. Each metamorphic event was a source for new miner-als. Frequently, each mineral grain presents chemical varia-tional function of P, T, fO2, fCO2, fCl2 etc. on the route of pro-grade and retrograde polyphasic metamorphism. The zona-tion of the pyroxenes and amphiboles – marginal and sectoral– is a good evidence of changes of metamorphic conditions.In the case of zoned amphiboles, the core is man-ganogrunerite (amphibolite facies) and the rim is constitutedof alkali blue amphiboles (blueschist facies). The sector-zoned arrangement of pyroxenes developed during rapidcrystal growth and involved differences of both compositionand cation order. It consists of bands or hour-glass texture ofsodic augite and omphacite pyroxenes. Beside the transfor-

mation of some amphiboles and some pyroxenes into otherphases, there are drastical transformations of pyroxenes intopyroxenoids (johannsenite into rhodonite), pyroxenoids intopyroxenoids (pyroxmangite into rhodonite), pyroxmangiteinto manganogrunerite, garnets into garnets (spessartine-calderite into spessartine, spessartine into anisotropic spes-sartine-andradite-grossular), calderite into pyroxmangite-magnetite, etc. are the best evidences of continuous variationof formation conditions.

The Mn ore have a predominant carbonate rather thansilicate mineralogical composition, which means a great CO2

fluid control in the carbonation and dehydration processesalong the many stages of the whole history of the ore and theTg2 level. The mineral reactions for the tephroite assem-blages were of decarbonation type, their temperatures werestrongly influenced by composition of metamorphic fluid,that is, the decarbonation reactions took place at high tem-perature and high XCO2 (corresponding to amphibolite fa-cies).

The olivines, carbonates, Mn-humites, garnets, pyrox-enes, pyroxenoids, amphiboles, some oxides, some phyllo-silicates and some sulphides offer useful petrological infor-mation. Metamorphic reactions and P-T path of the Bistritaores suggest that they have undergone at least five stages ofrecrystallisation in a subduction zone. The clockwise trend ofmetamorphism is in agreement to the structure of the compli-cated tectonic setting of the Crystalline Mesozoic Zone.Many minerals are accessory phases having a scientific im-portance, enriching the national mineralogical patrimony.

In the Bistrita Mn-deposits three types of assemblageswere determined on the basis of the bulk oxidation ratios:oxidised (i.e. containing Fe3+ and Mn3+), reduced (with Fe2+

and Mn2+) and neutral, with Mn2+ and Fe3+.Closely associated assemblages of diverse mineralogy

from Bistrita Mn ore suggest that XMn and Xfluid rather thanphysical conditions of metamorphism are the decisive factorsin forming the observed mineral diversity. The Bistritametamorphosed Mn-rich mineral assemblages evolved undera variety of constraints, including the diversity in the char-acter of the protolith and the nature of buffering of the fluidphase during metamorphism. Such a rich mineralogy whencompared with the limited number of minerals occurring inthe country rocks, make manganese ore from BM verypromising potential markers for P,T, fO2, fH2O, fCl, fB, fAs, etc.reconstructions, to supplement the country rocks mineralrecords (Tg2 level), strongly transformed or even erased bymetamorphism.


44

MINERALS OF THE METAMORPHOSED Mn-Fe DEPOSITS IN ROMANIA:OLD DEPOSITS, NEW SPECIES

HÎRTOPANU, P.1, UDUBAŞA, G.1 & SCOTT, P.21 Geological Institute of Romania, Caransebeş 1, RO-78344 Bucharest, Romania.E-mail: [email protected] Camborne School of Mines, Redruth, Cornwall, United Kingdom.

The main metamorphosed Mn-Fe deposits in Romaniaare hosted by metamorphic sequences of Upper Precambrian(South Carpathians) and Lower Cambrian ages (East Car-pathians) and their mineralogical composition is quite differ-ent, although the major minerals are the same, i.e. the oli-vines, rhodochrosite, pyroxmangite, rhodonite, etc: (1) Ra-zoare Mn-Fe deposit (Preluca Mts, East Carpathians), sili-cate-carbonate-oxide-suphide (2) Dadu, Colacu, Oita, Tolo-vanu, Puiu, Caprarie, Arsita, Argestru, Todireni, Sarisor,Dealu Rusului, Mandrileni, Ulm-Sihastria, Holdita, Brosteni,Borca Mn deposits (Bistrita Mts, East Carpathians), carbon-ate-silicate-oxide-sulphide; (3) Pravat, Leucus, Bretan,Strambu, Jigureasa, Valea Untului, Cugir Valley, Rovina,Rascoala Mn-Fe deposits (Sebes Mts., South Carpathians),silicate-carbonate (subsaturated, queluzite) and silicate-quartz (saturated, gondite); (4) Paltinis, Sadu Valley, SadurelValley Mn deposits (Cibin Mts, South Carpathians), spessar-tine type (gondite); (5) Delinesti Mn-Fe deposit (SemenicMts, South Carpathians), silicate-carbonate-oxide. About 350mineral species and mineral varieties have been identified inthe mentioned deposits. By far the Bistrita occurrences arethe richest in minerals, including rarities such as silicates-arsenates (schallerite, nelenite, etc.), Cl-bearing phyllosili-cates (manganpyrosmalite, friedelite, mcgillite, etc.), nambu-lite, bannisterite, androsite-(La), etc. not found yet in SouthCarpathian occurrences. In addition, the Bistrita mineralscommonly show compositional zoning, which was used toreconstruct the metamorphic evolution.

The minerals from Romanian Carpathian metamorphosedMn-Fe ores belong to the following mineral classes: I. Na-tive elements: gold , bismuth, graphite; II. Sulphides: ala-bandite, hauerite (?), pyrite, chalcopyrite, galena, pyrrhotite,cattierite, bornite, löllingite, tetrahedrite, tennantite,matildite, bournonite, semseyite, freibergite, boulangerite,molybdenite, Bi arsenide with Cl, sulphide-arsenide with Cl,Bi-telluride, tetradymite, skutterudite, matildite, nickeline,cobaltite, linneite, kësterite, arsenopyrite, safflorite, geerite,breithauptite, stannite, wurtzite, carrollite, glaucodot, ram-melsbergite, etc. III. Oxides: primary oxides: jacobsite,magnetite, bixbyite, braunite, neltnerite, hausmannite, pyro-phanite, iwakiite, hematite, ilmenite, senaite (with Sr, Ca, V,Nb and Zn), cassiterite, thorianite, högbomite, rutile, perov-skite, samarskite; quartz group: α-quartz, stishovite (?), coe-site (?), opal, moganite, etc. and secondary oxides: nsutite,pyrolusite, ramsdellite, manganite, hollandite, lithiophorite,manjiroite, goethite, ranciéite, todorokite, birnessite, coro-nadite, crednerite, cryptomelane, pyrochroite, asbolane, dias-

pore, groutite, etc. V. Carbonates: calcite, dolomite, rhodo-chrosite, kutnohorite, witherite, aragonite, magnesite, sid-erite, ankerite, Fe-rhodochrosite, smithsonite, azurite, mala-chite; Borates: tusionite. VI. Sulfates: barite, khademite,jarosite, rozenite, szomolnokite, gypsum, etc.; Wolframates:hübnerite, ferberite; VII. Phosphates: hydroxylapatite, car-bonate-hydroxylapatite, Mn-apatite, chlorapatite, fluorapa-tite, switzerite, brushite, monazite-(Ce), monazite-(La), evan-site, xenotime-(Y) (with Eu and Gd), variscite, etc.; Arsen-ates: magnussonite, sarkinite, johnbaumite, manganarsite,hedyphane, etc. Vanadates: Ba-vanadates. VIII. Silicates:A. Nesosilicates : 1.Olivine group: Mn-fayalite, Fe-tephroite,tephroite, Mg-tephroite; 2. Manganese humites: sonolite,alleghanyite, manganhumite; 3. Leucophoenicite humitesgroup: ribbeite, leucophoenicite, jerrygibbsite; 4. Garnets:spessartine, spessartine-calderite, grossular, Ti-spessartine-grossular, almandine, Mn-almandine, spessartine-andradite-grossular, anisotropic spessartine-andradite, etc. 5. Zircon,thorite, titanite, greenovite, etc. B. Sorosilicates: 1. Yoshi-muraite, bafertisite, etc.; 2. Epidote-zoisite group: epidote,piemontite, allanite, Mn-allanite, zoisite, “thulite”, androsite-(La), etc. C. Cyclosilicates: 1. Tourmaline group: dravite,schorl, etc. D. Inosilicates: 1. Pyroxenes: Mn-ferrosilite,Mn-hedenbergite, johannsenite, Fe-johannsenite, augite,diopside-augite, Na-augite, aegirine-augite, Ti-aegirine-augite, aegirine, namansilite, etc.; 2. Pyroxenoids: pyrox-mangite, rhodonite, nambulite, natronambulite, inesite, py-roxferroite (?); Amphiboles: grunerite, manganogrunerite,manganocummingtonite, kozulite, magnesioriebeckite, mag-nesiocummingtonite, “crocidolite”, riebeckite, winchite,ferroferriwinchite, ferro-anthophyllite, Li-eckermannite,richterite, K-richterite, magnesiohornblende, arfvedsonite,ferroglaucophane, “crossite”, Mn-actinolite, ferroactinolite,Mn-tremolite, etc. E. Phyllosilicates: phlogopite, Mn-phlogopite with Ni, norrishite, biotite, Ti-biotite, Mn-biotite,muscovite, kinoshitalite, anandite, illite, annite, chloritoid,bannisterite, Ba-bannisterite, ganophyllite, parsettensite,manganpyrosmalite, friedelite, caryopilite, schallerite, su-gilite, nelenite, minnesotaite, ottrélite, pennantite, clino-chlore, greenalite, antigorite, kellyite, nimite, lennilenapeite,coombsite, bementite, sepiolite, etc. F. Tectosilicates: 1.Feldspar group: albite, microcline, celsian, hyalophane, or-thoclase. 2. Helvite group: helvite, genthelvite, homilite.

For all the occurrences the metamorphic evolution isquite complex, generally showing several metamorphicevents, mainly of retrograde character.


45

SUPRA-SUBDUCTION ZONE (?) BASALTS FROM THE DELENI-6042 DEEP WELL(TRANSYLVANIAN DEPRESSION, ROMANIA)

HÖCK, V.1 & IONESCU, C.21 Institute of Geology and Palaeontology, University of Salzburg, Hellbrunnerstr. 34, A-5020 Salzburg, Austria.E-mail: [email protected] Department of Mineralogy, Babes-Bolyai University, 1, Kogalniceanu Str, RO-3400 Cluj-Napoca, Romania.

The Transylvanian Depression contains a number of gasfields, which were frequently drilled. Only a small number ofdrill holes penetrated the pre-Badenian formations. One ofthe deep wells, 6042-Deleni, was set up in the northern partof the major Deleni gas field. Initially it was planned to reacha depth of 6000 m for the well, but finally it stopped at 5062m in Jurassic (?) basalts. The whole stratigraphic range of thewell involves Cenozoic (Sarmatian, Badenian) and Mesozoic(Cretaceous and Upper Jurassic) rocks (Romgaz Archives,Media; unpublished data). It is shortly outlined as follows:

Down to the depth of 2997 m the well penetrates Sarma-tian sands, sandstones and marls and Badenian rocks, repre-sented mainly by marls, and subordinately by sands. Severaltuff levels were crossed for example the “Ghiris Tuff” in 924m and another tuff level at 1688 m. The presence of salt andtuffs (“Dej Tuff”) levels marks the boundary between Ceno-zoic and Mesozoic rocks (2997 m). The Cretaceous deposits,mainly siliciclastics (marls, sandstones, silts, clays) are be-lieved to include the Late Cretaceous and partly the EarlyCretaceous. Beneath the Lower Cretaceous deposits, at adepth of 3660 m, Upper Jurassic carbonate rocks occurred inthe well. The oldest rocks overlaying the volcanic sequencebelong to the base of Kimmeridgian as exemplified by Al-veosepta jaccardi, SCHRODT.

Starting with a depth of 4698 till 4742 m, strong under-ground eruptions of salt water and gases prevented the re-covery of the drill cores. For the first two meters of the inter-val, fragments of dolomites mixed with fragments of basaltswere caught in the well-screens, but beneath the depth of4700 m only basalt fragments appeared. The first massivedrill cores of the basaltic rocks are taken from the depth of4742 and continued till the depth of 5015.5 m. Because oftechnical problems, the recovery of the drill cores betweenthe depth of 5015.5 and the final depth of 5062 m was verypoor, only basaltic fragments remained on the well screens.

The basaltic rocks, crossed by the well between the depthof 4742 and 5015 m, are represented mainly by dark-coloured, blackish-greenish basalts, in general with variousdegrees of alteration, macroscopically marked by numerousveins, nests and pseudomorphs with calcite ± iron oxides,chlorite and serpentine minerals, microquartz, chalcedonyand smectites (see also IONESCU et al., 2003). The volcanicsequence is represented by massive basaltic lava flows;sometimes they are brecciated, mainly in the upper part ofthe interval. In general, the rocks are poor in phenocrysts

such as plagioclase, pyroxene and olivine. The micro-ophiticgroundmass, highly altered, contains microlites of plagio-clase, small grains of pyroxenes and olivine as well asopaque minerals (Ti-magnetite, hematite, goethite, etc.) andaltered glass. The structure is fluidal with the orientation ofthe feldspar microlites in the direction of the flow. Basalts,brecciated basalts, basalts with olivine, vesicular and amyg-daloidal basalts are the main petrographic types. Basalticandesites occur subordinately.

Nineteen samples of the basaltic sequence between adepth of 4742 and 5015 m were chemically analyzed formajor, minor, as well as trace and RE elements. After somecorrection for the alteration (see also IONESCU et al., 2003)the volcanics classify as basalts, basaltic andesites and ande-sites with partly a low content of alkalies. Three groups canbe distinguished from top to bottom: a low Cr/high Zr group,a high Cr/low Zr group and finally a low Cr/low Zr group.Other elements such as Ni, Y, Sr, Th etc. fit also with thisgrouping. The generally low contents of Zr, TiO2, Y as wellas a low Ti/V ratio (<20) argue for a formation of these ba-salts and basaltic andesites in a supra-subduction zone envi-ronment. The high Th/Yb ratio as well as the high Ce/Ybratio combined with a relatively low Ta/Yb ratio suggest acalc-alkaline nature of these volcanics. Comparison withother basaltic and andesitic volcanics in the South ApuseniMountains shows that the Deleni volcanics are obviously notgenetically related with the ophiolitic basalts described bySACCANI et al. (2001). On the other hand they might bequite well compared with some basaltic and andesitic vol-canics described by NICOLAE (1995) partly from the Ca-palnas-Techereu Nappe and partly from Rimetea (Bedeleu)Nappe (BALINTONI, 1997).

ReferencesBALINTONI, I. (1997): The geotectonics of the metamor-

phic terraines from Romania. Ed. Carpatica, Cluj-Napoca, 176 p. (in Romanian)

IONESCU, C., HÖCK, V. & TOPA, D. (2003). Acta Miner-alogica-Petrographica, Abstract Series 1, Szeged (thisvolume).

NICOLAE, I. (1995). Rom. J. Tec. & Reg. Geol., 76: 27-39.SACCANI, E., NICOLAE, I. & TASSINARI, R. (2001).

Ofioliti, 26: 9-22.


46

REFINEMENT OF THE SYNGENITE STRUCTURE AND INVESTIGATION OF ITSHEATING AND MOISTURING PRODUCTS BY MEANS OF IR-SPECTROSCOPY

IL’CHENKO, K. O.Institute of Geochemistry, Mineralogy and Ore Formation, National Academy of Sciences, Palladine Avenue 34, Kyiv,Ukraine.E-mail: [email protected]

We studied the sulphate mineral syngenite,K2Ca(H2O)[SO4]2, from Kalush, Ukraine, by IR-spectroscopy. On the IR-spectrum (obtained on KBr pellet)the following absorption bands related to the S–O bonds ofthe SO4-tetraheda were observed: ν3 (asymmetric stretch-ings) 1190, 1138, 1126 and 1110 сm-1; ν1 (symmetricstretchings) 1005 and 985 сm-1; ν2 (bendings) 470 and442 сm-1; and ν4 (bendings) 675, 645, 605 cm-1 and a shoul-der near 620 сm-1. The broad band with the main maximumat 3315 cm-1 and the shoulders at 3520 and 3385 cm-1 areusually attributed to the stretching vibration νОН of the watermolecule, while the band at 1675 cm-1 to the bending vibra-tion δОН of the water molecule. The interpretation of the bandat 750 cm-1 is not as obvious as those of the previous bands,since it could be caused both by one of the vibrations of theSO4-tetrahedra or the librations of the water molecule.

The presence of four bands in each of the ν3- and ν4-regions and two bands in the ν1-region is possible if the twoSO4-tetrahedra in the syngenite structure are not equivalent(CORRAZA & SABELLI, 1967). The factor-group calcula-tion for Р21/m (C2h

2) group, Z=2 yields two independent setsof vibrations: 2·[ν1(Вu) + ν2(Au+Bu) + ν3(Au+2Bu) +ν4(Au+2Bu)] that would be active in IR-spectra. However, thenumber of bands observed in the powder spectra is less thanthat of the calculated bands. To refine the structural positionof the SO4-tetrahedra, IR-reflection spectra of the (100),(110) and (101) faces of a single crystal were obtained(Fig. 1). Five out of six possible bands in the ν3-region wereregistered.

The IR-spectra of deuterated syngenite display not onlythe isotopic shift to the low frequencies of all bands relatedto the water molecule, mentioned above, but also the shift ofa rather intense band from 750 cm-1 to 550 cm-1

(νОН/νOD=750/550=1.36). This allows assigning the latterband undoubtedly to the librating vibrations of the watermolecule involved in hydrogen bonds with sulphate oxygenatoms belonging to one of the two different SO4-groups. The

other type of SO4-groups has no water molecules in its near-est surrounding.

Six maxima in the region of ν3 vibrations and four in theregion of ν4 vibrations of the IR-spectrum of the deuteratedsample represent a further argument in favour of the struc-tural non-equivalency of two SO4-groups.

The fractional loss of water on heating at 200 °C causessome structural changes and at 250 °C anhydrous sulphatephases (?) forms.

The mineral, moistened by water on air, slowly trans-forms into gypsum.

Fig.1: IR-reflection spectra of the different faces of syn-genite single crystal.

ReferenceCORRAZA, E. & SABELLI, C. (1967). Zeit. Kristal., 124/6:

398–408.


47

ALTERATION PROCESSES ON BASALTS FROM THE TRANSYLVANIAN DEPRESSION,ROMANIA (DEEP WELL 6042-DELENI)

IONESCU, C.1, HÖCK, V.2 & TOPA, D.21 Department of Mineralogy, Babes-Bolyai University, 1, Kogalniceanu Str, RO-3400 Cluj-Napoca, Romania.E-mail: [email protected] Institute of Geology and Palaeontology, University of Salzburg, Hellbrunnerstr. 34, A-5020 Salzburg, Austria.

A lot of boreholes were drilled in the Transylvanian De-pression (Romania) as it contains a number of gas fields. Inthe northern part of the Deleni gas field one of the deeperwells (6042-Deleni) penetrated sedimentary formations andvolcanics, reaching finally the depth of 5062 m. A more than320 m thick pile of volcanic rocks underlays the Cenozoicand Mesozoic sediments between the depth of 4742 and 5062m. From the whole range of the volcanics a total of 34 mwere cored by Romgaz. From that, a total of 20 core samplescould be studied in details by the courtesy of Romgaz.

Various petrographic types were observed macroscopi-cally and microscopically, such as basalts, brecciated basalts,porphyritic basalt with phenocrysts of olivine (?), clinopy-roxene and mainly plagioclase, vesicular and amygdaloidalbasalts. Combined with geochemistry basalts, basaltic ande-sites and andesites were identified. The general appearance isthat of more or less compact, hydrothermally highly alteredvolcanics, with blackish-greenish colour, frequently crossedby white, pinkish-white or greenish-grey veins and nests.Spheroidal and ellipsoidal vesicles, empty or filled (amyg-dales) with white, reddish or greenish-grey minerals (calcite,chlorite, smectite and chalcedony) are also frequently pres-ent. The groundmass displays a sub-ophitic to intergranulartexture and contains microlites of plagioclase randomly ori-ented or oriented in the direction of the flow. Furthermore,small grains of clinopyroxenes, titanite, opaque minerals(magnetite, ilmenite, chromite, hematite, pyrite, chalcopyrite,goethite, etc.) and sometimes olivine occur. The former glassis changed to smectite. The phenocrysts of plagioclase andclinopyroxene show often a glomerophyric structure. Thephenocrysts change from very well preserved, slightly al-tered, to completely replaced by calcite, chlorite and smec-tite.

Based on their geochemical features, three groups can bedistinguished (HOECK & IONESCU, 2003). They are frombottom to the top: a low Cr/low Zr group, a high Cr/low Zrgroup and finally low Cr/high Zr group. The differencesbetween the groups are not very pronounced at a macro-scopic scale. Nevertheless, some variability and variousdegrees of alteration were identified in thin sections, bymeans of X-ray diffractometry, TEM and microprobe analy-ses.

The lowest low Cr/low Zr group, is relatively homoge-nous with only microphenocrysts mainly of plagioclase. Ingeneral the basalts are characterized by a high quantity of

feldspar microlites and a low amount of former glass in thegroundmass. The phenocrysts as well as the groundmassexhibit intense alteration processes, expressed by the formingof smectite (Fe-rich saponite), microquartz and quartz withdisordered structure (chalcedony; FLÖRKE et al., 1991),magnetite, hematite, pyrite, chalcopyrite and calcite.

The intermediate group with high Cr/low Zr also has ahomogenous appearance, marked by the prevalence ofamygdaloidal basalts with olivine (?) as well as with clinopy-roxenes and plagioclase. The highly altered sub-ophitic andintergranular groundmass as well as numerous vesicles filledlater with minerals, such as Fe-rich clinochlore, Fe-richsaponite, nontronite, serpentine minerals, chalcedony, zeo-lites, calcite, are characteristic. The phenocrysts of plagio-clase, olivine and clinopyroxene present highly differentdegrees of alteration. As opaque minerals, magnetite, chro-mite and pyrite occur.

The uppermost level with low Cr/high Zr includes basal-tic breccias, basalts, basaltic andesites and andesites, thelatter displaying a higher amount of plagioclase microlitesand no olivine phenocrysts. The intergranular to sub-ophiticgroundmass exhibits transformation processes, mainly intocalcite, chlorite minerals and subordinately into smectites.Oxide minerals are represented by magnetite, chromite, chal-copyrite, hematite and pyrite.

Geochemically, the most conspicuous alteration is theaddition of calcite as expressed by a clear positive correlationof CaO and CO2. Other elements such as Na, K, Rb, and Bawere also clearly affected by the alteration processes. All ofthem may be depleted or enriched. The observed mineralogi-cal changes argue for relatively low temperature events. Thecauses for the hydrothermal alteration can be assigned eitherto the postmagmatic fluids or to seawater. The temperaturesof 110–117 °C (4502 m depth), 122–130 °C (4902 m depth)measured in the drill hole indicate that alteration processesmay still continue.

ReferencesFLÖRKE, O. W., GRAETSCH, H., MARTIN, B., RÖLLER,

K. & WIRTH, R. (1991). Neues Jahrb. Min. Abh., 163:19-42.

HÖCK, V. & IONESCU, C. (2003). Acta Mineralogica-Petrographica, Abstract Series 1, Szeged (this volume).


48

METASOMATIC-HYDROTHERMAL PROCESSES ALONG THE CONTACT ZONE OFA TEPHRITIC SILL AND BLACK SHALE IN THE EASTERN MECSEK MTS., SOUTH-HUNGARY

JÁGER, V. & MOLNÁR, F.Department of Mineralogy, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected]

In the Mecsek Mts., alkaline basaltic-phonolitic volcanicrocks and dykes of Lower Cretaceous age are widespread.The alkaline igneous activity is related to rifting events con-nected to the opening of Central European branches of theTethys Ocean. Alkaline dykes intrude into Lower-MiddleMesozoic sedimentary rocks at many places of the MecsekMts. In the Réka valley, the area of this study, a tephritic sillintruded into a Toarcian, organic-material rich black shale.This paper summarizes the mineralogical and petrographicalcharacteristics of the contact between the upper margin of thesill and the covering shale.

Rock-forming minerals in the black shale are clay-, car-bonate- and feldspar minerals associated with small amountsof quartz and pyrite. The sill consists of oligoclase, analcime,Ti-augite and biotite as major minerals with apatite, pyriteand titanomagnetite as accessories. Texture of the rock isophitic-subophitic. Occurrence of small pegmatoid lenses(ca. 10 cm in diameter) is also typical for the sill. The peg-matoid lenses consist of anorthoclase, aegirine, aegirine-augite, Ti-augite with aegirine coronas, biotite, analcime,titanomagnetite and apatite. Occurrence of these pegmatoidsindicates enrichment of magmatic fluids in pockets duringthe final stage of crystallization.

The first signs of contact-metasomatic alteration can befound about 2 meters from the black shale in the tephriticsill. Here, calcite appears in the groundmass of the igneousrock that develops intergranular texture. Towards the blackshale, the amount of calcite increases and calcite also appearsin the form of infillings of amygdules which also start todevelop towards the contact. Increase of the amount of cal-cite is also associated with the change of the rock texturefrom intergranular to intersertal and then to intersertal-amygdaloidal. Biotite occurs in groundmass far from thecontact; however, close to the contact it forms knot-like

aggregates and infillings in amygdules. In the zone of ap-pearance of biotite in knots, pyroxene disappears from therocks. Closer to the contact pyrite replaces biotite. About tencentimetres from the contact quartz appears in associationwith the amygdule-filling calcite. The maximum size ofamygdules (1 cm diameter) occurs about 3–4 cm from thecontact. In addition to amygdules, occurrences of tubulargas-cavities (also filled by calcite) are also typical to thiszone which therefore can be considered as the zone of maxi-mum enrichment in volatiles. In the chilled margin, rightalong the contact, amygdules are absent and the texture ofrock is microintersertal. The gradational change of textureand mineral composition, together with the appearance ofamygdules and their variation in size point towards the proc-ess of volatile enrichment of the crystallizing melt. Thesource of excess H2O, CO2, and S is evidently the clay-mineral, carbonate and sulphide rich country rock. Thecooling fractures in the sill are parallel with the bedding ofthe black shale, thus not only chemical, but physical effect ofthe country rock on the sill can be recognised. The thermaleffect on the pore fluids of the black shale resulted in a vig-orous fluid circulation yielding hydrothermal brecciation ofthe shale along the contact. The breccia is cemented byquartz and calcite. Secondary fluid inclusions of these miner-als have homogenization temperatures around 120 and 130°C. These inclusions with about 4–5 NaCl equiv. wt % salin-ity mark the final stage of pore-fluid circulation.

The secondary mineral paragenesis was developed duringweathering of primary and metasomatic-hydrothermal as-semblages and it consists of hematite, limonite and gypsum.The Ni-content of pyrite resulted in the formation ofdwornikite during these late processes.


49

ORE MINERALIZATION OF THE BANSKÁ ŠTIAVNICA STRATOVOLCANO, SLOVAKIA

JELEŇ, S.1, HÁBER, M.1, KODĚRA, P.2 & LEXA, J.21 Geological Institute, Slovak Academy of Sciences, Severná 5, SK-974 01 Banská Bystrica, Slovak Republic.E-mail: [email protected] Geological Survey of Slovak Republic, Mlynská dolina 1, SK-817 04 Bratislava, Slovak Republic.

The region of the Central Slovakian Neogene VolcanicField, with the biggest andesitic volcano Banská Štiavnica,has served as an important source of precious and base met-als for a long time. The Banská Štiavnica stratovolcano,including an extensive subvolcanic intrusive complex, largecaldera and remarkable resurgent horst, hosts the followingtypes of mineralization: 1. High-sulphidation system at Šo-bov, related to the subvolcanic diorite intrusion, 2. Magnetiteskarn deposits and occurrences at contacts of a subvolcanicgranodiorite pluton with Mesozoic carbonate rocks, 3.Stockwork/ disseminated base metal mineralisation along anirregular network of fractures in apical parts of the granodio-rite pluton and in remnants of basement rocks, 4. Por-phyry/skarn Cu±Mo, Au deposits and occurrences related togranodiorite/quartz-diorite porphyry dyke clusters and rockaround the granodiorite pluton, 5. Caldera collapse relatedepithermal gold deposit in the andesitic environment justabove the granodiorite pluton, 6. Hot spring type advancedargillic systems in caldera filling, 7. High sulfidation systemof Varta related to an assumed granodiorite porphyry stock,8. Vein type low sulfidation epithermal precious/base metaldeposits and occurrences at faults of the resurgent horst, 9.Replacement precious /base metal mineralization of a limitedextent in the Mesozoic carbonate rocks next to epithermalveins, 10. Carlin-like Au±Hg, Tl, Sb, As mineralization inTriasic dolomites at Bukovec, 11. Low temperature Au±Hg,Sb, As mineralization in rhyolite extrusive domes around theresurgent horst (LEXA, et al., 1999; LEXA, 2001).

Precious and base metal, vein-type mineralization andiron skarn mineralization were the most abundant and eco-nomically most important mineralizations in this region.

Magnetite skarn deposits and occurrences are situatedmostly in the western part of the horst and were the subjectof medieval mining. Two types of skarns are present: themagnesian type and calcic type. Mineralization formed dur-ing three basic stages: initial, with the garnet, diopside andwollastonite assemblage (epidote and tremolite further fromthe contact), metasomatic, with the epidote, tremolite, andra-dite and magnetite assemblage and retrograde, with the zonalgarnet, hematite and minor magnetite assemblage. Fluidinclusions from skarn garnets show a large variation in salin-ity (4–23 wt.% NaCl eq.) and Th (220–370 ºC), independentof the garnet types, reflecting variable amounts of magmaticfluids and low salinity meteoric waters. Inclusions in retro-grade stage minerals showed boiling and dilution processes,further indicated by O and H stable isotope data (KODĚRAet al., 1999).

Caldera collapse related epithermal Au-mineralization islocated at depth of 400–500 m below the surface at the area

of the Rozália mine and occurs as subhorizontal veins at thebase of pre-caldera stage andesites. Au mineralization isrepresented by quartz, carbonates, sulphides, rhodonite, rho-dochrosite, adularia and gold. It evolved during two stages,both associated with the boiling of low salinity fluids (0–3wt.% NaCl eq.) and moderate temperatures (290–310 ºC).Variable pressure conditions (114–45 bars) indicate continu-ous opening of the system and transition from hydrostatic +lithostatic towards hydrodynamic conditions at shallowdepths. δ18O and δD values suggest mixing of magmaticfluids with meteoric waters that have intermediate composi-tion between granodiorite-related and horst-related hy-drothermal systems in the ore district (KODĚRA et al.,2002).

Horst-related vein type low sulfidation epithermal pre-cious and base metal mineralization in more than 120 veinsmainly occur in propylitized pyroxene andesites, diorites,quartz-diorite porphyries and granodiorites. In the oressphalerite, galena, pyrite, chalcopyrite and hematite arewidespread, accompanied by sulfides, selenides and tellu-rides of Ag, sulfosalts of Ag-Cu-Pb-Bi-S and Ag-Cu-Sb-As-S, native gold, silver, electrum etc. The ore-forming proc-esses evolved during five stages and were accompanied byconcomitant decrease in temperature, salinity, oxygen andsulphur activities. The minerals precipitated from low-to-moderately saline aqueous solutions (0.2–11.5 wt.% NaCleq.) with NaCl, CaCl2 and MgCl2 as the major solute compo-nents. Different eutectic temperatures estimated in the upperparts of the veins indicate mixed sulphate-carbonate compo-sition of the mineral-forming solutions. Mineralization wasformed at temperatures from 380 to 50 ºC, pH from 3.5 to7.6 in depth from 0.4 to 1.6 km. The assumed age of themineralization is 12.1–11.2 Ma (K-Ar method), resp. 12.8–11.2 Ma (Rb-Sr method) (HÁBER et al., 2001).

ReferencesHÁBER, M., JELEŇ, S., KOVALENKER, V. &

ČERNYŠEV, I . (2001). Miner. Slov., 33: 215-224.KODĚRA, P., LEXA, J., RANKIN, A. H. & FALLICK, A.

E. (2002). Geol. Carpath., 53: 94-96.KODĚRA, P., RANKIN, A. H. & FALLICK, A. E. (1999).

In: Mineral deposits: processes to processing, Stanley etal. (eds). Proc. joint SGA-IAGOD conf. vol. 1, 51-54.(Balkema Press)

LEXA, J. (2001). Miner. Slov., 33: 203-214.LEXA, J., ŠTOHL, J. & KONEČNÝ, V. (1999). Miner.

Depos., 34: 639-654.


50

THE PECTOLITE SKARN FROM MIĘDZYRZECZE (BIELSKO-BIAŁA REGION) IN THEPOLISH CARPATHIANS

KARWOWSKI, Ł. & WŁODYKA, R.Department of Geochemistry and Petrology, University of Silesia, ul. Będzińska 60, PL-41-200 Sosnowiec, Poland.E-mail: [email protected]

In the western part of the Outer Polish Carpathians, be-tween Bielsko-Biała and Cieszyn, the occurrence ofteschenite sills and related rocks (diabase, picrite and lam-prophyre) were observed. They are widely distributed in theflysch sediments of the Cieszyn Subnappe (Cieszyn beds,Upper Kimmeridgian to Hauterivian).

In Międzyrzecze Górne near Bielsko-Biała, close to thetop of the picrite sill, the presence of a pectolite skarn wasstated. The pectolite endoskarn forms a lenticular body that isup to 2 m thick, 5 m wide and 12 m long. Abundant carbon-ate veins (up to 30 cm thick) intersect the central part of theskarn filling the tectonic fissures and cracks. The pectoliteskarn consists mainly of elongated (up to 2 mm long and to0.5 mm wide) pectolite crystals which poikilitically encloseabundant inclusions of Ti-garnets, diopside, analcime andaegirine. Poikilitic biotite crystals with inclusions of Ti-garnets sometimes coexist with other minerals such as natro-lite, calcite, apatite and titanite. Veins cutting the skarn bodycontain calcite, pectolite, natrolite, analcime, datolite, Ti-garnet and apophyllite. The spatial relationships between theabove mentioned minerals suggest that natrolite and anal-cime were the first to crystallize forming the vein margins,being followed by calcite. Pectolite, likewise datolite andapophyllite always formed after calcite had filled openspaces in the vein centres.

Datolite from Międzyrzecze occurs mainly as granularaggregate, rarely as automorphic crystals up to 1 cm in size,pale green in colour. Three morphological types of datolitecrystals were distinguished: pseudo-bipyramidal, prismaticand pinacoidal. Most of the datolite crystals are 0.5–0.8 cmin size and belong to the second type. They crystallized onthe walls of miarolitic cavities within calcite. On basal pina-coid faces of datolite numerous fluorapophyllite crystalsappear. Its chemical composition follows the crystallochemi-cal formula (K0.86Na0.03)0.89 Ca4.03 (Si7.91Al0.04P0.03)7.98 (F0.83

OH0.17)1.00O19.92 • 8.08 H2O. The datolite habit changes frompseudo-bipyramidal through prismatic to pinacoidal with pHdecrease. In the Międzyrzecze skarn, in individual cavities,datolite crystals of different habit coexisted. This situationmay reflect the local, labile conditions of datolite crystalliza-tion in the open system. The studied datolite has monoclinicsymmetry with the following lattice parameters: a = 4.8316Å, b = 7.6054 Å, c = 9.6287 Å and β = 90.143o. Its chemicalcomposition is close to the theoretical one, among trace ele-ments barium and strontium predominate. Datolite fromMiędzyrzecze is similar in composition to those from Žer-manice and Řepiště (Northen Moravia) (KUDĚLÁSEK etal., 1987).

There are two genetic types of pectolite: open-space fill-ing and metasomatic. Pectolite, like datolite, can crystallizeonly from solutions with very low concentrations of CO2, i.e.in zones of reduced pressure, where degassing of CO2 takesplace. In the veins intersecting the skarn body pectolite formsirregular massive aggregates of radial or fan-arranged crys-tals with size between a few millimeters and 12 cm. Large,up to 6 cm long, fibrous (with diameter below 0.01 mm) orneedle-shaped (up to 0.03 mm) crystals are white and silky.The second, metasomatic type of pectolite forms the endo-skarn body. The formula of the fibrous pectolite from thecentres of vein in endoskarn is Na0.98Ca2.00H1.01Si2.99P0.01O9.There are small chemical differences between two genetictypes of pectolite. The metasomatic type is enriched inAl2O3, FeO, MnO, and MgO compared to the open-spacesfilling type. Pectolite from the Międzyrzecze sill is triclinicwith the following lattice parameters: a = 7.986 Å, b = 7.017Å, c = 7.021 Å and α = 90.399o, β = 95.208o, γ = 102.554o.

In the pectolite skarn, two types of Ti-bearing garnet canbe distinguished:

1. Brown-black euhedral crystals (<0.02 mm) forming in-clusions in pectolite, biotite, titanite and diopside or fillingopen spaces in veins.

2. Larger (up to 0.7 mm across) atoll-shaped garnetsshowing narrow black-light brown rims completely distinctfrom cores consisting of spicular aegirine and a cryptocrys-talline mixture of natrolite and analcime. These garnets areclearly metasomatic type Ti-garnets. Both types of garnetfrom the pectolite skarn show very restricted changes in TiO2

content (12–15 wt%). Textural and chemical evidence showsthat the atoll garnets reflect replacement, mainly by analcimeand natrolite, progressing from the garnet interior towardsthe garnet margins. The garnet compositions plotted on theschorlomite (2R4+) – andradite (2R3+) – morimotoite (R2+R4+)diagram show that they are titanian andradites according tothe nomenclature of DEER et al. (1982). The data obtainedsupport the conclusion that the schorlomite substitution wasthe major factor in the formation of Ti-bearing garnet in theskarn from the Międzyrzecze sill.

ReferencesDEER, W. A., HOWIE, R. A. & ZUSSMAN, J. (1982).

Rock-forming minerals. Vol. 1A. Orthosilicates (2nd ed.)KUDĚLÁSEK, F., MATYSEK, D. & KLIKA, Z. (1987).

Čas. Mineral. Geolog., 32(2): 169-174.


51

PALEOCLIMATOLOGICAL STUDIES ON TRAVERTINES FROM BUDAKALÁSZ(BUDA MTS., HUNGARY): EVIDENCE FROM STABLE ISOTOPIC DATA

KELE, S.1, VASELLI, O.2 & SZABÓ, Cs.11 Lithosphere Fluid Research Lab, Department of Petrology and Geochemistry, Eötvös Loránd University,Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected] Department of Earth Sciences, University of Florence, Florence, Italy.

IntroductionTravertines from the Pannonian Basin have been studied

for almost one hundred years. However, principles, conceptsand technical background in geology have been dramaticallychanged during the past decades. As a consequence, besidestratigraphic and microfacies descriptions, valuable informa-tion can be contributed to paleohydrological and paleocli-matological studies by using geochemical and stable isotopedata obtained on travertines. The major goal of this work isto carry out a detailed C and O stable isotope study on Buda-kalász travertine (Buda Mts., Hungary) in agreement withprevious microfacies analyses (KOVÁCS, 1995) to find outthe origin of CO2 in water from which travertine deposited.

Geological background, sampling and applied techniquesThe Pleistocene Budakalász travertine deposit lies on

early Oligocene Hárshegy Sandstone and Kiscell Clay For-mations. Early Pleistocene limnic clay and gravel terrace canbe found under the limestone suggesting a former limnic andfluvial environment (SCHEUER et al., 1987). The travertineis covered by a few meters thick loess and overlain by a thinhumus layer. The Ezüsthegy quarry is approximately 800meters long and 15–20 meters high. Sixty travertine sampleshave been collected at three vertical sections of the travertinequarry. Microfacies and petrographic analyses have beenperformed on some samples. Selected travertines were ana-lyzed for δ13C and δ18O using Finningan 250 MAT Delta-Smass-spectrometer.

