Mineralogy, geochemistry and petrogenesis of the V-Ti-bearing and chromiferous magnetite deposits...

Cent. Eur. J. Geosci. • 6(4) • 2014 • 518-548DOI: 10.2478/s13533-012-0193-9

Central European Journal of Geosciences

Mineralogy, geochemistry and petrogenesis of theV-Ti-bearing and chromiferous magnetite depositshosted by Neoarchaean Channagiri Mafic-UltramaficComplex, Western Dharwar Craton, India:Implications for emplacement in differentiated pulses

Topical issue

Tadasore C. Devaraju1∗, Kallada R. Jayaraj1, Thavaraghatta L. Sudhakara1, Tuomo T. Alapieti2, BeateSpiering3, Risto J. Kaukonen2

1 Department of Studies in Geology, Karnatak University, Dharwad-580003, India

2 Department of Geosciences, University of Oulu, FIN-900014 Oulu, Finland

3 Steinmann Institut, Universitat Bonn, Poppelsdorfer Schloss, 53115 Bonn, Germany

Received 28 March 2014; accepted 30 June 2014

Abstract: The Channagiri Mafic-Ultramafic Complex occupies lowermost section of the Neoarchaean Shimoga supracrustalgroup in the Western Dharwar Craton. It is a segmented body occupying the interdomal troughs of granitoids.The magnetite deposits occur in the northeastern portion; typically occupying the interface zone between gab-bro and anorthositic. Mineralogically, the deposits are simple with abundant magnetite and ilmenite. Hogbomiteis a consistent minor mineral. Magnetites are typically vanadiferous (0.7-1.25% V2O5). Ilmenite consistentlyanalyses more MgO and MnO than coexisting magnetite. Chlorite, almost the only silicate present; lies in therange of ripidolite, corundophilite and sheridanite. The chromiferous suit occupying eastern side of Hanumala-pur block (HPB) contains Fe-Cr-oxide analysing 37.8-11.9% Cr2O3 and 40.5-80% FeOt . In these too, chlorite,typically chromiferous (0.6-1.2% Cr2O3), is the most dominant silicate mineral. Geochemistry of V-Ti- magnetiteis dominated by Fe, Ti and V with Al, Si, Mg and Mn contributing most of the remaining. Cr, Ni, Zn, Co, Cu, Gaand Sc dominate trace element geochemistry. The Cr-magnetite is high in Cr2O3 and PGE. Two separate cy-cles of mafic magmatism are distinguished in the CMUC. The first phase of first cycle, viz., melagabbro-gabbro,emplaced in the southeastern portion, is devoid of magnetite deposits. The second phase, an evolved ferro-gabbroic magma emplaced in differentiated pulses, occupying northeastern portion of the complex, consists ofmelagabbro→gabbro-anorthosite→V-Ti magnetite→ferrogabbro sequence. Increase in oxygen fugacity facili-tated deposition of V-Ti magnetite from ferrogabbroic magma pulse emplaced in late stages. The second cycleof chromiferous PGE mineralized suite comprises fine-grained ultramafite→alternation of pyroxinite-picrite→Cr-magnetite sequence formed from fractionation of ferropicritic magma. HPB also includes >65m thick sill-likedioritic phase at the base of the ferriferous suit and a sinuous band of coarse-grained ultramafite enclosed withinthe chromiferous suit; both unrelated to the two mafic magmatic cycles.

Keywords: segmented complex • two cycles • evolved ferrogabbroic–picritic magmas • differentiated pulses • late stagedeposition© Versita sp. z o.o.

∗E-mail: [email protected]

Tadasore C. Devaraju et al.

1. Introduction

Occurrence of titaniferous magnetite ore bodies in thearea discussed here is known for almost 100 years [1].These are among more than 55 occurrences reported from33 different localities of Western Dharwar Craton (WDC)[2]. Although quite small as compared to the V-Ti-Fedeposits of S. Africa, Russia, China and Canada, theknown deposits in Karnataka (viz.,∼19.6 million tons ofore =∼50,000 tons V metal) account for about 78% of thetotal vanadium reserves of India [3] and hold promise asan important source of this metal in the future. With thecomprehensive commercial utilization of V, Ti and Fe, the3 main ingredients of the ore, becoming a reality [4–8], theexploitation of this type of ore in India in the near futureshould be expected to receive priority. In the course of ourlong years of study of the CMUC, with a special focus onV-Ti-Fe deposits (KRJ 1988-1992) and PGE mineralizedzone identified in it (TCD & TTA 1993-2007), considerableinformation about field characteristics, petrography, min-eralogy and geochemistry of these deposits has been gen-erated. An attempt is made here to synthesize the gath-ered information and reconstruct the history of the complexas whole and V-Ti-bearing and Cr-magnetite deposits inparticular. Methods of study are given in Appendix-I.

Previous work

The first geological description of the area was providedby Slater [9, 10]. Jayaram [11] carried out subsequently arepeat survey. Smeeth and Sampath Iyengar [1] were thefirst to describe the magnetite deposits of the area. How-ever, a specific investigation/ prospecting of the depositsfor their chemistry and reserve estimation were under-taken almost six decades later by the geologists of theState Department of Mines and Geology and GeologicalSurvey of India. Channappa and Subramanya [12] under-took prospecting of Ubrani magnetite deposit and reporteda reserve of 3.6 million tons of ore with an average V2O5

content of 0.53%. Taking into account the commissioningof ferro-alloy steel plant with electro- smelting facilityat the Visvesvaraya Iron and Steel Ltd., (VISL), Bhadra-vati (∼60 km west of Masanikere magnetite ore body),and also encouraging results of a pilot scale experimen-tal production of ferro-vanadium analyzing up to 45% Vfrom Masanikere float ore with 1.0% V2O5, the Geologi-cal Survey of India made an attempt [13, 14] to estimatethe reserves of vanadiferous magnetite ore in Channagiritaluk. Besides, systematic prospecting of the Masanikeremagnetite deposit [15] was also taken up. Their inves-tigation included exploratory shallow drilling too. Theyestimated the availability of 4.2 million tons of in-situ and0.5 million tons of float ore with 1.0% V2O5. In the follow-

ing year, Ramiengar et al [16], based on ore microscopicexamination and chemical analysis of samples collectedduring prospecting, gave a comprehensive account of thedeposit. They not only identified the close associationof the ore with gabbro–anorthosite suite, but also pro-posed derivation of the ores as a late-stage differentiatefrom ferrogabbroic magma and endorsed the earlier re-port of association of V-Ti-Fe ore of Masanikere with Cumineralization [13]. Channappa and Subramanya [17] con-tinued their work in the area and prospected Tavarekereand Gaurapur deposits, and estimated the existence of atotal reserve of 1.7 million tons but, with lower V2O5 con-tent of 0.45% and 0.35% respectively. KRJ [18], as a partof his doctoral work, carried out a comprehensive field,petrographic, mineralogical and geochemical studies onthe V-Ti-Fe deposits occurring near Ubrani, Tavarekere,Masanikere and Magyatahalli (as Magyatahalli no moreexists, it is described here with reference to the nearestvillage, Hanumalapur). KRJ, however, has selectively pub-lished on hogbomite [19], a widely distributed minor oxidemineral not only in the CMUC deposits but also in the De-varanarasipur and Mulemane ore bodies studied by him,and on the chromiferous magnetite [20] identified exclu-sively in the Hanumalapur block (HPB). A more detailedand thorough examination of CMUC was triggered by thediscovery of ore level PGE mineralization in the chromif-erous zone of HPB [21, 22]. The exploration for PGE heldsustained interest of TCD and TTA over a prolonged pe-riod from 1993 to 2007 resulting in the generation of alarge amount of data not only for the PGE mineralizedzone but also for the closely associated V-Ti magnetiteand the host CMUC as a whole [23–25].Here, we have presented a synthesis of all the field,petrological, mineralogical and whole-rock geochemicaldata and made an attempt to reconstruct the petrogeneticevolution of the V-Ti and Cr-magnetite deposits and theCMUC.