Results and conclusionsBased on petroghraphic and microfacies analyses, the

Budakalász travertine samples of the three sections studiedcan be divided into two stratigraphic groups. The lower partof each section (approx. 15 meters thick) consists of massivetravertine that represents smooth slope facies, and in theterrace pools, shrub facies as the result of bacterial activity.The whole lower part of the sections is characterized byvalues of δ13C(PDB) = 2.2‰ and δ18O(PDB) = –12.1‰. Theupper part of the beds studied represents marsh pool facies,deposited from a small lake, and has values of δ13C(PDB) =1.7‰ and δ18O(PDB) = –10‰. Between the lower and upperparts of the sections calcareous mud layers were observedinferring to terrestrial period and could have been a relativelylong break in deposition. Based on the isotopic data, andusing PENTECOST’s (1995) classification, the Budakalásztravertine is thermogene fresh water limestone which formedpresumably associated with late activity of the Miocenevolcanism widely recognized around the studied area.

ReferencesKOVÁCS, A. (1995). M.Sc. thesis, Eötvös University, Bu-

dapest, Department of Applied and Environment Geol-ogy.

PENTECOST, A. (1994). Quaternary Science Review, 14:1005-1028.

SCHEUER, Gy., SCHWEITZER, F., & SZLABÓCZKY, P.(1987). Építőanyag, 39: 102-107.


52

ENVIRONMENTAL RADIOLOGICAL ASPECTS OF THE COAL MINING IN PÉCSBÁNYA(SOUTH HUNGARY)

KÓBOR, B.1, GEIGER, J.2 & PÁL MOLNÁR, E.11 Department of Mineralogy, Geochemistry and Petrology, University of Szeged, P. O. Box 651, H-6701 Szeged, Hungary.E-mail: [email protected] Department of Geology and Paleontology, University of Szeged, P. O. Box 651, H-6701 Szeged, Hungary.

It has been known since the first set of Hungarian radio-logical and geochemical research carried out in connectionwith uranium prospecting that the radioactive element con-centration of some coals (some brown coals in the TatabányaBasin, the coal of Ajka, and the Liassic coal in the MecsekMts.) are significantly above the average (SZALAY, 1962).During the 200 years of coal mining in the vicinity of Pécs(Mecsek Mts., South Hungary) materials with radioactivitylevels higher than that of the environment were brought tothe surface in vast quantities. The exact radiological assess-ment of the areas in question, the maintaining of the radioac-tive “zero level” of the territory, and the determination of thequality and quantity of the radioactive over-radiation of thepopulation is necessary for the successful and effective re-cultivation of the areas affected by mining.

We carried out total-gamma dose-capacity scaling andgamma-spectrometry survey in a 50 x 50 metre grid in ac-cordance with the proposals of the International AtomicEnergy Agency (IAEA), in the Pécsbánya Karolina opencastmining area, in the neighboring uncovered, landscaped, anduncultivated dumps, coal stocks, as well as in the entire areaof the town of Pécsbánya. As a result of our winter-summer“in situ” measurement series we constructed the total-gammadose-capacity map of the Karolina opencast mine and itssurroundings for winter and summer, characterised by sig-nificantly diverse meteorological conditions. According toour findings the radioactive “zero level” of the distant sur-roundings of the opencast mine in relation to the total-gamma dose-capacity is 90–92 nGy/h in the dry, hot sum-

mer, and 85 nGy/h in the wet, cold winter. The values oftotal-gamma dose-capacity in the areas currently beingstripped are 45–55% and on the waste stockpiles 20–25%higher than those of the distant surroundings. Those wastestockpiles which are permanently landscaped and coveredwith a 40–60 cm thick soil layer absorb the radioactive over-dose almost entirely: values measured there are higher thanthe radioactive “zero level” by a mere 2–5%. The highestlevels of total-gamma radiation were measured on oldburned, parched dumps, which are often left uncultivated.Mining raises the radioactivity levels of the close surround-ings by 20–25%.

The gamma-spectrometric measurements of the collectedrock specimens under laboratory conditions reveal that thehigher level of radiation is caused by the high K40-content inthe case of claystones, aleurolites and sandstones, and byhigh uranium and thorium content in the case of coal andcoal sandstones rich in organic matter. Out of the rocks of theopencast mine, those rich in clay minerals and organic matterat the same time, have the highest K40 and Th content abovethe global average (SWAINE, 1990).

ReferencesSWAINE, D. J. (1990) Trace elements in coal. Butterworths.

London. 278 p.SZALAY, S. (1962): Papers of the Engineering Department

of the Hungarian Academy of Sciences. Budapest, pp.168-185.


53

PETROLOGICAL AND GEOCHEMICAL ARGUMENTS FOR THE NATURE AND SOURCEOF THE SZARVASKŐ COMPLEX (NE-HUNGARY)

KOLLER, F.1 & AIGNER-TORRES, M.21 Institute of Petrology, Geo-Center, University of Vienna, Althanstraße 14, A-1090 Vienna, Austria.E-mail: [email protected] ETH-Zürich, Sonneggstraße 5, CH-8092 Zürich, Switzerland.

The Szarvaskő complex exposes a fragment of Jurassicmafic and ultramafic igneous rocks (DOWNES et. al., 1990).They have been described as a dismembered portion of aMesozoic ophiolitic sequence formed in a narrow basin ofthe Vardar Ocean (AIGNER-TORRES & KOLLER, 1999).The magmatic sequence consists mainly of extrusive basalticpillow lavas together with gabbroic sills intruding into terri-geneous shales, and minor ultramafic and plagiogranite rocks(BALLA et al., 1983, AIGNER-TORRES & KOLLER,1999). The basalts and some of the gabbros show fraction-ated N-MORB-like patterns with a low Nd, indicating apossible enriched source component. Some of the gabbrosand the unusual ultramafic rocks, described originally aswehrlites, have rather low REE pattern and are regarded ascumulates (AIGNER-TORRES & KOLLER, 1999).

These wehrlites contain according to AIGNER-TORRES(1996) dominant olivine (Fo0.51-0.49) and rare orthopyrox-ene (Fs0.38), higher amounts of a variable clinopyroxene(XMg 0.82-0.58) and minor brown amphiboles with a widecompositional range from tschermakite to magnesiohorn-blende. Besides minor An-rich plagioclase high amounts ofilmenite and titanium magnetite up to more than 20 vol% arethe main features of this rock type. The wehrlite samples canbe classified as hornblende peridotites or as olivine-ilmenitecumulate. In any case these samples represent a member of aclassical tholeiitic fractionation trend with high Fe- and Ti-enrichment. The low Cr- and high V-contents in contrast canbe only explained by a fractionation from an evolved basicmelt indication also rather high oxidation state.

On the other hand the plagiogranites show an inversepattern with overall high trace element contents and remark-able negative Eu anomalies. This sample suite with clear

magmatic mineral assemblages cannot be related solely byfractionation of a common MORB source only. They repre-sent a combination of a MORB-like fractionation of oli-vine+plagioclase+clinopyroxene±chromite and a minor, butstill important influence of assimilated terrigeneous sedi-ments abundantly present in the area. The most interestingminerals in the plagiogranites are strongly zoned almandinerich garnets and an Fe-rich epidote with high amounts ofREE, both are of magmatic origin.

The presence of the rare ultramafic cumulates and theplagiogranites beside the common pillow lavas and variousgabbros with N-type MORB composition are still the bestarguments for an ophiolitic nature of the Szarvaskő complex.Although, based on the geochemistry data, there is no sub-duction-related component, AIGNER-TORRES & KOLLER(1999) suggest a back-arc basin affinity for this complex.The secondary mineral assemblages with prehnite and pum-pellyite are either part of the oceanic metamorphism or morepossibly related to the Alpine overprint and define clearly thepost-magmatic history and the limits of the emplacementmechanism for the Szarvaskő complex.

ReferencesAIGNER-TORRES, M. (1996). Diploma thesis, University

of Vienna, NAWI Faculty, 128 p.AIGNER-TORRES, M. & KOLLER, F. (1999). Ofioliti, 24:

1-12.BALLA, Z., HOVORKA, D., KUZMIN, M. & VINOGRA-

DOV, V. (1983). Ofioliti, 8: 5-46.DOWNES, H., PANTÓ, Gy., ÁRKAI, P., & THIRLWALL,

M. F. (1990). Lithos, 24: 201-215.


54

MINERALS OF GYÓD SERPENTINITE BODY, HUNGARY

KOVÁCS, G.1, RAUCSIK, B.2 & HORVÁTH, P.31 Environmental Inspectorate of Lower Tisza Region, Felső-Tisza part 17, H-6721 Szeged, Hungary.E-mail: [email protected] Department of Earth and Environmental Sciences, University of Veszprém, Egyetem u. 10, H-8200 Veszprém, Hungary.3 Laboratory for Geochemical Research, Hungarian Academy of Sciences, Budaörsi út 45, H-1112 Budapest, Hungary.

In the earlier studies different mineral composition ofGyód serpentinite body were determined from which differ-ent conclusions were drawn concerning the ultramafic proto-lith and its alteration processes. On the basis of X-ray dif-fraction analysis ERDÉLYI (1970) determined numerousminerals (Table 1) of the serpentinized peridotite. SZED-ERKÉNYI (1974) and GHONEIM (1978) claimed that theprotolith of the serpentinite must have been pyroxenite orlherzolite or dunite. According to PAPP (1989) the mostfrequent serpentine minerals are lizardite, chrysotile andpolygonal serpentine. BALLA (1985) established that thechemical composition of Gyód serpentinite body is harzbur-gitic, and stated a multi-step metamorphic evolution path ofit.

Table 1: Mineral composition of the Gyód serpentinite body.

Author MineralsErdélyi, 1970 lizardite, hydrochrysotile, clino-

chrysotile, chlorite, talc, montmorillo-nite, biotite, muscovite, albite, by-townite, clinoenstatite, tourmaline,magnetite, böhmite, diaspore, lepido-crocite, brucite, wilkeite, calcite, dolo-mite, ankerite

Ghoneim, 1978 enstatite + olivine, lizardite + chrysotile,chlorite + dolomite, chromite, magnet-ite, pentlandite, pyrrhotite

Balla, 1985 enstatite1, olivine, enstatite2, anthophyl-lite, talc1, magnetite1, antigorite, talc2,carbonates, magnetite2, chlorite, Cr-magnetite, chrysotile, lizardite

Twelve samples were chosen for X-ray powder diffrac-tion and microprobe analyses from the whole drilling se-quence of the borehole No. Gy-2 on the basis of the prelimi-nary petrographic studies (KOVÁCS & M. TÓTH, 2000) inorder to resolve the contradictions of literature.

The main phases of the examined rocks are Fe-Mg phyl-losilicates, mostly serpentine minerals (30–60 %), talc (10–30%) and chlorite (10–20%). The determination ofmultiphase serpentine minerals is rather uncertain, however,in the several samples we analysed chrysotile (probably 2Orcl

eral samples we analysed chrysotile (probably 2Orcl symme-try orthochrysotile) and 1T-lizardite were surely determined.Most samples consist of more than one serpentine mineral,but antigorite was not detected. The most important minorphases are the dolomite, ferrite-spinel, quartz, calcite, ortho-pyroxene and olivine. Regarding phyllosilicates, the sepa-rated, oriented samples of < 2 µm fraction represent Mg-chlorite, and swelling phase is not detected. On the base ofpeak maxima between 7.06–7.10 Å and 3.48–3.53 Å, thepresence of kaolinite can be precluded.

By means of microprobe analysis we tried to determinethe chemical composition of the relict minerals. Olivine has90–91% forsterite content, orthopyroxene can be character-ised by 90–92% enstatite component and spinels consist of57–59% chromite and 22–28% magnetite, respectively. Gen-eral occurrence of plagioclase, clinopyroxene and amphi-boles were not pointed out. Although completely serpen-tinized amphiboles can be seen as bastites, these can not beidentified. Fresh amphiboles can only be found in one sam-ple where they occur together with talc in the alteration rimof enstatite. Unaltered anthophyllite was found only in aspecial location, near an aplite dyke.

The high ratio of forsterite component in olivine maysuggest that by the partial melting of a lherzolitic protolith, aresiduum of harzburgitic composition could have formed inthe upper mantle, representing the lower part of an ophiolitesequence.

ReferencesBALLA, Z. (1985). In Dobrecov, N. L. ed.: Rifeysko-

Nizhnepaleozoyskie ofiolity. Severnoy Evrazii, 136-148.ERDÉLYI, J. (1970). Manuscript, Hung. Geol. Survey, T. 2574.GHONEIM, M. F. (1978). Candidate Thesis, Hung. Acad.

Sci., Budapest.KOVÁCS, G. & M. TÓTH, T. (2000). Acta Mineral. Pet-

rogr., Supplementum, Szeged, XLI: 64.PAPP, G. (1989): Doctoral Thesis, Dept. of Petrol. Geo-

chem., Eötvös Univ., Budapest.SZEDERKÉNYI, T. (1974). Acta Geol. Sci. Hung., 18: 305-

313.


55

COMPOSITION AND PROVENANCE OF THE PONTIAN SAND AT SUPURU DE JOS(ROMANIA)

KOVÁCS-PÁLFFY, P. & THAMÓ-BOZSÓ, E.Geological Institute of Hungary, Stefánia út 14, H-1143 Budapest, Hungary.E-mail: [email protected]

The studied sand formation at Supuru de Jos (Romania)is situated in the NE part of the Pannonian Basin, the NWarea of the Şimleului Basin, which is surrounded by the Bâc,the Plopiş, the Meseş Mountains, and further by the NE-Carpathians. In the basin the Quaternary sedimentary rocksare underlain by alternating Pontian lignite and dark greysand layers, their thickness varies between 150–200 meters(CHIVU et al., 1966). The detailed examination of the min-erals in this sand is very useful to determine its source rocksand the post-depositional processes, and to the study of theprovenance of the Pliocene and Quaternary sedimentaryrocks in the Great Hungarian Plain.

MethodsWe used wet sieving, optical microscopic examination,

X-ray diffraction, microprobe, chemical analysis and SEM.

ResultsWe studied the upper part of the Pontian sandy sequence

at Supuru de Jos, borehole 123 H2P, in the interval of 41.8–46.7 m. It comprises dark grey, very well sorted, mediumsand. It is loose, but partly it is cemented to hard sandstone.The few pebbles and rock fragments (bigger than 2 mm) aremax. 30 mm in size, and they are subangular quartzite, vol-canic rocks (andesite) with different colours and roundness,metamorphic and sedimentary rocks.

Among the sand-size grains the most frequent mineralsare quartz (some have characteristic pyroclastic origin), feld-spars (plagioclases, and some K-feldspars, most of them arestrongly altered), muscovite, pyroxene (hypersthene, clinoen-statite, augite), amphibole (green and brown hornblende) andopaque minerals. Garnet, spinel, biotite, staurolite and rutileappear too. On the bases of the earlier data sphalerite, ga-lenite, tetrahedrite, melnikovite and native copper also occurin the sand (KOVÁCS-PÁLFFY et al., 1986). Pyroxenes andsometimes the amphiboles have “hacksaw” terminations,which are produced by post-depositional dissolution. Thegrains are frequently covered by thin silica cement layer inpatches, and sometimes small zeolite crystals can be seen onthe cement layer too. In the fraction of 0.1–0.2 mm the sandhas high heavy mineral content (19 wt%), low quartz / feld-spar ratio (1.4), and it contains high amount of magneticfraction (20 wt%).

According to the results of X-ray diffraction analysis,clay minerals (illite-sericite), zeolite (clinoptilolite), rhodo-chrosite, calcite, magnetite, zircon, chlorite, maghemite,ilmenite, goethite, chalcopyrite, jacobsite, bustamite, frank-linite and ulvöspinel also occur.

By the microprobe analysis ferroan-enstatite and ferro-hornblende were determined among the minerals, which have“hacksaw” terminations. In a ferrohornblende grain one goldinclusion appeared too. Ferro-actinolite and spinel (hercynite,ulvöspinel) also occurred in the sand. The cement containsmainly Si, and sometimes it has relatively high Mn content.

ConclusionsFacies: The studied Pontian immature, very well sorted,

medium sand was formed in a littoral environment in thestringing lagoons of the Şimleului Basin, which subsided anduplifted from time to time, and the sand altered with swampysediments.

Provenance: Most of the minerals in the sand originatedfrom different Neogene volcanic rocks of the NE-Carpathians (e.g. volcanic pebbles and rock fragment, partlythe quartz, feldspars, garnet, opaque minerals and most of thepyroxenes and amphiboles), and the nearest metamorphicformations (e.g. metamorphic pebbles and rock fragments,staurolite, muscovite, partly the quartz, feldspars, biotite,garnet, spinel). Jacobsite, rhodochrosite, and partly the mag-netite came from Precambrian metamorphic carbonate rocks,because these minerals are described from the Răzoare For-mation of the Preluca Mountains (HÂRTOPANU et al.,1993). Some minerals and rock fragments originated fromrecycling of older sedimentary sequences.

Diagenesis: The strong etching of some minerals, the“hacksaw” terminations of pyroxenes and sometimes theamphiboles, and the cementation of the sand caused by post-depositional processes. Diagenesis was related to theswampy, organic material rich environment, the carbonate-and volcanic rock fragment content of the sand, and subsi-dence and uplifting of the basin from time to time.

AcknowledgementsThis research was fund by Hungarian National Scientific

Fund (OTKA T-035168).

ReferencesCHIVU, M., DRAGU, V., ENACHE, GH., ISAC, D. &

MĂRGĂRIT, E. (1966). Dări de seamă, LII/1: 239-253.HÂRTOPANU, P., UDUBAŞA, G., UDRESCU, C. &

CRISTEA, C. (1993). Rom. Jour. Miner., 76: 15-21.KOVÁCS-PÁLFFY, P., DAMANIA, GH., POP, V., RO-

MAN, M., ROMAN, G. & NICOLOCI, AL. (1986).IPEG


56

MINERALOGICAL ASPECTS OF SOME HYDROTHERMAL ZEOLITES FROM COPACENI,ROMANIA

KRISTÁLY, F., STREMTAN, C. & TÓTH, A.Department of Mineralogy, Babes-Bolyai University, 1, Kogalniceanu Str, RO-3400 Cluj-Napoca, Romania.E-mail: [email protected]

The studied area is situated in the NE part of TrascauMountains, 20 km SE from Cluj-Napoca, in the close prox-imity of the European road E60 near Copaceni village, ClujCounty.

The geological formations occur in the area belong to theophiolitic type Mesozoic island-arc magmatism from TrascauMountains. These formations are characterized by the pres-ence of pillow-lava basalts and massive basalts, includedfrom a tectonical point of view in the Rimetea Nappe(NICOLAE et al., 2001). The analyzed samples were col-lected from an abandoned quarry, where an alternating suc-cession of compact basalts and basalt flow sequences can beobserved easily. In the upper part of this sequence a layer ofvolcanoclastics occurs.

The post-magmatic mineral association – hydrothermaland supergene – crystallized along the fractures and voidspaces of the basaltic rocks, especially volcanoclastics. Neo-formation minerals are basically represented by carbonates,

silica, clay minerals, and zeolites. The methods of investiga-tion we have used (transmission polarizing microscope, ste-reomicroscope, X-ray diffraction) helped distinguish thepresence of six zeolites (analcime, heulandite, wairakite,stilbite, barrerite, chabazite), associated with both micro- andmacro-crystalline calcite and silica.

The goal of this study is to perform the mineralogical de-scription of the area and also to emphasize the occurrence ofnew zeolites. For the near future, our aim is to begin a de-tailed case study to determine physical and mineralogicalproperties of one of the zeolites we found (barrerite) withextremely rare occurrence in general.

ReferenceNICOLAE, I., SACCANI, E. & TASSINARI, R. (2001).

Ofioliti, 26(1): 9-22.


57

BIOMOBILIZATION AND BIOACCUMULATION OF HEAVY METALS IN MONTANEOUSLANDSCAPE (BANSKÁ ŠTIAVNICA, SLOVAK REPUBLIC)

KRIŽÁNI, I.1, ANDRÁŠ, P.1 & DANÁKOVÁ, A.21 Geological Institute, Slovak Academy of Sciences, Severná 5, SK-974 01 Banská Bystrica, Slovak Republic.E-mail: [email protected] County Office, Križovatka 4, SK-969 00 Banská Štiavnica, Slovak Republic.

The most legible manifestation of exploitation activitiesin mining regions are rests of mining dumps, which representdumping grounds of dessintegrated rocks, fine-milled oresand chemical matters used during the dressing activities.Until now were these dumping grounds perceived only as a“memorials of the technical work“ or as an anthropogenicrelief-creating elements.

The surrounding of Banská Štiavnica is a very goodmodel area. All this region, is even during the Ancient times(maybe even during Primeval Age), extensively remarked bymining activity.

To confirm that the origination of the percolating watersacidity is the activity of chemical-litotrophic thionic bacteriathere were isolated the following species Thiobacillus ferro-oxidans, Thiobacillus thiooxidans, Leptospirillum ferrooxi-dans and Bacillus cereus. The mentioned bacteria in dump-ing grounds are metabolically connected with sulphides. Thedominant part of these sulphides is represented by fine-grained pyrite. It was proved that in percolating waters and inthe influenced soils micro-fungi are present. One of theproducts of the metabolism of microorganisms are organicacids. It is assumed that these acids have an important role inthe process of silicates and alumosilicates decay. Themechanism of biological oxidation under influence of thio-bacteria initiates the hydrolytic process of sulphide mineralsand cause creation of complex compounds of heavy metals.

These acid percolating waters extensively damage anddestroy the entire biotope, contaminate the undergroundwaters by Zn, Cu, Cd, Fe, Bi, Mn... The extraordinary nega-tive influence has Al. Its concentration in acid water is veryhigh. The result of biological-chemical environmental eventsis the biological transformation of the original sulphidic aswell as of the alumosilicates. The main consequence of theseprocesses is the pelitization and illitization. The affectationof H2SO4 and of the products of metabolism of species Ba-cillus cause releasing of Si, Al, Cr, Au, Ag... to the solution.The study of gold grain surfaces shows that the products ofthe bacterial metabolic processes reacted with Au and causedAu migration in the form of water-soluble complexes.

We recorded the following evolutionary vegetation stageson dumps and soils influenced by heavy metal pollution. On

dump areas with fine-grained substrate originate plant groupsin mosaic position: Tussilago farfara, Agrostis tenuis andArtemisia vulgaris, Tripleurospermum perforatum, Daucuscarota and Tanacetum vulgare. On places where there ismore humus, we can find next species: Avenella flexuosa,Nardus stricta, and mainly species from the surroundings:Arrhenatherum, Tithymalus cyparissias, Veronica chamaed-rys, Phleum pratense and Festuca rubra.

The oldest dumps from 14. to 16. centuries, worked asmeadows, are covered by grass, which consists of speciesresistant to heavy metals: Acetosella vulgaris, Luzula cam-pestris, Arrhenatherum elatius, Avenella flexuosa, Leucan-themum vulgare, Dianthus carthusianorum, Pilosella cy-mosa. The soil in this stage has well developed two or threesoil horizons.

Dumps from 18. and 19. centuries are predominantlyplanted by trees Pinus nigra, Pinus sylvestris and more rarelyby Picea abies. On the youngest dumps subsist by auto-sowing Betula pendula, Alnus glutinosa, Salix caprea andsome other plants. Analyses of plant tissues show high con-centrations of heavy metals, e.g. in acid soil (pH = 4) containAcetosella vulgaris up to 3500 mg Al in kg of dry sample.

Little mammals represent due their short living and lim-ited, max. of 1–2 ha extent life-area an extraordinary con-venient group for monitoring the contamination of environ-ment. 142 mammals of 5 species were caught: Apodemusflavicollis (54.2%), Microtus arvalis (23.9%), Clethrionomysglareolus (18.3%) and rare Pitimys subterraneus andClethrionomys suaveolens.

There were determined contents of Fe, Mn, Cu, Pb, Zn,Cd, Bi (Ni) in tissues of kidneys, livers and spleens of mostlyabundant species. High contents of heavy metals were de-scribed in liver dry-tissues of Apodemus flavicollis (mg.kg-1):Fe 3028, Ni 337, Mn 26, Cu 26, Zn 45, Pb 60, Cd 4 ppm andin spleen dry tissues of Microtus arvalis: Fe 952, Ni 2498,Cu 1371, Zn 295, Pb 122, Cd 5 ppm. Between heavy metalcontents in plants and internal organs of little mammals fromsurface levels of dumps was found a trend of important posi-tive correlation but it will be very convenient verify thesedata on the larger set of samples.


58

DIFFERENT MOBILITY OF HEAVY METALS IN HYDROQUARTZITE AND INSEDIMENTS OF TEILING POUNDS (BANSKÁ ŠTIAVNICA, WESTERN CARPATHIANS,SLOVAK REPUBLIC)

KRIŽÁNI, I.1, ANDRÁŠ, P.1 & DLUHOLUCKÁ, L.21 Geological Institute, Slovak Academy of Sciences, Severná 5, SK-974 01 Banská Bystrica, Slovak Republic.E-mail: [email protected] Secondary school, SK-969 01 Banská Štiavnica., Slovak Republic.

The pit quarry at the south slope of Malý Šobov Hill issituated in lense of hydrothermal quartzite (HQ). Finegrained waste from flotation plant of Banská Štiavnica OreMine State Plant is deposited in setting pit Sedem Žien at thecontact of village landmark of Banská Štiavnica and BanskáBelá.

The average sample of HQ (A) was prepared by homog-enization of crushed material from three bore holes for benchblasting in the low level of the quarry and from sediments ofsetting pit (B) after mixing of mentioned three samples fromthe external part of the dam. Nine portions of grain size <1mm with volume <25 cm3 from each sample were washed by250 ml solutions of destilled water (pH 6.5), solution H2SO4

+ HNO3 and NaHCO3 in destilled water (pH 4.5) and in

rainwater (pH 4.5). Contents of selected heavy metals inleaching were determined by atom absorption spectrometry.

The primary source of Fe, Cu, Zn, Pb, Ag and Cd in HQin the sediments of the setting pit are sulphide minerals andsulphosalts. Source of the Mn are in both cases carbonatesand silicates.

The important reason of the intensive leaching of theselected elements from HQ is caused by lower carbonatecontent in comparison with sediments of the setting pit. Thesecond reason is the long time activity of three species ofthio-bacteria and of products of their metabolism on the highreactive mineral phases of HQ. In the sediments of the set-ting pit dam was isolated already only Thiobacillus ferrooxi-dans.

Table 1: Contents of the most important oxides in wt.% in HQ and in sediments from the setting pit

SiO2 TiO2 Al2O3 Fe2O3 FeO MnO MgO CaO Na2O K2O P2O5

A 92.32 0.44 0.97 3.26 0.26 0.02 0.04 0.11 0.05 0.08 0.12B 71.68 0.31 7.72 2.36 2.20 1.03 1.14 2.28 2.22 3.79 0.10

Table 2: Contents of selected heavy metals (g/t) in HQ and in sediments from the setting pit

Cu Zn Pb Ag CdA 25 52 64 8.27 0.10B 478 3632 1138 5.50 18.40

Table 3: Average contents of heavy metals (mg/l) in leachings from samples A and B

Fe Mn Cu Zn Pb Ag CdxA 330 8.10 0.52 5.70 2.30 0.23 0.018xB 1.10 14.20 0.06 3.40 1.04 0.03 0.045

Table 4: Overview of thio-bacteria from Šobov and Nová šachta dumps and from setting pit Sedem Žien

BacteriaLocality

SamplesMedium

Samplenumber

pHTf Lf Tt

Šobov quarry and dump drainage water 6 2.0-2.4 + + +Nová Šachta dump drainage water 3 5.6-6.8 + + +Setting pit Sedem Žien leaching from sand 1 5.7 +3 – –

Explanations: Tf – Thiobacillus ferrooxidans, Lf – Leptospirillum ferrooxidans, Tt – Thiobacillus thiooxidans+ present, – not present


59

OPAL VARIETIES IN CARPATHIAN VOLCANIC ROCKS

KULCHYTSKA, G.1 & PAVLYSHYN, V.21 Institute of Geochemistry, Mineralogy and Ore Formation, National Academy of Sciences, Palladine Avenue 34, Kyiv,Ukraine. E-mail: [email protected] National University, 90 Vasylkivska, str., Kyiv, Ukraine.

A fair amount of water is a typical constituent of opal, ashort range order form of silica. Opals are distinguished bystructural attributes (opal-A, -C, -CT); their name may varyby colour (milky and black opal, chrysopal), by transparency(hyalite, hydrophane, cacholong) or by gem value (commonand noble opal). There is no opal classification based uponthe water content, though it varies from 1 to 30%. We do nothave enough information about the role of water in opal, notspeaking about the amount and role of other volatile compo-nents present.

Gas analysis of pyrolysed opal showed that during heat-ing not only the dominant water (vapour), but also hydrogenand volatile compounds of carbon (СО2, СО, СН4, СnHm)leave the samples. While degassing, many opal samplesgenerate compounds of nitrogen (N2, NO), and some of themalso compounds of sulphur (H2S, SO2, COS). The amount ofnon-water phases in the leaving gas mixtures decreases fromthe opaque to the transparent opals. (causing a reverse de-pendence for water).

In the current study we analysed the gas composition ofdifferent opal varieties and that of their volcanic parent rocks(from the Carpathians) on heating and compared these resultswith analyses of opals from the Ukrainian Shield (Table 1).

The two opals from the Ukrainian Shield gave interestingresults (PAVLYSHYN et al., 1993; KULCHYTSKA et al.,1997). They are closely connected, form a zonal structure.Their non-volatile chemical composition do not differ, whiletheir volatile composition differ considerably. The differ-ences in the volatile composition were interpreted in thefollowing way: The “amorphous” silica contains open orclosed pores. Opals with open pores contain less water thanopals with closed pores. In the first case water is consideredas „adsorbed”, while in the second case as “absorbed” (in thevacuole). Typical characteristic of opals with open pores is afair amount of carbon compounds and hydrogen in its py-rolysed gas. The different composition of volatile admixtureson the surface of silica globules was suggested to lead to theformation of two opal varieties, called “hydroxyl-opal”, with

OH-groups, and “organo-opal”, with CH-groups, respec-tively.

These two opal varieties were found also in Carpathianvolcanic rocks, but separately. Opal present in altered tuffs(Table 1, #5) resembles “hydroxyl-opal” the most, as vacuolewater dominates in it and there are very little hydrocarbonspresent. “Ungvarite”, a mixture of opal and nontronite (Ta-ble 1, #6), is similar to them, too. Precious opal from Dubnik(Table 1, #2–3) is similar to “organic-opal” in the amount ofhydrocarbons. On the other side the larger amount of“absorbed” and the fewer amount of “adsorbed” water in itgives us the reason to interpret that variety as a mixture of“hydroxyl-” and “organic-opal”. Kinetics of water separationsuggests the very small size of both the open and the closedpores. The amount of hydrocarbons, and also СО2 and par-ticularly СО decreases noticeably. from the translucent to thevitreous variety. The similar trends of changing of the СО,СnHm and H2 content suggests the common source of thesecompounds.

Based on the data of the parent rocks (Table 1, #1, 4) itcan be pointed out that 1) there is an inverse correlation be-tween the amount of organic groups in opal and in its (vol-canic) parent rock; 2) there is much nitrogen in the pyrolysedproducts of volcanic rocks, even without adsorbed nitrogen.(up to 0,005%).

To our point of view the differentiation of silica (causedby temperature and pressure changes), the formation of theopal varieties, was influenced also by the composition ofthese volatile admixtures.

ReferencesKULCHYTSKA, G., VOZNYAK, D. K., EGOROVA, L. N.

MELNIKOV, V. S. & PAVLYSHYN, V. I. (1997). Min-eral. Zhurnal, 19/1: 18-37.

PAVLYSHYN, V. I., VLASYUK, S. A., INDUTNY, V. V.,KVASNYTSYA, V. M., KULCHETSKAYA, A. A.,MELNIKOV, V. S. & RAKHMANGULOVA, D. Z.(1993). Mineral. Zhurnal, 15/4: 5-16.

Table 1: The amount of some components in the pyrolysed products of opals and their parent rocks.Temp. of pyrolysis (°C) 1 2 3 4 5 6 7 850–1050 3.60 3.59 3.45 6.67 7.26 6.65 1.49 4.95

H2O (wt%)50–250 0.72 0.85 0.32 0.86 0.54 1.18 1.06 0.26

CH4 (ppm) 50–1050 0.53 7.30 4.35 54.98 0.13 0.53 7.73 0.87C2H4+C2H6(ppm) 50–1050 0.38 16.50 2.94 64.70 1.03 0.10 16.00 1.30N2 (ppm) 250–1050 17.44 7.09 16.16 49.12 9.39 7.13 4.22 1.07No. of analyses 1 3 1 2 3 2 11 18

1) andesite, Dubnik, Slovakia; 2) milky and frost opal (from andesite), Dubnik, Slovakia; 3) vitreous opal from andesite, (fromandesite), Dubnik, Slovakia; 4) altered volcanic (crystal/vitritic) tuff, Slovakia; 5) translucent opal from altered volcanic tuff,Slovakia; 6) „ungvarite” (opal-nontronite intergrowth), Transcarpathians, Ukraine; 7) „organo-opal”, the Ukrainian Shield,Ukraine; 8) „hydroxyl-opal”, the Ukrainian Shield, Ukraine.


60

SIMPLE FORMS OF SYNGENITE (KALUSZITE) CRYSTALS

KVASNYTSYA, I. V.Kyiv National University, Kyiv, Ukraine.E-mail: [email protected]

Syngenite crystallography has been sufficiently studiedby J. Rumpf in 1872, V. Zepharovich in 1872, 1873, K. Ubrain 1873, A. Laskiewicz in 1927, 1934, 1936 (KO-ROBTSOVA, 1955) and L. Gorogotskaya in 1966. Our in-vestigations of many syngenite crystals from Dombroveoccurrence (Kalush area, Precarpathians) give evidence thattheir habit is often determined by {100} pinacoid (Fig. 1).

Syngenite crystals of {100} + {110} pinacoidal-prismatichabit and {110} prismatic habit are rare. Owing to peculiari-ties of syngenite structure (GOROGOTSKAYA, 1966)crystals are often prolonged along [001]. Well-developed andwidespread forms on investigated crystals are represented by{100}, {010}, {001}, {101}, {101}, {110} and {011}.

List of all known simple forms of syngenite crystals, theirdistribution and development according to their interplanardistances is next: {100} - dhkl, 9.486 (9.490) (theoretical dataand in brackets X-ray data, JCPDS 28-739); {010} – 7.147;{001} – 6.064; { 1 01} – 5.784; {110} – 5.708 (5.710);{101} – 4.626; {011} – 4.624 (4.624); { 1 11} – 4.496(4.496); { 2 01} - 4.271; {210} - 3.952 (3.954); {111} –3.883 (3.887); { 2 11} – 3.667; {120} – 3.344 (3.347); {211}– 3.042; {310} – 2.892 (2.891); { 1 12} – 2.856 (2.855);{ 2 21} – 2.741 (2.741); {221} – 2.448 (2.447); {410} –2.251 (2.250). The other forms {411}, {510}, {203}, {430},{520}, {610}, { 3 04}, {124}, {710}, {720}, {304}, {810},{ 7 04}, {504}, {650} and {10.3.0} are very rare. This list is

based on the crystallographic data published by GOLD-SCHMIDT (1922), PALACHE et al. (1951), LAZARENKOet al. (1962) and GOROGOTSKAYA (1966). Theoreticaldhkl have been calculated by us according to X-ray data(JCPDS 28-739, a0 = 9.777(2), b0 = 7.147(2), c0 = 6.250(2), β= 104˚01’(2)). It is clear that the forms with big values of dhkl

are most frequently occurring and well-developed faces on

syngenite crystals.

ReferencesGOLDSCHMIDT, V. (1922): Atlas der Krystallformen.

Band VIII. Carl Winters Universitätsbuchhandlung, Hei-delberg.

GOROGOTSKAYA, L. I. (1966). Collection of L’vov Uni-versity, 20/4: 481–489.

KOROBTSOVA, M. S. (1955): Mineralogy Potassium saltsdeposits of Eastern Precarpathians. In: Problem of Miner-alogy of Sedimentary Formations. Vol. 2. L’vov NationalUniversity Publ., L’vov, Ukraine, p.3–137 (in Russian)

LAZARENKO, E. K., GABINET, M. P. & SLYVKO, E. P.(1962): Mineralogy of Sedimentary Formations of thePrecarpathians. L’viv National University Publ., L’viv,Ukraine. – 482 p. (in Ukrainian)

PALACHE, C., BERMAN, H. & FRONDEL, C. (1951):Dana’s system of mineralogy. 7th Ed., vol. II.

Fig.1: Main morphological types of syngenite crystals from Dombrove quarry.


61

NEW DATA ON SYNGENITE (KALUSZITE)

KVASNYTSYA, V. M.1, VOZNYAK, D. K.1, IL’CHENKO, K. O.1, KVASNYTSYA, I. V.2 & HRYNIV, S. P.31 Institute of Geochemistry, Mineralogy and Ore Formation, National Academy of Sciences, Palladine Avenue 34, Kyiv,Ukraine.E-mail: [email protected] Kyiv National University, Kyiv, Ukraine.3 Institute of Geology and Geochemistry of Combustible Minerals, Ukrainian National Academy of Sciences, L’viv, Ukraine.

More than 50 mineral species were first discovered in theCarpathian region. Only two of them were found in theUkrainian part of the Carpathians: syngenite from Kalusharea (the Precarpathians, Miocene molasse sedimentaryrocks) and karpatite from Oleneve area (the Transcarpathi-ans). Syngenite was described almost simultaneously by J.Rumph and V. Zepharovich in 1872 (KOROBTSOVA,1955). The former author had discovered this mineral on halfyear earlier and named it as kaluszite, the later one named hisfind as syngenite. Later syngenite was found in other occur-rences of the Precarphathians (Morshyn, Stebnyk). Thesecrystals were described by R. Zuber in 1904, J. Tokarski in1910, 1913 and Cz. Kuzniar in 1934. In 1955 considerableprogress has been made in the systematical research of syn-genite (KOROBTSOVA, 1955).

Our main goal in this study is to present results of com-plex investigations of syngenite from new occurrence and tocompare them with already published data. New find ofsyngenite crystals was made in sediments of Golyn’ syncline(Kalush-Golyn’ group of potassium-magnesium salt depos-its). Here potassium-bearing strata has a thickness of 300-600 m. It contains layered and breccial clays with lens ofhalite and potassium salts which are represented by langbe-inite-kainite rock and sylvinite. Statistically representativeset of syngenite crystals (about 500 samples) from gypsum –clay cap (sole mark 265–270 m) of Dombrove quarry wasexamined. Syngenite crystals were extracted from gray clay.The crystal sizes are 0.5–30 mm along [001].

New data Some groups of fluid inclusions (primary and secondary)

have been determined in the syngenite crystals. Primaryinclusions of the first group have either isometric form ofnegative crystals (50–70 µm in size) or complex one with asize up to 1–3 mm. Most of big inclusions have high degreeof filling. All inclusions take place in the central part of thecrystals. Inclusions composition is: aqueous solution (90–95%) + gas (1–2 %) + solid phases (3–9%, isotropic mineralsprevail). Homogenization temperature of gaseous phase is

equal or less then 60–67 ˚C (± 1 ˚C). Eutectic temperature isin the range from –8.3 to –9.0 ˚C (± 0.2 ˚C).

The second group of primary inclusions (0.2–0.3 mm insize) consists of tubular and tabular negative crystals, whichcoincide with [001]. Gaseous bubble appears at cooling anddisappears at the temperature 40–47 ˚C. Teutectic is between –22.4 and –22.6 ± 0.2˚C. Tice melting is from –8.3 to 12.8 ˚C.Liquid inclusions in syngenite with Teutectic. is similar to thesystem NaCl–H2O (Teutectic.= –21.1 ˚C) and NaCl–KCl–H2O(Teutectic.= –22.9˚C). Its concentration is from 12.1 to 16.7wt% NaCl equiv.

Syngenite formation is a result interaction of the anhy-drite and halite rocks with solution enriched in KCl andK2SO4. For growth of syngenite high concentration of KCl insolutions is necessary (more 8% of KCl after Lepeshkov I.M.) (KOROBTSOVA, 1955); it is in good agreement withour data on fluid inclusions.

Concluding remarksThe syngenite crystals from Dombrove quarry often show

a combination of simple forms with big values of dhkl. Mostof the crystals have {100} pinacoidal habit. Main simpleforms of the crystals are {100}, {010}, {001}, {101},{ 1 01}, {110} and {011}. Obtained infrared spectra of thesyngenite crystals are typical for syngenite and confirm itsstructure peculiarities. Therefore the crystallization condi-tions of syngenite were optimal. At the beginning the syn-genite crystals grow from KCl-enriched solutions at the tem-perature equal or less then 60–67 °C (KCl–H2O system hasthe Teutectic. = –10.8 ˚C). At the end of syngenite crystalliza-tion it was held from NaCl-enriched solutions at the tem-perature equal or less then 40–47 ˚C. Concentration of solu-tions was 12.1–19.7 wt. % NaCl equiv.

ReferenceKOROBTSOVA M. S. (1955) Mineralogy Potassium salts

deposits of Eastern Precarpathians. In: Problem of Miner-alogy of Sedimentary Formations. Vol. 2. L’vov NationalUniversity Publ., L’vov, Ukraine, p.3 – 137 (in Russian)


62

PHYSICO-CHEMICAL CONDITIONS OF QUARTZ AND CARBONATE VEIN FORMATIONFROM THE CALDERA OF THE KELCHEY VOLCANO (TRANSCARPATHIANS, UKRAINE)

LAZARENKO, He., BLAZHKO, V. & KULIBABA, V.Institute of Environmental Geochemistry, National Academy of Sciences, Kyiv, Ukraine.E-mail: [email protected]

Zonal veins of 3–5 cm thickness cut andesite which fillsup the caldera of the Kelchey volcano (Kvasovo ore field).

The main minerals of the veins are “quartz I”, “quartz II”(amethyst) and “quartz III” (amethyst similar to quartz I) andcarbonates (calcite and rhodochrosite) crystallized in thesequence listed.

On the basis of homogenisation temperature and gas-phase content the following generations of fluid inclusionsmay be distinguished: in “quartz I”: 375 ºC (60% gas), 230–205 ºC (20% gas); in “quartz III”: 300 ºC (25–30% gas); in“quartz II”: 225–180 ºC (20% gas) and 170–165 ºC (10%gas). Fluid inclusions are not present in carbonates.

By gas chromatography the following components of thegas-liquid inclusions have been determined: Ar + O2, N2,CH4, CO, CO2, C2H6, and H2S.

CO and H2S contents (in cm3/kg) are different: in “quartzI” (CO 0.6, H2S 1.7) are less than in “quartz II” (CO 85, H2S87).

Cl ion, F-hydrocarbon are determined in “quartz I” and“quartz II” by the water-extract method. These componentsare absent in carbonates.

A large temperature range (375–165 ºC) of “quartz I” and“quartz II” crystallisation shows an unbroken evolution proc-ess of hydrothermal solution. The gas phase is prevailing atthe high temperature stage (>300 ºC).

The increase of reduced gases in the later stage of mineralformation (“quartz II”) shows that at low temperatures theoxygen fugacity was lower. The bulk crystallisation of rho-dochrosite suggests that Mn2+ was stable under these condi-tions.

The high homogenisation temperature of the gas inclu-sions indicates that mineral formation in early stages oc-curred within pneumatolytic conditions. The composition ofthis phase may reflect the volcanic gas composition.


63

MINERALS OF THE JÓZSEF HILL CAVE, BUDAPEST, HUNGARY

LEÉL-ŐSSY, Sz. & SURÁNYI, G.Department of Physical and Historical Geology, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest,Hungary.E-mail: [email protected]

In 1984, spelaeologists under the guidance of SzabolcsLeél-Őssy and Péter Adamkó explored the József Hill Cave,the most beautiful and most abundant in minerals member ofthe cave group in the environs of Budapest. As to its charac-ter and formations, this typical thermal karst cave, known atpresent in a length of 5.6 km, is similar to the LechuguillaCave (New Mexico, USA), called the most beautiful cave inthe world – even if the dimensions of the mineral precipita-tions and the passages are not to be mentioned in the samebreath.

In the laboratory of Stein-Erik Lauritzen, University ofBergen, Norway, in 1996, as well as in the laboratory of theEötvös Loránd University of Budapest during 2001–2002,uranium series dating measurements were carried out on theformations. The obtained data helped a lot in determining thegenetics of the precipitations.

On the main passage level of the cave, the host rock canbe investigated only at a few places, as the mostly whitecrystal coating covers uninterruptedly the wall almost eve-rywhere. Altogether 7 minerals can be examined and distin-guished with the unaided eye. The presence of 6 mineralswas demonstrated by X-ray powder diffraction examinationsand further 3 minerals were detected by heavy mineral analy-sis. Among them, mainly carbonates and sulphates, as wellas oxides–hydroxides and silicates could be found. The twodominant mineral species (gypsum and calcite) can be ob-served in very diversified forms of appearance.

Out of the 9 forms of appearance of the gypsum crystals,the 0.5–1.0 m gypsum chandeliers that hang down from theceiling are the most spectacular ones. Generally, the sidewalls are covered by small crystalline gypsum coating. Atseveral places, on the top of the some cm thick gypsum crust1–5 cm gypsum crystals, while at other places 1–3 mm wide,1–2 cm long needles are sitting. The pencil-thick, 10–15 cmgypsum flowers and gypsum snakes as well as the stragglyagglomeration of the hair-thin but locally 50–90 cm longcrystal needles, called needlegrass, are precious gypsumformations.

The material of the gypsum precipitations may be derivedpartly from the sulphate content of the former thermalsprings, partly from the pyrite content of the more than 10 mthick marl layer covering the cave. The coatings and the

needlegrass are living formations that precipitate from theinfiltrating water and the cave aerosol.

With its 13 separate forms of appearance in the cave, thecalcite occurs most frequently as common peastone. The 5–15 cm long sheaf-like clusters, standing out perpendicularlyfrom the side wall, are built up of green pea-sized deformedspheres of layered structure. There are angular and coralpeastones, as well. All of these peastones came into beingfrom the mist above the evaporating warm water cave lakethat condensed on the side walls some tens and hundreds ofthousand years ago, respectively.

The glass ball peastones are regularly spheroidal yel-lowish formations of about 0.3–0.8 cm diameter with asmooth surface. Unlike the most peastone varieties, theyprecipitated from the slowly flowing or dripping cold water.According to the results of the uranium series dating, theyare only some thousand years old.

From the point of view of age determination, the 0.2–3.0cm thick cave raft and several cm thick flowstone(multigenerational calcite crust) accumulations, covering theside wall at a lot of places, are the most important, as theywere precipitated shortly after the dissolution of the cave,near the surface of the warm water, filling the cavity. Theresults of their examination refer to the fact that the passagesof the József Hill Cave were dissolved about half a millionyears ago.

In the cave, the calcite is represented by several otherprecipitation types (e.g. dripstone, dog teeth, tetaratas, basinfingers, etc.), as well.

As to the spectacle, a determinant representative of thecrystals of the cave is the aragonite, the 1–2 mm thick crys-talline needles of which form hemispheres of 1–3 cm di-ameter and 4–8 cm long clusters. The 30,000–200,000 yearsold crystalline needles are sitting generally on the top of thepeastone grains. The infiltrating waters in the cave havealready re-dissolved the considerable part of the aragoniteneedles.

Besides the spectacular crystal formations, the clay min-erals: kaolinite and illite, accumulating from the detritus ofthe carbonate rocks, occur on the bottom of the passages in aconsiderable (locally several m) thickness.


64

OFFRETITE FROM THE BALATON HIGHLAND, HUNGARY

LÓRÁNTH, Cs.Department of Mineralogy, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected]

Offretite, a rare zeolite mineral was found in Bazsi(Karikás Hill quarry) near Sümeg. This zeolite was unknownin hydrothermal zeolite associations from the Balaton High-land area. The only occurrence in Hungary was Bagókő Hillnear Somoskő, Medves Hills. Offretite was found in smallcavities in the Pliocene basaltic rock in association withcalcite, analcime, and clay minerals. Offretite forms colorlesshexagonal needle shaped crystals up to ~1 mm in size. Theycover the walls of cavities. We have identified offretite fromthis new occurrence using transmission electron microscopy,

X-ray powder (Table 1) and selected area electron-diffraction. Regarding structural characterisation of offretitewe paid special attention to the published experiences ofGUALTIERI et al. (1998).

ReferenceGUALTIERI, A., ARTIOLI, G., PASSAGLIA, E., BIGI, S.,

VIANI, A. & HANSON, J. C. (1998). Amer. Mineral.,83: 590-606.

Table 1: X-ray powder diffraction pattern of offretite from Karikás-tető quarry, Bazsi.

OffretiteKarikás-tető, Bazsi

OffretiteJCPDS 22-0803

2*theta d(hkl) I(rel) d I(rel) hkl[deg] [Å] [%] [Å] [%]7.68 11.5078 5.41 11.50 100 10013.30 6.6561 2.10 6.64 20 11015.42 5.7467 3.88 5.76 35 20019.39 4.5772 2.11 4.58 4 20120.44 4.3457 8.64 4.35 60 21023.18 3.8365 8.09 3.84 45 30023.62 3.7670 5.22 3.77 10 21124.48 3.6363 3.06 3.60 4 10224.98 3.5640 3.51 3.43 2 30126.56 3.3561 1.31 3.32 20 22027.99 3.1877 5.93 3.19 18 31031.14 2.8718 5.45 2.88 65 40033.35 2.6871 5.25 2.69 4 40135.56 2.5245 14.78* 2.51 20 41038.70 2.3265 2.42 2.30 6 50040.57 2.2236 2.98 2.21 20 33042.79 2.1133 24.66* 2.11 2 30346.60 1.9490 7.54 1.96 2 50247.84 1.9013 3.37 1.89 2 430

Reflections of accompanying minerals are omittedOther minerals also contributed to starred intensities


65

PLUTONIUM BEHAVIOR IN BRINES AFTER EQUILIBRATION WITH PERICLASE (MgO)BACKFILL

LU, N.1 & CONCA, J. L.21 Los Alamos National Laboratory, Los Alamos, NM 87545, USA.2 Los Alamos National Laboratory, Carlsbad, NM 88220, USA. E-mail: [email protected]

Most radioactive waste disposal programs are consideringthe use of repository backfill materials to enhance the con-tainment of radioactive waste. The concepts include the useof backfill to provide well-defined chemical conditions,favorable hydraulic conductivity, and desirable physicalcharacteristics within the disposal facility. The backfill ma-terials have been classified into two groups according to theirprimary properties: 1) chemical backfills such as cement,iron, phosphates, and MgO, and 2) hydrological/physicalbackfills such as clay, salt and cement. Magnesium oxidewas proposed, and is being used, as a backfill material in asalt repository for transuranic waste in Carlsbad, New Mex-ico. It was chosen for its capacity to control pH and carbondioxide (CO2) concentrations through specific reactions,maintaining the pH of the repository between 8.5 and 10, therange in which many radionuclides exhibit their lowest solu-bilities. In past years, most research has focused on the hy-dration and carbonation of MgO. A separate, but relatedissue concerns the heterogeneity of the repository in terms ofrewetting after closure and the formation of new minerals inthe backfill. Plutonium, with its multiplicity of oxidationstates, is one of the primary actinides of concern for long-term disposal and storage of nuclear waste. The chemicalbehavior of plutonium is influenced strongly by its oxidationstate, which determines the strength of its complexationreactions, solubility, formation of colloids and sorption proc-esses. In this study, laboratory experiments were performed

to evaluate 1) stability of 239Pu(VI) in synthetic Brine G,Brine E, 5M NaCl and 3.7M MgCl2 • 6H2O as a function oftime, 2) behavior of 239Pu(VI) in the four brines after equili-brated with MgO backfill for 68 days at various water con-tent, 3) release of 239Pu from of Pu-MgO-brine agglomeratesas a function of time, 4) characterization of 239Pu-loaded –MgO-brine agglomerates. Equilibration experiments wereconducted at MgO-to-water ratios of 1:0.15, 1:0.25 and 1:10.Release of 239Pu from 239Pu-loaded MgO agglomerates wasdetermined in the presence or absence of hypochlorite(OCl-), under agitated and non-agitated conditions. After the239Pu(VI)-brines were equilibrated with MgO backfill for 68days, the solution pH and alkalinity changed dramatically,with 99% to 100% of the 239Pu(VI) being removed from thebrines (Figure 1). Only a small amount of 239Pu was subse-quently released from the 239Pu-loaded MgO-Brine G ag-glomerates after 110 days, but there was no 239Pu releasedfrom the 239Pu-loaded MgO-Brine E agglomerates. Ourfindings suggest that in NaCl-base brines such as Brine E,the studied MgO material is an effective backfill to buffer thepH to 9-10, which retards the release and migration of pluto-nium. In MgCl2-base brines such as Brine G, the MgO isslightly less effective because of buffering to a lower pH(8.0-8.5). The MgO showed great affinity for Pu under re-pository conditions and should perform well beyond its per-formance predictions.

9 9 ,89 9 ,91 0 0 ,0

9 9 ,99 9 ,99 9 ,2

1 0 0 ,0

1 0 0 ,01 0 0 ,0

9 9 ,9

0

2 0

4 0

6 0

8 0

1 0 0

1 2 0

B r in e G B r in e E 5 M N a C l 3 .7 MM g C l2 .6 H 2 O

B r in e s

%P

u-2

39 R

emov

ed

1 5 %2 5 %1 0 0 0 %

Fig. 1: Percentage of 239Puremoved from brines afterequilibrated with MgObackfill for 68 days.


66

MECHANISMS AND MICROSTRUCTURAL ELEMENTS OF THE EARLY, DUCTILEDEFORMATION PHASE IN LIMESTONES OF THE NE BÜKK MOUNTAINS, HUNGARY

MÁDAI, F.1 & NÉMETH, N.21 Department of Mineralogy and Petrology, University of Miskolc, H-3515 Miskolc-Egyetemváros, Hungary.E-mail: [email protected] Department of Geology and Mineral Resources, University of Miskolc, H-3515 Miskolc-Egyetemváros, Hungary.

According to field investigations (e.g. CSONTOS, 1999),the “main schistosity” in the NE Bükk is a generally recog-nised feature. It constitutes the axial plane of the early foldsformed by ductile deformation of the Late Palaeozoic-Triassic sequence. The ductile deformation elements are bestobservable in beds where limestone alternates with seams orlenses of materials with different competence, e.g. in chertylimestone.

It was supposed that the early, ductile deformation tookplace during the Alpine low-grade metamorphism (ÁRKAI,1973, 1983). According to these investigations, the condi-tions of the peak metamorphism can be characterised by 300-350 °C temperature and 200-300 MPa pressure. They alreadypointed out that there is no correlation between the pressureof metamorphism and the stratigraphic position (burial), themetamorphic event is proved to have mainly a dynamother-mal character. The later deformation phases took place underlower temperature (DUNKL et al., 1994), where ductiledeformation in the limestones cannot be formed.

In the present paper different microstructural elements oflimestones were studied which could have developed duringthe ductile deformation phase but were not overprinted bythe later phases. The position of the samples in an early foldwas also considered: samples both from the hinge and limbzones of folds were investigated. The following microstruc-tural elements were examined:

•grain shape preferred orientation (SPO) of the fine-grained (10-20 µm) matrix, examined by quantitativeimage analysis.

•shape of the intercrystalline boundaries in the matrix.•crystallographic preferred orientation (CPO) by con-

structing inverse pole figures.•formation and further deformation of calcite twins in

large (150-200 µm) pre-kinematic crystals.No correlation was found between the stratigraphic posi-

tion and the occurrence and intensity of these microstructuralelements. Conversely, it was detected that they depend on theposition of the sample relative to different fold elementsformed during the early deformation phase.

The SPO of the matrix was weak in the hinge zones,while it was intensive on the limbs. The strongest SPO val-ues were detected on samples from the limbs on sections cutnormal to shear direction. The sections cut parallel to sheardirection had more moderate SPO values.

The intercrystalline boundaries of the fine-grained matrixwere predominantly serrate in specimens from hinge zones.On the other hand, the grains of the matrix of samples fromlimbs had a fair proportion of straight (plain) boundaries.Planar grain boundaries with polygonal texture dominatedthe sections cut parallel to shear direction, while they wereless frequent in the normal sections.

According to inverse pole figures, the sample from ahinge zone had no CPO. Conversely, a weak but definiteCPO was detected on samples from the limb zones. Theyshowed a “c-axis fibre type” CPO (LEISS & ULLEMEYER1999) having a simple c-axis maximum normal to the mainschistosity. The slight CPO and the predominance of straightboundaries in the matrix indicate that the limestones in limbsof the early phase folds could deformed by “superplasticcreep” (SCHMID et al., 1977).

The deformation twins within and the grain boundaryzones around the large, pre-kinematic calcite crystals fromthe intensively sheared limbs were dynamically recrystal-lized: these elements were replaced by aggregates of small,isometric calcite grains with dominantly straight boundaries.Conversely, the large calcite crystals from the hinge zonesshowed only serrated grain boundaries and straight, unde-formed twins.

These features indicate that the differential stress duringthe early, ductile phase was relatively weak (about 20 MPa)in the hinge zones, the limestones here deformed by diffu-sion mass transfer (pressure solution). The additional shearstress on the limbs rose the differential stress (up to 35-60MPa) thus dynamic recrystallization and superplastic creepcould take place.

ReferencesÁRKAI, P. (1973). Acta Geologica Hung., 17(1-3): 67-83.ÁRKAI, P. (1983). Acta Geologica Hung., 26(1-2): 83-101.CSONTOS, L. (1999). Földt. Közl., 129(4): 611-651.DUNKL, I., ÁRKAI, P., BALOGH, K., CSONTOS, L. &

NAGY, G. (1994). Földt. Közl., 124(1): 1-24.LEISS, B. & ULLEMEYER, K. (1999). Z. dt. geol. Ges.,

150(2): 259-274.SCHMID, S. M., BOLAND, J. N. & PATERSON, M. S.

(1977). Tectonophysics, 43: 257-291.


67

THE ENVIRONMENTAL HAZARD OF THE GYÖNGYÖSOROSZI FLOTATION WASTEDUMP (MÁTRA MOUNTAINS, HUNGARY)

MÁDAI, V.Department of Mineralogy and Petrology, University of Miskolc, H-3515 Miskolc-Egyetemváros, Hungary.E-mail: [email protected]

Atmospheric effects can cause weathering of ore bodies.This is a natural phenomenon, which exists since millions ofyears ago. Originating low pH effluents, which containsolved toxic metal ions surely cause a dramatic effect on thebiota. Species living in surface waters may decrease in num-bers, and any biota will be necessarily poorer than before. Anew balance come into between the recreation capacity of thenature and the pollution of the weathering of the waste. LowpH and higher toxic metal concentration tolerant species mayspread in the polluted region.

ARD (Acid Rock Drainage) is generally regarded to bepresent if effluent pH is between 5-5.5 because in this pHrange there is a negative impact on biota.

Gyöngyösoroszi is situated in the north east part of Hun-gary in the county of Heves. The village, which is not farfrom the former mine, lies in the south part of the MátraMountains in the valley of Toka Brook. Gyöngyösoroszi OreMining Company was established in 1952. The mined orewas crushed, grinded and flotated on the spot. The productswere pyrite, sphalerite, galena, and galena with copper.Sphalerite, galena powder were smelted abroad. In 1962

during the reconstruction of the plant a new job was estab-lished: the heavy suspension beneficiation. The used aggre-gate was ferrosilicon (fersilicite). After flotation, waste wasput on a flotation waste dump with a pipeline. The dumpsituated in the middle part of the Száraz Brook Valley. Since1979, toxic heavy metal containing effluents were treated.The produced high gypsum containing toxic sludge wassampling in the Bence Valley. The mine was abandoned in1986 because of financial problems.

My task was to examin how hazardous the flotation wastedump of Gyöngyösoroszi from the point of ARD usingchemical methods for the determination.

The environmental hazard of the Gyöngyösoroszi flota-tion waste dump from the point of Acid Rock Drainage usingone of the most widely accepted static chemical test methodis negligible.

The NPR value: the ratio of NP (Neutralisation Potential)to AP (Acid producing Potencial):

274.25 : 39.8 ~ 7:1.


68

MONTICELLITE AND HYDROXYLELLESTADITE IN HIGH-TEMPERATURE SKARNSFROM ROMANIA

MARINCEA, Ş & DUMITRAŞ, D.-G.Geological Institute of Romania, Caransebeş 1, RO-78344 Bucharest, Romania.E-mail: [email protected]

The occurrences of high-temperature, gehlenite-bearingskarns are quite exotic: fewer than forty such occurrenceswere reported so far in the world. Four of them are known inthe Banatitic Magmatic and Metallogenetic Belt (BMMB)from Romania (BERZA et al., 1998). These occurrences arethose at Cornet Hill, Măgureaua Vaţei (Upper Cerboaia Val-ley), Ciclova (Ciclova and Ţiganilor valleys) and Oraviţa(Ogaşul Crişenilor). A very rich mineral association charac-terizes the high-temperature skarn areas in Romania:gehlenite, wollastonite, calcic garnet, vesuvianite and locallyspurrite and tilleyite are the most representative species(MARINCEA & DUMITRAŞ, 2001; PASCAL et al., 2002;MARINCEA et al., 2002).

Monticellite and hydroxylellestadite were also identified,but they are scarce. Due to their scarcity, their minute grainsize and the mixture with other mineral phases, very few dataare available on these mineral species. The purpose of thepresent paper is to gain additional data on the chemistry,physical and crystallographic parameters and mineral asso-ciations of these mineral species.

Monticellite occurs as accessory mineral in the endoskarnzones from all the four occurrences, being characteristicallyincluded by the gehlenite mass. The crystals are subhedral,with prismatic habit; they average 0.5 mm in length and haveup to 0.2 mm in width. In all cases, the mineral does notshow any significant chemical or optical zoning pattern.

The scattering of the analytical points at the scale of thesame thin section is minor, so that the microprobe analyseswere averaged and taken as mean compositions. The mineralhas average compositions ranging from 8.53 to 11.66 mol%kirschsteinite and from 0.91 to 2.52 mol% glaucochroite insolid solution in the samples from Oraviţa, from 4.55 to10.86 mol% kirschsteinite and from 0.62 to 1.01 mol% glau-cochroite in the samples from Ciclova and from 13.01 to13.29 mol% kirschsteinite and from 1.51 to 2.05 mol% glau-cochroite in the samples from Măgureaua Vaţei.

The refraction indices, measured and calculated densitiesand cell parameters, as measured for representative samplesfrom Oraviţa and Măgureaua Vaţei approaching the meancompositions are listed in Table 1.

Hydroxylellestadite must occur as scattered at randomgrains throughout the tinsleyite mass (at Cornet Hill), butalso as sparingly, randomly oriented inclusions in gehlenite(at Oraviţa and Măgureaua Vaţei). In both cases, the mineralhas an euhedral to subhedral, equant to short prismatic habit.Grains have an average diameter of 0.1 mm with a maximumlength of about 0.2 mm. No chemical or optical zoning wasobserved.

The average chemical composition recorded for thetinsleyite-included hydroxylellestadite from the exoskarnzone from Cornet Hill (mean of 47 microprobe point analy-ses) leads to the crystal-chemical formula:(Ca4.916Mg0.001Mn0.002Fe2+

0.004Na0.069K0.002)(Si1.492S1.354P0.154)[O12.180(OH)0.651F0.121Cl0.048].

This formula does not differ essentially from that estab-lished for the gehlenite-included hydroxylellestadite in theinner skarn zone from Oraviţa, which is, as calculated for anaverage composition taken as mean of 6 point analyses:(Ca4.975Mg0.004Mn0.001Fe2+

0.004Na0.057K0.005)(Si1.572S1.346P0.082)[O11.787(OH)1.164F0.031Cl0.018].

A P-rich, Si-poor hydroxylellestadite was identified in theinner skarn zone at Ciclova. It has the same morphology andoccurs in the same mineral association as the hydroxylell-estadite from Oraviţa, being engulfed by vesuvianite orgehlenite. The crystal-chemical formula, established for arepresentative sample on the basis of 6 point analyses is:(Ca4.972Mg0.001Fe2+

0.005Na0.041)(Si0.786S1.253P0.961)[O12.464

(OH)0.297F0.213Cl0.026].

ReferencesBERZA, T., CONSTANTINESCU, E. & VLAD, Ş. N.

(1998). Resource Geol. 48/4: 291-306.MARINCEA, Ş., BILAL, E., VERKAEREN, J., PASCAL,

M.-L & FONTEILLES, M. (2001). Can. Mineral., 39/5:1435-1453.

MARINCEA, Ş. & DUMITRAŞ, D. (2001). Rom. J. Miner.Dep., 79, Suppl. 2, 66-67.

PASCAL, M.-L., FONTEILLES, M., VERKAEREN, J.,PIRET, R. & MARINCEA, Ş. (2001). Can. Mineral.,39/5: 1405-1434.

Table 1.Occurrence α β (1) γ Dmeas.

(2) Dx(2) a (Å) b (Å) c (Å)

Oraviţa 1.645(2) 1.653(2) 1.659(2) 3.17(2) 3.177 4.817(2) 10.948(5) 6.314(3)Măgureaua 1.646(2) 1.653(2) 1.661(2) 3.13(1) 3.127 4.822(2) 11.130(5) 6.384(3)(1) calculated from the measured value of the optical angle (2Vα = 80°); (2) expressed in g/cm3; Dx calculated

from the chemical composition and the cell volume for Z = 4 unit cells per formula.


69

THE ORIGIN OF AMPHIBOLES OCCURRING IN MAFIC AND ULTRAMAFIC ROCKS OFTHE DITRĂU ALKALINE MASSIF (EASTERN CARPATHIANS, ROMANIA)

MÁRTON, I.1, PÁL-MOLNÁR, E.2 & LUFFI, P.31 S. C. Deva Gold S. A., Piata Unirii 9, RO-2700 Deva, Romania. E-mail: [email protected] Department of Mineralogy, Geochemistry and Petrology, University of Szeged, P. O. Box 651, H-6701 Szeged, Hungary.3 Department of Mineralogy, University of Bucharest, Bd. N. Baldescu 1, RO-70111 Bucharest, Romania.

The Ditrău Alkaline Massif, Middle Triassic to LowerCretaceous in age (PÁL MOLNÁR & ÁRVA-SÓS, 1995;DALLMEYER et al., 1997; KRÄUTNER & BINDEA,1998; STRECKEISEN & HUNZIKER, 1974), intruded intothe pre-Alpine metamorphic rocks of the Bucovina Nappe inseveral phases. This series are related to the Alpine exten-sional tectonism, which began with the detachment of theGetic-Bucovinian microplate from the margin of the Eura-sian platform (KRÄUTNER & BINDEA, 1998).

The mafic and ultramafic rocks of the massif occur in awell-defined area (Tarnica Complex), interdigited, withgradual transitions or forming intercalations (PÁL MOL-NÁR, 2000). MOROGAN et al. (2000) suggest that the ul-tramafic rocks (clinopyroxenites and olivine-clinopyroxenites) are cumulates of mantle origin and theyhave been carried to higher crustal levels by the first intru-sion of dioritic-gabbroic magmas.

The goal of our study is to describe samples from the ul-tramafic and mafic rocks, using detailed petrographic obser-vations and mineral chemistry analyses, trying to express thecharacteristics of different rock types, focusing mostly on thegenesis of the most abundant rock-forming component, theamphibole.

Detailed petrographic study shows that the occurrence ofamphiboles varies in different rock types. In alkaline dioritesand hornblendites, with shape-preferred orientation, theirhabitat is euhedral, prismatic indicating their primary mag-matic origin. Amphiboles in clinopyroxenites and olivineclinopyroxenites display typical textural features: 1) small,oriented crystals along clinopyroxene cleavages; 2) replacingand enclosing clinopyroxenes which cause poikilitic-liketextures; and 3) large amphiboles containing tiny relicts ofclinopyroxene. These textural features from type 1 to type 3suggest a pro-grading amphibole metasomatism. Amphibolesare pargasites, kaersutites, ferro-kaersutites and magnesium-hastingsites. Amphiboles differ in their compositions withrespect to their occurrence in different rock types. Amphi-boles in the hornblendites, with shape-preferred orientation,display strong chemical zonation, with high Si, Ti, Fe, and Kenrichment and Al, Mg, and Na depletion at the rims.

Compositional profiles through clinopyroxenes from cli-nopyroxenites suggest that infiltrated Na-Fe-K-Ti enrichedfluids reacting along with clinopyroxene cleavages formedamphiboles. It is typical in some cases for clinopyroxenes incontact with amphiboles, that directly next to the amphibolethey suddenly get depleted in mobile elements such as Na,Fe, K and Ti, which may be related to the metasomatic “fronteffect”.

The experimental results of SEN & DUNN (1994) formodal metasomatism were applied to constrain the amphi-

bole forming reactions. The reaction equation indicates thatan infiltrating alkaline/syenitic metasomatic melts give riseto continuous change in the composition of the origin ul-tramafic rocks, and that the production of amphiboles wascontrolled by the original clinopyroxene-olivine (-spinel)modal ratio. These “metasomatic amphiboles” have verysimilar compositions in all samples, indicating that thechemical character of fluids below the amphibolitisation wasstill the same and only the proportion of component mineralshas changed.

The P-T conditions of formation of amphiboles are esti-mated to be in the interval of 1030–820 oC and 7–10 kbar.NIIDA & GREEN (1999) presented experimental resultsdefining the water-undersaturated solidus and the amphibolestability limits of MORB pyrolite compositions. In this termsthe genesis of DAM ultramafites could be explained as fol-lows: (1) among upper mantle - crustal limit conditions cli-nopyroxenite cumulate containing no amphiboles wasformed in equilibrium with melt, (2) with the evolution ofprocesses (P-T change) from this melt the crystallization ofamphiboles has started. These amphiboles on the one handwere formed as new - nucleated crystals and on the otherhand because the melt has changed its composition by evo-lution, being to aggressive replacing and enclosing the pre-existent minerals some other type (“metasomatised”) amphi-boles were formed along the cleavage and contacts of clino-pyroxene (olivine, spinel) crystals. From this point of viewthe described metasomatism is suitable for the processes ofthe magmatic evolution, being a mechanism of it, appearingon the microstructural scale of the rock.

ReferencesDALLMEYER, R. D., KRÄUTNER, H. G. & NEUBAUER,

F. (1997). Geol. Carpathica, 48: 347-352.KRÄUTNER, H. G. & BINDEA, G. (1998). Slovak Geol.

Mag., 4: 213-223.MOROGAN, V., UPTON, B. G. & FITTON, J. G. (2000).

Miner. Petrol., 69: 227-265.NIIDA, K. & GREEN, D. H. (1999). Contrib. Mineral. Pet-

rol., 135: 18-40.PÁL MOLNÁR, E. (2000). Hornblendites and diorites of the

Ditró syenite massif., Szeged, 172 p.PÁL MOLNÁR, E. & ÁRVA-SÓS, E. (1995). Acta. Min-

eral. Petrogr., Szeged, 36: 101-116.SEN, C. & DUNN, T. (1994). Mineral. Petrol., 119: 422-

432.STRECKEISEN, A. & HUNZIKER, I. C. (1974). Schweiz.

Mineral. Petr. Mitt., 54: 59-77.


70

LIMESTONES FROM THE KRIVELJ QUARRY (EAST SERBIA) – PETROGRAPHIC STUDY

MATOVIĆ, V. & VASIĆ, N.Faculty of Mining and Geology, Belgrade University, Djušina 7, YU-11000 Belgrade, Yugoslavia.E-mail: [email protected]

The Lower Cretaceous shallow-marine carbonate sedi-ments in the East Serbia, belonging to the southwestern mar-gin of the Carpathian Belt, have a large extent and thickness.The investigated carbonate rocks of the Krivelj Kamen arethe part of the Kucaj-Tupiznica carbonate platform i.e. itseastern margin composing mostly of thick-bedded and mas-sive reef limestone with remains of corals colonies, oo-sparites etc. named Urgonian Limestones. These rocks ap-pear on the eastern margin of the Timok Magmatic Complexmaking an area of about 2 km2. The Krivelj quarry (0.7 km2)with four working benches, situated in the central part of it,represents a lens of Urgonian limestones thrusted over UpperCretaceous volcano-sedimentary rocks. Over them Albianglauconitic sandstones, shale and conglomerates are depos-ited. It mostly composed of limestones with number of va-rieties (as for example, dolomitic limestone), marbles, marblelimestones, fault breccias etc. Transition between limestoneand marbles is gradual, but dominated rock types arelimestones. Intrusions of quartz diorite during Laramian-Pyrenean orogene phase caused thermal metamorphic phe-nomena i.e. occurrences of marbles and marble limestones.By the latest tectonic events the lens of Urgonian limestoneswas broken into five blocks along the transform faults.

The limestones from the quarry are homogenous, non-bedded and intensively tectonized. The a-lineation markedby argillaceous component deposited on fault planes is visi-ble on the small tectonic blocks. Rocks are affected by dense

crack-net filled by calcite, limonite and argillaceous material.That material filled also frequent sinusoidal stylolites withthroat of weld from 0.1mm to 2 mm and amplitude height to1 cm. Limestones are generally grayish in color but variableamount of bituminous (organic) matter caused local changeof color from light to dark gray and black. Thin-sectionsstudy of samples extracted from the bottom to the top of thequarry revealed slightly sorted micritic limestones with dif-ferent amount of allochems. Among them the followingmicrofacies can be distinguish: dismicrites, intrabiomicritesto biomicrites. Some of them contain more than 10 % ofmarine macrofossiles (∼5 cm in size or larger) and defined asbiomicrudite. According to structure, beside micrite withstylolites, fenestral micrites (with spar–filled fenestraes i.e.birds-eye structure) are defined. Allochems are representedby bioclasts and intraclasts (very often recrystallization proc-esses preclude classification of allochems). Skeletal particlesare identified as molluscs (gastropods), corals, foraminifers(Miliolidae, Orbitolinae).

The quarried material is characterized as pure limestone.It does not contain detrital grains, iron oxides-hydroxides orclayey materials. The microfacies analysis revealed thatlimestones of Krivelj quarry were deposited in nereitic facies(shallow marine) of subtidal paleoenvironment during LowerCretaceous.


71

THE TWINNING STRUCTURE OF TRIDYMITE FROM MIAROLITIC DACITE OF THECHERNA MOUNTAIN (TRANSCARPATHIANS, UKRAINE)

MELNIKOV, V. S.Institute of Geochemistry, Mineralogy and Ore Formation, National Academy of Sciences, Palladine Avenue 34, Kyiv,Ukraine.E-mail: [email protected]

The alkali feldspars (sanidine, anorthoclase) and tridy-mite are the main high-temperature phases which crystallisedin miarolitic dacites (KVASNITZA et al., 1987). Transparenttabular crystals of tridymite represented an excellent objectfor X-ray (Laue and oscillation photographs) and light opti-cal investigation. On the basis of cell dimensions three typesof tridymite crystals have been discovered: 1. a = 51.83 Å,b = 29.99 Å, c = 49.2 Å; 2. a = 25.83 Å, b = 5.0 Å, c = 49.2Å; 3. a = 17.22 Å, b = 9.93 Å, c = 40.91 Å. The Laue photo-graphs of the first type of crystals show 6/mmm diffractionsymmetry. Three different optical domains are displayed.The symmetry of the twin domain is pseudo-orthorhombic.The cell dimensions of the twinned crystal correspond to thesuperstructure based on the monoclinic cell of MC-tridymite(TAGAI et al., 1977). The domain structure arises frompseudohexagonal twinning of the monoclinic cell. The twindomains are related to each other by a 60º rotation about [–201]. When only one domain in the crystal exists, the super-structure along the b axis disappears. That is the second typeof tridymite crystals. The cell dimensions of the third typecrystals correspond to a pseudo-orthorhombic tridymite OP-5(NIKUI & FLÖRKE, 1987).

Two different morphologic varieties of the domainboundaries exist in twinned tridymite. 1. Serrated (or saw-like) boundaries are dominant. Their orientation in mostcases conforms to {11-20} plane. The “teeth” of twinboundaries formed on the intersection of {10-10} and {11-20} planes. 2. The thin polysynthetic twins on serratedboundaries are rarely observed. The straight and narrow twindomains originate from saw “teeth” and then rapidly disap-pear when they move off from the boundary. The pseudo-

morph replacement of quartz by tridymite is an evidence thattridymite crystallised above 867 ºC. It is known (CARPEN-TER et al., 1998), that tridymite structure undergoes phasetransition (P6322 → C2221) below 353 ºC. It is suggestedthat subsequent transformation into monoclinic structure (<180 ºC) also accompanied twinning. Then, the transforma-tions at 353 ºC and < 180 ºC may be the reason of the pseu-dohexagonal and polysynthetic twinning. Below inversionpoint the domain size was small, but during the subsequentrock cooling the enlargement of the twin structure occurred.The following observations are the evidence of that. 1. Thefraction of the large domains in domain size distribution ispredominant. 2. The twin domain system is unbalanced be-cause only one of the three possible oriented domains ispredominant. 3. During domain enlargement, a reorientationof twin boundaries takes place. It should be noted thatsanidine coexisting with tridymite is not only untwinned butdoes not even show indications of exsolution. This suggeststhat the enlargement of tridymite twin domains was not real-ised by a diffusion mechanism.

ReferencesCARPENTER, M.A., SALJE, E. K. H. & GRAEME-

BARBER, A. (1998). Eur. J. Mineral., 10: 621–691.KVASNITSA, V.N., MELNIKOV, V.S., et al. (1987). Min-

eral. Zhurnal, 9/5: 22–29.NIKUI, A. & FLÖRKE, O. W. (1987). Amer. Mineral., 72:

167–169.TAGAI, T., SADANAGA, R., TAKEUCHI, Y., TAKEDA,

H. (1977). Mineral. J., 8/7: 382–398.


72

Cr-SPINELS FROM MESOZOIC VOLCANIC ROCKS FROM PODMANÍN (WESTERNCARPATHIANS, SLOVAKIA)

MIKUŠ, T. & SPIŠIAK, J.Geological Institute, Slovak Academy of Sciences, Severná 5, SK-974 01 Banská Bystrica, Slovak Republic.E-mail: [email protected]

Cr-spinels belong to the most important petrogenetic in-dicators of ultramafic and mafic rocks. Cr-spinel compositionwas used to classify the source material (POBER & FAUPL,1988, etc.). Cr-spinel detritus in Mesozoic complexes of theWestern Carpathians has been identified in different rocktypes (carbonates, sandstones and others) in central WesternCarpathians, in the Klippen belts, Manín unit, Tatricum,Fatricum and Hronicum. Mesozoic volcanics have beenconsidered one of the possible sources of Cr-spinels and dueto that we have focused on this rock type.

Cr-spinels from Podmanín were extracted from about 15kg of the concentrate from hyaloclastites–hydroclastic vol-canic breccias. Cr-spinel has been preserved as the onlyprimary mineral (from among olivine, pyroxene, amphiboleand Cr-spinels). Volcanics are part of the Manín unit andwere incorporated into Lower Cretaceous complex of strata.Chemical composition of fresh volcanics corresponds toprimitive alkali volcanites (HOVORKA & SPIŠIAK, 1988).Chemical composition of Cr- spinels was studied with JEOLSUPEPROBE 733 (GSDŠ Bratislava). The chemical compo-sition of Cr-spinels is presented in Table 1. On the basis ofchemical composition we have determined two types. Thefirst has low Cr and Fe contents and high Al and Mg contentscompared to the other type. The contents of Mn, N, Ti andZn are low in both these types. Two different types can berecognized also from histograms of Cr and Al distribution.