2. Geological setting

The CMUC lies to the south of Channagiri town and formsa small SE border portion of the Shimoga belt (Fig. 1),the largest supracrustal belt in the WDC occupying anarea of 30,000 sq.km. It contains essentially ∼3.0 Ga. oldbasement granitoids and Neoarchaean (<3 to 2.5 Ga. old)cover rocks of Dharwar Supergroup. The investigated 700km2 area stretches between the Long. 75◦50′ − 76◦10′East and Lat. 13◦45′ − 13◦50′ North. While the west-ern part of about 20 km. wide area represents a portionof the southeastern border of the Shimoga supracrustalbelt, the eastern ∼17 km wide area is occupied predomi-

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Mineralogy, geochemistry and petrogenesis of the V-Ti-bearing and chromiferous magnetite deposits hosted by Neoarchaean ChannagiriMafic-Ultramafic Complex, Western Dharwar Craton, India

Table 1. Lithostratigraphic sequence south of Channagiri area (after Devaraju 2000).

Formation Lithological featuresMafic dykes Range from quartz-dolerite to olivine-meladolerite. Postdate both basement grani-

toids and supracrustals, unaffected by metamorphism and deformation.Tuppadahalli Formation (THF) Mainly a suite of phyllites/argillites interstratified with a large number of ortho-

quartzite bands.Kur Gudda Formation (KGF) Dominated by phyllite and quartzo-feldspathic wackes and includes the metasedi-

mentory sequence of polymict conglomerate – quartzite – phyllite – chlorite schist –dolomitic limestone.

Hegdale Gudda Formation (HGF) Predominantly a metamorphosed sequence of gabbro - pyroxenite - peridotite withseveral prominent seams of V-Ti-magnetite, localized pods of anorthositic variationsand very restricted chromite-bearing ultramafite. Also includes smaller proportion ofmetavolcanic-sedimentory sequence of metabasites-phyllite-chlorite schist-quartzo-feldspathic wackes-quartzites- Cr-Ni- enriched silicious Mg-carbonates.

The Eastern Ultramafic Bodies Mostly ultramafic comprising of peridotite-chromite banded peridotite-dunite-chromitite sequence with local pods of chromitite and gabbroic variations. Typicallyinclude isolated patches of fine grained chlorite-enriched aluminous ultramafic rock.

Basement Granitoids Homogeneous tonalite–quartz-tonalite–traondhjemite on the west and multiphasebanded quartzofeldspathic ortho gneiss– granodiorite on the east.

nantly by the granitoids of the Peninsular Gneissic Com-plex (PGC). The western and eastern portions of the areaare separated by NE striking fault, designated by Chad-wick et al [26] as “main boundary fault”. More than 50%of the western portion of the area is composed of Dhar-war Supracrustals, classified as Hegdale Gudda - (HGF),Kur Gudda - (KGF) and Tuppadahalli - (THF) Forma-tions. Among the 3 supracrustal formations (Fig. 2), HGFhas undergone pervasive penetrative deuteric alterationand low-grade metamorphism, whereas, the other two aredistinctly less metamorphosed. The litho units of CMUCform essentially a part of HGF. Contrastingly, over 70%of the eastern portion of the area is made up of PGC,which includes a northwesterly striking linear array ofpredominantly ultramafic enclaves (see Fig. 2). UnlikeCMUC, these ultramafic (mafic) enclaves contain only podsand mm-cm scale bands of chromitite and are devoid ofboth V-Ti magnetite deposits and ore level PGE miner-alization [27]. Further, these are thought to be relatedto an older cycle of ultramafic magmatism, perhaps be-longing to the Mesoarchaean Sargur group (>3.4 – 3.5Ga.). Both supracrustals and basement granitoids are oc-casionally intruded by virtually unmetamorphosed olivine-to quartz-doletite dykes. No isotopic age data is avail-able for any of the rocks of the area. However, based onthe data obtained for the adjoining Chickmagalur grani-toids and the Bababudan-Chitradurga supracrustals [28],it is opined that the basement granitoids are ∼3 Ga. old.The Supracrustal rocks are younger (<3 Ga.) and maficdyke intrusions are Palaeoproterozoic (?).

Figure 1. Generalized geological map of the area south of Channa-giri.

Field occurrence of CMUCThe CMUC is a segmented body occupying interdomaltroughs of the basement granitoids and the borders be-tween younger KGF and THF with the granitoids (Figs. 1,2 & 3). It stretches in the SW-NE direction over astrike length of about 40 km. It is the major lithol-ogy of the HGF forming lowermost stratigraphic sec-tion of the Dharwar supracrustal group comprising thesequence HGF→KGF→Devarabetta→Channagiri→ THF(=Channeshpura) appearing in that order when tracedupwards [26]. However, in the area studied, associa-tion of HGF only with KGF and THF (see Fig. 2) isexposed. The magnetite seams described here are lo-cated entirely in the northeastern half of the complex;the southeastern extension is monotonously a metaba-sic unit without anorthositic variation or V-Ti magnetite

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Figure 3. Geological cross section across Channagiri mafic-ultramafic complex.

Figure 4. Detailed geological map of Hanumalapur block.

deposits. Due to their relative resistance to weather-ing process compared to host mafic-ultramafic units ofCMUC, the magnetite seams show up in the field promi-nently in the hillocks located in the vicinity of Masanikere,Tavarekere, Ubrani, Gaurapur and Hanumalapur. A largespread of float derived from ore seams has blurred itscontact relationships with the adjoining mafic-ultramaficrocks. The contacts of the host CMUC are also mostlycovered, but, where exposed, they comprise of a zone ofshearing. Apophyses of CMUC are not noted anywherealong the exposed contacts. Forming a part of the HGF,there is a suit of sedimentary rocks, which comprises ofthe sequence “quartzite→phyllite/metabasite→ chlorite-schist→quartzofeldspathic-wacke→carbonate”. The se-quence is best exposed on the eastern slopes ofMasanikere–Bukkambudi hills. Elsewhere, it is eithermissing or consists of only quartzite or an association ofquartzite and phyllite/ chlorite schist. Intrusive relation-ship of CMUC with the associated sedimentary sequenceis not apparent anywhere. We believe that the emplace-ment of CMUC along the interdomal troughs marked thebeginning of the basin formation and the deposition ofsedimentary sequence of HGF took place later. Mag-netite seams of the complex show strike persistence fromless than 30m to more than 2 km; pinch and swell is com-mon and widths vary from less than a meter to more than30 m.

Meso–macro banding and zonary distribution of the mainlitho units are well displayed in the northern HPB locatedin the N-S striking and easterly dipping Tavarekere seg-ment (Figs. 1 & 2). Because of the existence of PGE min-eralized zone, this block has been mapped in an enlargedscale of 1:2000 (Fig. 4) and examined in detail not onlybased on outcrop study but also on the basis of exploratorydrilling of about 2 km of southern portion of the block. Thestudy has brought to light that the central zone of about

522


100-150 m. is largely composed of ultramafic units, whichon the eastern side are fine grained, chromiferous andbear evidence of PGE mineralization. The block variesoutwards on either side from melagabbro to ferrogabbrowith V-Ti magnetite seams occupying the interface zonebetween the said units. The small anorthositic lenses/patches identified are also located in the vicinity of thisinterface zone. However, there are important differencesbetween the western and eastern portions of the block.While the magnetite seam on the western side is typi-cally massive and relatively coarse grained, that on theeastern side is partly chromiferous and partly normal V-Ti variety. Further, along the western margin of the HPBthere is >65 m zone of diorite and on the eastern side asinuous vein/lens of coarse-grained pegmatitic ultramafiteshowing diffused contacts occurs (Fig. 4). Also, very typ-ically on either side of the block, constituting the borderzone of V-Ti magnetite seams, ferrogabbroic layers (an-alyzing 30 wt% or more of Fe2O3; refer Table 5) occur,containing alternate bands enriched in V-Ti-Fe oxide andsilicate minerals.