On the basis of Cr-spinels classification (KLEIN & HUL-BURT, 1985) both these types are close to spinel solid solu-tion.

We have compared the composition of studied Cr-spinelswith those from Mesozoic picrites from Poniky and fromMesozoic sediments of a wider area. With its chemical com-position the first spinel type corresponds to the spinels frompicrites from the area of Banská Bystrica (SPIŠIAK & HO-VORKA, 2000). These rocks are ranked to the formation ofLower Cretaceous alkaline basalts-basanites.

These are no equivalent for the 2nd spinel type amongspinels from Mesozoic sequences of the close vicinity. Ow-ing to the available data it can be compared to the 1st spineltype from serpentinite sandstones of the Šambron zone(SPIŠIAK et al., 2001). According to geochemical criteriathese spinels are likely to come from ultrabasites of Alpinetype. They show lherzolite affinity (derived from the Pen-ninic Ocean?). In the present state of knowledge we are notable to say unambiguously whether the second spinel typewas brought from another source to volcanoclastics, or it waspulled off the host rocks during the ascent of volcanites.

On the basis of different discriminant diagrams, (e.g.JAN & WINDLEY, 1990) the Cr-spinels being studied andcompared are lying in the field of residual peridotites ofophiolite complexes.

Table 1

Type I Type II 1 2 3 4 5 6 7 8

FeO 11.13 11.66 11.83 11.63 17.87 17.81 18.36 19Al2O3 55.28 55.44 56.51 55.89 36.36 34.35 36.32 32.92Cr2O3 12.43 11.31 11.22 11.09 27.81 29.14 27.63 30.56MgO 20.46 21.13 20.71 20.75 17.77 17.06 17.61 17.27TiO2 0 0 0 0 0.99 1.1 0.89 1MnO 0.03 0.07 0.02 0 0.08 0.1 0.1 0.09NiO 0 0.02 0 0 0 0 0 0ZnO 0 0 0.01 0 0 0 0 0Total 99.33 99.63 100.3 99.36 100.88 99.56 100.91 100.84

formula based on 4 oxygensFe2+ 0.2 0.18 0.2 0.19 0.28 0.29 0.28 0.29Fe3+ 0.04 0.07 0.05 0.06 0.14 0.13 0.15 0.16Al 1.7 1.69 1.71 1.71 1.2 1.16 1.2 1.1Cr 0.25 0.23 0.22 0.22 0.62 0.66 0.61 0.68Mg 0.8 0.81 0.79 0.8 0.74 0.72 0.73 0.73Ti 0 0 0 0 0.02 0.02 0.01 0.02


73

CHARACTERIZATION OF As-RICH IRON OCHRE PRECIPITATES FROM MINEDRAINAGE WATER OF KOLÁRSKY VRCH Sb (Au) DEPOSIT (MALÉ KARPATY MTS.,SLOVAKIA)

MILOVSKÁ, S.Geological Institute, Slovak Academy of Sciences, Severná 5, SK-974 01 Banská Bystrica, Slovak Republic.E-mail: [email protected]

The natural arsenic-iron ochres formed from mine drain-age waters in the abandoned Sb (Au) deposit (Kolársky vrchdeposit, Malé Karpaty Mts., Slovakia) were studied. All ofthem precipitate and accumulate at near-neutral to neutralpH, whereby no distinct seasonal fluctuations in pH wererecorded. Chemical compositions of water differed mostly inconcentrations of SO4

2-, As, and Sb. Concentration of As andSb, to a smaller extent Fe and SO4

2-, reflects seasonalchanges. These are best pronounced in the samples fromtailing drainage pipe.

After removal of organic and mineral detritus and dis-solved salts, samples of ochreous precipitates were dried anddigested in hydrochloric acid for the total element determi-nation. Ratios of oxalate to dithionite-extractable iron (ex-traction in ammonium oxalate, and sodium dithionite-citrate-bicarbonate solution, respectively) were used to assess therelative crystallinity of poorly ordered iron oxyhydroxides.Mineral composition of fresh precipitates was determinedusing X-ray powder diffraction and infrared absorptionspectroscopy. Morphology of precipitates was studied bymeans of transmission electron microscopy.

The iron ochre accumulations from the tailing drainagepipe form accretion cone of intercalating red- and yellow-coloured ochres, situated on the streambank and partiallyflooded by stream water. Except of newly precipitated ochresthe accretion cone contains organic and mineral detritus.

Red-coloured ochres (?maturated) accumulate in the cen-tre of accreted cone and are overlain by the layer of yellow-coloured younger precipitates. Chemical composition ofthese two phases strongly differs: red precipitates are ex-tremely enriched in As (up to 13.02 wt%, mole ratio Fetot/As

= 1.84) and Sb (up to 1.64 wt%), whereas in yellow phaseconcentration of these elements is distinctively lower (hun-dreds ppm).

Organic compounds were encountered in all samples,contents of total organic C were up to 4.7 wt%. Also infraredspectra clearly evidence its presence by the COO-band at1387–1399 cm-1.

The high contents of As in samples from tailing im-poundment drainage pipe sediments is pronounced in IRspectra. Features at 812 cm-1 could be assigned to AsO3- orAsO4- compounds (FARMER, 1974). Absorption bands of v1

(SO42-) at 980 cm-1 and v4 (SO4

2-) at 610 cm-1 are supressedprobably due to increased As-contents (CARLSON &BIGHAM, 1992). Unfortunately the present state of knowl-edge does not allow for proper determination of As specia-tion in oxyhydroxides. Infrared spectra of the samples fromtwo other localities (Budúcnosť and Sirková adits) indicatepresence of ferrihydrite.

X-ray diffraction patterns show for poorly ordered mate-rial in all studied samples, diffractograms consist of one orexceptionally two very broad maxima at d-values typical foriron oxyhydroxides.

This study was financially supported by the Slovak Sci-entific Agency (VEGA 2062).

ReferencesCARLSON, L. & BIGHAM, J. M. (1992). V. M. Confer-

ence, Reiton, VA.FARMER, V. C. (1974): The infrared spectra of minerals.

Mineralogical Society, London.


74

CONTACT METAMORPHIC PROCESSES ON METAMORPHIC XENOLITHSIN NEOGENE INTRUSIVE BODIES FROM SOUTHERN PART OF RODNA MOUNTAINS(EAST CARPATHIANS, ROMANIA)

MOSONYI, E.Department of Mineralogy, Babeş-Bolyai University, 1, Kogălniceanu Str, RO-3400 Cluj-Napoca, Romania.E-mail: [email protected]

The Rodna Mountains consist of orogenic metamorphicrocks, dynamic metamorphosed rocks (associated to the Pre-Alpine and Alpine shear zones), post-tectonic sedimentaryrocks and Neogene intrusive rocks.

The composition of intrusive bodies ranges between dio-ritic and granodioritic. They are employed in Eocene sedi-mentary rocks and metamorphics, too. The metamorphic hostrocks underwent slight, locally developed transformationsunder chlorite-, biotite- and garnet zone conditions (green-schist facies) at the contact zone, while xenoliths enclosed inmagma suffered higher grade processes.

The main purpose of our research was to decipher thecontact and orogenic metamorphic processes in metamorphicxenoliths and to establish their PT-path.

The observed characteristics of metamorphic xenolithsare the followings: the degree of contact metamorphicchanges is directly related to the primary composition ofxenoliths; the most impressive mineralogical changes havebeen observed in gneissic and pelitic xenoliths; zonalchanges in gneissic xenoliths could be detected (from contactto the inner zone of xenoliths: opaque mineral zone; recrys-tallized zone: biotite, garnet, feldspar, amphibole; neoblas-thesis zone: garnet, staurolite, spinel, andalusite, cordierite,sillimanite (“fibrolite”) and chlorite); granoblastic, massive

fabrics, disequilibrium testifying reaction coronas aroundporphyroblasts; relic foliated structures, mimetic overgrowthof relic foliation by neoblastic phyllosilicates and generaltendency to obliterate oriented fabrics.

The gneissic relict mineral assemblages were generatedin garnet-amphibolite facies conditions (peak conditions) oforogenic metamorphism and retrogression in greenschistfacies conditions (T ~ 400 °C, P ~ 2.5–3 kbar; in MOSONYI,1992) were suffered. In gneissic xenoliths contact metamor-phic transformation and conditions were deduced from min-eral reaction coronas and petrogenetic grid: Tmax = 400 °C +∆T/2 ~ 770 °C and P ≤ 4 kbar conditions in the opaque zone,while into the central zone of xenoliths the lowered tem-peratures (530–600 °C) determined recrystallized zone (relicbiotite, garnet recrystallization and structural-textural reset-ting ) and newly crystallized mineral zone (cordierite + an-dalusite + biotite; andalusite + biotite; staurolite + cordierite+ andalusite + garnet + hercynite). After these conditions theandalusite sillimanite (“fibrolite”) transformation resultedand due to the temperature decreasing phyllosilicate(“pinite”) were formed.


75

NACARENIOBSITE IN PHONOLITES IN THE MECSEK MTS. (HUNGARY) – SECONDOCCURRENCE IN THE WORLD?

NAGY, G.Research Centre for Earth Sciences, Laboratory for Geochemical Research, Hungarian Academy of Sciences, Budaörsi út 45,H-1112 Budapest, Hungary.E-mail: [email protected]

Phonolites are highly differentiated members of the Cre-taceous submarine volcanic/subvolcanic alkaline rock suitein Mecsek Mts. (PANTÓ, 1980; DOBOSI, 1987; HARANGIet al., 1996). They are enriched in light rare earth elements(REE) that are hosted mainly by accessory minerals(PANTÓ, 1980). By means of electron microprobe analysis(EMPA) the following accessory REE minerals have beenfound in the phonolites: britholite [(Ce,Ca)5(SiO4,PO4)3

(OH,F)]; cheralite [(Ce,Th,Ca)(P,Si)O4]; nacareniobsite[NbNa3Ca3REE(Si2O7)2OF3]; rarely bastnäsite [Ce(CO3)F].

Nacareniobsite was described by PETERSEN et al.(1989) from nepheline syenite in South Greenland. It ismonoclinic, P21/a, “forms ruler-shaped crystals”. It “belongsto the same group of minerals as rinkite*, johnstrupite* andrinkolite*” (ibid.) (*Recently all three minerals are taken assynonyms or variants of mosandrite, see JONES et al.,1996). Their published analyses show deficiency in sodiumand, in lower extent, calcium, which was attributed to leach-ing. Since 1989 no other occurrence of this mineral has beenmentioned.

Microscopic grains (with up to 140 µm lengths and 10-15µm widths) of nacareniobsite were found in all of the phono-lite occurrences of the Mecsek Mts. They are often idiomor-phic or hypidiomorphic, associated with albite and alkalifeldspar, sometimes with pyroxene. Their energy dispersiveX-ray spectra (EDS) and compositions unequivocally iden-tify them. Based on the REE evolution model established byPANTÓ (1980), this mineral (as well as britholite and cher-alite) may have crystallized from the residual melt of thedifferentiated alkali magma.

This work was supported by the Hungarian Scientific Re-search Fund (OTKA) program no. T032198, conducted byGy. Pantó.

ReferencesDOBOSI, G. (1987). N. Jb. Miner. Abh., 156: 281-301.HARANGI, Sz., SZABÓ, Cs., JÓZSA, S., SZOLDÁN, Zs.,

ÁRVA-SÓS, E., BALLA, Z. & KUBOVICS, I. (1996).Internat. Geol. Rev., 38: 336-360.

JONES, A. P., WALL, F. & WILLIAMS, C. T. (1996): RareEarth Minerals, 1-372.

PANTÓ, Gy. (1980). Doctoral thesis, 1-152.PETERSEN, O. V., RONSBO, J. G. & LEONARDSEN, E.

S. (1989). N. Jb. Miner. Mh., 84-86.

Nacareniobsite compositions measured by EMPA

1) From PETERSEN et al. (1989) (average of 10 analyses)2) In phonolite from Kövestető, Mecsek Mts. (average of 5analyses)

1) 2)

SiO2 29.63 29.78TiO2 2.79 1.26Nb2O5 11.61 14.92Ta2O5 0.34 0.00Na2O 10.01 8.34CaO 19.92 20.54SrO 0.27 0.40Y2O3 0.78 0.66La2O3 4.09 4.72Ce2O3 10.32 9.21Pr2O3 1.42 0.83Nd2O3 4.19 2.41Sm2O3 0.81 0.36Eu2O3 n.a. 0.10Gd2O3 n.a. 0.39Dy2O3 0.05 0.18ThO2 n.a. 0.71F 6.87 6.23Total 103.10 101.03F=O 2.89 2.62Total* 100.21 98.40

EDS spectrum of nacareniobsite


76

PROBLEMS OF MONAZITE DATING BY EMPA

NAGY, G.Research Centre for Earth Sciences, Laboratory for Geochemical Research, Hungarian Academy of Sciences, Budaörsi út 45,H-1112 Budapest, Hungary.E-mail: [email protected]

TheoryMonazite is suitable for age determination due to the

following properties: 1) It can incorporate Th and U (up to>10%). 2) It is stable even at high P-T conditions. 3) Due tothe low diffusion rate the emerging Pb does not escape.

The radiogenic lead emeging during t time is:

Pbrad(t) = Th ·k1 ·(exp{λTh ·t}-1) + U ·[k2·(exp{λ238U ·t}-1)+k3 ·(exp{λ235U ·t}-1)]

If t<400Ma it can be approximated linearly:

Pbrad(t) ≈ 4.46 ·Th* ·10-5 ·t[Ma] where Th*= Th + 3.2 ·U

By electron microprobe analysis (EMPA) the local Th, Uand Pb contents can be determined so that even small andinhomogeneous monazite grains can be dated.

Analytical problems and conditionsThe amount of radiogenic Pb is usually small, near to

the detection limit. (If Th* = 10%, t = 200Ma, Pb ≈ 0.09%;the background intensity is equivalent with 0.2% Pb con-tent.) Pb Mα line was used for analysis, which is relativelyfree of overlaps, however due to numerous high-order andsatellite lines it was difficult to find the proper spectrometerpositions for background determination.

The analyses were performed at 20 kV, 80 nA, with fo-cussed electron beam; counting times 100 s on peaks, 50 s onboth background positions. Mα lines measured on PET crys-tals were used for all three elements. Differential discrimi-nator was applied to decrease Pb background. Lead wasmeasured twice in each point and has been corrected for Y Lγoverlap. On standards and applied ZAF correction factors seeNAGY et al. (2002). The standard deviation for individualPb analyses obtained from 200 duplicates: σPb = 0.014wt-%,the statistical limit is ≈ 0.012%.

Evaluation1) Isochron method according to SUZUKI et al. (1991)

starting from the fact that in the Th*–Pb plane the isochronsare straight lines. A line is fitted to the data points by leastsquares method, the ages are calculated from the slope andthe uncertainties from the confidence intervals. This methodcan be used only if the Th* values fall in a wide range.

2) Method of MONTEL et al. (1996). Accepted thatnon-radiogenic Pb in monazite is negligible, each Th-U-Pbdata set is evaluated individually and weighted average isformed. They described also a statistical method by whichmultiple events can be discriminated.

3) More recent method of COCHERIE & ALBAREDE(2001) approaches the data by a straight line in the plane ofTh/Pb – U/Pb quotients. The ages are calculated from axisintercepts. This method can be applied only for relatively U-rich monazites.

ResultsIn metamorphic rocks of Sopron Hills (Eastern Alps)

two monazite generations were found, giving ages of ca. 300Ma and ca. 75 Ma (NAGY et al., 2002). The method hasbeen applied to Hungarian and Iberian granitoids and Vepo-ric migmatites, too.

The present work is supported by the Hungarian Na-tional Research Fund (OTKA) pogamme no. T032198.

ReferencesCOCHERIE, A. & ALBAREDE, F. (2001). Geochim. Cos-

mochim. Acta, 65: 4509-4522.MONTEL, J-M., FORET, S., VESCHAMBRE, M.,

NICOLLET, C. & PROVOST, A. (1996). Chem. Geol.,131: 37-53.

NAGY, G., DRAGANITS, E., DEMÉNY, A., PANTÓ, Gy.& ÁRKAI, P. (2002). Chem. Geol., 191: 25-46.

SUZUKI, K., ADACHI, M. & TANAKA, T. (1991). Tecto-nophysics, 235: 277-292.


77

CONDITIONS OF FORMATION OF THE GOLD-BEARING STOCKWORK-TYPE BODIESOF THE BEREGOVE ORE FIELD (TRANSCARPATHIANS, UKRAINE)

NAUMKO, I., KOVALYSHYN, Z. & MATVIISHYN, Z.Institute of Geology and Geochemistry of Combustible Minerals of the Ukrainian Academy of Sciences and National Joint-Stock Company “Naftogaz of Ukraine”, Naukova st. 3a, UA-79053 Lviv, Ukraine.E-mail: [email protected]

The search and estimation of new gold-bearing ore bodiesare acquiring great significance for the Beregove ore regionin the Ukrainian Transcarpathians where famous gold depos-its of industrial importance are known. They are the mostperspective within the limits of the north zone of the (s.s)Muzhieve deposit (Kuklia ore occurrence), in its southernand eastern flanks, and in zones of transition from quartzvein (lower horizons) to stockwork-type (upper horizons)formations. Here stockwork-type ore bodies developedwhere Au is found as quartz-clay gold ores.

The deposits of this type in the Ukrainian Transcarpathi-ans belong, together with the similar deposits of Hungary,Slovakia and especially Romania, to a single metallogenicprovince of epithermal gold-polymetallic mineralization.There is a need for the investigation of the genetic peculiari-ties of these ore-bearing parageneses.

Thermometrical and geochemical fluid inclusion researchwas carried out on minerals of one of the typical stockworkore bodies. This formed the basis of specific criteria for theestimation of the perspective of their gold content. Thesedata are supplemented by data from geological-structuralanalysis (with our participation) which showed that severaladditional factors can be used in the localisation of such ore

bodies (bends of joints; superposition of various age gold-bearing fluids; zones of brecciation; increased content of themain associated elements of native gold (As, Sb, Ag, Ba,Mo)).

The generalisation of the results of investigations of par-ageneses with minerals of native gold, their typomorphism,especially of fluid inclusions, follows. The solutions in theperiod of forming of gold-bearing stockwork-type bodieswere characterised by sulfate–bicarbonate salt compositionwith the predominance of calcium and magnesium ions. Thegaseous phase of inclusions in minerals is enriched by nitro-gen (64.5–41.4 vol%) compared to CO2 (24.0–12.5 vol%).The optimal temperature interval of ore (gold) formingcomes to 250–170 ºC. The ore bodies were formed when thegold-bearing hydrothermal systems intensively boiled andfluids of different origin (deep-seated and surface) mixed inzones of mineral forming. The movement of mineral formingfluids from a depth in the direction from northwest to south-east was traced in a prevalent increase of temperatures ofhomogenisation of fluid inclusions in the same direction. Theprecise regional temperature zonality with predominance oflateral over vertical is observed.


78

MINERAL MICROINCLUSIONS HOSTED IN SULFIDES OF MAIN NEOGENE PORPHYRYCOPPER AND EPITHERMAL ORE DEPOSITS OF THE SOUTH APUSENI MOUNTAINS,ROMANIA

NEDELCU, L., ROSU, E. & COSTEA, C.Geological Institute of Romania, Caransebeş 1, RO-78344 Bucharest, Romania.E-mail: [email protected]

The Neogene porphyry copper and epithermal ore depos-its of the South Apuseni Mountains are related to calc-alkaline intermediate volcano-plutonic complex structuresclosely connected with extensional deep-seated faults. Thesestructures contain a large variety of ore deposit types, butwith a strong specialization for Cu-Au that would involve aunique source (ROSU et al., 2000).

The sulfides of main porphyry copper and epithermal oredeposits of this region contain a lot of mineral microinclu-sions. In order to establish the role of these solid microinclu-sions in the magmatic-hydrothermal fluid evolution the aimof our study is to determine, using SEM/EDAX analyses,their chemical composition.

The SEM/EDAX analyses were performed in open cavi-ties by splitting of pyrite and sphalerite crystals from differ-ent ore deposit types: porphyry copper, base metal/gold brec-cia pipe and low/high-sulfidation epithermal deposits. Thechemical composition of the mineral microinclusions wasdetermined using a PHILIPS electron microscope (METAV-Bucharest Laboratory) and a REMMA 202 electron micro-probe (IGR Laboratory) both equipped with EDAX analyzer.The operating conditions were an accelerating voltage of 30kV and a counting time of 50 s.

Thus, based on about 170 SEM/EDAX analyses, the fol-lowing mineral microinclusions have been determined:

• chlorides: halite, sylvite, CaCl2

• complex chlorides: (Na,K)Cl; (K,Fe)Cl;(K,Fe,Cu)Cl; (K,Fe,Zn)Cl; (K,Fe,Au)Cl; (K, Zn, Au)Cl

• sulfides: chalcopyrite, bornite, molybdenite,sphalerite, galena, pyrite, pyrrhotite, marcasite

• oxides: hematite, rutile, zircon, spinel, quartz• sulfates: anhydrite, gypsum• phosphates: apatite, chlorapatite±Th±Cu• carbonates: calcite, dolomite, siderite,

ankerite• phyllosilicates: illite, sericite• silicates: Al, Ca silicates• silicate glass

All mentioned data lead us to some conclusions, as fol-lows:

1. Mineral microinclusions mainly appear as daughterphases trapped within fluid inclusion cavities during fluidevolution from magmatic to hydrothermal stage.

2. Chloride and silicate glass microinclusions from por-phyry systems studied fill up to 50–90 vol% of fluid inclu-sion cavities, especially that of potassic zone, suggesting thatthey could be considered as really salt melt and silicate meltinclusions as in paragenetic quartz (PINTEA, 1997).

3. The ubiquity of the chloride and sulfide microinclu-sions hosted in pyrite and sphalerite of all porphyry copperand epithermal ore deposits studied reveals the role playedby Cl and S as complexing ligand components during themagmatic-hydrothermal fluid evolution. This one could in-volve a metal fractionation between the coexisting fluids(HEINRICH et al., 1999). According to DRUMMOND &OHMOTO (1985) Cl mainly fractionates into the salineliquid (see the chloride microinclusions), whereas S usuallyfractionates into the vapour phase (see the sulfide microin-clusions). Therefore the liquid-partitioning elements proba-bly include in our case Na, K, Fe, Zn, (P, Th?) and also lowcontents of Cu and Au, especially as complex chlorides inporphyry copper and epithermal ore deposits. As regards thevapour-partitioning elements these could include, to a certainextent, Au, Cu (Valea Morii, Voia and Rosia Poieni por-phyry copper deposits) and Au, As, Sb, Cu (Baia de Ariesgold breccia pipe deposit).

4. Anhydrite microinclusions suggest that magmatic-hydrothermal fluids operated under oxidizing conditions,also supported by magnetite presence.

ReferencesDRUMMOND, S. E. & OHMOTO, N. (1985). Econ. Geol.,

80: 126-147.HEINRICH, C. A., GUNTER, D., AUDETAT, A., ULRICH,

I. & FRISCHNECHT, R. (1999). Geology, 27: 755-758.PINTEA, I. (1997). ECROFI XIVth, Nancy, Abstracts: 266-

267.ROSU, E., NEDELCU, L., UDUBASA, G., PINTEA, I. &

IVASCANU, P. M. (2000). ABCD-GEODE 2000WORKSHOP Borovets, Bulgaria, Sofia, May 2000, Ab-stracts: 72.


79

MINERALS OF THE CARPATHIANS: FIRST UPDATE

ONAC, B. P.Babeş-Bolyai University & “Emil Racoviţă” Institute of Speleology, 1, Kogalniceanu Str, RO-3400 Cluj-Napoca, Romania.E-mail: [email protected]

This abstract presents an update to the Minerals of theCarpathians book (SZAKÁLL, 2002). The entries listedbelow largely consist of new species of minerals describedfrom various caves in Romania and few other minerals thatare in course of publication (both from caves and old mininggalleries). Chemical and mineralogical characterization ofthese minerals was undertaken by XRD, XRF, energy-dispersive, atomic absorption, and infrared spectrometry,thermal and electron-microprobe analyses, optical and scan-ning electron microscope observations. The specimens aredeposited in the Mineralogical Museum of the “Babeş-Bolyai” University and at the “Emil Racoviţă” Institute ofSpeleology in Cluj-Napoca and Bucharest, Romania.

Minerals discovered before 2002Monohydrocalcite - CaCO3 • H2O, was reported to occurs

in the composition of white hydrated moonmilk in Humpleuand Lucia Mică caves (Bihor Mts.) (ONAC & GHERGARI,1993).

Darapskite - Na3(SO4)(NO3) • H2O and nitratine -NaNO3 were found closely associated within the sedimentsaccumulated on the floor of Şălitrari Cave (Cerna Mts.) (DI-ACONU & LASCU, 1999).

Mineral species described in caves and old mine galleriesfrom the Romanian Carpathians in 2002

Berlinite - AlPO4 was found as grayish or colorless finecrystals growing along cracks in well-cemented clay or im-pregnating the body of this clay in Cioclovina Cave, ŞureanuMts. (ONAC et al., 2002).

Burbankite - (Na,Ca)3(Sr,Ba,Ce)3(CO3)5 appears as a thincrust composed of sub-millimeter yellow grayish anhedralcrystals. This rare anhydrous carbonate was found in asso-ciation with colorless or milky white needle-like brushite andgypsum crystals in Cioclovina Cave (ONAC et al., 2002).

Cesanite - Na3Ca2(SO4)3(OH) was found closely associ-ated with hydroxylapatite in ochre to red-brown crusts alongthe walls in Măgurici Cave (Someş Plateau) (ONAC &VEREŞ, 2003).

Collinsite - Ca2(Mg,Fe2+)(PO4)2 • 2H2O appears as trans-lucent millimeter thin-walled balloons lining dissolutioncavities within a thick hydroxylapatite crusts collected fromCioclovina Cave (ONAC et al., 2002).

Foggite - CaAl(PO4)(OH)2 • H2O was identified within ablack earthy-mass aggregates collected from below brown-reddish crandallite-rich clays in Cioclovina Cave (ONAC etal., 2002).

Francoanellite - H6(K, Na)3(Al, Fe3+)5(PO4)8 • 13H2Oforms soft and unctuous to the touch, white nodular aggre-

gates (3 to 50 mm in diameter) and earthy masses in thelower part of the fresh guano that that overlies the argilla-ceous floor deposits from Măgurici Cave (ONAC & VEREŞ,2003).

Glaukosphaerite - (Cu,Ni)2(CO3)(OH)2 occurs in WaterCave from Codreanu mine (Băiţa) as thin coatings of deepgreen color in association with malachite and rosasite.

Jokokuite - Mn2+SO4 • 5H2O forms pale pink, rosette-likeaggregates (2-3 cm in length) intimately associated withrozenite. The jokokuite crystals have vitreous luster andshow no cleavage (ONAC et al., unpublished).

Lansfordite - MgCO3 • 5H2O was first described as acave mineral from Valea Rea Cave (Bihor Mts.) were it ap-pears as white fine powdery masses associated with hydro-magnesite (ONAC & FEIER, 2003).

Leucophosphite - KFe23+(PO4)2(OH) • 2H2O forms thin

pale yellowish-brown crusts (less than 1 mm thick) withinwhite taranakite veins in a section below the Bivouac Room,Cioclovina Cave (ONAC et al., 2002).

Norsethite - BaMg(CO3)2 appears as well crystallizedwhite nodular aggregates on the walls of two skarn-hostedcaves (Crystal and Surprise) in the Băiţa metallogenic district(ONAC, 2002).

Phosphammite - (NH4)2HPO4 occurs as sparse, colorless,and transparent anhedral crystals (0.5 mm in size) in thetower part of the guano deposit hosted by the Măgurici Cave(ONAC & VEREŞ, 2003).

Tinsleyite - KAl2(PO4)(OH) • 2H2O appears in smallquantities, as composite aggregates, early diagenetic mineralin the bat guano deposit from Cioclovina Cave (MARINCEAet al., 2002).

ReferencesDIACONU, G. & LASCU, C. (1999). Theor. Appl. Karstol.,

11-12: 47-52.MARINCEA, Ş., DUMITRAŞ, D. & GIBERT, R. (2002).

Eur. J. Mineral., 14: 157-164.ONAC, B. P. (2002). Can. Mineral., 40: 1551-1561.ONAC, B. P., BREBAN, R., KEARNS, J. & TĂMAŞ, T.

(2002). Theor. Appl. Karstol., 15: 27-34.ONAC, B. P. & FEIER, N. (2003). Studia Univ. Babeş-

Bolyai, Geologia, XLVIII/1.ONAC, B. P. & GHERGARI, L. (1993). Cave Science, 20/3:

107-111.ONAC. B. P. & VEREŞ, D. Ş. (2003). Eur. J. Mineral., in

press.SZAKÁLL, S. (ed.) (2002): Minerals of the Carpathians.

Granit, Prague, 480 p.


80

DEPOSITIONAL ENVIRONMENT OF SECONDARY PHOSPHATE MINERALSIN MĂGURICI CAVE (ROMANIA)

ONAC, B. P. & VEREŞ, D. Ş.Babeş-Bolyai University & “Emil Racoviţă” Institute of Speleology, 1, Kogalniceanu Str, RO-3400 Cluj-Napoca, Romania.E-mail: [email protected]

The Măgurici Cave is located in northwestern Romania,approximately 100 km north of the town of Cluj, in the northcentral part of the Someş Plateau. The floor of the EntrancePassage comprises boulders and rubble fallen from the roofand walls. Throughout the rest of the cave the floor com-prises argillaceous sediments of unknown thickness. Themain guano deposits are at the far end of the cave, reachedthrough several tight clefts and low passages. Isolated batcolonies have formed small guano deposits along the BatGallery and Clay Passage. Dry powdery guano covers thecave floor, limestone blocks and parts of the walls except inthe Guano Gallery, where most of the organic sediment isfresh and damp. Throughout the sampled part of the cave, therelative humidity ranges from 85 and 100% while the meantemperature remains constant year-round in the range of 9-10.2 °C (Borda, pers. comm.). A temperature increase (inaverage with 5–6 °C higher) was measured within both freshand fossil guano deposits.

Fig. 1: Mineral paragenesis sequences in Măgurici Cave.

The mineral assemblages investigated in Măgurici Caveare diverse. The phosphatization of argillaceous sedimentsand limestone leads to the generation of a complex suite ofphosphate minerals. Two tendencies were observed: (a) inthe presence of excess alkali, the mineral formed initially istaranakite, which partially dehydrates to francoanellite due to

a decrease in the water vapour partial pressure (phenomenonrestricted to certain locations within the cave), and (b) asequence of Ca-rich phosphate minerals formed when guanoreacts with limestone bedrock or fallen blocks. In the secondsituation, four main mineral assemblages were documented(Fig. 1). We interpreted their precipitation as a response tochanges in the pH and relative humidity of the environment,along with a progressive increase of the Ca/P ratio (Fig. 1).In addition, an interesting observation is that all Ca-richphosphate minerals appear in paragenesis with differentsulphates, each of them strengthens the physico-chemicalconditions of the depositional environment.

The coexistence of the described minerals within thephosphate aureole gives information about genetic environ-ments. Brushite and taranakite form under damp conditionsfrom solution with a pH lower than 6. Partial or total dehy-dration under the same acidic pH results in the precipitationof francoanellite and monetite, respectively. Although arde-alite may form over a wide range of relative humidity values,

its field of nucleation lies between pH 6.2and 7. The presence of hydroxylapatiteindicates a slightly alkaline environment,which precipi-tates and is stable under suchconditions (POSNER et al., 1984). Itsabundance when comparing to the otherphosphates in this cave clearly suggests thatthe depositional environment throughoutmuch of the cave extent is slightly alkaline,being acidic or neutral only in the vicinity ofguano accumulations.

In addition, the present study presents thesecond worldwide reported occurrence ofphosphammite discovered in a caveenvironment. This rare mineral occurs as

small transparent crystals within the guano deposit, precipi-tated in an early stage from the liquid fraction of guano.

ReferencePOSNER, A. S., BLUMENTHAL, N. C. & BETTS, F.

(1984). Chemistry and structure of precipitatedhydroxylapatites. in Nriagu, J. O. & Moore, P. B. (Eds.):Phosphate minerals, Springer-Verlag, Berlin, 330-350.


81

SECONDARY MINERALS FOUND IN OLD MINE GALLERIES FROM ROŞIA MONTANĂ,ROMANIA

ONAC, B. P.1, VEREŞ, D. Ş.1, KEARNS, J.2, CHIRIENCO, M.3, MINUŢ, A.4 & BREBAN, R.41 Babeş-Bolyai University & “Emil Racoviţă” Institute of Speleology, 1, Kogalniceanu Str, RO-3400 Cluj-Napoca, Romania.E-mail: [email protected] Pennsylvania State University, USA.3 Department of Mineralogy, Babeş-Bolyai University, 1, Kogalniceanu Str, RO-3400 Cluj-Napoca, Romania.4 S. C. Roşia Montană Gold Corporation S. A., Roşia Montană, Romania.

Recent investigations carried out on some secondaryminerals formed along old mining galleries in the Cârnicdistrict (Roşia Montană) enabled us to characterize eightminerals, out of which, according to a recently publishedinventory (SZAKÁLL, 2002), one (jokokuite) is for the firsttime mentioned in the Carpathians. Another mineral (apjoh-nite) seems to represent a new occurrence in Romania as itwas neither mentioned on UDUBAŞA’s (1999) checklist norin SZAKÁLL (2002). The precipitation of the minerals de-scribed below is largely controlled by changes in temperatureand water vapor partial pressure of the galleries microenvi-ronment, and also by the cation substitutions. All the miner-als described were identified by routine X-ray powder dif-fraction analyses, being subsequently investigated by meansof energy-dispersive spectrometry, electron-microprobeanalyses, optical and scanning electron microscope observa-tions. The specimens are deposited in the MineralogicalMuseum of the “Babeş-Bolyai” University in Cluj-Napoca,Romania.

Jokokuite - Mn2+SO4 • 5H2O forms pale pink, rosette-likeaggregates up to 2-3 cm in length on the walls of an oldmining gallery at horizon +958 m, intimately associated withrozenite. The jokokuite crystals have vitreous luster, nocleavage and are easily soluble in water. The average cellparameters obtained on the basis of 29 powder reflections area = 6.38(2) Å, b = 10.70(1) Å, c = 6.22(2) Å, α = 97.619(5)°,β = 110.493(8)°, γ = 75.88(9)°. The c cell parameter issmaller than the reported value in the ICDD file 31-836,which may reflect the substitution of Mn2+ with Fe2+.

Apjohnite - Mn2+Al2(SO4)4 • 22H2O. Found in severalsamples collected from either floor or walls of old adits. Itforms white to yellowish brown or greenish crusts or fibrousand needle-like crystals (up to few centimeters). The unit cellof a representative sample (#1538) as refined by least squaresof 48 reflections were found to be a = 6.266(5) Å, b =24.502(2) Å, c = 21.281(3) Å, and β = 98.692(8)°. In sample#1541 it appears associated with pickeringite.

Alunogen - Al2(SO4)3 • 17H2O appears in associationwith pickeringite as efflorescences on dietrichite botryoidalaggregates. The prismatic crystals of alunogen are up to 2mm in length and are extremely thin (<0.5 mm). Up to now,this mineral was mentioned to occur only as efflorescences

on metamorphic or igneous rocks (RĂDULESCU & DIMI-TRESCU, 1966).

Dietrichite - (Zn,Fe2+,Mn2+)Al2(SO4)4 • 22H2O formstufted aggregates of acicular crystals and efflorescencesalong galleries’ ceiling. The color is dirty yellow or some-times greenish. The type locality for this mineral is BaiaSprie (Maramureş, Romania) whereas Roşia Montană repre-sents its second occurrence in Romania.

Halotrichite - Fe2+Al2(SO4)4 • 22H2O was observed asyellowish-brown mammillary aggregates with vitreous lus-ter. It was also found as hair-like efflorescences.

Kalinite - KAl(SO4)2 • 11H2O is rather abundant in thegallery we investigated and appears as delicate, tiny fibersoverlying halotrichite aggregates. Crystals are translucentand if removed from the gallery environment will decomposewithin minutes into a white milky powder.

Melanterite - Fe2+SO4 • 7H2O forms colorless to translu-cent, sometimes slightly green fibrous aggregates (up to 4cm) having vitreous luster. Upon exposure to dry air crystalsbecome white-yellowish and opaque.

Pickeringite - MgAl2(SO4)4 • 22H2O was first identifiedin Romania in Diana Cave, Băile Herculane (DIACONU &MEDEŞAN, 1973). In our investigated occurrence at RoşiaMontană the mineral forms shining white to silky thin crys-tals (3-5 mm in length) covering apjohnite crusts.

Rozenite - Fe2+SO4 • 5H2O is the main component of therosette-like aggregates found on the ceiling of abandonedadits of the gold deposit at Roşia Montană. The white orcolorless fibrous aggregates of rozenite form directly onhighly weathered dacites and can reach 3 to 5 cm in length.

ReferencesDIACONU, G. & MEDEŞAN, A. (1973). Trav. Inst. Spéol.

„Emile Racovitza”, XII: 303-309.RĂDULESCU, D. & DIMITRESCU, R. (1966). Mineralo-

gia topografică a României. Ed. Academiei Române, Bu-cureşti, 376 p.

SZAKÁLL, S. (ed.) (2002). Minerals of the Carpathians.Granit, Prague, 480 p.

UDUBAŞA, G. (1999). Rom. J. Mineralogy, 79: 3-30.


82

ROCK-FORMING MINERALS OF BATTONYA AND CSONGRÁD UNIT GRANITOIDS

PÁL-MOLNÁR, E., BATKI, A. & KÓBOR, B.Department of Mineralogy, Geochemistry and Petrology, University of Szeged, P. O. Box 651, H-6701 Szeged, Hungary.E-mail: [email protected]

The crystalline mass of the Tisia Composite Terrane ischaracterised by granitoid ranges and anticline wings ofmiddle and high grade metamorphites. This paper presentsthe results of a mineralogical analyses on the granitoid rocksoriginating from characteristic uplifts of the basement (Al-győ-Deszk-Ferencszállás-Makó - [ADFM] High and Pusz-taföldvár-Battonya - [PB] High) of the Békésia Terrane,Tisia Composite Terrane.

The granitoid samples of PB High are mainly of lightgrey, greenish grey colour. Most of them have a holocrystal-line, inequigranular texture, however, some samples are ofequigranular texture. The colour of ADMF High granitoidrocks is mainly light grey, subordinately pale rose-colour.Their texture is mostly holocrystalline, medium-grainedinequigranular and equigranular. Based on the orientation ofmica, in some places the studied rocks are characterised by apreferred orientation in terms of their texture. Concerning themineral composition and texture of the rocks, significantdifferences cannot be detected, thus they can be consideredof similar character (PÁL-MOLNÁR et al., 2002a, b). Themajor rock forming minerals are quartz, K-feldspar, plagio-clase feldspar and mica (biotite, muscovite). The usual sizeof minerals falls between 1-3 mm, however microcline por-phyroblasts of 2-3 cm are not rare either. Accessory compo-nents are apatite, zircon, monazite, less frequently garnet andtitanite. Secondary components are chlorite, sericite, carbon-ate, epidote, limonite and opaque minerals.

Rock forming and accessory minerals were investigatedwith electron microprobe analysis. Representative results onthe minerals are presented in Table 1.

Sample 1315 1318 1318 1214 1241Mineral

rim coreSiO2 36,8 37,3 35,6 35,9 45,7 47,7 68,2 65,9 65,0 0,38 0,17 SiO2 0,83TiO2 2,99 3,08 2,91 3,19 1,28 0,46 - 0,06 0,07 0,02 nd CaO 1,45Al2O3 17,4 17,2 16,6 16,4 31,8 34,5 19,8 21,3 18,4 0,23 0,06 P2O5 28,9FeO* 17,6 16,8 20,48 20,2 3,3 1,6 0,06 0,07 0 0,11 nd La2O3 13,5MnO 0,22 0,3 0,59 0,48 0,04 0,04 - 0,03 0,06 0,12 0,02 Ce2O3 28,0MgO 9,5 8,8 8,2 8,4 0,7 0,7 - 0,04 nd 0,03 nd Pr2O3 2,02CaO 0,16 0,12 0,11 0.05 nd 0 0,87 2,59 0,04 52,6 52,7 Nd2O3 9,95Na2O 0,23 0,150 0,22 0,14 0,30 0,39 11,42 10,3 0,89 nd 0,51 ThO2 8,88K2O 9,24 7,33 9,13 9,00 9,49 9,64 0,09 0,08 15,98 0,28 ndP2O5 nd nd nd nd nd nd - - nd 40,6 41,3Total 94,19 91,05 93,89 93,85 92,59 94,89 100,45 94,38 94,71 93,73

Si 5,62 5,79 5,56 5,58 6,30 6,33 2,99 2,89 2,99 0,03 0,01 Si 0,034Al 3,14 3,15 3,05 3,02 5,17 5,41 1,02 1,10 1,00 0,02 0 Ca 0,064AlIV 2,39 2,22 2,44 2,42 - - - - - - - P 1,001AlVI 0,75 0,92 0,61 0,60 - - - - - - - La 0,204Ti 0,34 0,36 0,34 0,37 0,13 0,05 - 0 0 0 - Ce 0,419Fet 2,24 2,19 2,67 2,63 0,38 0,18 0 0 0 0 - Pr 0,030Mn 0,03 0,04 0,08 0,06 0,01 0,01 - 0 0 0 0 Nd 0,145Mg 2,16 2,03 1,91 1,94 0,15 0,14 - 0 - 0 - Th 0,083Ca 0,03 0,02 0,02 0,01 - 0 0,04 0,12 0 4,70 4,68Na 0,07 0,05 0,07 0,04 0,08 0,10 0,97 0,87 0,08 - 0,08K 1,80 1,45 1,82 1,79 1,67 1,63 0 0 0,94 0,03 -P - - - - - - - - - 2,87 2,90

nd - not detected element; FeO* - as total iron

Cations to4 oxygens

Cations to12 oxygens

Table 1. Representative microprobe analyses of minerals from granites of Battonya- and Csongrád Unit

biotite muscovite feldspar apatite12411610 1315 1214

monazite

Cations to 8 oxygensCations to 22 oxygens

The dominant mineral assemblages are feldspars and mi-cas. K-feldspar and microcline are abundant in the studiedgranites, and orthoclase is generally present as well. Theoften zoned plagioclase feldspars of ADMF High granitoids

are albite-oligoclase in composition, the plagioclases of PBHigh granitoid rocks are albite-andesine (Fig. 1).

The biotites of PB and ADMF High granitoids are rich inFe (Fig. 2). Besides, biotites can also be considered as petro-genetic indicators for early stage granite genesis, since theirMg content reflects the grade of magma fractionation(HECHT, 1993). Parallel to proceeding magma fractionationthe Mg content of biotites decreases while the AlVI contentremains constant, i.e. its value varies between 0.54 and 0.93.Thus, based on the composition of biotites ADMF granitesare more fractioned than PB granitoids (Fig. 3). According tothe Mg vs Altot ratio in biotites, the granites proved to becalc-alkaline.

Sani

dine

Andesine Labradorite Bytownite Anorthite

An

Or

Anorthoclase

Albite Oligoclase

Ab

2,0

2,2

2,4

2,6

2,8

3,0

0 0,2 0,4 0,6 0,8

Fe/(Fe+Mg)

Al(

IV)

Phlogopite Annite

Eastonite Siderophyllite

0,2

0,4

0,6

0,8

1,0

1,2

1,4

0,0 0,5 1,0 1,5 2,0 2,5 3,0

Mg

Al(

VI)

AcknowledgementsThe financial background of this work was ensured by

the Hungarian National Science Found (OTKA) (Grant No.F/029061) and the János Bolyai Research Grant.

ReferencesHECHT, L. (1993). Münchener Geol Hefte, 10, 221.PÁL-MOLNÁR, E., KOVÁCS, G. & BATKI, A. (2002a).

Acta Mineralogica-Petrographica, Szeged, 42: 21-31.PÁL-MOLNÁR, E., KOVÁCS, G. & BATKI, A. (2002b).Acta Mineralogica-Petrographica, Szeged, 42: 51-58.

Fig.1. Feldspars from PB ( )and ADMF ( )granitoids.

Fig. 2. AlIV vs. Fe/(Fe+Mg) ratio inbiotites from PB ( ) and ADMF( ) granitoids.

Fig. 3. Mg vs. AlVI ofbiotites from PB ( ) andADMF ( ) granitoids.


83

ORIGIN OF GRANITOID ROCKS OF THE DITRĂU ALKALINE MASSIF, TRANSYLVANIA,ROMANIA

PÁL-MOLNÁR, E.1, KOVÁCS, G.2 & BENŐ, É.31 Department of Mineralogy, Geochemistry and Petrology, University of Szeged, P.O. Box: 651, H-6071 Szeged, Hungary.2 Environmental Protection Inspectorate of Lower Tisza Region, Felső-Tisza part 17, H-6721 Szeged, Hungary.E-mail: [email protected] Dipartimento di Scienze Mineralogiche e Petrologiche, Università degli Studi di Torino, Via Valperga Caluso 35, I-10125Torino, Italy.

Recent analyses of the granitoid rocks of the Ditrău Al-kaline Massif (DAM) have shown that the massif is morecomplex than it was suggested earlier. The modal analysesenabled the identification of nine different rock types froman area that was handled as a homogenous granite body be-fore. The most abundant accessory minerals are apatite, zir-con, sphene and allanite, suggesting that the granites of theDAM were formed by magmatic differentiation processes(BROSKA & UHER, 1991).

On the basis of ASI, varying between 0.92-1.06 (mean =1.01), most of the samples are peraluminous. When consid-ering their geochemical character, two groups, namely subal-kaline and alkaline can be identified. Rocks of higher SiO2

content are subalkaline, while those of lower SiO2 contentare alkaline (e.g. COX et al., 1979). A magmatic evolution-ary differentiation and fractionation relationship can also bedetected among the examined rocks. The most fractionatedsamples are those oversaturated rocks (granites) which repre-sent the subalkaline branch of the magmatic trend. The otherbranch is alkaline, and involves Qtz-monzonites, Qtz-syenites, syenites and probably nepheline syenites (PÁL-MOLNÁR, 2000; MOROGAN et al., 2000).

Based on the comparison of major and trace elementsfound in some characteristic samples, the granitoid rocks ofDAM have higher Al2O3, Na2O, K2O, Rb, Sr, Nb, Zr, Ga andlower MgO, CaO, Ba, Pb, Y, Ni contents. These data suggestthat the examined rocks belong to A-type granites, which isalso supported by discrimination diagrams. The examinedrocks plot to the A1 subgroup. The Harker variation dia-grams for major, trace and REE elements show that the sam-ples are representatives of the evolutionary trend character-ising magmatic differentiation. The value of (Eu/Eu*)ch indi-cates different degree of fractionation in terms of the exam-ined samples. The lowest value (0.10) represents the mostfractionated sample which is monzogranite, while the highestvalue (0.48) refers to a slightly differentiated Qtz-monzonitesample. The Nb/Ta ratio varies in a wide range: 13.2 and

32.3, indicating heterogenites. Besides, it refers to the frac-tionation and differentiation trend as well.

The morphology of zircons shows that they were crystal-lised under a high temperature (800–850 °C), in a hyperalka-line environment, which also proves the mantle derivation ofthe magma.

Applying geothermobarometry on quartz inclusions (Thand salinity data) the trapping temperature and pressure offluid inclusions were also estimated: T = 620–680 °C, P =6.2–10.2 kbar. These results show that the crystallization ofquartz took place in the upper crust.

K/Ar radiometric dating of the examined granitoid rockssuggests that they have magmagenetic relationship withhornblendites and nepheline syenites (PÁL-MOLNÁR,2000). The rocks represent a Middle Triassic-Lower Jurassiccomagmatic suite which can be separated from youngerdiorites and syenites of DAM on the basis of dating. Geo-chronology also confirms that these granitoids are end-products of the magmatic differentiation of mantle derivedultramafic rocks.

Considering the results above, it is possible that thesource of the examined rocks were mantle derivatives formedin an extensional, within-plate tectonic environment andsubsequently modified by differentiation and crustal con-tamination.

ReferencesBROSKA, I. & UHER, P. (1991). Geol. Carpath., 42/5: 271-

277.COX, K. G., BELL, J. D. & PANKHURST R. J. (1979): The

Interpretation of Igneous Rocks. George Allen & Unwin,London.

MOROGAN, V., UPTON, B. G. J. & FITTON, J. G. (2000).Mineralogy and Petrology, 69: 227-265.

PÁL-MOLNÁR, E. (2000). Hornblendites and diorites of theDitró Syenite Massif. Ed. Department of Mineralogy,Geochemistry and Petrology, University of Szeged,Szeged, 172p.


84

A SEARCHABLE DATABASE OF MINERAL LOCALITY NAMES OF THE CARPATHIANREGION

PAPP, G.Department of Mineralogy and Petrology, Hungarian Natural History Museum, Pf.: 137, H-1431 Budapest, Hungary.E-mail: [email protected]

After twenty years of collection practice and science his-tory research one can conclude that the locality names of theCarpathian Region may cause much trouble even to an expe-rienced “aboriginal”. For a better orientation in this jungle ofnames the manuscript Gazetteer of the mineral localitynames of the Carpathian Basin (PAPP, 1996) was developedinto a searchable database. At present the database containssome 11,800 variants of 4300 locality names of the area.These variants were collected from topographical and de-scriptive mineralogies published since the XVIIIth century.The resulting records (one screen per record) of a givenquery contain the present name corresponding to the input,the type of the named feature (populated place, stream, min-ing area etc.), the country and the administrative unit where itbelongs to and other data (geographical co-ordinates or rela-tive position) helping the localisation of the name. Name ofthe relevant historical region (if any) and the last officialHungarian name and administrative subdivision is also given

(from the 1913 Official Gazetteer of Hungary). An auxiliaryrecord on the same screen lists all spelling variants to befound in the database corresponding to the given entry.

The original gazetteer was compiled with the financialsupport of the OTKA (Hungarian National Research Fund)grant F18007. The editorial work was helped by many localexperts. The database was developed with the financial sup-port of the Pro Renovanda Cultura Hungariae Foundationwith the kind assistance of M. RAJCZY (Dept. of Botany,Hungarian Natural History Musem).

Development plans include geographical broadening (tothe external areas of the Carpathians) and facilitating of theaccess (a web searchable version).

ReferencePAPP, G. (1996). Acta Mineral.-Petrogr. (Szeged), 37

(Suppl.): 89.


85

MICROMINERALOGICAL AND CLAY MINERALOGICAL STUDY OF THE EPLÉNYLIMESTONE FORMATION, ÚRKÚT, HUNGARY

PEKKER, P.1, WEISZBURG, T. G.1 & POLGÁRI, M.21 Department of Mineralogy, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected] Laboratory of Geochemical Research, Research Centre of Earth Sciences, Hungarian Academy of Sciences, Budaörsi út 45,H-1112 Budapest, Hungary.

This presentation reports on the mineralogical study ofthe Eplény Limestone Formation (Dogger) overlying theÚrkút Manganese Ore Formation in the Bakony Mts., Hun-gary.

The sequence consists of three types of sedimentary rocksappearing as thin and apparently randomly alternating beds.The three types can easily be distinguished both on the wallsin the adits and in the laboratory, during density and grainsize separations, in thin sections, X-ray powder diffracto-grams, chemical and electron microanalytical investigations.

The soft, greenish type of layers has low silica content. Itconsists of lamellae of Bositra shells and small amounts ofsiliceous radiolarians and sponge spicules in a micritic–clayey matrix.

In the lamellar, harder, greenish grey transitional typelayers the lamellae of Bositra shells are cemented by opal.They alternate with micritic–clayey lamellae similar to thematerial of the previously described type, containing largenumbers of both siliceous and pyritic radiolarians and spongespicules.

The third type, a hard, grey, silicic limestone is charac-terised by high silica content, an almost complete lack ofsheet silicates, randomly oriented Bositra shells and many(not pyritic) radiolarians and sponge spicules.

All three types have a high carbonate content (27–40wt%), apatitic fish fossils, quartz grains, muscovite, a littlebiotite and a small amount of fine-grained pyrite aggregates.It can be seen that the differences between the beds show upmainly in the extent of diagenetic silicification-opal forma-tion and pyritisation and in clay mineral content.

The results of the study include the description of pyriticfossils, the relation between Bositra shells and opal forma-tion and the identification of apatite grains as fish fossils.These results serve as a basis for further research that mayprovide a better characterisation of this marine successionand supplement new data for the better understanding ofchemical and biological processes on the sea floor.

This work was supported by the OTKA (Hungarian Sci-ence Foundation) grant #T032140 and T25873.

Fig. 1: Schematic comparative drawings of thin sections of the three different rock types described. The height of the picture isabout 3 mm. The black parts represent the fine grained clayey matrix, the thin white strips the Bositra shells, while the largerwhite areas refer to silica precipitation.The differences among the three rock types are mainly in the size and orientation of the Bositra shells and in the intensity ofsilica precipitation. The soft greenish rock (samples U1/98 etc.) contains smaller and oriented shells, a larger amount of fishfossils (white spots on the left side figure) and no trace of silica precipitation can be observed. For the lamellar, harder rocktype (U3/98 etc.) larger shells in less oriented position are typical. The shells are cemented by silica (opal). Pyritic and sili-ceous radiolarians and sponge spicules (small white dots on the middle figure) are frequent. The hard, grey rock type containslarger blocks of opal (a syndiagenetic precipitate) and larger shells. No trace of (diagenetic) pyritisation of the radiolarians andsponge spicules (small white dots on the right side figure) can be observed.


86

ROŞIA MONTANĂ, ROMANIA: FROM MUSEUM SAMPLES TO THE IMPLICATIONS OFA NEW “GOLD RUSH”

POP, D.1, URECHE, I.2 & BEDELEAN, H.31 Mineralogical Museum, Babeş-Bolyai University, 1, Kogălniceanu Str, RO-3400 Cluj-Napoca, Romania.E-mail: [email protected] Geological Institute of Romania, Cluj Branch, P.O. Box 181, RO-3400 Cluj-Napoca, Romania.3 Department of Geology and Palaeontology, Babeş-Bolyai University, 1, Kogălniceanu Str, RO-3400 Cluj-Napoca, Romania.

Since prehistoric times, gold has been a mineral with aspecial status, influencing the complex development of cer-tain areas of the world. In Europe, the most famous gold areawas traditionally considered the Golden Quadrilateral in theWestern Carpathians, with the mining center at Roşia Mon-tană (RM). RM is located in the NErn part of the Metallifer-ous Mountains, in the neighborhood of the towns Abrud andCâmpeni. The long lasting mining activity in the region re-sulted, among others, in famous museum samples that can befound today in several Romanian museums, as well as inmost of the important mineralogical collections all aroundthe world. The paper starts with a brief overview and evalua-tion of the gold collection at the Mineralogical Museum ofthe Department of Mineralogy, Babeş-Bolyai University inCluj-Napoca (MMBBU) mainly focusing on the samplesfrom RM. Then a historical presentation of the mining activ-ity in the area follows, including the current status of thegold mining project.

In Romania, The Gold Museum from Brad owns the mostrepresentative collection, with specimens especially origi-nating from the local mines; MMBBU hosts the second mostvaluable collection in the country. The gold collection con-sists at present of about 500 samples from Romania and fromabroad. Among them 31 % are from Roşia Montană, 41 %from about 20 other localities in the Western Carpathians, 6% from other Romanian occurrences, 9 % from abroad and13 % have an unknown occurrence. Accordingly, it can besaid that the RM samples represent the core of the collection.Museum gold samples are considered to have an intrinsichigh value due to their content of precious metal, as well asto the interest they present for the public. Still, there aremineralogical and museological criteria that can be usedwhen evaluating such individual samples or collections,among which: form of crystallization, mineral assemblage,genesis, status of the occurrence (closed mines etc.). Thesecriteria were applied for evaluating the RM samples in ourcollection.

Besides its fame and richness in gold, another fact thatmakes RM unique is the long history of the mining activity.Proofs of alluvial gold panning as well as surface and under-ground mining by Geto-Dacians were revealed by historians.The best-preserved antique mining works go back to theRoman times (106-273 a. D.). Between 1786-1855 50“waxed plates” dating from the period 131-167 a. D. wereidentified in the region; one of them (plate no. XVIII, fromthe 6th of February, 131 a. D.) contained the name of RM inthat times (Alburnus Maior). Prior to the XVIIIth century

mining was a private business, then in parallel it becamepartly state-owned. A huge network of surface and under-ground works was created. Several successive state-ownedcompanies were operating in RM starting with 1948; in 1970the largest open cast mine for gold in Romania was openedhere.

The actual economic politics promoted by the Romaniangovernment (The Mining Law, 1998) encouraged privatiza-tion in the field on mining. The mining area RM was con-ceded by the Canadian company Gabriel Resources Ltd., andlately the mixed Romanian-Canadian company Roşia Mon-tană Gold Corporation S.A. (RMGC) was given the exploi-tation license. The current mining project concerns the explo-ration, large-scale surface mining, and processing of thegold-silver ores from several perimeters (Cetate, Cârnic,Orlea, and Jig) in RM area.

According to the data presented by RMGC a total reserveof 225,740,000 tons of ore was estimated, with an averagemetal content of 1.7 g/t gold and 9.1 g/t silver. The miningactivities are planned to start in 2005 and based on the esti-mated reserves, the duration of the exploitation would be of17 years. The Au-Ag ore from the opencast mines would becrushed and milled by using conventional methods, and thenprocessed with open cyanide (“carbon-in-leach” type).RMGC planned to build a cyanide destroyer unit, where theconcentration would be reduced to 1 ppm prior to the storageof the waste into the tailing pond that would be located onthe present-day location of Corna village.

The current mining project was the target of an intensepublic debate. Representatives of various local NGOs, and ofinternationally recognized official bodies evidenced the im-plications that could arise from the implementation of theproject. Among them, long-term social and environmentalimpacts, such as the resettlement and relocation of 1800people (affecting 38 % of the RM commune surface), possi-ble failure of structures and dams leading to cyanide leakinginto the soil, ground water, river and air pollution not onlywith cyanide but also with other metals (As, Pb, U, Hg, Fe,Ni, Cd, etc.)

The impressive cultural heritage values concentrated heregive an additional weight to the final process of decision-making. Archaeologists and historians from all around theworld underlined the importance of the conservation of thisarchaeological site that could be declared as “archaeologicalpark of an European interest”.


87

COMPLEX APPLICATION OF THE METHODS OF PRACTICAL THERMOBAROCHEMIS-TRY AND GEOINDICATION: DECYPHERING OF AERIAL COSMIC PRODUCTION IN THESTUDY ORE GENERATING SYSTEMS

POPIVNYAK, I., KOLODIY, O., LYAKHOV, Y., EKHIVANOV, V., NIKOLENKO, A., NIKOLENKO, P., PAVLYUK, T.,KOVALEVSKY, V., MARUSYAK, V., OLIYNIK, T. & TSIKHON’, S.Lviv National University, Hrushevskiy 4, UA-79005 Lviv, Ukraine.E-mail: [email protected]

In the Baley ore region of the Transbaikalian area, duringthe studying of the gold deposits the methods of practicalthermobarochemistry were used in conjunction with geoindi-cational decoding of aerial cosmic production.

Two types of ore-mineralisation were established: pneu-matolytic-hydrothermal (moderate-sulphide medium-depthformation; 470–60 °C, 120–40 MPa) and proper hydrother-mal (low sulphidation low-depth formation; 310–50 °C, 3–4 MPa; data of Lyakhov et al.).

The mineralisation is genetically connected to the seriesof the observed, radial-circular volcano-plutonic structures ofthe central type with a diameter up to 20 km. Among themthe domed and depressive forms are singled out (Kolodiy).The mineralisation of medium-depth formation is also con-nected to the domed forms, and low-depth mineralisation isconnected with the volcano-depressive forms. Known are thezones combined with the fractures. Topographic mineralogi-cal analysis (Popivnyak) showed that the high temperaturemineral associations change into the low temperature onesfrom the centre of the structure to the peripheral areas.

Temperature gradients are about 20 °C per 100 m fromthe deep horizons to the surface, and 5–7 °C per 100 m later-ally. Spatial directivity of paleotemperature vectors is underthe control of radial faults and is focused on the centralstocks.

Gold occurrences formed in the average temperaturerange (300–200 °C) and are localised in the middle part of

volcano-plutonic structures at a certain distance from thecentral stocks.

Complex assessment made possible to correct explorationworks and to establish new gold-bearing bodies (Kolodiy).

In Ukraine, in the limits of the Kirovograd block thedomed radial-circular structure with the diameter about 150km was discovered by decoding of aerial cosmic productionand by morphotectonic analysis. Gold mineralisation spa-tially coincides with certain parts of the structure. The condi-tions of gold mineralisation in the western and eastern partsare similar. In both of them the process of mineral formationis characterised by cyclic penetration of fluids into the zonesof ore localisation during five stages. Gold deposition tookplace at 270–225 °C (the eastern part; Nikolenko, Popiv-nyak) and 280–220 °C (western zone; Popivnyak, Karamys-heva, Kovalevsky) in the intensively boiling fluids. Complexapproach made it possible to outline the areas perspective forgold.

We must note that in the coal-bearing seams of the Don-bas the gold mineralisation is also connected with the forma-tion of the radial-circular structure (Ekhivanov).

Analogous complex approach made it possible to deter-mine the Beregove ore field of the Transcarpathians as avolcanic radial-circular structure, leading to the discoveriesof new ore zones (Kolodiy).


88

STRUCTURE, COMPOSITION, AND MAGNETIC PROPERTIES OF MINERALS INMAGNETOTACTIC BACTERIA

PÓSFAI, M.1, ARATÓ, B.1, DUNIN-BORKOWSKI, R. E.2, FRANKEL, R. B.3 & BUSECK, P. R. 41 Department of Earth and Environmental Sciences, University of Veszprém, P. O. Box 158, H-8200 Veszprém, Hungary.E-mail: [email protected] Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, UK.3 Department of Physics, California Polytechnic State University, San Luis Obispo, California, USA.4 Department of Geological Sciences and Chemistry/Biochemistry, Arizona State University, Tempe, Arizona, USA.

Magnetotactic bacteria form chains of nanometer-scale,magnetic iron oxides or sulfides (magnetite and greigite,respectively) inside their cells. The bacterium uses the chainsof magnetic minerals as an internal compass for orientingitself in its aquatic environment, following geomagnetic fieldlines in order to reach an optimal position in a chemicallynon-uniform medium (water or sediment) (BAZYLINSKI &MOSKOWITZ, 1997). In order to assess the impact of mag-netotactic bacteria on sediment and rock magnetism, it isnecessary to characterize mineral species within contempo-rary bacteria and to compare them with magnetic minerals ingeological specimens. Since magnetotactic bacteria producesingle-domain magnetic crystals that have specific mor-phologies and sizes, such crystals could have practical appli-cations in fields such as medicine or magnetic recording; it isthus important to obtain a better knowledge of biologicalcontrol over crystal growth. Nanometer-scale magnetitecrystals from the geological environment have also beeninterpreted as “magnetofossils” signatures of former life. Themost notable among the reports of biogenic magnetite arestudies that claim to have identified relics of former life onMars in the form of “prismatic” magnetite crystals in Martianmeteorite ALH84001 (MCKAY et al., 1996). However, it isdifficult to distinguish with confidence the biogenic or inor-ganic origins of these minerals. A knowledge of the magneticmicrostructures of biogenic iron minerals is also importantfor a better understanding of their paleomagnetic contribu-tions.

We studied the sizes, morphologies, microstructures andcompositions of magnetite from several morphological typesof magnetotactic bacteria, from both cultured and “wild”strains, collected from lakes and streams in Hungary. Thewidespread occurrence of magnetotactic species indicatesthat they are significant contributors to the magnetic mineralcontent of freshwater sediments. We also studied iron sul-fides from a marine organism that was earlier described as a“multicellular magnetotactic prokaryote” (MMP) (DELONGet al., 1996). Our goals were to better understand the process

of biologically-controlled mineralization of iron oxides andsulfides, and to define criteria that could be used to distin-guish bacterial from inorganically formed minerals in geo-logical specimens.

Our transmission electron microscope (TEM) observa-tions showed that ferrimagnetic greigite in magnetotacticbacteria forms from nonmagnetic mackinawite (tetragonalFeS) and possibly cubic FeS. Greigite crystals typically con-tain defects and show uneven, blotchy contrast in TEM im-ages. In contrast, we found no precursor mineral for magnet-ite from magnetotactic bacteria. We also used electron holog-raphy in the TEM to study magnetic domain structures, mag-netocrystalline and shape anisotropies, and magnetostaticinteractions between oriented, nano-scale magnetic particles.

Crystal size distributions (CSDs) convey informationabout the growth histories of crystal populations (EBERL etal., 1998). We found that magnetite from magnetotacticbacteria typically produces asymmetric, negatively-skewedCSDs, whereas greigite from the MMP has a Gaussian CSD.Since inorganically-formed crystals commonly have lognor-mal distributions, the statistical analysis of crystal sizes pro-vides a tool for identifying biogenic iron minerals in bothterrestrial and extraterrestrial geological specimens.

ReferencesBAZYLINSKI, D. A. & MOSKOWITZ, B. M. (1997). Rev.

Mineral., 35: 181-223.DELONG, E. F., FRANKEL, R. B. & BAZYLINSKI, D. A.

(1996). Science, 259: 803-806.EBERL, D. D. DRITS, V. A. & SRODON, J. (1998). Amer.

J. Sci., 298: 499-533.MCKAY, D. S., GIBSON, E. K., Jr., THOMAS-KEPRTA,

K. L., VALI, H., ROMANEK, C. S., CLEMETT, S. J.,CHILLIER, X. D. F., MAECHLING, C. R. & ZARE, R.N. (1996). Science, 273: 924-930.


89

ZIRCON IN MIGMATIC ROCKS OF THE SOUTH CARPATHIANS (ROMANIA)

ROBU, I. N. & ROBU, L.Geological Institute of Romania, Caransebeş 1, RO-78344 Bucharest-32, Romania.E-mail: [email protected]

Migmatic rocks are spread in a large area of the SouthCarpathians, occurring in the western part (Semenic Moun-tains) to the central (Sebes-Lotru and Fagaras Mountains)and eastern ones (Iezer-Papusa Mountains).

They are enclosed in different metamorphic series ortectonic units, their genesis being considered in connectionwith different geological events and phenomena, so that thereare no an unitary opinion about their origin.

They are considered to be either: (i) metasomatic (Faga-ras Mountains), (ii) generated by magmatic and metamorphicevents, (iii) formed in tectonic conditions (ductile-brittleregime), having a granitoid protolith (Sebes Mountains), (iv)upper zone (cupola zone) of an anatectic granitoid bodydeveloped in lower parts of the crust (Fagaras Mountains).

Zircon, through its characteristics could help to elucidatesome problems connected to the origin of the rocks, takeninto account its well-known resistance to chemical and me-chanical weathering.

Study of zircons from migmatites of South Carpathians,with special attention to their morphological and opticalproperties, tried to solve the origin of this type of rocks.

Morphologically, they mainly belong to the same type (Stype), but a large variety of subtypes, each of them with veryspecific concentrations, have been observed.

In the northern part of the Sebes Mountains, S is the ex-clusive morphological type and G and P types accompany itin migmatites from the rest of the South Carpathians.

The most spread subtypes, found in the majority of in-vestigated samples, are S16 – S17.

The proportion of S, G and P types is variable from westto east, the S type decreasing from the Sebes Mountains tothe Iezer-Papusa Mts.

The same variations have been emphasized by the opticalproperties: the majority of crystals is light-dark pink, with agood and very good transparency; the light-dark browncrystals and those translucent ones are fewer in the westernpart of South Carpathians, but their number is increasing tothe east, so that such kind of crystals is much more numerousin the migmatic rocks from the Iezer-Papusa Mountains.

Zoned or/and overgrown crystals are few and they are ab-sent in the North Sebes migmatites.

Petrogenetically, the properties of zircons correspondmainly to crustal type, especially for zircons of the NorthSebes migmatites, and this character decreases from West toEast, so that in the Iezer-Papusa migmatites the mantle ormainly mantle component becomes predominant.


90

CRYSTALLOCHEMISTRY OF CHLORITES ASSOCIATED WITH ULTRAMAFIC BODIESFROM SOUTH CARPATHIANS (ROMANIA)

ROBU, L. & ROBU, I. N.Geological Institute of Romania, Caransebeş 1, RO-78344 Bucharest-32, Romania.E-mail: [email protected]

Chlorites are one of the most widespread mineral groupsof the phyllosilicates, associated with the ultramafic rocksfrom the South Carpathians.

They have been observed in ultramafic bodies enclosed inboth major tectonic units of the South Carpathians (Danubianand Getic) with similar morphological, physical and opticalcharacteristics: pale-dark green microscopic or large flakes,grouped in geometrical packets, randomly distributed in themass of the ultramafic rocks, in veins crossing the bodies, orin the marginal zones of them.

Chemical investigations have emphasized the presence ofspecific cations [Mg (mainly) Al, Fe3+, Fe2+, Mn, Cr, Ni, invariable proportions] for clinochlore, with some obvioussubstitutions in tetrahedral and octahedral sheets.

The structure of clinochlore belongs to the trioctahedraltype (2:1:1), determined by the entire filling of the octahedralpositions in both of its sheets, octahedral and octahedralinterlayer ones.

As an exception one has to mention the Tisovita-Iuti oc-currence, where have been found a tri-dioctahedral chlorite.

The most frequent substitution in the tetrahedral sheets isbetween Si and Al, more obviously in the Getic chlorites;sometimes Fe3+ is present in the tetrahedral positions in chlo-

rites investigated from ultramafites from Banat (Tisovita–Iutioccurrence).

The octahedral sheets, in the majority of chlorites, are oc-cupied mainly by Mg and octahedral interlayer ones arefilled by Mg and others, respectively Al, Ti, Fe3+, Fe2+, Mn,Cr and Ni.

The substitutions in the octahedral sheets determined afew changes of the magnesian character of clinochlore; insome occurrences clinochlore has a ferric/ferrous character(Sebes-Cibin Lotru, Semenic and Almaj Mountains), it isless aluminous in the chlorites from Semenic Mountains andit contains Cr - Ni cations in chlorites collected from Cibin,Sebes, Semenic and Almaj Mountains.

The variations of the reticular cell parameters reflect allMg substitutions, but they are similar to those mentioned inthe literature: a = 5.322–5.329 Å; b = 9.233–9.249 Å; c =14.100–14.267 Å.

The lack of difference between Danubian and Getic chlo-rites pointed out the similar conditions of their crystalliza-tion, the emphasized differences being determined by localvariation of the chemistry of crystallization environment.


91

MAPPING MINERALS IN OBSIDIAN GLASSES BY USING MICRO-PIXE TECHNIQUE

RÓZSA, P.1, ELEKES, Z.2, SZÖŐR, Gy.1, SIMON, A.2, UZONYI, I.2, KISS, Á. Z.2 & SIMULÁK, J.11 Department of Mineralogy & Geology, University of Debrecen, P. O. Box 4, H-4010 Debrecen, Hungary.2 Institute of Nuclear Research of the Hungarian Academy of Sciences [ATOMKI], P. O. Box 51, H-4001 Debrecen, Hungary.E-mail: [email protected]

The subject of the current paper is to map mineralsmainly in Carpathian obsidian glasses by nuclear microprobebased Particle Induced X-ray Emission (PIXE) method pro-viding analytical data on them for the first time. The sampleswere basically collected in order to study the glassy materialfrom archaeometrical and geochemical point of view(ELEKES et al., 2000; RÓZSA et al., 2000). Most of theanalysed obsidian specimens containing different pheno-crysts come from the Tokaj Mountains. These mountains(NE Hungary, Borsod-Abaúj-Zemplén County) form thesouthern part of the Tokaj−Prešov Tertiary volcanic range.Some samples from Armenia, Greece are also involved tomake a comparison with the Carpathian specimens.

Although the routine analysis of mineral phases is usuallycarried out by electron microprobe (EPMA) technique, theapplications of nuclear microprobes (NMP) with the use ofwell-established proton induced X-ray emission (PIXE)method have become more and more common and acceptedduring the last decade (RYAN, 1995). Concerning elementalanalysis, NMPs have approximately similar resolution (1x1�m2) as EPMAs but NMPs provide superior detection limitsthat can be especially advantageous when minor and traceelements are to be measured.

The following minerals are identified and analysed: pyr-rhotite, chalcopyrite, pyrite, zircon, pyroxene, biotite, plagio-clase feldspar, and anhydrite. Although our main goal is toreport on the above minerals, on the basis of rock-formingsilicate minerals, some petrologic processes are outlined, aswell. Moreover, with the identification of accessory minerals(such as anhydrite, pyrrhotite, chalcopyrite, pyrite), somegeological conclusions are also drawn.

On the basis of the study of phenocrysts observed in theobsidian glasses some petrologic conclusions can be drawn.Hf contents of zircon crystals in obsidian samples from twolocalities of the Tokaj Mts. (Sima in Hungary and Viničky inSlovakia) show definite differences. It seems that Ca-poororthopyroxene crystal in the sample from Sima (Hungary) is

in equilibrium, while Ca-rich pyroxene crystals of obsidiansfrom Melos and Giali (Greece) may be in equilibrium withthe residual glass. Therefore, it is possible that these crystalscannot be regarded as xenocrysts. However, Ca-rich plagio-clase feldspars detected in samples from Viničky (Slovakia)and Melos (Greece) have probably been incorporated in theglass. Anhydrite-chalcopyrite and pyrrhotite-pyrite-chalco-pyrite assemblages in obsidians from Aragats Mountain(Armenia) and Viničky (Slovakia) were formed by hy-drothermal activity. However, it is questionable whether thesolid obsidian rocks suffered the hydrothermal activity orthese crystals were incorporated by the rhyolitic melts. It isalso possible that sulphur was stored in a coexisting fluidphase; in this case these minerals could be regarded as pri-mary ones.

AcknowledgmentsThis work has been supported by the Hungarian National

Science Research Foundation (OTKA) under Res. ContractsNo. A 080, T 025771, T 019516, by the National Committeefor Technological Development under Res. Contract No. 97-20-MU-0030 and by the Project for Higher Educational Re-search and Development (FKFP) under Res. Contract No.0135/1999.

ReferencesELEKES, Z., UZONYI, I., GRATUZE, B., RÓZSA, P.,

KISS, Á. Z. & SZÖŐR, Gy. (2000). Nuclear Instrumentsand Methods in Physics Research B, 161-163: 836–841.

RÓZSA, P., SZÖŐR, Gy., SIMULÁK, J., GRATUZE, B.,ELEKES, Z. & BESZEDA, I. (2000): Applied Mineral-ogy, 1, Rotterdam: Balkema, 217–220.

RYAN, C. G. (1995). Nuclear Instruments and Methods inPhysics Research B, 104/1-4: 377–395.


92

A NEW LOVERINGITE OCCURRENCE: ORIENTED RODS IN GARNET FROMTHE FOLTEA LHERZOLITE, SOUTH CARPATHIANS, ROMANIA

SĂBĂU, G.1 & ALBERICO, A.21 Geological Institute of Romania, 1 Caransebeş St., RO-78344 Bucharest 32, Romania.E-mail: [email protected] Dipartimento di Scienze Mineralogiche e Petrologiche, Università di Torino, Via Valperga Caluso 35, I-10125 Torino, Italy.

Loveringite - (Ca, REE)(Ti, Fe, Cr,...)21O38 is a relativelyrare mineral, belonging to the crichtonite group, identified sofar in a number of occurrences related to layered mafic intru-sions and their metamorphosed equivalents. TARKIAN &MUTANEN (1974) suggested that it could be more wide-spread than actually recognised, being overlooked due to itssmall grain size and optical properties similar to those ofother oxide minerals. The material described as lunar Cr-,Ca-, Zr-, Nb- armalcolite (HAGGERTY, 1973) (CCZNA)displays strikingly similar chemical composition and opticalproperties (e. g. LÉVY et al., 1972), implying that the firstdiscovery of loveringite precedes by a few years its officialrecognition as a new mineral species by GATEHOUSE et al.(1978), though in a completely different setting. A remark-able occurrence was described by WANG et al. (1999) in theGarnet Ridge (Arizona) kimberlite pipe, where loveringite iscited together with other oxides (rutile, crichtonite, srilankite,carmichaelite) as oriented rod-like inclusions in garnet crys-tals.

The Foltea garnet lherzolite is an isolated ultramafic bodyenclosed in upper crustal metapelitic and gneissic rocks ofthe polymetamorphic basement (the Lotru MetamorphicSuite) of the Getic Nappe in the South Carpathians. Pyrope-rich garnet is a common component in the rock itself or ingarnet-clinopyroxenite veins and nests, hosting a variety ofoxide, silicate, sulfide and carbonate-rich inclusions. Oxideinclusions usually occur as a net of µm-sized rods and bladesoriented along four directions consistent with <111> of hostgarnet, and consist chiefly of rutile and loveringite.

Loveringite appears as rods up to 5 µm thick and 300 µmlong, blades up to 300 µm and rare elongated grains borderedby crystal faces, all oriented with respect to the host garnet. Itis almost opaque, being however translucent in deep olive-green shades in very thin grains. SAED patterns are consis-tent with a loveringite cell (trigonal symmetry, aH = 10.34 Å,cH = 20.68 Å). The chemical composition recalculated after

WD microprobe analyses is given in Tab. 1 (average of 3analyses).

Loveringite, together with associated microinclusions ingarnet indicates metasomatic processes in the mantle frag-ment where the Foltea ultrabasite was sampled from. In par-ticular, metasomatism is responsible for HFSE-enrichmentrecorded by the oxide microinclusions hosted by garnet. Thetopotactic relationships with host garnet most presumablyresulted from epitaxial co-precipitation, a mechanism thathas to be considered also in other instances in which garnetcontains oriented oxide or silicate rods, usually deemed asexsolution features. An interpretative option between co-precipitation vs. exsolution has to be supported in particularcases by concurrent evidence, given its paramount conse-quences on the interpretation of the rock geodynamic history.

ReferencesGATEHOUSE, B. M., GREY, I. E., CAMPBELL, I. H. &

KELLY, P. R. (1978). Amer. Mineral., 63: 28-36.GRÉGOIRE, M., LORAND, J. P., O’REILLY, S. Y. &

COTTIN, Y. (2000). Geochim. Cosmochim. Acta, 64(4):673-694.

HAGGERTY, S. E. (1973). Proc. 4th Lunar Sci. Conf., Geo-chim. Cosmochim. Acta, Suppl. 4(1): 777-797.

LÉVY, C., CHRISTOPHE-MICHEL-LÉVY, M., PICOT, P.& CAYE, R. (1972). Proc. 3rd Lunar Sci. Conf., Geo-chim. Cosmochim. Acta, Suppl. 3(1): 1115-1120.

LORAND, J. P., COTTIN, J. Y. & PARODI, G. C. (1987).Can. Mineral., 25: 683-693.

SCHULZE, D. J. (1990). Amer. Mineral., 75: 97-104.TARKIAN, M. & MUTANEN, T. (1987). Mineral. Petrol.,

37: 37-50.WANG, L., ESSENE, E. J. & ZHANG, Y. (1999). Contrib.

Mineral. Petrol., 135: 164-178.

Table 1: Chemical composition of loveringite from the Foltea ultrabasite.