3. Petrography and Mineralogy

The V-Ti magnetite of CMUC is medium to coarse grainedand commonly displays granular to mutual boundarytextures. The ores consist of granular aggregates ofmagnetite-titanomagnetite and ilmenite (Fig. 5A). Thegrain boundaries are generally straight to gently curved,defining a triple junction with 120◦ interfacial angle.Small polygonal crystals of ilmenite occupy interspacesdefined by bigger crystals of magnetite-titanomagnetiteand ilmenite. Crystallographic orientation of elongatedlath-shaped ore grains is a common feature. Most com-mon are the lamellar intergrowths of ilmenite along thecubic planes of magnetite. The fine to coarse ilmenitelamellae have sharp margins and no swelling is observedat the intersection of these lamellae (Fig. 5B). Fine in-tergrowths of ilmenite in magnetite forming Widmanstat-ten texture or trellis intergrowth are seen in all the oresamples studied except in chromiferous magnetite sam-ples. In addition, small unoriented blebs, rounded andpolygonal exsolutions of ilmentite are not uncommon inlarge grains of magnetite-titanomagnetite and these oxidegrains may carry inclusions of pyrite, chalcopyrite, hog-bomite and spinel. Idioblasts of pyrite within and alonggrain boundaries in sulphide-rich ores of Masanikere havegiven rise to panidiomorphic texture. Exsolutions of hog-bomite occur both as prismatic crystals occupying grainboundaries of magnetite and as blebs/ patches within it.Cr-magnetite is granular and conspicuously fine-grained.

The ore grains occur as cumulates which have grownby mutual attraction between the adjacent crystals [29].In the fine-grained ultramafite, the ferriferous chromiteoccurs as cumulates and as dispersed coarse subhedralgrains embedded in a matrix containing variable propor-tions of densely packed scales of chlorite (Fig. 5D). Fillingof fractures as well as cleavage planes of Fe-chromite withfine scales of chlorite is a common feature and appearsmore pronounced with increase in intensity of deforma-tion and alteration of the ore (Fig. 5E).The most common secondary texture noted in nearly allthe ore samples examined (most apparent in Masanikeresamples) is a variable degree of martitization ofmagnetite-titanomagnetite, along grain boundaries andoctahedral planes (Fig. 5C). Ilmenite is resistant to alter-ation, and if any, it is mostly restricted to fracture planesin the mineral. Relicts of ilmentite enclosed in martitizedmagnetite produce ’relict texture’. Intense oxidation cou-pled with hydration has resulted in the formation of collo-form bands of goethite around Ti-Fe oxides and martiteand alteration of ilmenite to leucoxene.Mineralogically, the magnetite seams of CMUC are simplewith oxides making up 73 to 93% of the samples. Mag-netite is the most abundant oxide with ilmenite taking thesecond position. Pyrite and chalcopyrite assume impor-tance in zones of sulfide mineralization. In the Masanikerebody in particular, Ti-magnetite and magnetite-gabbrobands are reported to analyse 0.4 to 0.6% Cu [15]. Hog-bomite is the most common minor mineral noted in nearlyall the samples examined. Spinel, ulvospinel and rutile arethe other sporadically occurring accessory minerals. Chlo-rite is almost the only silicate mineral recorded in bothV-Ti and Cr-magnetite ores of CMUC, with some samplescontaining up to 22 vol%. Biotite is very sparse havingbeen recorded only in one drill core sample of V-Ti mag-netite of HPB. The common secondary minerals, martiteand goethite appear in variable amounts depending uponthe degree of alteration of the ore.

4. Mineral chemistryElectron probe analytical data obtained for several of theminerals of the CMUC ores are compiled in Tables 3A to3J. The distinctive characteristics of the minerals analyzedare summarized in the following:1) Magnetite present in the normal V-Ti-Fe ores nearlyapproaches the ideal composition with Fe2O3 +FeO mak-ing up 89.17 to 97.43 wt% of the total. Other constituentspresent in significant amounts are V2O5 (concentrationsranging from 0.83 to 1.22 wt%; av. 1.02%), Cr2O3 (0.1-1.55%; av. 0.54%), Al2O3 (0.0-0.49%; av. 0.21%) and TiO2

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Figure 5. A- Typical mutual boundary texture seen in V-Ti-Fe ores; B- Thin and broad ilmenite lamellae in magnetite/titano-magnetite; C- Marti-tization of titano-magnetite (MTM) along grain boundaries and weak planes; D- Fe-rich chromite in chlorite-rich matrix and with weakplanes filled by chlorite; E- Abundant Fe-rich chromite embedded in chlorite matrix (all under crossed nicols).

Table 2. Modal analyses of representative Ti-V-bearing and Cr- magnetite ores of Channagiri mafic-ultramafic complex.

1 2 3 4 5 6 7 8 9Sample M-16 M-14 M-15A M-13 M-32 M-35 M-20 M-22 M-80AFe-Ti-V oxide 95.0 91.0 86.3 89.6 73.1 78.3 89.7 85.0 74.7Chlorite 0.3 2.2 3.8 16.0 0.3 2.3 12.4Hogbomite 4.7 6.8 9.9 10.4 26.9 3.6 10.0 12.7 12.9

10 11 12 13 14 15 16 17Sample M-3 M-4 M-100 M-92 M-93 M-2 M11 M5Fe-Ti-V oxide 93.2 77.6 92.4 75.0 66.3 Fe-Cr oxide 58.5 57.3 43.1Chlorite 1.0 22.4 1.4 33.7 Chlorite 41.5 42.7 56.9Hogbomite 5.8 6.2 25.01:Tavarekere; 2-4: Ubrani; 5-6: Masanikere; 7-8: Gaurapur; 9:Virapur; 10-12:Hanumalapur (West); 13-14: Hanumalapur (East); 15-17: Hanumalapur CentralPGE mineralized Fe-Cr oxide-Chlorite rock

(0.02-0.44%; av. 0.14%). Substitution of all these con-stituents in the structure of magnetite has lowered theideal Fe2O3: FeO ratio of 69:31. All other constituentsanalysed viz., SiO2, MnO, MgO, ZnO, NiO, CoO and CuOare present in barely detectable levels and are insignifi-cant (Table 3A). In Stevens classification [30] the mineraloverwhelmingly corresponds to magnetite proper (Fig. 6).2) The titanomagnetite from CMUC analyses 1.4 to 4.5%TiO2 (av. 2.74%), whereas the coexisting magnetite con-tains 0.02 to 0.44% TiO2 (Table 3B). It might be of interestto mention here that KRJ [18] has recorded the occurrenceof maghemite analyzing up to 13.42 wt% TiO2 in the Mule-mane V-Ti magnetite3) Cr-magnetite –Ti-Al-Fe Chromite: Distinctly differ-

ent from magnetite proper of V-Ti magnetite seams of thecomplex is the Fe-chromite present in the host rock ofthe PGE mineralized ultramafite and the Cr-magnetiteforming a part of the magnetite seam on the eastern sideof HPB. The Cr-Fe oxide, constituting 26 to 77 vol% ofthe chromiferous ore, contains 11.91 to 37.8% Cr2O3 and41.31 to 85.58% Fe2O3 + FeO (refer Table 3C) and corre-sponds to Cr-magnetite in Stevens [30] classification (seeFig. 6) It also shows a large variation in TiO2 (0.06 -10.6%) and Al2O3 (0.16 -17.6%). Such high contents oftitania and alumina, to result in the occurrence of Ti-Fechromite, Ti-Al-Fe chromite and Al-Fe chromite (see Ta-ble 3D), are unusual. Roach et al. [31], however, havereported comparable compositions from a distinctly higher

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70.

000

0.01

50.

188

0.13

80.

137

0.11

20.

094

0.09

9Cr

0.09

40.

131

0.15

10.

093

0.12

10.

108

0.09

70.

088

0.02

40.

116

0.08

70.

000

0.00

40.

101

0.09

70.

230

0.36

10.

340

0.04

9V

0.25

80.

269

0.22

90.

222

0.20

60.

187

0.22

30.

235

0.31

50.

178

0.17

00.

342

0.40

80.

205

0.20

30.

231

0.30

00.

189

0.23

7Fe

3+15

.498

15.5

1215

.538

15.4

9915

.436

15.5

4215

.064

14.8

7615

.483

15.0

5813

.135

15.4

5715

.350

15.0

3015

.245

11.7

6215

.132

15.4

0315

.358

Fe2+

7.82

17.

891

7.90

57.

870

7.84

37.

836

8.42

88.

465

7.88

98.

359

8.29

88.

071

8.08

98.

234

8.11

09.

126

7.81

18.

116

8.10

8M

n0.