Na2O K2O CaO SrO MgO FeO NiO MnO Fe2O3 Cr2O3 Al2O3 TiO2 ZrO2 SiO2 VO2 Σ

0.23 0.15 2.59 0.45 4.05 9.40 0.08 0.14 1.35 0.94 5.04 70.28 3.36 0.08 0.39 98.52

K Na Sr Ca Σ Mn Fe2+ Ni Mg Fe3+ Cr Al V Ti Zr Si Σ O

0.05 0.12 0.07 0.76 1.00 0.03 2.15 0.02 1.65 0.28 0.20 1.63 0.08 14.48 0.45 0.02 21.00 38.00


93

PETROGRAPHIC AND GEOCHEMICAL STUDIES ON A TRAVERTINE CONE IN SOUTHVÉRTES MTS. (HUNGARY): EVIDENCE FOR MAGMATIC FLUID INFLUENCE?

SIKLÓSY, Z.1, GÁL-SÓLYMOS, K.1, KORPÁS, L.2 & SZABÓ, Cs.11 Lithosphere Fluid Research Lab, Department of Petrology and Geochemistry, Eötvös Loránd University,Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected] Geological Institute of Hungary, Stefánia út 14, H-1143 Budapest, Hungary.

IntroductionSpectacular reddish brown carbonate cone was found in

the southern part of Vértes Mts. (Transdanubian CentralRange), close to NW of village Gánt (PEREGI & KORPÁS,2002). Some red calcite dikes were already described fromother parts of the Transdanubian Central Range (HAAS etal., 1984; DEMÉNY et al., 1997). These dikes are mostlysituated in Upper Triassic carbonates and never cut Tertiaryrocks. There are two localities where their Upper Cretaceousage could be stratigraphically determined. The origin of thesered calcite formations is different from the other calcite veinsthat can be found in almost all Mesozoic and Tertiary car-bonates. A detailed stable isotope and fluid inclusion studyof DEMÉNY et al. (1997) suggested that percolation ofmagmatic fluids played a significant role during the forma-tion of the red calcite dikes. PEREGI & KORPÁS (2002)postulated a travertine spring cone origin for the Gánt occur-rence and we have carried out a careful petrographic andgeochemical study to determine its relation to the red calcitedikes.

Fig. 1: The studied carbonate cone in the Vértes Mts.

Structure of the carbonate coneThe isometric and elliptical carbonate cone is 40 to 50 m

long and 7 to 8 m high. It has a ring structure likened to awillow-tree that differs totally from the surrounding UpperTriassic Hauptdolomite (Fig. 1). The middle part of the coneis vertically bedded, whereas at the rim the beddings turn toless steep: 10-50°. The carbonate material itself has a typical

travertine fabric and consists of alternating massive, layeredand porous calcite.

Results and conclusionsSamples are composed of mostly calcite crystals that can

grow up to 0.5 mm. The calcite crystals mostly banded dueto the zonation of Fe-oxide layers. Based on petrographicstudy, the carbonate cone can be described as a travertinedeposit. Electron microprobe and scanning electron micro-scope techniques and neutron activation analyses were alsoused to determine the accessories minerals of sitting in thecarbonate material. Xenomorphic zircon, xenotime andmonazite were found as small grains (up to 10 µm). Based onthe textural features, only monazite and xenotime can beconsidered as autochthon minerals. The carbonate cone isrelatively enriched in light rare earth elements (La, Ce, etc.)particularly samples collected close to the hypothetical ventfacies. Also, each sample has a positive U anomaly (up to3.73 ppm). The presented geochemical data are partiallycharacteristic and similar to the Quaternary thermal Budatravertine as indicated by KORPÁS et al. (2003). In our casea generic relation to the Late Cretaceous lamprophyres oc-curring in the northern part of the Transdanubian CentralRange (SZABÓ et al., 1993) can be considered.

ReferencesDEMÉNY, A., GATTER, I., & KÁZMÉR, M. (1997).

Geologica Carpathica, 48: 315-323.HAAS, J., JOCHÁNÉ EDELÉNYI, E., GIDAI, L., KAISER,

M., KRETZOI, M., & ORAVECZ, J. (1984). GeologicaHungarica Series Geologica, 20: 353 p.

KORPÁS, L., KOVÁCS-PÁLFFY, P., LANTOS, M.,FÖLDVÁRI, M., KORDOS, L., KROLOPP, E.,STÜBEN, D., & BERNER, Zs. (2003). Quaternary Re-search (submitted)

PEREGI, Zs., & KORPÁS, L. (2002). Földtani Közlöny,132: 477-480.

SZABÓ, Cs., KUBOVICS, I. & MOLNÁR, Zs. (1993).Mineralogy and Petrology, 47: 127-148.


94

ADSORPTION OF LEAD ON A LUVISOL PROFILE FROM THE CSERHÁT MTS.,NE HUNGARY

SIPOS, P.1, NÉMETH, T.1, MOHAI, I.2 & DÓDONY, I.31 Laboratory for Geochemical Research, Hungarian Academy of Sciences, Budaörsi út 45, H-1112 Budapest, Hungary.E-mail: [email protected] Research Laboratory of Material and Environmental Chemistry, Chemical Research Center, Hungarian Academy of Sci-ences, Pusztaszeri út 59-67, H-1025 Budapest, Hungary.3 Department of Mineralogy, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.

Geochemical analyses using sequential extractionmethod, lead adsorption and analytical TEM studies werecarried out in order to characterize the distribution and ad-sorption behaviour of lead on each genetic horizon of a Luvi-sol profile. This soil was developed on schlier, and it is char-acterized by clay illuviation as the most important pedogenicprocess. Clay minerals are presented in the profile by“chloritized” vermiculite species with increasing chloritecomponent downward. The amount of carbonate mineralsstrongly increases in the lower part of the profile resultingabrupt rise in soil pH within small distance (from 5.66 to8.41).

The average Pb concentration of this soil is at the level ofnatural geochemical background in Hungary (14 ppm), andits amount decreases with depth suggesting the binding of Pbto soil organic matter (27 ppm at 5 cm, 15 ppm at 35 cm, 4ppm at 65 cm). According to the sequential extraction analy-sis the organic matter is an important sink of lead: with de-creasing organic matter content the amount of lead bound toit decreases, but its proportion increases. The distribution oflead among soil constituents varies especially in the functionof the carbonate content of soil, as well. These effects vary inthe different soil horizons.

Lead adsorption experiments were carried out on wholesoil samples, soil clay fractions, as well as on their carbonate

and organic matter free variant. The different soil horizonsadsorb lead to different extent depending on their organicmatter, clay mineral and carbonate content, and the minera-logical features of soil clays significantly affect their leadadsorption capacity. The clay fraction adsorbs 25% morelead than the whole soil, while in the calcareous subsoil thelead precipitated due to the high pH. 10% and 5% of ad-sorbed Pb can be leached with distilled water in the organicmatter and clay mineral dominated soil horizons, respec-tively.

Samples treated with the highest amount of lead contain-ing solution (2000 mg/l) were studied by analytical TEM.The results show that among mineral phases the most im-portant lead adsorbing ones are the vermiculite and the chlo-rite. The amount of adsorbed lead increases with the in-creasing iron content of this phases. The lead also adsorb onFe oxides in smaller extent, but lead adsorption on carbon-ates was not found.

These results suggest that the soil organic matter playsdecisive role in the adsorption of Pb, but the fixation by clayminerals is stronger. The carbonate phases plays role in leadadsorption through their pH buffering capacity.


95

SELECTED MINING DUMPS IN SLANSKÉ VRCHY MTS. (SLOVAKIA): GEOCHEMICALCONDITIONS AND THEIR INFLUENCE OF VEGETATION

SITÁŠOVÁ, E.Eastern Slovakian Museum, Hviezdoslavova 3, SK-041 36 Košice, Slovak Republic.E-mail: [email protected]

Mining dumps are specific anthropogenic habitats aftermining of raw materials. According to the presence of oreminerals in dumps and their chemical composition in soilsdeveloped on dumps, we supposed higher concentration ofsome elements (arsenic, copper, mercury, lead, antimony).Dumps in the Slanské vrchy Mts. have different soil con-tamination by observed heavy metals. The most contami-nated are the soils with high content of As, Hg and Sb. Itrelates to their increased content in substratum, which can becaused by natural and anthropogenic factors. Increased mer-cury content relates to the battering and processing activityand increased mineralisation of soil horizon by componentscontaining structurally bound mercury.

Chemical analyses of leaking mining waters and watersrunning over observed mining dumps in the Slanské vrchyMts. and in Merník demonstrate by documents that:

– at Dubník in the Slávik exploratory gallery even aftertotal flooding very acidic mineralising waters still develop,which then leak onto the surface and join the JedľovecBrook. This brook farther runs over peat marshes at thedump of Jozef gallery at Dubník. These waters preserve theiracidic pH value in the interval 2.30–2.47.

From a scientific viewpoint the results confirm the mi-gration of heavy metals and their accumulation in the envi-ronment. Our aim was to observe the natural succession ofplants at dumps, their development and stand conditions atindividual localities. We discovered some differences be-tween the growth of young and old dumps. Colonisation ofdumps by vegetation took place and still takes place slowly

and we can record certain similarity at certain types ofdumps. In plants the content of Hg, As exceed the values ofash. It is exhibited the most strikingly in the case of bentgrass (Agrostis capillaris). In another species there is a highconcentration of Hg from each locality (SITÁŠOVÁ, 2001).

It is deduced from the results that the contamination byheavy metals is caused not only by mining activity butmainly by weathering of hydrothermally altered rocks withsulphide content.

Considering already ascertained facts about the types andamount of heavy metals at observed dumps and their nega-tive influence on the other components of environment ortheir contamination (SITÁŠOVÁ, 2001) we suggest:

– to ensure the dumps in a way that can eliminate adverseinfluences on the environment;

– we do not recommend, considering the high toxicity ofmaterials in some dumps, to use this material for surfacingroads in forests, fixture of road communications or as abuilding material, because uncontrollable diffusion of heavymetals into the natural environment occurs;

– it is necessary to recultivate the dumps and cover themwith soil and plant trees or another plants for building in thisarea to the immediate surroundings.

ReferencesSITÁŠOVÁ, E. (2001). Natura Carpatica, 42: 55–64.SITÁŠOVÁ, E. (2001). Natura Carpatica, 42: 177–182.


96

GLAUCONY IN THE LOWER JURASSIC DEPOSITS OF THE KRIŽNA UNIT(TATRA MTS., POLAND)

STARZEC, K. & JACH, R.Institute of Geological Sciences, Jagiellonian University, ul. Oleandry 2a, PL-30-063 Cracow, Poland.E-mail: [email protected]

The Lower Jurassic glaucony-bearing deposits crop out inthe Długa Valley of the Križna Unit (Western Tatra Mts.,Poland). They occur locally above limestone/marl alternatedcomplex, covered with phosphatic stromatolites up to 3 cmthick. The complex is probably Toarcian in age. The glau-cony-bearing deposits are, in turn, covered with a condensedsection of red nodular limestones. The glaucony-bearingdeposits developed as dark green marlstones, up to 20 cmthick. They contain abundant crinoidal ossicles, belemniteguards, and relatively high amount of fish teeth. In thin sec-tion they display wackestone texture. The crinoidal ossiclesare poorly rounded and sorted. Their internal pores aremostly impregnated by green material.

The collected rocks were disaggregated, submitted tomagnetic separation and hand-picking. Physical propertiesand chemical composition of green grains were determinedby applying optical microscope, scanning electron micro-scope with energy dispersive spectrometry (SEM-EDS) andX-ray diffraction (XRD) of oriented powder samples.

The grains are mainly 0.1– 0.4 mm in size and medium todark green in colour. Mostly sub-rounded, irregular shapesare present, rarely tabular or well-rounded ovoidal shapeswere observed. The most important elements shown by EDSpoint analysis are Si, Al, Fe, Mg, K, with some minor ad-mixtures of Ti. Thus the green grains are rich in K(K2O>7%) but reveal relatively small amount of Fe2O3 (up to19%) and high content of Al2O3 (from 13% to 20%). Al-richglaucony has been interpreted to reflect the results of diage-

netic alteration (ODIN & MATTER, 1981; IRELAND et al.,1983). In spite of very high potassium content the XRD pat-tern show that the grains do not represent well-ordered glau-conite phase. They are at an evolved stage of glauconitiza-tion. Some amount of calcite was also found in these grains(it is because calcite fills the cracks).

The above mineralogical and geochemical evidencesshow that discussed glaucony represents autochthonous type(see AMOROSI, 1997). Facies geometry and their lateralvariation suggest that described deposits represent the crestor the slope of pelagic carbonate platform. Sedimentologicaland palaeontological characteristic of glaucony-bearing de-posits confirm the above interpretation and prove that thedeposits in question originated during periods of very lowrate of deposition.

The research is partly financed by the Polish State Com-mittee for Scientific Research grant no 3PO4D 017 22. R.J.is also supported by the Polish Geological Society in frameof the Beres Scholarship in 2003.

ReferencesAMOROSI, A. (1997). Sediment. Geol., 109: 135-151.IRELAND, B. J., CURTIS, C. D. & WHITEMAN, J. A.

(1983). Sediment., 30: 769-786.ODIN, G. S. & MATTER, A. (1981). Sediment., 28: 611-

641.


97

GRANITIZATION PHENOMENA IN THE GILĂU MOUNTAINS (ROMANIA).A GEOCHEMICAL APPROACH

STUMBEA, D.University “Al. I. Cuza”, 20A Carol I. Bvd., RO-6600 Iaşi, Romania.E-mail: [email protected]

The Gilău Mountains represents a morphological subdivi-sion of the Apuseni Mountains. The later unit is localized inthe western part of the Romanian territory and considered asone of the three units of Romanian Carpathians.

The geological background of Gilău Mountains is pro-vided by the medium-grade metamorphicseries of Someş, built up mainly by mig-matites, leptynites, gneiss, micaschistswith almandine, disthene, staurolite andsillimanite. The geology of the area iscompleted by the granite body of Mun-tele Mare that penetrates the metamor-phic formations and by numerous peg-matite bodies hosted both by granite andmetamorphic rocks. Our last studies carried out on pegma-tites (STUMBEA, 2000) seem to confirm MÂRZA’s (1980)hypothesis, which attach to these rocks a metamorphic gene-sis (metamorphic differentiation or even anatexis).

Granitization phenomena in the Gilău Mountains havebeen reported almost forty years ago. In the span of time of adecade, STOICOVICI & TRIF (1961), TRIF (1961), TRIF &STOICOVICI (1963), TRIF (1968) lead research works –mostly field works followed by both macroscopic and micro-scopic observations; the outline of their conclusions consistin a spatial superposition of granitization phenomena on themost intense metamorphic phenomena (metamorphic differ-entiation and/or anatexis).

The geochemical approach of the granitization phenom-ena consist in establishing the geochemical balance betweenthe rocks arisen by means of granitization and those pre-sumed not being affected by this process; in this respect, thestandard cell of these two types of rocks has been deter-mined. The results of the geochemical balance have beencompared to the theoretical modeling of input and output inthe rocks during the granitization process (Si, Al, K inputand Ti, Fe, Mg, Mn output).

Taking into account the above mentioned hypothesis wehave been able to identify features of granitization-like proc-ess regarding the following pairs of rocks: micaschist/granitegneiss; paragneiss/ granite gneiss; granite gneiss/ plagioclase+ microcline-bearing pegmatite (PM pegmatite), hosted bymetamorphic rocks; granite gneiss/ plagioclase + microcline+ muscovite-bearing pegmatite (PMm pegmatite), hosted by

metamorphic rocks; plagioclase + microcline-bearing peg-matite, hosted by metamorphic rocks/granite of MunteleMare (the words wrote in italic characters represent the termspresumed as arising by means of granitization process). Inthe following scheme, our main results are exhibited:

This scheme shows that granite gneiss can arise as a re-sult of micaschist granitization and it reveals also that PMpegmatites, PMm pegmatites (both hosted by metamorphicrocks) and granite can be generated by the granitization phe-nomenon of gneiss. But the most interesting conclusion re-vealed by the geochemical balance and pictured in thescheme above is the granitization-like feature of the balancebetween PM pegmatite and granite. Though the granite bodyof Muntele Mare is much younger than the metamorphicrocks of Someş series and it can’t be the result of theiranatexis, the result could represent a geochemical proof ofthe possibility of granite engendering through this way.

ReferencesMÂRZA, I.. (1980). Anuarul I. G. G., Bucureşti, 57: 423-

432.STOICOVICI, E. & TRIF, A. (1961). Studia Univ. “Babeş-

Bolyai”, Cluj, I: 71-82.STUMBEA, D. (2000). Publishing House of “Al. I. Cuza”

University, Iaşi, 264p.TRIF, A. (1961). Studia Univ. “Babeş-Bolyai”, Cluj, I: 47-

70.TRIF, A. (1968). Studia Univ. “Babeş-Bolyai”, Cluj, I: 59-

70.TRIF, A. & STOICOVICI, E. (1963). Studia Univ. “Babeş-

Bolyai”, Cluj, I: 7-28.

Micaschist → PM pegmatitein metamorphic rocks

↓→ Granite gneiss → Granite

Paragneiss → PMm pegmatitein metamorphic rocks


98

COMPOSITION AND EVOLUTION OF LITHOSPHERIC MANTLE BENEATHTHE PANNONIAN BASIN: A PETROGRAPHIC AND GEOCHEMICAL REVIEW

SZABÓ, Cs., FALUS, Gy., BALI, E., KOVÁCS, I., ZAJACZ, Z. & HIDAS, K.Lithosphere Fluid Research Lab, Department of Petrology and Geochemistry, Eötvös Loránd University,Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected]

IntroductionKnowledge of the lithosphere beneath the Carpathian-

Pannonian Region (CPR) have been greatly improved bypetrologic, geochemical and isotopic studies of upper mantlexenoliths hosted in Plio-Pleistocene alkali basalts of StyrianBasin, Little Hungarian Plain, Bakony-Balaton Highland,Nógrád–Gömör and East Transylvanian Basin (EMBEY-ISZTIN et al., 1989; DOWNES et al., 1992; SZABÓ &TAYLOR, 1994; VASELLI et al., 1995, 1996). The CPRmantle xenoliths are mostly spinel lherzolites, however sub-ordinate pyroxenites, websterites, wehrlites, harzburgites anddunites are also present. Garnet-bearing mantle fragmentshave not been reported, however breakdown products ofgarnet were recognized in some mantle xenoliths (TÖRÖK,1995; FALUS et al., 2000).

Textural featuresThe peridotite (basically spinel lherzolite) xenoliths, rep-

resenting residual material of the mantle with complex his-tory, show variable textural features. In order of increasingdeformation, protogranular, porphyroclastic and equigranulartextures can be distinguished. Also, minor secondary recrys-tallized xenoliths have been found as a result of mantle re-laxation. The lithospheric mantle is more deformed in thecentral part of the CPR than towards the western and easternedges. The deformation could have been associated withasthenospheric upwelling and extension in the late Tertiaryaffected strongly the central part of the subcontinental litho-sphere of the CPR.

The pyroxenite xenoliths, composed of mostly clinopy-roxene, are also widespread in the CPR but in low number.Textures of these xenoliths are slightly variable: coarse-grained igneous textural features can be observed; sign ofrecrystallization and deformation is not common.

Geochemical featuresThe peridotite xenoliths have a bulk compositions rang-

ing from 36 to 46 wt% MgO, 0.5 to 4.0 wt% CaO and 1.0 to4.5 wt% Al2O3. There are no significant chemical differencesamong the xenoliths of the major localities. Nevertheless,mineral composition, particularly in case of clinopyroxene,varies according to the xenolith textures. Less deformedxenoliths have clinopyroxene with higher content of basalticmajor elements (Al, Ti, Na and Fe) compared to the moredeformed samples. However, clinopyroxenes in the more

deformed xenoliths are enriched in strongly incompatibletrace elements (e.g. light rare earths elements).

Chemical composition of the pyroxenite xenoliths showsenrichment in basaltic and light rare earths elements. Theserock fragments represent mafic melts crystallized as pyrox-enite dykes or cumulate bodies in the lithospheric mantle.

Hydrous phases, pargasitic and kearsutitic amphibolesand phlogopitic micas occur as evidence of modal metaso-matism in both peridotite and pyroxenite xenoliths. Amphi-boles, occurring as interstitial phases, veins and selvages, aremore common than phlogopites. A portion of both hydrousphases is texturally and chemically in equilibrium with theanhydrous mantle minerals in the peridotites. However, am-phiboles frequently in veins and pyroxenites show enrich-ment in K, Fe and light rare earth elements.

Existence of carbonate-bearing melt pockets and veinsrelated to melting of amphiboles and clinopyroxenes, andexistence of silicate melts, sulfide and CO2 inclusions,trapped in the anhydrous mantle minerals, indicates the pres-ence and migration of melts and/or fluids, which causedmetasomatic interactions at different time and under differentPT conditions (BALI et al., 2002). The source of the meta-somatic melts/fluids might have related to subduction, oc-curred beneath the CPR during the late Tertiary times.

ReferencesBALI, E., SZABÓ, Cs., VASELLI, O. & TÖRÖK, K.

(2002). Lithos, 61: 79-102.DOWNES, H., EMBEY-ISZTIN, A. & THIRLWALL, M. F.

(1992). Contrib. Miner. Petrol., 107: 340-345.EMBEY-ISZTIN, A., SCHARBERT, H. G., DIETRICH, H.

& POULTIDIS, H. (1989). J. Petrol., 30: 79-106.FALUS, Gy., SZABÓ, Cs. & VASELLI, O. (2000). Terra

Nova, 12: 295-302.SZABÓ, Cs. & TAYLOR, L. A. (1994). Inter. Geol. Rev.,

36: 328-358.TÖRÖK, K. (1995). Acta Vulcanol., 7: 285-290.VASELLI, O., DOWNES, H., THIRLWAAL, M. F., DO-

BOSI, G., CORADOSSI, N., SEGHEDI, I., SZAKÁCS,A. & VANNUCCI, R. (1995). J. Petrol., 36: 23-53.

VASELLI, O., DOWNES, H., THIRLWAAL, M. F., VAN-NUCCI, R. & CORADOSSI, N. (1996). Mineral. Petrol.,57: 23-50.


99

NEOGENE-QUATERNARY VOLCANISM OF THE CARPATHIAN-PANNONIAN REGION.A VOLCANOLOGICAL PERSPECTIVE

SZAKÁCS, A.Institute of Geodynamics, Romanian Academy, 19-21 Jean Louis Calderon str., RO-70201 Bucharest, Romania.E-mail: [email protected]

The Carpathian-Pannonian Region (CPR) records a ca. 20Ma old volcanic activity closely related to the geodynamicevolution of the area. Eruption styles are different for thethree main compositional groups of the feeding magmas –felsic calc-alkaline, intermediate calc-alkaline and alkali-basaltic. The time-space evolution of volcanism, inferredusing K-Ar geochronology, shows that volcanism startedwith felsic magmas and ended with alkali-basaltic magmas inmost of CPR.

Felsic calc-alkaline magmas, sometimes with alkaline af-finity, mostly produced large-volume explosive eruptionsgenerating welded and non-welded ash-flow deposits as wellas their reworked counterparts deposited both on land andunder water. Since most of their occurrences are buried be-neath younger sediments, their respective eruptive centers aredifficult to identify. However, a few centers have tentativelybeen localized – e.g. as buried calderas in the central part ofthe Pannonian Basin. Felsic and intermediate calc-alkalinevolcanics are closely related in both space and time in vari-ous areas of CPR.

Andesite-dominated intermediate calc-alkaline magmas –traditionally thought as being subduction-related – generatedvolcanics with an obvious geochemical signature, however,coeval subduction is very unlikely for most of the areas inCPR, since most of the volcanism is postcollisional. Thisvolcanism first developed in the western part of CPR with anareal-type spatial distribution. An obvious magmatic arc witha definable volcanic front has been active after ca. 14 Mafrom Eastern Moravia to the Calimani and Gurghiu Mts. inthe East Carpathians, until ca. 8 Ma ago. Arc segmentation –

and related specific evolution patterns – are due to features ofthe overriding plates, unlike most modern analogues world-wide. Eruptions occurred at a large number of centers, mostof them being composite volcanoes with variable size andcomplexity, located in various paleogeographic environ-ments. Some of them evolved until large caldera systemsincluding post-caldera resurgence stages or even multiplecaldera-forming events. Edifice instability led to sector col-lapse and generation of large-volume debris avalanche de-posits at a few volcanoes. Spatial distribution of volcaniccenters shows close spacing of edifices in most areas, leadingto complicated patterns of merging, interfingering and over-lapping of various volcanic facies at neighboring volcanoes.Interaction between large volcanic edifices and their base-ment including low yield-strength rocks have been observedat some volcanoes in the East Carpathians.

Alkali-basaltic volcanism is clustered in a number ofrather well-localized areas, corresponding to narrow-sectionmantle plumes. They form fields of small-sized monogeneticvolcanoes, including maar structures, Strombolian cindercones and lava fields. The size of the fields, number of cen-ters included and duration of volcanism are variable.

The most recent volcanic activity in CPR occurred ca.35–42 Ka ago in the Ciomadul Massif at the southeasternend of the East Carpathian volcanic arc, and ca. 0.1 Ma agoin the Central Slovakian Volcanic Field. Further eruptionscannot be ruled out in these areas and volcanic hazard shouldbe considered for the unforeseeable future.


100

SYNCHYSITE-(Ce) FROM THE KOMLÓ COAL DEPOSIT, MECSEK MTS.,SOUTH HUNGARY

SZAKÁLL, S.1, NAGY, G.2 & SAJÓ, I. E.31 Department of Mineralogy and Petrology, University of Miskolc, H-3515 Miskolc-Egyetemváros, Hungary.E-mail: [email protected] Research Centre for Earth Sciences, Laboratory for Geochemical Research, Hungarian Academy of Sciences,Budaörsi út 45, H-1112 Budapest, Hungary.3 Chemical Research Centre, Hungarian Academy of Sciences, Pusztaszeri út 59-67, H-1025 Budapest, Hungary.

A REE-bearing mineral, synchysite-(Ce), was identifiedfrom the Komló coal deposit, Mecsek Mts. Its appearancewas probably influenced by the surrounding phonolite area.

Some REE (such as lanthanum, yttrium) were earlieridentified by complex trace element studies in the coal de-posit (CSALAGOVITS & VIGHNÉ FEJES, 1969), but REE-bearing minerals have not been found. In the close geologicalenvironment of the coal deposit (partly in the coal seamstoo), submarine volcanic/subvolcanic alkaline rocks, espe-cially phonolite occur in some outcrops. Electron microprobeanalyses proved the presence of some accessory REE miner-als like britholite, bastnäsite, nacareniobsite and joaquinite inthe phonolite (PANTÓ, 1980; NAGY, 2003; SZAKÁLL,unpublished).

A mineral-rich paragenesis was identified in the septarianfissures of pelosideritic concretions at Zobák shaft, Komló inthe last few years. The main fissure fillings are: quartz, cal-cite, siderite, pyrite, marcasite and kaolinite. The rare acces-sory minerals are: barite, galena, sphalerite, millerite, etc.

The synchysite-(Ce) was shown as pale rose, prismaticcrystals (up to 1.5 mm) in close association with quartz andcalcite. The crystals always have pseudohexagonal habits.The prism is always strongly striated because of its oscillat-ing development.

The synchysite at Komló proved to be rich in cerium andneodymium by electron microprobe analyses. The result ofEPMA (average of five analyses in weight %): CaO 16.80,Y2O3 0.26, La2O3 4.21, Ce2O3 18.82, Pr2O3 3.67, Nd2O3

18.95, Sm2O3 2.79, Eu2O3 0.37, Gd2O3 0.96, Tb2O3 0.00,Dy2O3 0.01, Ho2O3 0.01, Er2O3 0.00, F 3.24, Σ 70.08. Theminerals in the synchysite-subgroup of bastnäsite-synchysite-parisite group are distinguished according to the dominantREE as synchysite-(Ce), synchysite-(Nd) and synchysite-(Y)(FLEISCHER, 1978). Considering the EPMA, the Komlósynchysite can be identified as synchysite-(Ce) because the

Ce and Nd content are very similar, but the ionic number isCe = 1.85; Nd = 1.74.

The chemical formula, which was calculated from EPMAis as follows: Ca(Ce0.38Nd0.37La0.08Pr0.07Sm0.05Ga0.02Eu0.01)(CO3)2F0.57.

The X-ray diffraction data support the results of thechemical analyses, the d values show good correlation withthe bibliographic data of synchysite-(Ce), but the intensity ofthe reflections are different, assumable due to the high Nd-content. The most important d values are the following (thedata of JCPDS 18-284 file are in the brackets): 9.07 (9.1),4.54 (4.53), 3.54 (3.55), 2.79 (2.80), 2.04 (2.06), 1.91 (1.87).Unit cell data are: a = 7.082 Å, c = 54.565 Å. It shows tran-sitional values between synchysite-(Ce) (a = 7.126 Å, c =55.08 Å; ICDD PDF2 # 44-1438) and synchysite-(Nd) (a =6.984 Å, c = 54.27 Å; ICDD PDF2 # 35-0589). The Ca :REE ratio is near 1 : 1 (4.7822 : 4.8118), this is also an evi-dence for synchysite. TEM study, however, signed someinhomogenities in the synchysite; in these places both pa-risite and röntgenite may appear.

The appearance of synchysite-(Ce) can be in connectionwith the REE-enrichment of the magmatic environment. TheREE was mobilized by post-magmatic processes, togetherwith other elements. The close paragenesis of synchysite-(Ce) demonstrate definitely hydrothermal conditions.

Investigated synchysite-(Ce) sample from Komló is pre-served in the mineral collection of Herman Ottó Museum(Miskolc, Hungary) under catalogue number 18590.

ReferencesCSALAGOVITS, I. & VIGHNÉ FEJES, M. (1969). MÁFI

Évk., 51: 520–591.FLEISCHER, M. (1978). Can. Mineral., 16: 361–363.NAGY, G. (2003). Acta Mineral- Petrogr., this volumePANTÓ, Gy. (1980). Doctoral thesis, 1–152.


101

EUHEDRAL CALCITE IN CARBONATIC CONCRETIONS FROM QUATERNARYPALEOSOL ENVIRONMENT, GYÖNGYÖSVISONTA, HUNGARY

SZILÁGYI, V.1, SZINGER, B.1, WEISZBURG, T. G. 1, HORVÁTH, Z.2 & MINDSZENTY, A.21 Department of Mineralogy, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected] Department of Applied and Environmental Geology, Eötvös Loránd University, Pázmány Péter sétány 1/C,H-1117 Budapest, Hungary.

Carbonate concretions, including grown up, fine, euhe-dral crystals of calcite were discovered in the open cast lig-nite mine at Gyöngyösvisonta, in the southern foreland of theMátra Mountains, Hungary. The concretions are embeddedin a thick (8–10 m) paleosol (red clay) sequence sedimentedon Pannonian age strata. They attracted our attention becausesuch calcite crystals are very common in hydrothermal envi-ronments, but seemed to be unusual in a soil-related envi-ronment.

Our aim was to describe the morphological appearance ofthe crystalline calcite in the concretions and to obtain infor-mation about their formation.

In order to get morphological data we applied stereomi-croscopy, scanning electron microscopy and two-circle re-flecting goniometer measurements. Two main morphologicaltypes of calcite were found. The rhombohedral type is builtup of the combination different rhombohedra, while the sca-lenohedral type is built up of the combination of rhombohe-dra and scalenohedra.

X-ray powder diffraction patterns showed two types ofcalcite. The micritic wall of the concretions and the root zoneof the euhedral crystals consisted of pure calcite. In the coro-nal zone of the crystals, beside the pure calcite, another,sligtly substituted calcite of shorter lattice parameter(d104 = 2.98 A) can also be detected.

That substituted calcite region was studied in detail bycathode luminescent microscopy and by SEM+EDX. Wefound growth zoning of calcite in that part of the samples.The width of the individual zones varies between 50 and150 µm. The zoning is caused by chemical substitution. Inthe cathode luminescent microscope an unusually strongluminescence of these zones (in “pure” calcite) could beseen. Back scattered electron images showed the presence ofcation(s) of larger average atomic number than calcium inthe luminescent zones. Based on EDX measurements thesubstituting element is manganese (3–6 cation%). Pure cal-cite and manganese bearing calcite are separated by sharpboundaries. The oscillatory precipitation of the two phasesresulted in the formation of several, sometimes many tens,manganese free and manganese containing zones.

Carbon and oxygen stable isotope analysis was carriedout on a set of samples representing 1) the micritic wall of

the concretions, 2) the root zone and 3) the coronal zone ofthe euhedral calcite crystals. The results can be interpreted asthe euhedral crystals precipitated in a closed system insidethe concretions. There is no data indicating any elevatedtemperature (hydrothermal) formation condition.

The closed system crystallization raises the question onthe origin of the growth zoning of calcite. In an open systemchemical changes of the fluid could be assumed, in a closedsystem physical environmental parameters, in our casemainly temperature and maybe temperature related biologicalactivity could be responsible for the entrance of manganesein the calcite lattice.

For a better understanding of the genetic conditions westudied also the black, mm sized nodules to be found both inthe paleosol (red clay) environment of the concretions andencapsulated in the micritic wall of the concretions them-selves. Based on X-ray diffractometry and optical emissionspectroscopy they turned out to be mixtures of (detrital)quartz and poorly crystallized oxides and oxy-hydroxides ofiron (goethite and hematite). Their manganese content is inthe 1000–10000 ppm range. There was no significant differ-ence between the nodules separated from the micritic walland from the red clay, thus we consider the former ones asrelicts of the red clay environment in the concretions.

Based on our data we reconstruct the formation of theconcretions as follows:

In the first phase loose, calcareous concretions formed inthe red clay sequence. In a second step volume changes,coming from alternation of dry and humid climatic periodscaused cracks in the concretions within the soil. In thesecracks calcite growth started, resulting both the thickening ofthe wall of the concretions and, simultaneously or subse-quently, the precipitation of the root zone of the euhedralcrystals. Concretions became thick-walled, at most 35–40 cmin diameter, bodies due to subsequent solutions and finaldesiccation. Inside the concretions, in the closed cavitiescrystallization of euhedral calcite continued, resulting biggerand bigger crystals towards the inside of the concretions.

We hope that our results contribute not only to the betterunderstanding of the formation of concretions, but also tothat of the development of the whole soil environment.


102

HYDRONIUM JAROSITE FROM IZA CAVE (RODNEI MTS., ROMANIA)

TAMAS, T.1 & GHERGARI, L.21 Department of Mineralogy, Babeş-Bolyai University & “Emil Racoviţă” Institute of Speleology, 1, Kogalniceanu Str,RO-3400 Cluj-Napoca, Romania.E-mail: [email protected] Department of Mineralogy, Babeş-Bolyai University, 1, Kogalniceanu Str, RO-3400 Cluj-Napoca, Romania.

Several secondary deposits consisting of crusts and flow-stones have been investigated in Iza Cave (Rodnei Moun-tains, Maramureş county, Romania). The cave is formed atthe contact between Eocene limestones and conglomeratesand crystalline rocks (sericite-chlorite schists and crystallinelimestones).

Previous studies carried out in Iza Cave reported a largeclay-like deposit, consisting of muscovite, illite, kaolinite,dickite, quartz and possibly rutile, formed by subaerialweathering of schists in the cave environment (VIEHMANNet al., 1979, 1981). We found that the heavy fraction of theweathered schists is composed mainly of quartz and pyrite,evidenced by XRD and SEM - EDAX.

The secondary deposits studied consist of hydroniumjarosite [(H3O,K)Fe3(SO4)2(OH)6] deposited over goethiteflowstone. Hydronium jarosite forms millimeter to centime-ter–sized orange crusty nodules, composed of small (1–3µm), relatively isometric rhombohedral crystals.

The X-ray diffraction pattern shows the major participa-tion of hydronium jarosite, associated with small amounts ofalunite (most intense reflections, partially covered by hydro-nium jarosite lines), and quartz (the peak at 3.34) and kao-linite (peak corresponding at 7.2), the latter two as impuri-ties.

The normative calculus based on the EDAX analysis al-lowed us to determine the participation of hydronium jaro-site, which is the main mineral (87.50%), associated with

small amounts of alunite (5.1%), quartz (4.97%), and kao-linite (0.67%).

The thermal analysis on the sulfate sample shows aweight loss of 5.79% until 163 °C, which was assigned to theloss of H3O. The following weight losses, totaling 9.75%,were assigned to the decomposition of OH from the jarositestructure, which was theoretically calculated at 9,77%.

Both goethite and hydronium jarosite formed through theaction of percolating water over pyrite that is present as ac-cessory mineral in the crystalline schists.

Minerals from the jarosite group are rarely present incaves; a survey of the known records around the worldshows very peculiar depositional conditions (HILL &FORTI, 1997). Iza Cave is the first known occurrence ofhydronium jarosite in Romania. Moreover, this mineral hasnot been previously reported from the cave environment.

ReferencesHILL, C. & FORTI, P. (1997). Cave minerals of the world.

2nd ed. NSS, Huntsville, 463p.VIEHMANN, I., DEMETER, I., LUNGU, V. &

SARKADY, P. (1981). Trav. Inst. Speol. “E. Racovitza”,XX: 213-215.

VIEHMANN, I., SILVESTRU, E. & FABIAN, C. (1979).Trav. Inst. Speol. “E. Racovitza”, XVIII: 201-207.


103

A DOS PROGRAM FOR SUPPORTING MODAL ANALYSIS OF ROCKS (MOD_EL v. 2.12)

TÓTH, S.1, CSÁMER, Á.2 & RÓZSA, P.21 Darabos u. 10, H-4026 Debrecen, Hungary.2 Department of Mineralogy and Geology, University of Debrecen, P.O. Box 4, H-4010 Debrecen, Hungary.E-mail: [email protected]

Modal analysis is a basic petrographic method for deter-mination of mineralogical composition and grain-size distri-bution of rocks. Two types of data series can be obtained bythis method: (1) relative quantity of rock forming minerals,and (2) grain-size distribution of the studied rock. Moreover,using an appropriate method, grain-size distribution of themain mineral components can be also determined. This way,further petrological conclusions (such as classification of thetexture, distinction of rock varieties and facies, etc.) can bedrawn. Any method of the modal analysis should satisfythree principal requirements: (1) appropriate accuracy, (2)simplicity, and (3) speed.

Amongst methods of modal analysis (CHAYES, 1956)the authors regard the classic Rosiwal’s method (ROSIWAL,1898) − measuring along the line − as the most efficient.First, this method does not require special equipment, andsecond, relative quantity of the rock forming minerals as wellas grain-size distribution can be simultaneously determined.Moreover, in the case of necessary measurements its accu-racy is acceptable (JÁRAI et al., 1997). However, a rela-tively long line has to be measured, and large amount of datahas to be evaluated to obtain precise results.

MOD_EL v. 2.12 software package introduced by thispaper is able to use data recorded in simple text and special

XLS (MS-Excel) file formats, and to evaluate these datastatistically. It gives the minimal measuring length for therequired accuracy, and compiles tables and graphs for repre-senting the results of the measurement. Minimal hardwareand software requirements are to run the software: AT 386compatible computer with (4 MB RAM, 20 MB hard diskspace, monochromatic monitor, MS-DOS 5.5 operation sys-tem. Of course, MOD_EL v. 2.12 runs on Windows OS(Windows 9x/NT/2000), too. Both English and Hungarianversions are available. As a final result, the program lists thegrain-size and mineral components data in a summarizedtable, and makes grain-size distribution curves (Fig. 1).

AcknowledgementThis work was supported by the OTKA Grant T-029058.

ReferencesCHAYES, F. (1956): Petrographic Modal Analysis. John

Wiley and Sons Inc., New York. 113 pp.JÁRAI, A., KOZÁK, M. & RÓZSA, P. (1997). Math. Geol.,

29/8: 977–991.ROSIWAL, A. (1898). Verh. der k. k. Geol. Reichanstalt,

Wien, 5–6: 143–175.

Fig. 1: Grain-size distribution curves drawn by MOD_EL v. 2.12 program.