002

0.00

00.

000

0.00

60.

006

0.00

70.

000

0.00

00.

000

0.00

00.

008

0.00

00.

000

0.00

00.

014

0.03

30.

000

0.00

00.

006

Mg

0.05

40.

028

0.02

00.

054

0.04

30.

058

0.05

30.

010

0.02

20.

010

0.02

70.

002

0.02

30.

010

0.00

00.

569

0.07

60.

009

0.00

6Zn

0.00

70.

007

0.01

20.

000

0.00

00.

015

0.00

00.

034

0.05

80.

000

0.00

00.

000

0.00

20.

041

0.00

00.

018

0.00

00.

017

0.02

1N

i0.

008

0.00

00.

012

0.00

90.

020

0.02

10.

016

0.02

10.

020

0.01

30.

015

0.00

00.

019

0.02

10.

010

0.00

90.

012

0.01

30.

000

Co0.

013

0.00

00.

000

0.00

00.

000

0.00

00.

015

0.00

00.

000

0.00

00.

000

0.00

00.

000

0.00

00.

000

Cu0.

018

0.00

00.

015

0.00

00.

000

0.00

00.

000

0.00

00.

006

0.00

80.

010

0.00

00.

000

0.00

00.

000

S0.

010

0.02

10.

089

0.00

00.

035

0.01

40.

000

0.04

30.

033

0.04

90.

052

0.09

20.

152

0.00

10.

000

23.9

6223

.983

24.0

5923

.818

23.8

4123

.857

24.0

024

.00

24.0

0524

.00

24.0

023

.97

24.0

124

.00

24.0

023

.966

23.9

2524

.304

24.0

03Fe

/Fe+

Mg

0.99

80.

999

0.99

90.

998

0.99

80.

998

0.99

40.

999

0.99

90.

999

0.99

70.

999

0.99

70.

999

0.99

90.

974

0.99

70.

999

0.99

9*T

otal

Feas

FeO

1-3

(JS-

85)&

4-8

JS-1

7):

Ubr

ani;

9(J

S-43

)&10

-15

(JS-

3):

Tava

reke

re;1

6-17

(JS-

73)&

18(5

-IND

-93)

19(9

-IND

93)H

anum

alap

urwe

st

525


Figure 6. Cr-Al-Fe+3 ternary discrimination plotting for Magnetiteand Chromite analyses (after Stevens, 1944)

level in the stratagraphic section of Muskox layered intru-sion (Austrlia). The average V2O5 content (0.94%) of theCr-magnetite ore is conspicuously higher as compared tothe normal magnetite ore (av. 0.77%) of the complex (Ta-ble 4B), and the presence of Cr as an important constituentin the unit, as per the recent finding [32], should augmentthe value of the ore available in the HPB of CMUC.4) Analysis of Ilmenite occurring in four different seams ofV-Ti magnetites of CMUC (Table 3E) has revealed that:(i) it shows only a limited variation from the ideal il-menite composition, (ii) ilmenite of different modes of oc-currence viz., discrete grains, interstitial patches and in-tergrowths/ exsolution lamellae in magnetite hardly dif-fer in their composition, (iii) it is low in V2O5, Al2O3 andCr2O3 but moderately high in MnO and MgO as comparedwith co-existing magnetite, (iv) FeO of ilmenite shows anapproximate negative correlation with both MgO and MnO(Figs. 7), (v) being resistant to oxidation, ilmenite con-tains Fe entirely as FeO or only a small amount of Fe2O3

(the maximum recorded is just 3.7%). It may be mentionedhere that several of the chemical characteristics of CMUCilmenite are similar to the best known mafic-ultramaficcomplexes of the World [33–35].5) Hogbomite is present in nearly all the samples of V-Timagnetites, but, it is almost absent or present sporadi-cally in the Cr-magnetite lenses. It is generally a minor/accessory mineral accounting for less than about 5 vol.%,but, in a few samples, it accounts for 25-27 vol.% (Ta-ble 2). Probe data obtained for samples from Tavarekere,Ubrani and Hanumalapur look very similar with only alimited variation in contents of all the major constituentsviz., Al2O3, FeO, MgO and TiO2 (Table 3F). Among theminor constituents, while V2O5 and MnO are relativelylow, those of ZnO, NiO and CoO are significantly high

Figure 7. FeO Vs MgO and MnO binary plot of Ilmenite showingnegative correlation between the two constituents.

Figure 8. Binary plots of Hogbomite analyses showing diadochic re-lation between Mg & Fe and Ti & Fe.

526


Table 3B. Titano-magnetites.

1 2 3 4 5SiO2 0.22 0.01 0.12 0.06 0.07TiO2 4.51 1.40 1.37 3.70 3.54Al2O3 0.14 0.15 0.45 0.53 0.41Cr2O3 0.04 0.02 0.33 0.03 1.02V2O5 1.50 1.58 0.99 0.77 1.01Fe2O3 60.75 63.55 58.24 56.67 54.82FeO 29.85 29.64 30.90 31.50 38.27MnO 0.05 0.00 0.05 0.18 0.14MgO 0.00 0.02 0.00 0.48 1.34ZnO 0.00 0.01 0.00 0.00 0.08NiO 0.08 0.11 0.04 0.12 0.04CoO 0.01 0.00 0.00 0.00 0.00CuO 0.12 0.10 0.00 0.00 0.00S 0.05 0.03 0.21 0.09 0.00Total 97.32 96.62 92.71 94.13 100.74

Number of ions on the basis of 32 (O)Si 0.069 0.005 0.040 0.021 0.021Ti 1.046 0.332 0.340 0.901 1.931Al 0.052 0.055 0.175 0.201 0.137Cr 0.011 0.006 0.086 0.008 0.230V 0.305 0.329 0.216 0.200 0.231Fe3+ 14.100 15.034 14.462 13.800 11.762Fe2+ 7.700 7.795 8.527 8.525 9.126Mn 0.012 0.000 0.014 0.049 0,0327Mg 0.000 0.011 0.000 0.233 0.569Zn 0.000 0.004 0.000 0.000 0.018Ni 0.020 0.027 0.011 0.031 0.009Co 0.001 0.000 0.000 0.003 0.000Cu 0.028 0.025 0.000 0.000 0.000S 0.029 0.019 0.130 0.053 0.001

23.373 23.640 23.31 24.025 23.967Fe/Fe+Mg 1.000 1.000 1.000 0.990 0.9731-2 (JS-66): Masanikere, 3 (JS-3) & 4 (JS-43):Tavarekere; 5 (JS-73): Hanumalapur west

as compared to coexisting ilmenite. The analytical datagiven (Table 3F) represents both larger prisms occupyingthe borders of Fe-Ti oxides and exsolution inclusions. Theminor variations recorded in major constituents are pos-sibly related partly to replacement of Mg and Zn by Ti[36, 37] and partly to reciprocal replacement of Ti↔ 2R2

and Ti↔ 2Al [38]. The balancing of impaired charge inthe involved replacements may have been brought aboutby oxidation of Fe [37]. The Fetot/(Fetot+Mg) ratios ofCMUC hogbomites range from 0.32 to 0.58, which is wellwithin the range recorded (viz., 0.02-0.62) by a number ofother workers. The substitution relationship of TiO2 andMgO by FeO is displayed in Figs. 8.6) Spinel occurs sporadically in small grains in a fewmagnetite samples. One relatively large grain identifiedin a sample from Ubrani ore happens to be zincian (∼5%ZnO) (Table 3G) with distinctly high Cr2O3, CoO, V2O5

and MnO as compared with co-existing ilmenite.7) Chlorite analysis occurring in all the four major V-

Ti magnetite seams of CMUC (Table 3H and 3I) has re-vealed the following: (i) Masanikere (MK) chlorite hasthe highest FeO content and significant V2O5 and NiO;(ii) Tavarekere (TK) chlorite is on an average most magne-sian; (iii) Ubrani (UB) chlorite is the most aluminous andlowest in iron; (iv) Hanumalapur (HP) chlorite from thechromiferous PGE mineralized zone is significantly highin Cr2O3 (av. 0.8%). Further, in the widely adopted classi-fication of Hey (39), the chlorites of CMUC lie within thelimits of corundophilite (MK), ripidolite (HP and TK) andsheridanite (UB) (Fig. 9). Biotite with a Mg:Fe ratio of0.88 (Table 3J) has been recorded only in a core sampleof V-Ti magnetite from western side of HPB, collected ata depth of 150.96 m.The mineral chemistry of CMUC V-Ti magnetite depositssubstantiates the findings of a host of other workers whohave investigated the best known Bushveld and other de-posits of the world. Following are the partitioning pat-terns of some of the elements among the co-existing min-erals identified:

V : magnetite-titanomagnetite > ilmenite > hog-bomite > spinel

Mg : hogbomite > ilmenite > magnetite

Mn : ilmenite > hogbomite > magnetite

The present study further reiterates the fact that, as inBushveld and other well studied V-Ti magnetite depositsof the world, in the CMUC deposits too, separate V min-erals do not exist; the metal overwhelmingly occurs con-cealed in the structure of magnetite.

Figure 9. Classification of Chlorites based on Fe/(Fe+Mg) Vs Si val-ues (after Hey, 1954).

527


T abl

e3C

.C

hrom

ifero

usM

agne

tites

.

12

34

56

(3)

78

SiO

20.

000.

020.

030.

010.

010.

010.

050.

11Ti

O2

0.06

0.11

0.06

0.63

0.11

0.42

0.25

0.83

Al2O

30.

230.

330.

260.

300.

290.

410.

660.

54Cr

2O3

12.7

113

.37

11.9

112

.74

13.2

418

.64

20.7

423

.16

V 2O

51.

441.

611.

391.

361.

490.

82Fe

2O3

54.1

654

.19

54.9

653

.98

53.6

044

.91

44.4

241

.87

FeO

30.6

531

.11

30.6

231

.61

30.7

334

.81

30.9

331

.56

MnO

0.00

0.00

0.00

0.00

0.00

0.28

0.19

0.41

MgO

0.04

0.01

0.01

0.02

0.02

0.06

0.01

0.07

ZnO

0.12

0.13

0.22

0.26

0.02

0.12

0.09

0.05

NiO

0.13

0.13

0.08

0.11

0.08

0.05

CoO

0.04

0.00

0.00

0.00

0.00

CuO

0.01

0.00

0.05

0.00

0.08

S0.

020.

010.

000.

000.

00To

tal

99.7

010

1.02

99.5

910

1.02

99.6

796

.09

97.3

498

.60

Num

bero

fion

son

the

basi

sof

32(O

)Si

0.00

00.

007

0.00

80.

003

0.00

50.

005

0.01

60.

034

Ti0.

014

0.02

50.

014

0.01

40.

024

0.09

50.

058

0.19

0Al

0.12

90.

118

0.09

30.

107

0.10

60.

147

0.24

10.

193

Cr3.

076

3.19

22.

889

3.04

23.

203

4.50

15.

067

5.59

8V

0.35

30.

390

0.34

10.

329

0.36

70.

201

Fe3+

12.4

7512

.310

12.6

8512

.272

12.3

407.

246

10.3

319.

632

Fe2+

7.84

77.

855

7.85

57.

987

7.86

410

.324

7.99

58.

070

Mn

0.00

00.

000

0.00

00.

000

0.00

00.

073

0.05

00.

106

Mg

0.01

70.

005

0.00

70.

011

0.00

90.

025

0.00

50.

033

Zn0.

027

0.02

90.

051

0.05

70.

005

0.02

70.

021

0.01

2N

i0.

033

0.03

10.

019

0.02

60.

020

0.01

2Co

0.01

00.

000

0.00

00.

000

0.00

0Cu

0.00

10.

000

0.01

20.

000

0.01

9S

0.01

20.

008

0.00

00.

001

0.00

023

.904

23.9

7023

.973

23.8

4823

.962

22.6

5623

.757

23.8

68Fe

/0.

999

1.00

01.

000

0.99

91.

000

0.99

80.

999

0.99

6Fe

+M

g1-

5(J

S-29

),6

(3-IN

D-9

3),7

(1-IN

D-9

3)8

(2-IN

D-9

3)Ce

ntra

lPG

Em

iner

-al

ized

zone

,Han

umal

apur

Tabl

e3D

.Ti

-Cr-A

lMag

netit

e.

12

(2)

3(4

)4

56

7Si

O2

0.03

0.07

0.08

0.09

0.13

0.06

0.10

TiO

29.

678.

1010

.58

0.42

2.11

2.25

3.90

Al2O

30.

2313

.92

13.7

013

.63

13.8

717

.59

15.2

6Cr

2O3

10.3

933

.32

25.7

434

.47

37.8

029

.98

29.2

6V 2

O5

1.12

Fe2O

339

.65

2.57

3.57

14.0

28.

1410

.78

11.5

4Fe

O40

.23

38.7

240

.43

31.1

533

.17

33.3

634

.65

MnO

0.00

0.95

1.03

1.05

0.91

0.83

0.99

MgO

0.04

0.24

0.29

0.21

0.19

0.30

0.30

ZnO

0.19

1.15

1.00

0.86

1.27

1.23

1.13

NiO

0.00

CoO

0.00

CuO

0.09

S0.

00To

tal

101.

6498

.04

96.4

295

.90

97.5

996

.38

97.1

3Io

nson

the

basi

sof

32(O

)Si

0.00

80.

0203

0.02

180.

0260

0.03

730.

0184

0.27

4Ti

2.16

81.

7263

2.28

850.

0909

0.45

360.

4796

0.83

68Al

0.00

04.

6463

4.64

274.

6697

4.66

685.

8770

5.12

65Cr

2.44

07.

2395

5.85

36.9

240

8.53

426.

7195

6.59

41V

0.26

7Fe

3+8.

395

0.54

770.

7724

3.06

691.

7497

2.29

912.

4762

Fe2+

10.0

329.

1744

9.72

407.

5750

7.92

187.

9100

8.26

10M

n0.

000

0.22

820.

2503

0.25

750.

2210

0.19

890.

2389

Mg

0.01

70.

1023

0.12

330.

0893

0.08

090.

1279

0.12

68Zn

0.04

20.

2409

0.21

230.

1851

0.26

700.

2578

0.23

70N

iCo Cu S

23.3

692.

658

2.65

42.

654

2.65

92.

654

2.68

6Fe

/0.

999

0.98

90.

987

0.98

80.

990

0.98

40.

985

Fe+

Mg

1(J

S-29

,2-7

(7-IN

D-9

3):

Cent

ralP

GE

min

eral

ized

zone

,Han

u-m

alap

ur

528


T abl

e3E

.Ilm

enite

s.

12

34

56

78

910

1112

1314

1516

1718

SiO

20.

000.

030.

00.0

00.

010.

000.

000.

010.

010.

000.

000.

000.

010.

030.

020.

010.

020.

01Ti

O2

51.6

150

.51

51.8

453

.43

51.6

151

.23

49.7

152

.49

52.5

253

.38

57.0

251

.23

51.4

055

.40

52.3

351

.49

48.8

751

.66

Al2O

30.

030.

330.

150.

010.

120.

100.

150.

020.

020.

070.

010.

030.

050.

020.

020.

010.

040.

02Cr

2O3

0.00

0.00

0.05

0.03

0.05

0.06

0.00

0.07

0.00

0.06

0.02

0.02

0.00

0.00

0.00

0.02

0.05

0.08

V 2O

50.

240.

380.

170.

240.

240.

210.

290.

260.

370.

600.

580.

470.

440.

590.

670.

460.

400.