104

HISTORICAL-MUSEOLOGICAL DATA OF THE METEORITE OF KISGYŐR(BORSOD-ABAÚJ-ZEMPLÉN COUNTY, HUNGARY)

TÓTH-SZABÓ, T.Department of Mineralogy, Herman Ottó Museum, Kossuth u. 13, H-3525 Miskolc, Hungary.E-mail: [email protected]

Meteors (falling stars) and their parts falling on Earth, aswell as meteorites are exciting the curiosity of mankind. Ifonly we consider the history of mankind, which is neglect-able in time compared to that of Earth, than we find that thenumber of them is quite significant.

There have been impacts recorded in Hungary as well,both recently and in past times. Considering the historicalbackground one of the oldest meteorite falls was that ofDiósgyőr in 1559 (1449? or 1560?). Furthermore, not farfrom Miskolc, at Kisgyőr a meteorite has also been docu-mented in 1901, centuries later. Examining the arrivingagenda of the natural history collection of the predecessor ofHerman Ottó Museum, the Borsod–Miskolc Museum, I havefound the particles of the Kisgyőr materials entered underregister number 180. According to that there were 5 parts ofthe meteorite presented to the museum’s fossil and mineralcollection by SámuelNagy. The notes only describe that theparts touched down near Miskolc, at Kisgyőr — as it wasknown before — on 23rd May 1901. Some collection infor-mation could be found in the 1902 catalogue of the Borsod–Miskolc Museum. According to those the listed parts wereput on exhibition in section “A” and “E” of the main hall onthe ground floor. The list contained the meteorites of Kisgyőrunder the numbers “120”, “121”, “122”, “123”, “124”. Thatmay mean that the parts arrived to the museum not long aftertheir impact. From 1905 the fossil and mineral collection didnot form a separate part, but was handled together withsimilar collections under the name of “natural history collec-tion”, which makes the processing of the collection agendaharder. They have probably been in museum property formany decades. Their time of destruction is supposed to bethe 50s, when the natural history collection was eliminated.The geological material became part of the natural sciencecollection of the National Museum. After all these the ques-tion is whether the meteorite found in the meteorite catalogueof TOKODY & DUDICH-VENDL (1951) and kept at thelatter place derives directly from Kisgyőr or is a remainder of

the handover in the 1950s. It is mentioned under log number“b 121” here. Its weight is determined to be 3,61 grams. Ifthe latter version is valid, than the only question is: what hashappened to the other 4 particles, for according to the data, asI have previously mentioned, there were 5 parts recorded inthe Borsod–Miskolc Museum, while there is only one in themeteorite catalogue. However if those were a part of a newcollection enlargement it is also worth to examine their fur-ther destiny. Where are they? Are they still on storage? Ifnot, what has happened to them? Later the Hey’s meteoritecatalogue (HEY, 1906) mentions them, though on the basisof the letter of Viktor Zsivny they are considered to be ques-tioned, questionable meteorites. However, according toMTM, that part was also destroyed in the destruction reach-ing most of the mineral collection in 1956. The fact that thecatalogue of Csaba Ravasz, prepared in 1969, mentions onlytwo sites, the ones at Ófehértó and Zsadány, seems to sup-port that. The collection shows the circumstances after thetragic conflagration of 1956. Though it is still not clear forme, whether that destruction reached only the part mentionedin the catalogue in 1951, or the parts from Miskolc were alsoincluded.

ReferencesBUDAI, J. (1902) in: Molnár, J. (ed.): Borsod-Miskolci

Múzeum ismertető katalógusa (Information Catalogue ofthe Borsod–Miskolc Museum), Szelényi és Társa,Miskolc.

HEY, M. H. (1906): Catalogue of Meteorites (Trustees of theBritish Museum), London.

RAVASZ, Cs. (1969): Catalogue of Meteorites of the Hun-garian Natural History Museum. Fragm. Miner. Paleon.

TOKODY, L. & DUDICH-VENDL, M. (1951): Magyaror-szág meteoritgyűjteményei (Meteorite collections ofHungary). Akadémiai Kiadó, Budapest.


105

MINERAL FORMATION PROCESSES IN KARST CAVE SYSTEMS OF THE MIDDLEMIOCENE BADENIAN GYPSUM (CARPATHIAN FOREDEEP, WEST UKRAINE)

TURCHINOV, I. I.Lviv Geological Survey Expedition, Turgeneva 33, UA-79018 Lviv, Ukraine.E-mail: [email protected]

Giant labyrinth cavern systems (largest of them – Opti-mistic Cave – has a length more than 210 km) are a result ofdeep karst processes in the middle Miocene Badenian gyp-sum in the outer part of Carpathian Foredeep. These systemsare characterized as lateral labyrinth networks of karst cavi-ties. Air temperature in the caves is +8,2–10,5 °C, air hu-midity 96–100%, CO2 concentration 0,1–4,8%, radon con-centration up to 23700 Bq/m3. Original geological, physicaland chemical conditions have determined a wide develop-ment of mineral formation processes here.

Minerals originated in karst cavern systems of the Mio-cene gypsum belong to classes of sulphates (gypsum, celes-tine), carbonates (calcite, rhodochrosite), silicates (chalced-ony), oxides and hydroxides (minerals of iron and manga-nese, ice). Formation of minerals is determined by followingprocesses:

- crystallization after evaporation of thin film ofwater (gypsum, celestite, calcite);

- crystallization after evaporation of seeping in-terstitial water (gypsum);

- crystallization from free flowing water aftercarbon dioxide loss (calcite, rhodochrosite);

- crystallization in clay filling of cavities (gyp-sum);

- crystallization from water in joints (gypsum,calcite);

- crystallization from aerosol (gypsum);- subaqueous crystallization (calcite);- crystallization from gels (chalcedony);- biochemical precipitation (iron and manganese

oxides and hydroxides);- freezing crystallization (ice).

Processes of mineral formation in the karst cave systemsof the Miocene gypsum are low-temperature. Minerals origi-nated as a result of these processes occur in the form of spe-cific aggregates – speleothems (crusts, stalactites, helictites,etc.). Subaerially-formed speleothems predominate, and theirgrowth is controlled by air currents in the cavities.


106

OUTSTANDING MINERAL OCCURRENCES IN ROMANIA: WHAT’S NEW?

UDUBAŞA, G.Geological Institute of Romania, Caransebeş Street No. 1, RO-78344 Bucharest-32, Romania.E-mail: [email protected]

To date some 900 mineral species are known in Romania,much more than UDUBAŞA (1999) reported, i.e. about onequarter of the minerals in the world. The increase of numberof mineral species is considerable as compared to about 450in 1966. An attempt was also made to identify the most“productive” occurrences (“sacred monsters”) (see table)both as concerns the total number of mineral species andsome unusual crystal forms or intergrowths (UDUBAŞA,1994).

Among the “sacred monsters” the hydrothermal andskarn deposits are by far dominating. In addition to the oldskarn deposits quoted in the table, the high temperature skarnoccurrences at Măgureaua Vaţei near Brad (Cornet Hill andCerboaia Valley localities) have proved to contain also nu-merous other high–T calcium silicates as well as the rarechlorosulphide, djerfisherite, and hydroxylellestadite (PAS-CAL et al., 2001; MARINCEA et al., 2001). Neverthelessthe caves and the stratiform Mn-Fe ores show a greater min-eral diversity after recent careful investigations by ONAC &DAMM (2002), ONAC et al. (2000), MARINCEA et al.(2002) and HARTOPANU (2002), respectively. Metatyuya-munite, wittichenite, scawtite, tinsleyite, taranakite, nor-sethite etc were thus identified in different caves. The wholeseries of the manganhumites, some silicates-arsenates, nam-bulite, bannisterite etc are only few among the 300 mineralspecies and varieties discovered in the Mn-Fe ores in theBistriţa Mts. (HARTOPANU, 2002 and this volume). It isexpected that the Ditrău “monster” will produce soon manynovelties as about one quarter of the proposals for new min-erals submitted to CNMMN is delivered by alkaline massifs.

Table“Sacred monsters” of mineral occurrences in Romania

(1 to 8 acc. to UDUBASA, 1994).

1. Săcărâmb / Nagyág: 120 mineral species, 6 times typelocality.

2. Baia Sprie / Felsőbánya: 80 m.s.; 6xTL; Felsőbányahabit of “adularia”.

3. Băiţa Bihor / Rézbánya: 120 m.s.; 5xTL.

4. Ocna de Fier / Moravicza / Vaskő / Eisenstein: 100 m.s;2xTL. Also many pyrite crystal forms have their TLhere.

5. Ditrău / Ditró: 60m.s.; a new Bi-Pb sulphotelluride.6. Răzoare/Macskamező: 70m.s.; many rarities!7. Roşia Montană / Verespatak: 50 m.s.; twin law of high

quartz.8. Uroiu/Arany/Aranyerberg: 20 m.s.; TL of pseudo-

brookite.9. Bistriţa Mts (Iacobeni, Dadu, Tolovanu, Oiţa deposits,

etc): some 300 mineral species and varieties discoveredin the last 10 years (HARTOPANU, 2002 and the paperin this volume).

10. Bihor Mts caves: mineral rarities: taranakite,metatyuyamunite, norsethite, glaucosphaerite, scawtite,etc. (ONAC & DAMM, 2000; ONAC et al., in press).

11. Cioclovina Cave: TL of ardealite; also brushite, crandal-lite, tinsleyite, etc. (MARINCEA et al., 2002)

12. Măgureaua Vaţei: high T skarns with scawtite, tilleyite,spurrite, gehlenite and many other Ca silicates, as well ashydroxylellestadite, djerfisherite etc. (PASCAL et al.,2001; MARINCEA et al., 2001).

ReferencesHARTOPANU, P. (2002). Ph.D. Thesis, Univ. of BucharestMARINCEA, Şt., BILAL, E., VERKAEREN, J., PASCAL,

M. L. & FONTEILLES, M. (2001). Canadian Mineralo-gist, 39: 1435-1453.

MARINCEA, Şt., DUMITRAS, D. & GIBERT, R. (2002).Eur. J. Mineral., 14: 157-164.

ONAC, B. P. & DAMM, P. (2002). Studia Univ. Babes-Bolyai, Geologia, XLVII: 93-104.

ONAC, B. P., KEARNS, J., DAMM, P., WHITE, W. B. &MATYASI, S. (2000). Rom. J. Mineralogy, 80: 5-10.

PASCAL, M. L., FONTEILLES, M., VERKAEREN, J.,PIRET, R. & MARINCEA, Şt. (2001) Canadian Miner-alogist, 39: 1405-1434.

UDUBAŞA, G. (1994). Anal. Univ. Bucuresti, XLIII,Suppl.: 34-35.

UDUBAŞA, G. (1999). Rom. J. Mineralogy, 79: 3-30.


107

MAGMATIC DIFFERENTIATION PROCESSES DURING EVOLUTION OF NEOGENECALC-ALKALINE MAGMATITES OF THE SUBVOLCANIC ZONE IN THE EAST-CARPATHIANS

URECHE, I.1, PAPP, D. C.1 & NIŢOI, E.21 Geological Institute of Romania, Cluj-Napoca Branch, C. P. 181, RO-3400 Cluj-Napoca, Romania.E-mail: [email protected] Geological Institute of Romania, 1, Caransebeş str, RO-78344 Bucharest-32, Romania.

This paper evaluates Neogene calc-alkaline magmatismfrom Rodna-Bârgău Mts. based on new data on mineralcompositions, and new major and trace element data forestimating specific chemical and P-T conditions of the dif-ferent magmatic structures. Great variety of petrographictypes (from basaltic andesites to rhyolites), preponderance ofintermediary and basic rocks which form more extendedintrusive structures compared with acid ones, as well as pres-ence of cognate xenoliths only in the intermediary facies,deal with conjugate processes of assimilation, fractionalcrystallization, and repeatedly refilled magma chambers.

Amphiboles are the main mafic mineral within the mag-matic rocks in the Rodna–Bârgău area. Most of the amphi-bole phenocrysts, especially those found in the andesites andmicrodiorites, as well as the amphiboles in mafic cognatexenoliths hosted by these rock types can be defined as mag-nesiohastingsites. The amphiboles belonging to more acidicfacies (dacites, quartz andesites) are represented by tscher-makite. The chemical composition of the amphiboles in cog-nate xenoliths is also relatively heterogeneous; it correspondsto various species such as magnesiohastingsite, magnesio-hornblende, and pargasite.

Pyroxenes are present only in the more basic petrographi-cal types, quantitatively subordinated to the amphiboles.They are also found in a number of cognate xenoliths. Withinthe cognate xenoliths the Ca-rich pyroxenes (diopside) ispresent, while in the host-rocks the Mg and Fe-rich variety(augite).

In most of the petrographic types the plagioclase feld-spars (oligoclase to bytownite) show normal zoning, andoscillatory normal zoning. The normal oscillatory zoningindicates modification of the crystallization conditions (i.e.magma chamber refilling and/or rapid cooling during theemplacement of the intrusive body). Potassic feldspars (or-thoclase, sanidine) are present in very small amounts, mostlyin the cognate xenoliths.

The garnets are present only in the quartz andesites anddacites (1–2 wt% of the rock volume). The analyzed garnetcrystals are almandine (over 55%). Garnets are fresh, with noinclusions and reaction zones.

Discrimination between two series of rocks is better evi-denced in the K2O–SiO2 diagram. The first series comprisesandesites, dacite, and rhyolite. It characterizes the medium-to low-K domain. The second series contains basaltic ande-

sites, andesites and microdiorites. It trends towards the high-K domain.

The major elements host rocks TiO2, FeO, MgO, andCaO variation with SiO2 content shows trends of negativecorrelation, whereas K2O and Na2O increase with increasingSiO2. These trends are consistent with fractional crystalliza-tion starting from basic magmas. Rb, Nb, Pb, Sr, Zr, Y showa scattered variation with SiO2. This indicates diverse condi-tions of magma generation for different magmatic structures.LIL and LREE enrichment as compared to primitive mantledeal with crustal assimilation processes.

Using Al content in hornblende as geobarometer and am-phiboles-plagioclase geothermometer, we obtained a tem-perature range from 798 to 936 °C, and a more significantpressure variation from 6201 bars to 8886 bars. Generally,the cognate xenoliths display slightly lower P-T values com-pared with their host rocks. The pressure estimates for hostrocks and cognate xenoliths suggest mid-crustal depths ofapproximately 15–25 km, which probably represent thedepth of intermediate chambers where mixing-minglingprocesses took place.

Each intrusive structure encountered specific magmaticevolution processes, which have been controlled by absenceor presence of an intermediate magmatic chamber and itsdepth, by magma volume, and by refilling of magma cham-ber. The acidic rocks from the medium to low-K series formmuch smaller structures, and the petrographic and geochemi-cal characteristics are not consistent with the existence ofintermediate magmatic chambers. The presence of primarymagmatic garnets and the absence of cognate xenoliths indi-cate rapid ascent toward the surface.

The evolution of the rocks from high-K series was morecomplex; thus, the presence of intermediate large magmachambers situated in the upper crust where AFC processestook place is to be considered. These rocks are well crystal-lized, have high K and Sr content.

Within this chamber different process type could occur:complex magma mixing and crustal assimilation. Beside theassimilation process of the middle crust, an additional proc-ess of repeated fed of magma chamber could explained theabundance of cognate xenoliths, including pyroxenites, andthe low SiO2 content of these rocks. Such processes couldalso explain the chemical and isotopic heterogeneity of thecognate xenoliths found in these units.


108

COMPUTER SIMULATION BY ENERGY MINIMISATION ON FIBROUS ZEOLITESTRUCTURES

VÁCZI, T.1 & WARREN, M. C.21 Department of Mineralogy, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected] Department of Earth Sciences, University of Manchester, Manchester M13 9PL, UK.

There is an extensive set of papers dealing with fibrouszeolites in past and recent literature, focussing largely onorder–disorder issues. The hottest debate concerns the ques-tion of tetragonal species sharing natrolite topology, i.e. thevalidity of and distinction between gonnardite and tetrana-trolite (e.g. ALBERTI et al., 1995; ARTIOLI & GALLI,1999; EVANS et al., 2000). The aim of this presentation is toreport the first results of computer simulation on structureswith natrolite topology.

Two input structures were analysed in depth, a reportedlycompletely ordered natrolite (ARTIOLI et al., 1984) and acompletely disordered gonnardite structure (ARTIOLI &TORRES SALVADOR, 1991). The method chosen was tocalculate the lattice energy of the structures with the GULPcode (GALE, 1997). This method has previously been usedto locate extraframework species in zeolite A by HIGGINSet al. (2002), and the interatomic potentials used in that workwere applied. The structure and unit cell of each phase wereoptimised by energy minimisation whenever possible. Initialatomic coordinates were directly taken from the neutrondiffraction data of ARTIOLI et al. (1984) in the case of na-trolite and occupancies were all set to 1. In the case of gon-nardite (sample no. 3 in ARTIOLI & TORRES SALVA-DOR, 1991, Rietveld refinement from X-ray powder data), Hpositions were added to the data set and T1 and T2 positionswere given shared occupancies by Si and Al.

In all successful calculations on all cell contents, cell pa-rameters a and b are slightly smaller than experimental ones.In unsuccessful calculations the reason for failure was mostlythe unreasonable displacement of channel contents, espe-cially H2O. Water molecules are well known to be difficult tomodel empirically and further development of the potentialsmay be advantageous.

Simulation runs on the natrolite structure were unsuccess-ful. With symmetry constraints on, the structure could not beoptimised. With symmetry off, the non-primitive cell firstdistorted (β the most, i.e. through monoclinic) and then thecalculations failed completely, the distortion did not stabilisethe structure. The reasons are yet unknown, could be that thepotentials used were derived for a different system.

The first few tentative simulation runs on the tetragonalstructure were simplified to the level of using only Na assecondary cation and omitting W2’s (additional H2O notpresent in natrolite) completely. These configurations weresuccessfully optimised with symmetry constraints. The intro-

duction of Ca + H2O for Na substitution was more problem-atic. Static lattice calculations represent shared or partialoccupancies by calculating appropriate weighted potentials.This approach is invalid in the case of fibrous zeolites be-cause in the shared/partial occupancy model each hybridsecondary cation is paired with a “partial” H2O moleculewhereas the water molecule W2 should only be present inconjunction with Ca. If in the (Na, Ca) positions there are“hybrid” atoms (e.g. 0.75 Na and 0.25 Ca), W2 in the re-sulting configuration behaves differently from what is ex-pected.

To correct the problem, the structure was rebuilt with P1symmetry, i.e. all positions symmetrically inequivalent (160atoms per unit cell altogether). This allows looking at hypo-thetical substitution configurations, in such a way that thecomplete but long range disorder is not taken into accountand “pure” channel contents are present with an occupancyof 1. (However, the shared occupancy of the T positions wasretained for simplicity.) The calculations have shown that thesplit W2 positions in ARTIOLI & TORRES SALVADOR(1991) cannot be optimised in static simulation runs. After“probing” several W2 positions, a structure with one Ca andone adjacent H2O in the average of the two W2 positions,however, was found to achieve optimisation. Another simu-lation run on a structure with 2 Ca + 2 H2O(W2) in the unitcell was also optimised when all the channel contents wereallowed to move (the framework was held fixed in position).

ReferencesALBERTI, A., CRUCIANI, G. & DAURU, I. (1995). Eur. J.

Mineral., 7: 501–508.ARTIOLI, G. & GALLI, E. (1999). Am. Mineral., 84: 1445–

1450.ARTIOLI, G. & TORRES SALVADOR, M. R. (1991). Ma-

ter. Sci. Forum, 79–82: 845–850.ARTIOLI, G., SMITH, J. V. & KVICK, Å. (1984). Acta

Cryst., C40: 1658–1662.EVANS, H.T., KONNERT, J. A. & ROSS, M. (2000). Am.

Mineral., 85: 1808–1815.GALE, J. D. (1997). J. Chem. Soc. Faraday Trans., 93: 629–

637.HIGGINS, F. M., DE LEEUW, N. H. & PARKER, S. C.

(2002). J. Mater. Chem., 12: 124–131.


109

MAJOR ELEMENT MODELING OF THE BRNJICA GRANITOIDS (EASTERN SERBIA)

VASKOVIC, N.1, KORONEOS, A.2, CHRISTOFIDES, G.2, SRECKOVIĆ-BATOCANIN, D.1 & MILOVANOVIĆ, D.11 Faculty of Mining and Geology, University of Belgrade, Djušina 7, YU-11000 Belgrade, Yugoslavia.E-mail: [email protected] Department of Mineralogy, Petrology and Economic Geology, Aristotle University of Thessaloniki, GR-54124 Thessaloniki,Greece.

The Brnjica granitoid pluton has an exposed area of ca.27 km2 intruding Proterozoic gneisses (subordinate mi-caschist and amphibolite) and Ripheo-Cambrian meta-volcanosedimentary series with a variety of green rocks. TheBrnjica granitoids occur in the Kučaj terrane (KRSTIĆ &KARAMATA, 1992), the oldest rocks of which are the Pro-terozoic Osanica metamorphic rocks, followed by the lateProterozoic to early Cambrian “Green Complex”. During theVariscan magmatism the Brnjica pluton intruded the aboverock formations, as a late- to post-kinematic intrusion, caus-ing an extensive thermal metamorphic phenomena(KARAMATA & KRSTIC 1996; VASKOVIC & MATO-VIC,1997).

The Brnjica pluton, comprising tonalite (TON), granodio-rite (GRD), two-mica granite (TMG) and leucogranite (LG),has Fe-biotite and magnesiohornblende, as main mafic min-eral constituents. Muscovite occurs subordinately. Plagio-clase is of oligoclase-andesine composition. Pressure of 2.3to 4.1 kb and temperatures from 626 to 813 °C were calcu-lated for TON, using hornblende and co-existing hornblendeand plagioclase compositions respectively. SiO2 in TON andGRD ranges from 64.2 to 68.25 wt.% and from 67.7 to 72.5wt.% while in TMG is 73.8 wt.% and in LG 75.7 to 75.9wt.%. Most of the oxides (TiO2, Al2O3, Fe2O3t, MgO andCaO) in TON and GRD form well-correlated trends. In TMGand LG most of the elements (TiO2, Fe2O3, MgO, CaO,Na2O, K2O and total alkalies) follow the general trend ofGRD. All samples analyzed are slightly peraluminous withA/CNK=1.0-1.3. Based on the R1-R2 diagram, the TON andmost of the GRD plot in the pre-plate collision granites(VAG). The granites and the most evolved GRD plot in thesyn-collision granite field or around it. Combined mineraland rock major element chemistry suggests the involvementof fractional crystallization for the evolution of the Brnjicarocks. Major element modeling, using the less evolved (BRJ-208) and the most evolved (BRJ-223L) samples as parentaland daughter magma respectively, requires 24% (F=0.76)crystallization of the assemblage Pl55.5Kfs8.4Bt9.8Hbl21.1Ap0.3

Mgt2.1Ttn2.9 for the evolution of the TON. In the model forthe GRD evolution the less evolved sample BRJ-227 and themost evolved sample BRJ-231 were used as the parentalmagma and as the daughter magma respectively. The model

requires 50% crystallization (F=0.5) of the mineral assem-blage Qz24.9Pl52.3Bt18.2Zrn0.1Ap1.5Mgt1.7Ttn1.2 to give thedaughter magma (BRJ-231). A model using the most evolvedTON (BRJ-223L) as parental for the evolution of GRD failedto give reliable results. The TON could originate in the crustby melting of amphibolites and basalts under various P-Tconditions, which gives melts having 61-67 wt% silica. TheGRD could also originate in the crust by melting of amphi-bolites, basalts and pelites, which gives melts with 64-70wt% silica. Lastly, the source of the granites could be crustalmelts produced by melting of amphibolites, gneisses, gray-wackes and pelites.

ReferencesBATCHELOR, R. A. & BOWDEN, P. (1985). Chem. Geol.,

48: 43-55.BEARD, J. S. & LOFGREN, G. E. (1991). J. Petrol., 32:

365-401.BEARD, J. S. et al. (1994). J. Geoph. Res., 99: 21591-

21603.GARDIEN, V. et al. (1995). J. Geophys. Res., 100: 15581-

15591.HOLLAND, T. & BLUNDY, J. (1994). Contrib. Mineral.

Petrol., 116: 433-447.HOLTZ, F. & JOHANNES, W. (1991). J. Petrol., 32: 935-

958.KARAMATA, S. & KRSTIC, B. (1996): In “Terranes of

Serbia and neighbouring areas” 25-40.MONTEL, J. M. & VIELZEUF, D. (1997). Contrib. Mineral.

Petrol., 128: 176-196.PICKERING, J. M. & JOHNSTON, D. (1998). J. Petrol., 39:

1787-1804.RAPP, R. P. & WATSON, E. B. (1995). J. Petrol., 36: 891-

931.RAPP, R. P. et al. (1991). Precambrian Res., 51: 1-25.SCHMIDT, M. W. (1992). Contrib. Mineral. Petrol., 110:

304-310.SKJERLIE, K. P. & JOHNSTON, D. A. (1993). J. Petrol.,

34: 785-815.VASKOVIC, N. & MATOVIC, V. (1997). Proc. Intern.

Symp. “Geology in the Danube Gorges”, 130-141.


110

GENERAL TRENDS IN THE EUROPEAN HIGHER EDUCATION AND THEIR EFFECTS ONTHE TEACHING OF MINERAL SCIENCES.

WEISZBURG, T.G., BUDA, GY., LOVAS, GY.A., (Eötvös Loránd University, Pázmány Péter sétány, Budapest, H-1117),BENEA, M., POP, D. (Babeş-Bolyai University, str. Kogalniceanu, Cluj-Napoca, RO-3400), CHRISTOFIDES, G., KORO-NEOS, A. (Aristotle University, Panepistimioupolis, Thessaloniki, GR-54124), COMPAGNIONI, R., FERRARIS, G. (Uni-versity of Turin, via Valperga Caluso, Torino, I-10125), EFFENBERGER, H.S., TILLMANNS, E. (University of Vienna,Althanstrasse, Wien, A-1090), GEIGER, C.A. (Christian-Albrechts University, Olshausenstrasse, Kiel, D-24098), MERLINO,S., PASERO, M. (University of Pisa, Via S. Maria, Pisa, I-56126), MÜLLER, W.F. (Technical University of Darmstadt,Karolinenplatz, Darmstadt, D-64289), PÓSFAI, M. (University of Veszprém, Egyetem utca, Veszprém, H-8200) &VAUGHAN, D.J. (Manchester University, Oxford Road, Manchester, M13 9PL, U.K.)E-mail: [email protected]

In Europe, the general landmarks for modern higher edu-cation were established by a series of agreements signed bygovernmental representatives from more than 30 countries(Sorbonne Declaration, 1998; Bologna Declaration, 1999;Prague Communiqué, 2001).

The Bologna Declaration introduced the concept of aEuropean Higher Education Area (EHEA; to be establishedby 2010) based on the compatibility of the degree structure(two main cycles: undergraduate and graduate studies), thecredit system (ECTS and compatible), the promotion of stu-dent and staff mobility, the quality assurance, and the pro-motion of the European dimensions in higher education.

The introduction of the first cycle (undergraduate,“bachelor-type” degree, of a minimum length of 3 years) +second cycle (graduate, “master-type” degree) structure aimsat creating convergence only, and is explicitly “not a pathtowards the ‘standardisation’ or ‘uniformisation’ of Europeanhigher education”. Concerning the European dimensions thePrague Communiqué emphasizes the importance of “thedevelopment of modules, courses and curricula at all levelswith ‘European’ content, orientation and organisation”, in-cluding the preparation of “degree curricula offered in part-nership by institutions from different countries and leading toa recognised joint degree”.

Mineral Sciences (MS), a group of sciences dealing withnatural and analogous solid substances, have been tradition-ally taught in geoscience-centred curricula in Europe, thoughtheir century long connection to physics and chemistry re-mained unchanged and their interactions with new fields, like

environmental science and material science became veryimportant in the last few decades.

That multidisciplinary character and the expensive appa-ratuses needed for proper teaching of MS in addition to therelatively limited number of students in MS resulted in thestep-by-step loss of the position of these disciplines withinthe different curricula and within the university structures,too.Accordingly, teaching of MS had to follow the trends,and to reformulate its topics, goals and targets and to fit thatrenewed content in the new EHEA.

A break-out point from the present situation could be aharmonised teaching of MS in the first cycle at home univer-sities, which would give a solid base for a recognised Euro-pean joint degree system (EuroMaster in Mineral Sciences)in the second cycle. Between 1998–2001 a group of 10European universities gathered their efforts in preparing a“Co-ordinated European Core Curriculum in MS” (for thefirst cycle, undergraduate level) in the frame of a SOCRA-TES/ERASMUS CDI project sponsored by the EC. Theseactivities led to a proposal for the minimum mineral sciencerelated content and structure of the first cycle degrees (=inputlevel of the second cycle; see figure). From the academicyear 2002/03, as a continuation, work has started on thesecond cycle (CDA, graduate) part. This part will be com-pleted in the academic year 2004/05. The project is open intwo ways for universities not partners in the consortium: 1)the results of the project are freely available for local adapta-tion at any university, 2) by the summer of 2003 furtheruniversities can officially join the third year of the project.

Eurobachelor in Mineral Sciences

Eurobachelor in

Geosciences

Eurobachelor in Applied Mineralogy

3rd y

ear (

leve

l 3);

(F

IRST

CYC

LE)

OR

IEN

TATI

ON Basics of

Mathematics, Physics, Chemistry (Fundamental research)

Basics of other Geosciences (Mineralogy applied to Geosciences)

Basics of Applied Mineralogy (Environmental and Technical Mineralogy)

1st &

2nd

yea

r (le

vel 1

&2)

; (F

IRST

CYC

LE)

INTR

OD

UC

TIO

N

Mineralogy (Mineral Sciences) GeologyEarth Sciences

Environ- mental Sciences

Material Sciences & Engineering


111

CHEMISTRY-BASED NOMENCLATURES VERSUS DISCRIMINATING ANALYTICALMETHODS (FTIR, XPD) IN THE CELADONITE-GLAUCONITE FAMILY

WEISZBURG, T. G.1, POP, D.2 & TÓTH, E.11 Department of Mineralogy, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected] Mineralogical Museum, Babeş-Bolyai University, Kogălniceanu St. 1, RO-3400 Cluj-Napoca, Romania.

Celadonite and glauconite are VIFe3+-rich dioctahedralmica-type layer silicates. In the last 20 years three chemistry-based nomenclature proposals were published for them bythe IMA-CNMMN (RIEDER et al., 1998) and the AIPEA(BAILEY, 1980; 1986). In practice, infrared spectroscopy(IR) and X-ray powder diffraction (XPD) were found to beuseful distinguishing tools between the two green layer sili-cates (BUCKLEY et al. 1978), and these methods becameincorporated into the first AIPEA nomenclature (BAILEY,1980), too. This work tries to compare the three chemistry-based classification schemes and evaluate their relationshipwith the two distinguishing analytical methods.

The three classification schemes are partly overlapping,partly divergent. Based on the three possible cation positionsin these minerals, a positive charge diagram xT–xO–xIL wasdesigned for the interpretation of the species definitions. Inthe diagram, the following charge ranges were plotted (usinga formula unit based on 11 oxygen atoms): 0–1 for theinterlayer charge, 5–6 for the octahedral layer charge and 15–16 for the tetrahedral layer charge, respectively.

In the IMA terminology celadonite is described in termsof four true mica end-members while glauconite represents aseries of interlayer-deficient micas. The decisive discrimina-tion between celadonite and glauconite is the interlayercharge, with the dividing value of 0.85 per formula unit. Inthe AIPEA nomenclature of 1980, discriminative is the tetra-hedral layer charge with a value of 15.8 (this corresponds to0.2 IVAl per formula unit). The 1986 recommendation usedhowever, the octahedral layer charge, and the discriminativevalue was this time 5.3 per formula unit.

Celadonite and glauconite have thus been distinguishedby the charge values of all the three possible cation positions.

Concerning IR spectroscopy, both minerals have absorp-tion bands at similar wave numbers, but celadonite has sharpand distinct peaks in the OH-stretching region (3400–3700 cm–1) while glauconite is characterized by lesspronounced, broader peaks. The sharpness of the absorptionbands in the OH-stretching region is dependent on the cationordering in the octahedral sheet. This is influenced by boththe chemistry of the octahedral sheet and the tetrahedral Alsubstitution. The 1980 AIPEA nomenclature (BAILEY,1980) defines the border between the two minerals upon thetetrahedral Al substitution, the 1986 AIPEA nomenclature(BAILEY, 1986) mainly upon the charge of the octahedralsheet, thus the AIPEA nomenclatures are somehow coherentwith the infrared spectroscopic data of the literature (e.g.BUCKLEY et al., 1978; ODIN, 1988). The IMAnomenclature (RIEDER et al., 1998), on the other side,differentiates between the two minerals upon the interlayercontent, suggesting that celadonites and glauconites can have

donites and glauconites can have similar tetrahedral Al sub-stitution, similar VIR2+ / VIR3+ ratio and consequently, similargrade of ordering in the octahedral sheet and similar infraredpattern shapes.

Based on numerous XPD data (BUCKLEY et al., 1978),an almost linear relationship is supposed between the VIFe3+-content of the phyllosilicate and the d060 spacing. It is sug-gested that the phyllosilicate is celadonite if the d060 < 1.51 Åand glauconite if d060 > 1.51 Å. As mentioned earlier, the1.51 Å d060 value was adopted as a discriminating value bythe AIPEA nomenclature (BAILEY, 1980) though VIFe3+-content is not a distinguishing criterion in none of the classi-fication schemes. The IMA nomenclature (RIEDER et al.,1998) does not deal with the applicability of any simple andpractical XPD parameter for that discrimination, moreover itis clear that the IL occupancy (i.e. the distinguishing featurebetween the two minerals) should not be in direct relation-ship with the d060 spacing in the mica structure.

It seems that only in the case of the AIPEA nomencla-tures (BAILEY, 1980, 1986) can we expect simple IR andXPD criteria for discriminating between celadonite and glau-conite. Except for the complete chemical analysis itself thereis no other – simple – analytical method that could be usedfor the application of the IMA nomenclature. Even the for-mation conditions, used frequently by geologists (glauconite– clearly sedimentary environment, celadonite –always influ-enced by some kind of hydrothermal activity) may be mis-leading, as we know “classical” sedimentary glaucony grainsof IL charge > 0.85 and celadonite can also be present inseemingly “normal” sediments (WEISZBURG et al., 2003)

This work was supported by the OTKA grant #T25873.

ReferencesBAILEY, S. W. (1980). Clays Clay Miner., 28: 73–78.BAILEY, S. W. (1986). Suppl. to AIPEA Newsletter 22.BUCKLEY, H. A., BEVAN, J. C., BROWN, K. M., JOHN-

SON, L. R. & FARMER, V. C. (1978). MineralogicalMagazine, 42: 373–382.

ODIN, G. S. (ed., 1988). Green marine clays. Developmentin sedimentology, 45. Elsevier, Amsterdam.

RIEDER, M., CAVAZZINI, G., D’YAKONOV, Y. S.,FRANK-KAMENETSKII, V. A., GOTTARDI, G.,GUGGENHEIM, S., KOVAL, P. V., MÜLLER, G.,NEIVA, A. M. R., RADOSLOVICH, E. W., ROBERT,J., SASSI, F. P., TAKEDA, H., WEISS, Z. & WONES,D. R. (1998). Canadian Mineralogist, 36: 905–912.

WEISZBURG, T. G., TÓTH, E. & BERAN, A. (2003). ActaMineralogica-Petrographica, Szeged, 44: (accepted)


112

NEW MINERALS FROM PICRITE SILL IN MIĘDZYRZECZE, POLISH CARPATHIANS(TYPE AREA OF THE TESCHENITE-PICRITE ASSOCIATION)

WŁODYKA, R. & KARWOWSKI, Ł.Department of Geochemistry and Petrology, University of Silesia, ul. Będzińska 60, PL-41-200 Sosnowiec, Poland.E-mail: [email protected]

Evidence of the Mesozoic volcanic activity can be foundin all the main West Carpathian geotectonic zones. The west-ern part of the External Carpathians is a classic area of theteschenite-picrite association occurrence. The Cretaceousvolcanism extends from Nowy Jičin (NE Moravia, CzechRepublic) to Cieszyn and Bielsko Biała (Poland) for over100 km. Its geochemical pattern close to the interplate alkalirocks (SPIŠIAK, 2002).

The Międzyrzecze sill belongs to the most interestingones in the western part of Polish Flysch Carpathians. Thatsmall 12 m thick sill was emplaced into the Cieszyn UpperJurassic (Tithonian) limestones. It shows division into twomain parts. The wall effect played a significant role in devel-opment of olivine-free, up to 1.5 m thick external parts of thesill. Migration of the olivine towards the centre of the sillresulted in formation of a central plug of phenocrysts (up to 9m thick). The high amount of olivine (up to 30 vol%) andlower amount of diopside (below 20 vol%) in the central partand the very elevated content of diopside (up to 60 vol%) inthe olivine-free parts with trace of olivine shows the differ-ences between the main parts of the sill. Textural relationsamong minerals indicate that diopside began to crystallizefrom homogeneous silicate melt when the intrusive flowceased, but prior to the crystallization of phlogopite. Theolivine and chromium spinels were the first minerals crystal-lized before the emplacement of the sill. The amount ofphlogopite makes up to about 30 vol% in both parts of theMiędzyrzecze sill. Spinels, apatite and perovskite belong tothe minor phases.

Mafic alkaline rocks often contain clinopyroxenes of dif-ferent origin providing information about the evolution of thehost magmas. Megacrysts of clinopyroxenes have beenfound in the Międzyrzecze sill. They are composed of col-ourless cores and pale brown rims. The cores are rounded orembayed indicating resorption prior to the rims formation.Occasionally the core of megacrysts encloses poikiliticallyeuhedral olivine and Cr-spinels. The cores of megacrysts arechrome-diopsides. Their mg-number ranges between 0.88and 0.92 while the AlVI/AlIV values fall within the field of“granulites and inclusions in basalts” (AOKI & SHIBA,1973). The TiO2 content is very low, below 0.9 wt%,whereas Cr2O3 ranges from 0.74 to 1.57 wt%. The rims arecomposed of diopsides with mg-numbers from 0.71 to 0.83,while TiO2 and Al2O3 contents vary between 1.67–5.11 and3.34–7.53 wt%, respectively. Their AlVI/AlIV values fallwithin the field of “igneous rocks” on diagram of Aoki andShiba. The wide range of the rim compositions result from

the presence of sector zoning. We suppose that the dominantfactor controlling the forming of complex megacrysts werepolybaric conditions. The chrome-diopside cores can beinterpreted as xenocrysts, derived from disaggregation of themantle xenoliths which became unstable during ascent andwere resorbed in great parts. These partly resorbed xeno-crysts thereafter acted as nucleation sites for subsequent rimcrystallization when the magma had reached the crustal lev-els.

In the Międzyrzecze sill spinels occur in two size classes.The first type includes anhedral, large grains (0.15 to 1.12mm). They display concentric zoning; the core is reddish-brown (zone A), while the mantle is opaque (zone B). Thisnarrow (from 0.02 to 0.15 mm) opaque rim contains verytiny (about 1µm), trapped solid inclusions, most likely py-roxenes. The core of the chromium spinel is optically homo-geneous and it has a sharp and embayed contact with thetitanomagnetite rim. The second type of spinel with titano-magnetite composition consists of small subhedral to anhe-dral grains (up to 0.08 mm), forming up to 6 vol% of therock. The central part (A) is rich in Cr, Al and Mg, poor in Tiand low in Fe, with wide range of the Cr/Cr+Al ratio. Itscomposition is very similar to Al-rich spinels from Alpine-type peridotite bodies or peridotite nodules from basalticvolcanic rocks. The opaque rim (B) is rich in Fe and Ti, poorin Mg and Al whereas Cr content gradually decreases to-wards the grain margins through the sharp chemical bound-ary between zones A and B. Recalculation of total iron toFe2+ and Fe3+ shows a contrast between a low state of oxida-tion in the deep crust or upper mantle (zone A) and higheroxygen fugacity in the near-surface environments (zone Band groundmass spinels).