39Fe

2O3

2.11

1.25

0.00

0.00

0.00

0.88

0.35

0.00

0.00

0.00

0.00

0.42

1.53

0.00

0.00

0.00

0.00

0.00

FeO

42.1

341

.45

38.9

638

.13

38.5

641

.92

40.9

443

.68

43.9

343

.13

35.5

444

.67

44.9

839

.15

43.5

444

.96

47.3

443

.91

MnO

1.03

0.95

0.99

0.89

0.88

1.02

1.03

1.09

0.91

1.15

0.71

1.19

1.08

1.03

1.05

1.08

0.94

1.05

MgO

1.83

1.82

1.86

1.53

1.60

1.80

1.59

2.13

2.09

0.04

0.07

0.12

0.10

0.09

0.11

1.74

1.68

2.00

ZnO

0.00

0.00

0.00

0.00

0.00

0.13

0.00

0.00

0.00

0.05

0.06

0.00

0.02

0.07

0.04

0.18

0.00

0.04

NiO

0.00

0.01

0.00

0.00

0.00

0.09

0.04

0.01

0.00

0.00

0.01

0.00

0.03

0.04

0.03

0.00

0.00

0.04

CoO

0.00

0.00

0.00

0.00

0.00

0.00

0.04

0.00

0.07

0.00

0.00

0.00

0.04

0.00

0.01

0.00

0.01

0.02

CuO

0.00

0.00

0.03

0.00

0.04

0.03

0.00

0.00

0.00

0.01

0.00

0.00

0.00

0.00

0.00

0.01

0.00

0.00

S0.

000.

020.

000.

020.

000.

000.

010.

000.

000.

000.

020.

000.

000.

010.

000.

000.

000.

0399

.98

96.7

594

.05

94.2

893

.11

97.4

794

.15

99.7

699

.92

98.4

994

.04

98.1

599

.68

96.4

397

.82

99.9

699

.35

99.2

5N

umbe

rofi

ons

onth

eba

sis

of6

(O)

Si0.

000

0.00

10.

000

0.00

00.

001

0.00

00.

000

0.00

10.

000

0.00

00.

000

0.00

00.

001

0.00

10.

001

0.00

00.

001

0.00

0Ti

1.95

21.

951

2.03

82.

083

2.04

81.

968

1.97

71.

973

1.97

22.

030

2.19

41.

976

1.95

52.

115

2.01

11.

948

1.88

41.

959

Al0.

002

0.02

00.

009

0.00

10.

007

0.00

60.

010

0.00

10.

001

0.00

40.

001

0.00

20.

003

0.00

10.

002

0.00

10.

003

0.00

1Cr

0.00

00.

000

0.00

20.

001

0.00

20.

002

0.00

00.

003

0.00

00.

002

0.00

10.

001

0.00

00.

000

0.00

00.

001

0.00

20.

003

V0.

008

0.01

30.

006

0.00

80.

009

0.00

70.

010

0.01

00.

015

0.02

00.

020

0.01

60.

015

0.02

00.

023

0.01

80.

016

0.01

6Fe

3+0.

080

0.04

80.

000

0.00

00.

000

0.03

40.

014

0.00

00.

000

0.00

00.

000

0.01

60.

058

0.00

00.

000

0.00

00.

000

0.00

0Fe

2+1.

772

1.78

01.

703

1.65

31.

701

1.79

11.

811

1.82

61.

834

1.82

41.

521

1.91

61.

903

1.66

21.

860

1.89

12.

029

1.85

2M

n0.

044

0.04

10.

044

0.03

90.

040

0.04

40.

046

0.04

60.

038

0.04

90.

031

0.05

20.

046

0.04

40.

046

0.04

60.

041

0.04

5M

g0.

137

0.13

90.

145

0.11

80.

126

0.13

70.

125

0.15

80.

156

0.00

30.

006

0.00

90.

008

0.00

70.

008

0.13

00.

128

0.15

0Zn

0.00

00.

000

0.00

00.

000

0.00

00.

005

0.00

00.

000

0.00

00.

001

0.00

20.

003

0.00

10.

003

0.00

20.

007

0.00

00.

002

Ni

0.00

00.

001

0.00

00.

000

0.00

00.

004

0.00

20.

001

0.00

00.

000

0.00

00.

000

0.00

10.

002

0.00

10.

000

0.00

00.

002

Co0.

000

0.00

00.

000

0.00

00.

000

0.00

00.

002

0.00

00.

003

0.00

00.

000

0.00

00.

002

0.00

00.

000

0.00

00.

001

0.00

1Cu

0.00

00.

000

0.00

10.

000

0.00

20.

001

0.00

00.

000

0.00

00.

000

0.00

00.

000

0.00

00.

000

0.00

00.

001

0.00

00.

000

S0.

000

0.00

20.

000

0.00

20.

000

0.00

00.

001

0.00

00.

000

0.00

00.

002

0.00

00.

000

0.00

10.

000

0.00

00.

000

0.00

23.

995

3.99

63.

948

3.90

53.

934

4.00

03.

997

4.01

84.

019

3.93

63.

777

3.99

13.

992

3.85

53.

953

4.04

24.

104

4.03

2Fe

/Fe+

Mg

0.93

20.

931

0.92

40.

935

0.93

30.

932

0.93

70.

922

0.92

30.

998

0.99

60.

995

0.99

60.

996

0.99

60.

937

0.94

20.

927

1-7

(JS-

3)&

8-9

(JS-

43):

Tava

reke

re;1

0-15

(JS-

66):

Mas

anik

ere;

16-1

8(J

S-85

)&19

-22

(JS-

17):

Ubr

ani;

23-2

4(J

S-73

),25

(5-IN

D-

93),

Han

umal

apur

Wes

t;

529


Table 3E. Ilmenites contd.

19 20 21 22 23 24 25 26 27SiO2 0.00 0.00 0.00 0.00 0.00 0.00 0.07 0.01 0.03TiO2 52.22 52.77 53.50 54.23 52.35 53.27 50.46 48.71 50.20Al2O3 0.03 0.03 0.05 0.03 0.02 0.03 0.02 0.00 0.01Cr2O3 0.07 0.08 0.00 0.07 0.04 0.08 0.00 0.01 0.15V2O5 0.43 0.44 0.43 0.15 0.32 0.44 0.36 0.40 0.23Fe2O3 3.70 2.16 1.27 0.00 3.49 0.00 0.00 0.00 0.00FeO 39.16 38.99 40.20 40.95 39.52 41.94 46.61 47.61 44.76MnO 1.26 1.23 1.19 1.13 1.18 1.20 1.02 0.96 1.21MgO 3.69 4.08 3.78 3.53 3.58 3.78 0.10 0.15 0.24ZnO 0.00 0.00 0.00 0.00 0.00 0.01 0.04 0.02NiO 0.04 0.02 .00 0.03 0.00 0.02 0.06 0.07CoO 0.01 0.06 0.01 0.00 0.02 0.03CuO 0.00 0.00 0.00 0.00 0.05 0.01S 0.00 0.00 0.00 0.00 0.00 0.00

100.61 99.86 100.43 100.12 100.57 100.81 98.68 97.97 96.98Number of ions on the basis of 6 (O)

Si 0.000 0.000 0.000 0.000 0.000 0.000 0.020 0.001 0.009Ti 1.917 1.944 1.963 1.999 1.925 1.961 10.430 1.916 10.505Al 0.002 0.002 0.003 0.002 0.001 0.002 0.001 0.000 0.003Cr 0.003 0.003 0.000 0.003 0.001 0.003 0.000 0.001 0.016V 0.014 0.014 0.014 0.006 0.010 0.017 0.069 0.017 0.052Fe3+ 0.136 0.080 0.047 0.000 0.128 0.000 0.000 0.000 0.000Fe2+ 1.598 1.598 1.640 1.679 1.616 1.717 10.708 2.083 10.419Mn 0.052 0.051 0.049 0.047 0.049 0.050 0.000 0.043 0.286Mg 0.269 0.298 0.275 0.258 0.261 0.275 0.238 0.006 0.101Zn 0.000 0.000 0.000 0.000 0.000 0.000 0.041 0.001 0.003Ni 0.002 0.001 0.000 0.001 0.000 0.001 0.003 0.016Co 0.000 0.002 0.000 0.000 0.001 0.001Cu 0.000 0.000 0.000 0.000 0.002 0.000S 0.000 0.000 0.000 0.000 0.000 0.000

3.992 3.992 3.991 3.996 3.994 4.027Fe/Fe+Mg 0.869 0.853 0.863 0.870 0.873 0.86526 (9-IND-93): Hanumalapur West; 27 (3-IND-93): Hanumalapur central PGEmineralized zone