Perovskite occurs in both zones of the Międzyrzecze sillfilling the interstices between silicate minerals (diopside andphlogopite). The perovskite grains range in size from 0.07 to0.6 mm forming up to 2 vol%. The perovskite encloses nu-merous trapped melt inclusions with a diameter below 1 µm.Perovskite studied is almost pure CaTiO3 (perovskite sensustricto) with low level of REE (2.60–4.20 wt% REE2O3), Nb(2.40–3.60 wt% Nb2O3), Fe (0.40–1.20 wt% Fe2O3) and Na(0.80–1.10 wt% Na2O).

ReferencesAOKI, K. & SHIBA, I. (1973). Lithos, 6: 41-51.SPIŠIAK, J. (2002). Geol. Carpathica, 53: 183-185.


113

CENOMANIAN–TURONIAN BOUNDARY EVENTS IN POLISH PART OF THE PIENINYKLIPPEN BELT IN THE LIGHT OF GEOCHEMICAL DATA

WÓJCIK-TABOL, P.Institute of Geological Sciences, Jagiellonian University, Oleandry 2a, PL-30-063 Cracow, Poland.E-mail: [email protected]

Geological settingThe Pieniny Klippen Belt (PKB) represents a long and

narrow arch-like structure situated in the Paleo-Alpine Ac-cretionary wedge, between the Inner and the Outer Carpathi-ans (cf. BIRKENMAJER, 1986; MISIK, 1997).

SamplesThe Cenomanian–Turonian Boundary Events (CTBE) in

the Pieniny rock formations is marked as the grey andbrownish black layers in marls of the Jaworki Formation.The Magierowa Member (Mg. Mb.) represents dark sedi-ments in the Pieniny Succession. It consists of alternatingbeds of laminated black shales and bioturbated green mud-stones. The Sneżnica Member (Sn. Mb.) is equivalent ofMagierowa Mb. in the Niedzica Succession. Grey marls withoccasional intercalations of turbiditic calcarenites are domi-nant (GASIŃSKI, 1988; BIRKENMAJER & GASIŃSKI,1992).

MethodsTotal organic carbon (TOC) content, HI/OI ratio and Tmax

were determined the Rock–Eval pyrolysis and LECO com-bustion – infrared instrumentation.

The major and trace element concentrations were ana-lyzed by INNA and ICP-OES.

ResultsThe Mg Mb. samples have a hydrogen index (HI) ranging

from 27 to 52 mg HC/g TOC, oxygen index (OI) varies be-tween 33 and 97 mg CO2 /g TOC. The temperatures ofmaximum pyrolysis (Tmax) values pass 465 °C. In the Sn Mb.HI and OI values are between 36 and 104, and between 9 and190, respectively. T values exceed 430 °C except one sam-ple, PSk, with Tmax below 400 °C, at around 360 °C.

Significant metal enrichment is correlative with high or-ganic carbon content within black sediments and diminish inadjacent, organic-poor layers. The enrichment factors for

particular elements are as follows: Ag, Cd > 10; Cu, Zn, V >5. V/V + Ni > 0.7 and V/Cr < 2 are associated with negligi-ble low Mn content. Black shales, unlike the Sn. Mb, wherethey occur as thin intercalation, in the Mg. Mb. compriseprevailing sediments.

ConclusionsRock-Eval pyrolysis data indicate that organic matter in

the Mg Mb samples are represented by mature, gas prone IVtype kerogen. The Sn Mb. consist of II and III type kerogen.Maturation degree corresponds to the oil-window stage.Abnormally low value of PSk might be explained by theimpregnation of heavy hydrocarbons or asphaltens resultingfrom oil migration (ESPITALIE, 1993).

Trace metal analyses for the Sn. Mb. suggest that this se-quence was deposited in an alternating oxic-anoxic environ-ment. High trace element contents for the Mg. Mb. seem toshow its deposition under increasing reductive conditions(anoxic-euxinic) (ALBERDI-GENOLET & TOCCO, 1999)

AcknowledgementsThis work has been financially supported by Grant no 3

PO4 D 027 22 (State Committee for scientific research).

ReferencesALBERDI-GENOLET, M. & TOCCO, R. (1999). Chem.

Geol., 160: 19-38.BIRKENMAJER, K. (1986). Stud. Geol. Pol., 88: 7-32.BIRKENMAJER, K. & GASIŃSKI, M. A. (1992). Creta-

ceous Research, 13: 479-485.ESPITALIE, J. (1993). In: M. L. Bordenave (Editor), Ap-

plied Petroleum Geochemistry. Technip, Paris, 524 pp.GASIŃSKI, M. A. (1988). Cretaceous Research, 9: 217-247.MISIK, M. (1997). Geol. Carpathica, 48/4: 209-220.


114

REMEDIATION OF GROUNDWATER CONTAMINATED WITH Zn, Pb AND Cd USINGAPATITE II

WRIGHT, J. V.1 & CONCA, J. L.21 PIMS NW Inc., Carlsbad, NM 88220, USA.2 Los Alamos National Laboratory, Carlsbad, NM 88220, USA. E-mail: [email protected]

Phosphate-Induced Metal Stabilization (PIMS) usingApatite II stabilizes a wide range of metals (Pb, Cd, Zn, Cu,U, Pu) in situ or ex situ, by chemically binding them intonew stable phosphate minerals and other low-solubility min-erals that are stable over geologic time. The concept resultedfrom paleochemical oceanographic studies, in the 1970s and1980s, of phosphatic sedimentary materials from the Cam-brian period (570 my ago) to the Present (WRIGHT et al.,1987). These studies showed that apatite hard parts of marineanimals, and even abiotic phosphorite deposits, developedidentical trace metal signatures of the seawater with whichthey were in contact, but with concentrations enriched by sixor seven orders of magnitude. The chemical reactions wererelatively fast and the chemical signatures were retained overgeologic time, even after burial, lithification, heating, andweathering. Recent laboratory and field studies have demon-strated the applicability of apatite towards remediation ofmetal-contaminated waters and soil. Some form of mineralapatite is necessary for efficient metal remediation underenvironmental conditions. A special form of biogenic apatite,Apatite II, has been developed that, unlike any other apatite,has the optimal structural and chemical characteristics formetal and radionuclide remediation: 1) no substituted fluo-rine, 2) a high degree of substituted carbonate ion, 3) lowinitial trace metal concentrations, 4) extremely poor crystal-linity (basically amorphous) coupled with random nanocrys-tallites, and 5) high microporosity. The driving force for therobust performance of reactive phosphate is the extremestability of metal-phosphate phases, e.g., pyromorphites[Pb5(PO4)3(OH,Cl); logKsp = -76.5] and autunites[Ca(UO2)2(PO4)2 • 10H2O; logKsp = -49.0]. Non-apatite phos-phate will not perform as well, if at all, under environmentalconditions. The apatite can be emplaced as a permeable re-active barrier (PRB) to capture groundwater or seeps, mixedinto contaminated soil or waste, used as a disposal liner, oremplaced by any method that brings the soluble metal intocontact with the apatite surface.

A PRB was emplaced in the field at the Success Mine sitein Idaho State to treat groundwater contaminated with Zn,Pb, Cd and Cu up to concentrations of 250 ppm, 10 ppm, 1ppm and 20 ppm, respectively. Various reactive media wereinvestigated to determine which would be most effective atthis site for removing Pb, Cd and Zn. Materials includedzeolites (clinoptilolite and chabazite), compost, variouspolymers, iron filings and oxides, and apatites [cowbone,phosphate rock, and three different formulations of ApatiteII]. Apatite II performed best with respect to stabilization ofthese three metals, sequestering almost 20% of its weight inPb, and about 5% of its weight in Zn and Cd (CHEN et al.,1997). The bioavailability of the metals from the contami-

nated soil was also greatly reduced using Apatite II evenwhen the metal was not in an apatite phase. Pb precipitatedas pyromorphite while Zn and Cd both sorbed onto particlesand precipitated as hopeite, zincite, hydrocerussite, and ota-vite. As a result of these tests, a PRB of Apatite II was em-placed between the Success Mine Tailings pile and NineMile Creek and has been operating for over two years. It is a13.5-ft high, 15-ft wide and 50-ft long baffled vault filledwith 100 tons of Apatite II that reaches down to bedrock andis designed to capture most of the subsurface drainage fromthe 500,000-ton tailings pile. The concentrations of metalsentering the barrier averages 500 ppb Cd, 1,000 ppb Pb and100,000 ppb Zn. The pH has been between 4.5 and 5.0. Theaverage concentrations of metals leaving the barrier has been< 2 ppb Cd, < 5 ppb Pb and about 100 ppb Zn. The exitingpH has been between 6.5 and 7.0. Flow rates are seasonaland vary between 1 gpm and 50 gpm. Based on periodicdaily metal-loading averages over the 2.2 years since it wasemplaced, the Apatite II barrier has sequestered over 75 lbsof Cd (both sorbed onto the Apatite II as well as precipitatedas CdS), over 125 lbs of Pb (precipitated as pyromorphite),and over 6,000 lbs of Zn (both sorbed onto the Apatite II aswell as precipitated as ZnS). The second half of the barrier isanaerobic and supports a robust Entercocci population thatalso reduces Zn to ZnS. This results from the residual or-ganics on the Apatite II, the small amount of P released, andthe buffering capacity of the Apatite II. The effluent is ableto be released back into the river with no further treatment.Performance was successfully predicted using MINTEQ-A2,a thermodynamic speciation model. This barrier is estimatedto last over thirty years for Cd and Pb, but Zn should begin tobreakthrough in a few years based upon the feasibility re-sults. Either the Apatite II can be replaced, or a second bar-rier can be emplaced behind the first one, allowing the firstone to continue to sequester Cd and Pb and condition the pHwhile the second captures Zn as it begins to breakthrough thefirst barrier. The cost of the Apatite II was about $350/ton forthe approximately 100 tons used in this barrier. Emplacementused traditional backhoe and earth-moving equipment totrench the vault. The Apatite II was gravel-sized for easyflow. This technology should work for most acid mine drain-age problems with most metals under most field conditions.

ReferencesCHEN, X.-B., WRIGHT, J., CONCA, J. L. & PEURRUNG,

L. M. (1997). Water, Air and Soil Pollution, 98: 57-78.WRIGHT, J., SCHRADER, H. & HOLSER, W. T. (1987).

Geoch. Cosmoch. Acta, 51: 631-644.


115

MINERAL COMPOSITION OF THE PELITIC FRACTION OF THE DNISTER RIVERBOTTOM SEDIMENTS (UKRAINE): DATA OF SEMI-QUANTITATIVE ANALYSIS

YAREMCHUK, Ya., SKUL’S’KA, L. & KOSHIL’, M.Institute of Geology and Geochemistry of Combustible Minerals of the National Academy of Sciences of Ukraine andNational Joint-Stock Company “Naftogaz of Ukraine”, St. Naukova, 3а, UA-79053 Lviv, Ukraine.E-mail: [email protected]

Investigation of the mineralogy of the pelitic componentof the riverbed sediments is an integral part of the environ-mental–geochemical studies of the hydroecosystem as awhole, as fine-dispersed muds possess increased sorptionability (in comparison with sands), and can accumulateplenty of mineral salts and heavy metals. The sorption ca-pacity of the pelitic fraction increases in the presence of sheetsilicates (e.g. kaolinite and montmorillonite).

The quantitative phase identification was carried out withthe methodology developed in the Karpynskyi`s GeologicalResearch Institute, which is based on the dependence of theintensity of diffraction peaks of a crystalline phase on itsrelative quantity in a powdered sample (PONOMARIOV etal., 1980).

The diffractograms were recorded on an ADP-2 auto-mated powder diffractometer with cobalt radiation and ironfilter (40 kV, 10–15 mА).

Oriented samples from the fraction ~0,005 mm were pre-pared. The mineral composition, with the identification ofdifferent varieties of illites and chlorites, was studied in de-tail.

It was proved by semi-quantitative of analysis that hy-dromica (illite) (reflections 10 Å, 4.9–5.0 Å, 3.32–3.34 Å,2.5 Å), montmorillonite-chlorite (14.2–15.5 Å), kaolinite(7.0–7.1 Å, 3.52–3.57 Å, 2.38 Å), chlorite (13.8–14.0 Å,7.0–7.1 Å, 4.7 Å, 3.52 Å, 2.87–2.89 Å) and illite-montmorillonite (rectorite) (11.0–11.2 Å) are the basic sedi-

mentary clay minerals of the Dnister river bottom sediments(KOSHIL’, 2000). Quartz, calcite, feldspar and gypsum areamong the non-clay minerals.

Average clay mineral contents are the following: hydro-mica 27%, montmorillonite-chlorite 15%, kaolinite 4%, andchlorite 3%. On the basis of the observed data the allocationof clay minerals was carried out on the Dnister catchmentarea. Hydromica, chlorite, montmorillonite and montmoril-lonite-chlorite content increases from upstream to down-stream Dnister. In this direction some “refining” clay com-ponent from terrigenous impurities (feldspars, quartz, gyp-sum) is noted. It is interesting to note that kaolinite content ispractically the same on the entire investigated territory. Cal-cite content sharply increases from west to east.

The results have demonstrated the expediency of apply-ing semi-quantitative X-ray phase analysis for a more de-tailed analysis of the mineral composition of the pelitic frac-tion and established laws of allocation of basic sedimentaryminerals.

ReferencesКOSHIL’, М. (2000). Miner. Zbirnyk, 50/2: 106–109.PONOMARIOV, V. et al. (1980). Methodic recommenda-

tion on quantitative analyses of the mineral content of theclay rocks by using X-ray diffractometry. Moscow:VSEGINGEO, (in Russian), 38.


116

MINERALOGY OF THE CAVE No. 4 FROM RUNCULUI HILL (METALIFERI MTS.,ROMANIA)

ZAHARIA, L.1, SUCIU-KRAUSZ, E.1 & TAMAS, T.21 Babeş-Bolyai University, 1, Kogălniceanu St., RO-3400 Cluj-Napoca, Romania.E-mail: [email protected] Babeş-Bolyai University & “Emil Racoviţă” Institute of Speleology, 1, Kogalniceanu Str, RO-3400 Cluj-Napoca, Romania.

Trestia-Baita is a metallogenetic region located in thecentral part of the Metaliferi Mountains (South EasternApuseni Mts.), characterized by a complex geological set-ting: Tithonic reef limestone blocks are disposed over anEarly Jurassic ophiolitic basement. Both limestones andophiolites are part of Capalnas-Techereu Nappe(BALINTONI, 1997), affected by the Neogene volcanicactivity (andesitic pyroclastic deposits and lava flows). Thehydrothermal activity associated to the Neogene volcanismresulted in the formation of several sulfide veins, emplacedboth within limestones and basalts.

Cave No. 4 (D = 127.4 m, H = 10 m), discovered in2002, is the largest cave in the Trestia-Baita karst area. Oneof the cave passages connects with a 13 m long mine gallerywith collapsed entrance, which ends in a hydrothermal vein.

Thirteen samples taken from the cave and from the oldmine gallery were analyzed by means of X-ray powder dif-fraction, optical and scanning electron microscopy (includingEDX), electron microprobe, infrared and Raman spectros-copy. Apart from calcite, aragonite and gypsum – the mostcommon minerals in limestone caves – in Cave No. 4 aninteresting range of other minerals were reported from bothcave and mine gallery. These minerals are sulfates: barite -BaSO4, serpierite - Ca(Cu,Zn)4(OH)6(SO4)2 • 3H2O; sulfides:galena - PbS, pyrite - FeS2; carbonates: cerussite - PbCO3,smithsonite - ZnCO3; quartz and goethite. Along with theseminerals some silicates such as kaolinite, montmorilloniteand muscovite form a consistent clay layer covering the floorand partially the walls of the cave (Table 1).

It is worth mentioning that cerussite has not been previ-ously reported from a Romanian cave environment, whereasserpierite is also the first known occurrence in Romania.Furthermore, serpierite is a relatively rare mineral that was

documented only from two other occurrences in the area ofthe Carpathians (Hungary and Slovakia, SZAKÁLL, 2002).

Table 1: Minerals found in Cave No. 4 and in the minepassage

Mineralgroup

Mineral nameOccurrence

(1-cave,2-mine gallery)

CarbonatesCalciteAragoniteCerussite

1, 221

SulfatesGypsumBariteSerpierite

1, 21, 2

2

SulfidesGalenaPyrite

11, 2

Oxides,hydroxides

QuartzGoethite

1, 21

SilicatesKaoliniteMontmorilloniteMuscovite

1, 222

ReferencesBALINTONI, I. (1997). Geologia terenurilor metamorfice

din Romania, Carpatica, Cluj-Napoca.SZAKÁLL, S. (ed.). (2002). Minerals of the Carpathians,

Granit, Prague, 480 p.


117

MINERALOGICAL STUDIES ON HUNGARIAN GEOLOGICAL PROFILES CROSSING THEPERMIAN/TRIASSIC BOUNDARY

ZAJZON, N.Department of Mineralogy, Eötvös Loránd University, Pázmány Péter sétány 1/C, H-1117 Budapest, Hungary.E-mail: [email protected]

In the frame of a multidisciplinary research we arestudying the Permian/Triassic (P/Tr) boundary, to understandbetter the dramatic and abrupt ecological change in this pe-riod. At the P/Tr boundary about 90% of the marine speciesbecome extinct (SEPKOSKI, 1996).

The current presentation is a preliminary report of someof the mineralogical data on Hungarian geological sectionscrossing this border.

Having sampled several P/Tr sections we started with thedetailed mineralogical study of the two most promising setsof samples. The first set is from the borehole Gá-1a fromGárdony, Hungary (about 40 km SW of Budapest). In thatborehole the Upper Permian cyclic lagoonal dolomitic facieschanges, probably due to a eustatic sea level rise, into anEarly Triassic shallow marine limestone facies containingmore or less terrigenous material as well (HAAS, 2001). Ourresults show that the dominating clay mineral in the bound-ary zone (both in the limestone and in the earlier reported 20cm thick clay bed) is illite. The micromineralogical descrip-tion of the profile is still in progress.

Our second, main, section is located close to the top ofthe Bálvány Hill in the Bükk Mountains (about 120 km NEof Budapest). This is a composite section, exposed in twooutcrops in a distance of a few hundred meters from eachother. The outcrop containing the lower part, is on the north-ern slope of the hill (“Bálvány North”). The upper part islocated on the eastern side of the hill (“Bálvány East”). Thesection contains the top of the black, thick bedded Nagyvis-nyó Limestone Formation (NLF; samples #BE1–7, Fig. 1)and the lower part of the Gerennavár Limestone Formation(GLF). The GLF starts with the fine siliciclastic “Basal Bed-set” (BBS; #8–11 and #18–25, Fig. 1) followed by the thinbedded “Transitional Bedset” (TBS; #12, 26–27, Fig. 1)(HIPS & PELIKÁN, 2002).

Going upward in the Nagyvisnyó Limestone the marlcomponent increases (from 2 to 40%, see Fig. 1). The marl ofthe BBS is very homogeneous with an average carbonatecontent of 26%, except for a 2 cm thick limestone and a 3 cmthick sandstone bed. The thin bedded TBS containslimestones, interlayered by marls and clay horizons.

Through the section, the terrigenous grains are rare, ex-cept in the above mentioned sandstone layer in the BBS.Beside the dominating actinolite there are about 20 moreminerals to be found, from strongly resistant to easily weath-ering species. In the upper part of the TBS the resistant min-erals are missing. The sandstone layer in the BBS contains amuch (two magnitude) higher amount of terrigenous grains.This population is mature. Zircon represents most of thegrains. The rest is tourmaline and rutile, some actinolite isalso present.

The samples from the section usually contain few mag-netic spherules. In the “Basal Bedset” their amount is re-duced, there are usually none or only a few of them present.The uppermost bed of the Nagyvisnyó Limestone contains avery high amount of spherules (88 pieces/kg). Previousmeasurements support that the material of the spherules ismagnetite.

This project was sponsored by the research grant OTKA#T037966.

ReferencesHAAS, J. (ed.) (2001). Geology of Hungary. Eötvös Univer-

sity Press, Budapest. p. 317.HIPS, K. & PELIKÁN, P. (2002). Geologica Carpathica,

53/6: 351–367.SEPKOSKI, J. J., Jr. (1996). Patterns of Phanerozoic extinc-

tion: A perspective from global databases. - In: Wallisier,O. H. (ed.): Global events and the event stratigraphy inthe Phanerozoic. Springer, Berlin, pp. 35–51.

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

BE 1

BE 2

BE 3

BE 4

BE 5

BE 6

BE 7

BE 8

BE 18

BE 9

BE 19

BE 20

BE 21

BE 22

BE 23

BE 24

BE 10

BE 11

BE 25

BE 12

BE 26

BE 27

>63 µm

< 63 µm

Carbonate

Fig. 1: Composition (wt%) of the Bálvány North section,showing the acid soluble (carbonate) and the non-solublefractions. The latter is divided into two size fractions. For theidentification of the samples see the text.


118

MINERALOGICAL PECULIARITIES AND FORMING CONDITIONS OF VEINLETMINERALISATION IN THE PALAEOZOIC SEDIMENTARY SERIES OF CARPATHIANFORELAND

ZINCHUK, I., KALYUZHNYI, V. & NAUMKO, I.Institute of Geology and Geochemistry of Combustible Minerals of the Ukrainian Academy of Sciences and National Joint-Stock Company “Naftogaz of Ukraine”, Naukova st. 3a, UA-79053 Lviv, Ukraine.E-mail: [email protected]

The forehand of Ukrainian Carpathians, called L’viv Pa-leozoic depression, developed on the southwest margin of theUkrainian Shield and it is represented by a trough subparallelto the main structures of the Carpathians. The Lower Palaeo-zoic sedimentary series of this depression are consideredlately as perspective for hydrocarbon prospecting. Significantamounts of veinlet katagenetic and hydrothermal mineralisa-tion of various ages within the sedimentary complexes aredetected. These veins often contain bitumen and oil filledopenings. Quartz and calcite, the main minerals of the vein-lets often contain numerous, essentially water or hydrocarbonfluid inclusions. Investigations of these inclusions can givewell-grounded information about the conditions of post-sedimentation transformations of rocks, as well as informa-tion about the composition and migration behaviour of hy-drocarbon-bearing fluid palaeosystems. But the lack ofknowledge about mineralogy and formation stages of veinformations in rocks makes interpretation of fluid inclusiondata difficult.

Mineralogical peculiarities are investigated and previousparagenetic scheme of the stages of veinlet mineral genesisin the rocks of the region is proposed. During the post-sedimentary history of the trough the following stagesformed: 1 – carbonate concretions and septarian calciteveinlets in them with admixtures of crystals of brown sideriteor ankerite, dickite, sometimes quartz and pyrite; 2 – calciteand quartz–calcite nests and veinlets, zones of recrystallisa-tion, dolomitisation, silicification of limestones connectedwith katagenic processes; 3 – post-katagenetic hydrothermalvein formation in fractured zones; 4 – late marcasite–calcitemineralisation in coal beds in surrounding rocks.

The age of the veinlets ranges from Carboniferous forkatagenetic formations to post-Carboniferous–pre-Cretaceous for hydrothermal ones.

According to the structural and mineralogical featuresthere are about three stages of vein formation connected bothwith katagenetic and hydrothermal processes. Distinguishingbetween katagenetic and hydrothermal veins is difficult. Veinmineralisation in tectonic fractures coincident with definitedisjunctive structures is regarded as hydrothermal. Hy-drothermal veins consist mainly of calcite with 2–3 genera-tions of the mineral. The veins also contain quartz crystals,and accessory barite, celestite, sphalerite.

Quartz and calcite contain numerous primary coexistinginclusions of water solution and hydrocarbon fluid. This is anevidence for the heterogeneous two-phase state of the min-eral forming system. The salt concentration of water solutionamounts to 0.9–9.0 wt%, rarely 10–12 wt%. The main dis-solved components are NaCl, CaCl2, Na2SO4.The volatilecomponents of hydrocarbon inclusions consist of CH4 (81–99 vol%), CnH2n+2 (up to 15 vol%) with admixtures of CO2

and N2.As derived from microthermometrical data for oil and

water inclusions, the minerals precipitated at 220–140 ºC forquartz and 200–110 ºC for calcite. A clear lateral zonationwas established by inclusion composition. From the north-western to the southeastern part of the depression the organicpart of heterogeneous fluids changes from light oils to sub-stantially methane fluid. This information could be used asthe basis of oil and gas prospecting.


119

PHYSICAL CHARACTERISTICS OF COAL DEPOSITS DETERMINED FROM BOREHOLELOGS. APPLICATION IN THE SUBCARPATHIAN ZONE OF MUNTENIA, ROMANIA

ZUGRĂVESCU, D., POLONIC, G. & NEGOIŢĂ, V.Institute of Geodynamics, Romanian Academy, 19-21 Jean Louis Calderon str., RO-70201 Bucharest, Romania.E-mail: [email protected]

The geology of Romania is dominated by the formationof the Carpathian mountain belt during the Alpine orogeny.The arc reflects the complex suturing of microplates (in-cluding the Moesian and Apulian terrains) onto the Europeanplate margin during the Tethyan Ocean closure.

The Carpathians may be divided into the Overthrust Belt(Carpathian Flysch) and the molass basins of the CarpatianForedeep which includes our study area, the so-called Mun-tenia’s Miopliocene subzone.

The Pliocene present in this Carpathian subzone is situ-ated below the pebbles, conglomerates, sands and marlsbelonging to Quaternary fluviatile facies.

The geological formations involved in this study belongto the Levantine and Dacian lacustrine facies and consist ofsands, silts, marls and lignite deposits.

Throughout the study area, soft brown coal (lignite ac-cording to ASTM coal class) have been met by numerousboreholes crossing the Levantine and Dacian coal seamsbefore reaching their deeper oil and gas-exploitation targets.

Nowadays 7 mining exploitations are actve in Muntenia'sarea in which the coal rank parameters related to organicmatter maturation takes the following average values: 3 – forlevel of organic metamorphism and a little less than 0.3% forthe vitrinite reflectance.

The search for potential mining exploitation required abetter knowledge of coal seam physical parameters and withthis aim in view we started a program of quantitative evalua-tion of coal deposits on the basis of well logs recorded inmore than 300 boreholes. Complete well log suites includingelectric, radioactive, acoustic, etc., are available without anyextra cost in the petroleum data banks. An adequate method-ology for log processing and quantitative evaluation was alsoelaborated using linear equations and specific plots.

The final results were expressed as relative amounts ofcarbon, ash and moisture of rock bulk volume, together withcoal bed thickness, qualification index and elastic moduli forsurroundings rocks-dynamic competence estimation.

The graphical representations, maps, tables and otherillustrating documents related to our study are presented inthe form of posters.

ReferencesNEGOIŢĂ, V (1973). Erdoel – Erdgas Zeitschrift., 5: 174-

180.NEGOIŢĂ, V (1980). Rev. Roumaine de Geologie et

Géophysique. Serie Geoph., 24/2: 307-321.

120

AUTHOR INDEX

Aigner-Torres, M. 53 Alberico, A. 92 Andráš, P. 3, 4, 5, 57, 58 Arató, B. 88 Babić, D. 6, 7 Bajnóczi, B. 8 Bali, E. 98 Barabás, A. 9 Batki, A. 82 Bedelean, H. 86 Benea, M. 10, 110 Benkó, Zs. 11 Benő, É. 83 Berbeleac, I. 12 Besutiu, L. 13 Bilal, E. 28 Bilonizhka, P. 14 Blazhko, V. 62 Breban, R. 81 Breitner, D. 9 Broska, I. 15 Buda, Gy. 110 Bükös, M. Cs. 16 Burda, J. 17 Burján, Zs. 9 Burke, E. A. J. 18 Buseck, P. R. 88 Chirienco, M. 81 Chovan, M. 3, 4, 19 Christofides, G. 109, 110 Cocić, S. 20 Compagnioni, R. 110 Conca, J. L. 65, 114 Constantina, C. 21 Costea, C. 78 Csámer, Á. 22, 103 Damian, F. 23, 24, 25 Damian, Gh. 23, 24, 25 Danáková, A. 57 Diaconu, G. 28 Dluholucká, L. 58 Dódony, I. 16, 26, 94 Dordea, D. 13 Dorofeev, V. 40 Ďuďa, R. 27 Dumitraş, D.-G. 28, 68 Dunin-Borkowski, R. E. 88 Edelstein, O. 29 Effenberger, H. S. 110 Ekhivanov, V. 87 Elekes, Z. 91 Erić, S. 20 Falus, Gy. 42, 98 Fehér, B. 30 Fekete, J. 31 Ferraris, G. 110

Frankel, R. B. 88 Fulín, M. 32 Füri, J. 33 Gajić, B. 34 Gál-Sólymos, K. 9, 93 Gawęda, A. 35, 36 Geiger, C. A. 110 Geiger, J. 52 Georgiţă, M. 37 Ghergari, L. 38, 39, 102 Gorea, M. 10 Gorie, J. 13 Gorovaya, N. 40 Gorovoy, A. 40 Gorshkov, A. A. 41 Háber, M. 41, 49 Hidas, K. 42, 98 Hîrtopanu, P. 43, 44 Höck, V. 45, 47 Horváth, P. 54 Horváth, Z. 101 Hryniv, S. P. 61 Il’chenko, K. O. 46, 61 Ionescu, C. 38, 39, 45, 47 Jach, R. 96 Jáger, V. 48 Jeleň, S. 41, 49 Kalyuzhnyi, V. 118 Karwowski, Ł. 50, 112 Kasztovszky, Zs. 33 Kearns, J. 81 Kele, S. 51 Kępińska, B. 35 Kiss, Á. Z. 91 Kóbor, B. 52, 82 Kodĕra, P. 49 Koller, F. 53 Kolodiy, O. 87 Koroneos, A. 109, 110 Korpás, L. 93 Koshil’, M. 115 Kotulová, J. 5 Kovács, G. 54, 83 Kovács, I. 98 Kovács-Pálffy, P. 55 Kovalevsky, V. 87 Kovalyshyn, Z. 77 Král, J. 4 Kristály, F. 56 Križáni, I. 57, 58 Kulchytska, G. 59 Kulibaba, V. 62 Kvasnytsya, I. V. 60, 61 Kvasnytsya, V. M. 61 Lazar, C. 38 Lazarenko, H. 62

121

Leél-Őssy, Sz. 63 Lexa, J. 49 Lóránth, Cs. 64 Lovas, Gy. A. 26, 110 Lu, N. 65 Luffi, P. 69 Luptáková, J. 5 Lyakhov, Y. 87 Mádai, F. 66 Mádai, V. 67 Marincea, Ş. 28, 68 Márton, I. 69 Marusyak, V. 87 Marynowski, L. 35 Matović, V. 70 Matviishyn, Z. 77 Melnikov, V. S. 71 Merlino, S. 110 Mikuš, T. 72 Milovanović, D. 109 Milovská, S. 73 Mindszenty, A. 101 Minuţ, A. 81 Mohai, I. 94 Molnár, F. 11, 48 Molnár, Zs. 9 Mosonyi, E. 74 Müller, W. F. 110 Nagy, G. 30, 75, 76, 100 Nagy-Balogh, J. 9 Naumko, I. 77, 118 Nedelcu, L. 78 Negoiţă, V. 119 Neiva, A. M. R. 4 Németh, N. 66 Németh, T. 94 Nikolenko, A. 87 Nikolenko, P. 87 Niţoi, E. 107 Oliynik, T. 87 Onac, B. P. 79, 80, 81 Ozdín, D. 3, 19 Pál-Molnár, E. 52, 69, 82, 83 Papp, D. C. 107 Papp, G. 84 Pasero, M. 110 Pavlyshyn, V. 59 Pavlyuk, T. 87 Pekker, P. 85 Pieczka, A. 36 Polgári, M. 85 Polonic, G. 119 Pop, D. 21, 86, 110, 111 Popivnyak, I. 87 Pósfai, M. 88, 110 Raucsik, B. 54 Robu, I. N. 89, 90 Robu, L. 89, 90 Rosu, E. 78 Rózsa, P. 91, 103 Rusu-Bolindet, V. 39

Săbău, G. 92 Sajó, I. E. 100 Schroll, E. 4 Scott, P. 43, 44 Seres-Hartai, É. 8 Shkolnik, E. L. 41 Siklósy, Z. 93 Simon, A. 91 Simulák, J. 91 Sipos, P. 94 Sitášová, E. 95 Skul’s’ka, L. 115 Spišiak, J. 72 Srecković-Batocanin, D. 20, 109 Starzec, K. 96 Stremtan, C. 56 Stumbea, D. 97 Suciu-Krausz, E. 116 Surányi, G. 63 Szabó, Cs. 9, 42, 51, 93, 98 Szakács, A. 99 Szakáll, S. 8, 30, 100 Szakmány, Gy. 33 Szilágyi, V. 101 Szinger, B. 101 Szöőr, Gy. 91 T. Bíró, K. 33 Tamas, T. 102, 116 Thamó-Bozsó, E. 55 Tillmanns, E. 110 Topa, D. 47 Tóth, A. 56 Tóth, E. 31, 111 Tóth, S. 103 Tóth-Szabó, T. 104 Tsikhon’, S. 87 Turchinov, I. I. 105 Udubaşa, G. 44, 106 Ureche, I. 86, 107 Uzonyi, I. 91 Váczi, T. 108 Vaselli, O. 51 Vasić, N. 70 Vasković, N. 34, 109 Vaughan, D. J. 110 Vereş, D. Ş. 80, 81 Voznyak, D. K. 61 Warren, M. C. 108 Weiszburg, T. G. 31, 85, 101, 110, 111 Włodyka, R. 50, 112 Wójcik-Tabol, P. 113 Wright, J. V. 114 Yaremchuk, Ya. 115 Zachariáš, J. 4 Zaharia, L. 116 Zajacz, Z. 98 Zajzon, N. 117 Zhegallo, E. A. 41 Zinchuk, I. 118 Zugrăvescu, D. 119

122

Notes

123

Notes

124

Notes

INSTRUCTIONS FOR AUTHORS GENERAL Acta Mineralogica-Petrographica (AMP) publishes articles (papers longer than 4 printed pages but shorter than 16 pages, including figures and tables), notes (not longer than 4 pages, including figures and tables), and short communications (book reviews, short scientific notices, current research projects, comments on formerly published papers, and necrologies of 1 printed page) dealing with crystallography, mineralogy, ore deposits, petrology, volcanology, geochemistry and other applied topics related to the environment and archaeometry. Articles longer than the given extent can be published only with the prior agreement of the editorial board. Occasionally, in the form of supplement issues AMP publishes materials of conferences, or other events of scientific interest. The journal accepts papers that represent new and original scientific results, which have not appeared elsewhere before, and are not in press either. All articles and notes submitted to AMP are reviewed by two referees (short communications will be reviewed only by one referee) and are normally published in the order of acceptance, however, higher priority may be given to Hungarian researches and results coming from the Alpine-Carpathian-Dinaric region. Of course, the editorial board does accept papers dealing with other regions as well, let they be compiled either by Hungarian or foreign authors. The manuscripts (prepared in harmony of the instructions below) must be submitted to the Editorial office in triplicate. All pages must carry the author’s name, and must be numbered. At this stage (revision), original illustrations and photographs are not required, though, quality copies are needed. It is favourable, if printable manuscripts are sent on disk, as well. In these cases the use of Microsoft Word or any other IBM compatible editing programmes is suggested. LANGUAGE The language of AMP is English. PREPARATION OF THE MANUSCRIPT The different parts of the manuscript need to meet the instructions below: Title The title has to be short and informative. No subtitles if possible. If the main title is too long, an additional shortened title is needed for the running head. Author The front page has to carry (under the main title) the name(s) (initials, surname), affiliation(s), current address(es), e-mail address(es) of the author(s). Abstract and keywords The abstract is required to be brief (max. 250 words), and has to highlight the aims and the results of the article. The abstracts of notes are alike (but max. 120 words). As far as possible, citations have to be avoided. In the near future the abstracts are going to be distributed in digital form, as well. The abstract has to be followed by 4 to 10 keywords. Text and citations The format of the manuscripts is required to be: double-spacing (same for the abstract), text only on one side of the page, size 12 Times New Roman fonts. Margin width is 2.5 cm, except the left margin, which has to be 3.5 cm wide. Underlines and highlights ought not be used. Accents of Romanian, Slovakian, Czech, Croatian etc. characters must be marked on the manuscript clearly. When compiling the paper an Introduction – Geological setting – Materials and Methods – Results – Conlclusions structure is suggested. The form of citations is: the author’s surname followed by the date of publication e.g. (Szederkényi, 1996). If there are more than two authors, after the first name the co-authors must be denoted as “et al.”, e.g. (Roser et al., 1980). REFERENCES The reference list can only consist of published papers, M.Sc., Ph.D. and D.Sc. theses, and papers in press. Only works cited previously in the text can be put in the reference list. Examples: Szederkényi, T. (1996): Metamorphic formations and their correlation in the

Hungarian part of Tisia Megaunit (Tisia Megaunit Terrane). Acta Mineralogica-Petrographica, 37, 143-160.

Rosso, K. M., Bodnar, R. J. (1995): Microthermometric and Raman

spectroscopic detection limits of CO2 in fluid inclusions and the Raman spectroscopic characterization of CO2. Geochimica et Cosmochimica Acta, 59, 3961-3975.

Roser, B. P., Childs, C. W., Glasby, G. P. (1980): Manganese in New Zealand. In Varentsov, I. M., Grasselly, Gy. (eds.): Geology and Geochemistry of Manganese, Vol. II., 199-211. Akadémiai Kiadó, Budapest.

Nesse, W. D. (2000): Introduction to Mineralogy. Oxford University Press. 442 pp.

Pál-Molnár, E. (1998): Geology and petrology of the Ditró Syenite Massif with special respect to formation of hornblendites and diorites. Ph. D. thesis, University of Szeged, Szeged, Hungary. 219 pp.

The full titles of journals ought to be given. In case more works of the same author are published in the same year, then these has to be differentiated by using a, b, etc. after the date. ILLUSTRATIONS Finally, each figure, map, photograph, drawing, table has to be attached in three copies, they must be numbered and carry the name of the author on their reverse. All the illustrations ought to be printed on separate sheets, captions as well if possible. Foldout tables and maps are not accepted. In case an illustration is not presented in digital form then one of the copies has to be submitted as glossy photographic print suitable for direct reproduction. Photographs must be clear and sharp. The other two copies of the illustrations can be quality reproductions. Coloured figure, map or photograph can only be published at the expense of the author(s). The width of the illustrations can be 56, 87, 118, or 180 mm. The maximum height is 240 mm (with caption). All figures, maps, photographs and tables are placed in the text, hence, it is favourable if in case of whole page illustrations enough space is left on the bottom for inserting captions. In the final form the size of the fonts on the illustrations must be at least 1,5 mm, their outline must be 0,1 mm wide. Digital documents should be submitted in TIFF-, BMP- or JPG-format. The resolution of line-drawings must be 400 dpi, while that of photographs must be 600 dpi. The use of Corel Draw for drawing is appreciated. PROOFS AND OFFPRINTS After revision the author(s) receive only the page-proof. The accepted and revised manuscripts need to be returned to the Editors either on disc, CD or as an e-mail attachment. Proofreading must be limited to the correction of typographical errors. If an illustration cannot be presented in digital form, it must be submitted as a high quality camera-ready print. The author(s) will receive 25 free offprints. On payment of the full price, further offprints can be ordered when the corrected proofs are sent back.

Manuscripts for publication in the AMP should be submitted to: Dr. Pál-Molnár Elemér e-mail: [email protected] Phone: 00-36-62-544-683, Fax: 00-36-62-426-479 Department of Mineralogy, Geochemistry and Petrology University of Szeged P. O. Box 651 H-6701 Szeged, Hungary

Acta Mineralogica-Petrographica

Documents

Transcript of Acta Mineralogica-Petrographica