5. Geochemistry

31 samples of V-Ti magnetite and 21 of chromiferous unitsrepresenting the main ore bodies of CMUC have beenanalyzed for major and a set of trace elements (AppendixII). Separate FeO determinations have been done only in20 samples. In the remaining, total Fe is determined asFe2O3 and for the same reason, the totals in several ofthe samples are high. Besides, 13 V-Ti magnetites and23 chromiferous units are analyzed for PGE + Au and 7of these for REE. The data obtained are given in Tables 4Ato 4D. The main features of the data are summarized inthe following sections:The major element geochemistry of V-Ti magnetite ores isdominated by Fe, Ti and V. The other elements contribut-ing to the major element chemistry are Al, Si, Mg andMn. Ca, Na and K hardly show up in more than seconddecimal wt% values. While magnetite-titanomagnetite to-gether with ilmenite determine bulk of Fe, Ti, V and Mn

concentrations, chlorite accounts for most of Al, Si and Mgand some amounts of Fe of the ores. Variable amounts ofAl, Fe, Mg, Ti and V are also contributed by hogbomite.Cr, Ni, Co, Zn and Cu (also Ga and Sc) are the minor/trace elements. (see Appendix II). The first four of theseare almost fully accounted by various oxides of the oresviz., magnetite–titanomagnetite, ilmenite and hogbomite,which invariably contain minor amounts of these metals;Cu and S are largely linked to chalcopyrite and pyritewhich are sporadically distributed. F and Cl are possi-bly in chlorite, but, not substantiated by analytical dataobtained so far for the mineral. Zr (and Hf) is thought tobe interlinked with occasional tiny crystals of beddeleyiterecorded in the probe examination of ores.

As compared to ’normal’ V-Ti magnetite, Cr-magnetite ofHPB has very high Cr2O3, contrastingly elevated MgO,Ni, Zn and Co, significantly high Al2O3, V2O5 and Sc,markedly lower TiO2 and somewhat depleted Zr, Sr andGa (Table 4B).

530


T abl

e3F

.H

ogbo

mite

s. 12

35

45

67

89

1011

1213

1415

1617

SiO

20.

010.

030.

000.

010.

020.

030.

000.

020.

010.

010.

020.

030.

000.

020.

010.

020.

010.

01Ti

O2

6.78

6.42

7.42

5.68

7.58

6.45

7.71

8.10

9.70

8.98

8.82

8.84

7.35

9.38

8.14

10.1

510

.74

6.81

Al2O

359

.42

59.1

858

.43

61.1

358

.20

59.6

661

.21

62.0

060

.46

61.4

159

.98

61.1

861

.05

61.0

561

.13

60.3

461

.09

61.5

6Cr

2O3

0.50

0.24

0.32

0.33

0.40

0.27

0.05

0.01

0.04

0.32

0.51

0.00

0.23

0.33

0.54

0.18

0.32

1.11

V 2O

50.

310.

220.

170.

280.

120.

170.

390.

230.

200.

240.

220.

310.

340.

340.

230.

160.

220.

27Fe

O20

.32

17.3

019

.80

17.8

920

.92

19.0

517

.39

15.5

717

.78

17.2

017

.47

17.3

620

.09

17.2

317

.38

12.6

611

.68

16.2

4M

nO0.

130.

130.

180.

170.

230.

120.

030.

140.

150.

120.

110.

130.

100.

120.

090.

090.

110.

16M

gO9.

269.

659.

0510

.39

8.50

9.96

10.6

611

.42

10.8

59.

839.

0810

.12

8.79

9.69

9.50

14.0

914

.26

13.4

5Zn

O1.

081.

291.

321.

680.

921.

221.

150.

441.

571.

401.

351.

301.

431.

351.

900.

670.

670.

38N

iO0.

090.

080.

030.

140.

050.

080.

070.

100.

140.

210.

170.

100.

140.

200.

050.

060.

120.

15Co

O0.

110.

090.

040.

080.

080.

090.

070.

040.

170.

050.

100.

080.

100.

110.

040.

050.

030.

09Cu

O0.

030.

030.

010.

000.

000.

000.

000.

000.

000.

000.

000.

040.

020.

090.

000.

010.

000.

00S

0.01

0.00

0.01

0.00

0.01

0.01

0.01

0.00

0.00

0.00

0.00

0.01

0.00

0.00

0.00

0.00

0.00

0.01

Σ98

.05

94.6

596

.78

97.7

897

.03

97.1

198

.74

98.0

710

1.07

99.7

797

.83

99.5

099

.64

99.9

199

.01

98.4

899

.25

100.

24N

umbe

rofi

ons

onth

eba

sis

of32

(O)

Si0.

001

0.00

60.

001

0.00

30.

004

0.00

60.

000

0.00

40.

001

0.00

30.

005

0.00

60.

000

0.00

50.

002

0.00

40.

003

0.00

3Ti

1.10

11.

066

1.22

10.

914

1.24

81.

050

1.22

31.

276

1.51

21.

411

1.41

81.

393

1.17

11.

474

1.29

21.

579

1.65

01.

057

Al15

.117

15.3

8815

.055

15.4

2015

.018

15.2

3115

.211

15.3

1114

.772

15.1

2415

.113

15.1

0615

.255

15.0

3415

.218

14.7

0914

.706

14.9

81Cr

0.08

50.

041

0.05

50.

056

0.06

90.

046

0.00

80.

002

0.00

60.

053

0.08

60.

000

0.03

90.

054

0.09

00.

030

0.05

10.

181

V0.

044

0.03

20.

025

0.04

00.

018

0.02

40.

066

0.03

80.

034

0.03

90.

038

0.05

30.

058

0.05

70.

040

0.02

20.

029

0.04

5Fe

3+*

0.75

40.

539

0.86

60.

484

0.89

50.

699

0.71

60.

658

1.18

80.

784

0.76

30.

842

0.64

80.

855

0.65

31.

240

1.21

40.

812

Fe2+

*2.

914

2.65

22.

755

2.71

82.

935

2.75

22.

351

2.07

01.

894

2.22

12.

361

2.20

02.

914

2.15

62.

417

0.95

00.

782

1.99

1M

n0.

024

0.02

40.

034

0.03

10.

043

0.02

30.

005

0.02

50.

026

0.02

10.

020

0.02

40.

018

0.02

20.

015

0.01

60.

020

0.02

7M

g2.

978

3.17

32.

948

3.31

62.

774

3.21

43.

351

3.56

63.

353

3.06

12.

893

3.15

92.

779

3.01

82.

992

4.34

44.

342

4.13

8Zn

0.17

10.

210

0.21

40.

265

0.14

90.

195

0.17

90.

067

0.24

10.

215

0.21

40.

201

0.22

50.

208

0.29

60.

102

0.10

00.

058

Ni

0.01

60.

014

0.00

50.

024

0.00

80.

013

0.01

30.

017

0.02

30.

035

0.02

90.

017

0.02

40.

034

0.00

80.

010

0.02

00.

026

Co0.

020

0.01

60.

007

0.01

30.

014

0.01

50.

012

0.00

70.

028

0.00

90.

018

0.01

40.

017

0.01

80.

007

0.00

90.

006

0.01

5Cu

0.00

40.

004

0.00

20.

000

0.00

00.

000

0.00

00.

000

0.00

00.

000

0.00

00.

006

0.00

30.

013

0.00

00.

001

0.00

00.

000

S0.

005

0.00

00.

004

0.00

00.

005

0.00

50.

004

0.00

00.

000

0.00

00.

000

0.00

30.

000

0.00

00.

000

0.00

00.

000

0.00

423

.234

23.1

6423

.189

23.2

8323

.181

23.2

7223

.137

23.0

4223

.078

22.9

7522

.957

23.0

2323

.151

22.9

4723

.030

23.0

1422

.922

23.3

39Fe

/Fe+

Mg

0.55

40.

503

0.55

40.

494

0.58

30.

520

0.47

80.

436

0.48

10.

497

0.52

00.

493

0.56

30.

501

0.50

80.

337

0.31

70.

406

Fe+

Mg

6.64

66.

364

6.65

86.

517

6.60

46.

666

6.41

86.

294

6.43

56.

066

6.01

76.

201

6.34

16.

029

6.06

26.

533

6.33

86.

942

Reca

lcul

ated

acco

rdin

gto

Zakr

zews

ki(1

977)

1-6

(JS-

3)&

7-9

(JS-

43):T

avar

eker

e;10

-15

(JS-

85)&

16-1

7(J

S-19

):U

bran

i;18

(JS-

73):

Han

umal

apur

Wes

tsea

m

531


T abl

e3G

.Sp

inel

.

1Si

O2

0.01

T iO

20.

28Al

2O3

61.9

0Cr

2O3

1.62

V 2O

50.

15Fe

O17

.83

MnO

0.07

MgO

13.0

6Zn

O5.

05N

iO0.

08Co

O0.

22Cu

O0.

02S

0.03

Σ10

0.32

32(O

)bas

isSi

0.00

2Ti

0.04

5Al

15.5

11Cr

0.27

3V

0.03

4Fe

3+*

0.18

5Fe

2+*

3.17

1M

n0.

013

Mg

4.14

0Zn

0.79

3N

i0.

014

Co0.

037

Cu0.

004

S0.

011

24.2

33JS

-85:

Ubr

ani

Tabl

e3H

.C

hlor

ites.

12

34

56

78

910

11Si

O2

22.0

921

.82

21.5

922

.57

23.0

623

.05

24.7

327

.30

27.2

123

.95

25.1

2Ti

O2

0.25

0.02

0.03

0.13

0.33

0.19

0.23

0.07

0.31

0.04

0.04

Al2O

335

.18

36.0

036

.10

22.4

722

.16

22.5

828

.32

24.1

924

.90

22.6

921

.37

Cr2O

30.

100.

040.

080.

090.

010.

000.

060.

030.

030.

050.

13Fe

2O3

0.00

0.00

0.00

0.00

0.00

0.74

0.00

0.00

0.00

0.35

2.50

FeO

2.99

2.82

2.87

25.5

826

.29

26.7

58.

575.

254.

7825

.87

23.8

2M

nO0.

000.

000.

000.

170.

080.

140.

100.

070.

000.

230.

03N

iO0.

000.

010.

020.

140.

150.

110.

010.

040.

010.

020.

00Co

O0.

020.

000.

000.

000.

030.

040.

050.

000.

010.

0016

.27

MgO

26.7

426

.79

26.5

612

.03

12.7

712

.75

25.5

929

.05

28.8

713

.96

0.08

ZnO

0.02

0.04

0.00

0.03

0.14

0.09

0.00

0.10

0.00

0.12

0.00

V 2O

30.

050.

010.

000.

140.

160.

220.

100.

000.

000.

08SO

30.

000.

030.

020.

000.

010.

020.

000.

000.

020.

00H

2O12

.79

12.8

312

.78

10.7

010

.91

11.0

612

.47

12.4

512

.51

11.2

511

.60

Tota

l10

0.23

100.

4110

0.05

94.0

596

.10

97.7

510

0.23

98.5

598

.65

98.6

210

1.02

Si4.

1422

4.07

924.

0519

5.05

815.

0698

4.99

784.

7587

5.25

845.

2170

5.10

455.

196

Ti0.

0353

0.00

280.

0042

0.02

190.

0546

0.03

100.

0333

0.01

010.

0447

0.00

640.

006

Al7.

7747

7.93

207.

9848

5.93

505.

7419

5.77

026.

4226

5.49

145.

6266

5.69

955.

209

Cr0.

0148

0.00

590.

0119

0.01

590.

0017

0.00

000.

0091

0.00

460.

0045

0.00

840.

021

Fe3+

0.00

000.

0000

0.00

000.

0000

0.00

000.

1210

0.00

000.

0000

0.00

000.

0565

0.39

0Fe

2+0.

4689

0.44

090.

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The PGE mineralized ultramafite of HPB containing Fe-chromite - Cr-magnetite and chlorite analyses distinctlyhigher SiO2, Al2O3, Cr2O3, MgO, MnO, Ni, Cu, Zn andCl but markedly lower TiO2 and V2O5 (refer Table 4B).High Cr2O3 and also Al2O3, Ni, Zn, Mn and Mg corre-lates with the occurrence of abundant ferriferous chromite,which carries higher amounts of these constituents. De-pleted TiO2 content is correlated mainly with the lowerilmenite content of these rocks.

REE distribution patternREE contents are low in V-Ti magnetite, Cr-magnetiteand PGE mineralized ultramafite. Bulk of the REE is ac-counted by Ce, Pr, Nd, La and Gd. Tb and Tm are alwaysbelow detection limits. In the main PGE mineralized ul-tramafite itself the total absolute REE contents vary fromzero to 1.73 ppm. The samples with ore level PGE con-tent (viz., M2, M5 and M11) are among the five analysedsamples containing a higher total REE (0.81 to 1.73 ppm).Interestingly, between the normal V-Ti magnetite and Cr-magnetite, the latter has nearly 3.5 times more of totalREE (0.76 ppm) as compared to the former with 0.22 ppm(Table 4C). The primitive mantle normalized patterns ob-tained for the analyzed samples look almost flat with onlya slight enrichment in both LREE and HREE. It may alsobe noted from the patterns that the Cr-magnetite analysedis relatively depleted in LREE but enriched in HREE com-pared to the samples of fine-grained ultramafite (FUM),(Fig. 10).

PGE distribution and its significanceTaking note of the association of chromiferous magnetite(with evidence of PGE mineralization) and normal V-Timagnetite, forming the eastern magnetite seam of HPB,an attempt was made to verify whether comparable closeassociations of these two phases of magnetite existed evenin the other magnetite seams of CMUC. 11 magnetite sam-ples have been analyzed for all PGE and Au and 14 sam-ples only for Pt, Pd and Au (Table 4D). The analysesshow that normal V-Ti magnetites are very low in PGEwith Os < 2, Ir < 0.3, Ru < 26, Rh < 0.5, Pt < 20, Pd <34 and Au < 19 (ppb). On the other hand, the Cr mag-netite analyses show Os 5-16, Ir 16-31, Ru 40-110, Rh37-101, Pd 100-2080, Pt 41-930 and Au 12-370 (ppb).Even higher (ore level) PGE values are recorded in thecentrally located fine-grained ultramafite of HPB (4-130Os, 4-96 Ir, 10-300 Ru, 14-385 Rh, 33-4000 Pt, 24-3050Pd and 2-82 Au–values in ppb). Plotting of Ni/Pd againstCu/Pt values [40] (Fig. 11) obtained for PGE mineralizedchromiferous suit of HPB has indicated that these largelyoccupy the field defined by similar PGE mineralized lay-ered intrusions, suggesting genetic similarities between

the two.

Significance of geochemical dataHarker-type binary plotting of TiO2, Al2O3, Fe2O3, MgO,and Ga against SiO2; TiO2, MgO against Fe2O3; Gaagainst Fe2O3; and Ni against MgO (Fig. 12A to 12H& 12M) define certain trends and familiar positive/ neg-ative correlations in respect of the different pairs of ox-ides. In all the ternary and binary diagrams, a strikingfeature is the consistent separation of Cr-magnetite orefrom the ’normal’ V-Ti magnetite ore, which is in accor-dance with our interpretation that the two are geneticallyunrelated. Further, average compositions of V-Ti bear-ing magnetite occurring at different locations of CMUCand the chromiferous magnetite in the HPB are plot-ted in the Fe2O3+TiO2–MgO–Ca0+Al2O3, Al-Fe+Ti-Mg[41, 42] and CaO-MgO-Al2O3 [42, 43] (Figs. 12I to 12K)ternary discrimination diagrams. These plots have indi-cated an overall komatiitic affinity of chromiferous mag-netite and tholeiite affinity of V-Ti magnetites. Also, theplotting of average V-Ti magnetite compositions from var-ious locations in CMUC in the binary discrimination dia-gram of Pearce [44] (Fig. 12L) indicates the formation ofthese in the tectonic setting of ocean-floor basalts.

6. An overview of petrogenetic evo-lution of CMUC and the associated V-Ti and Cr-magnetite oresOrigin of V-Ti Magnetite ore deposits is one of the longdebated topics and many workers have attempted to in-terpret it. Attention of the reader is specifically drawn tothe contributions of the following: Wager and Brown [29],Himmelberg and Ford [33], Mathison [34], Hall [45], Bate-man [46], Osborn [47], Buddington and Lindsley [48], Lister[49], Collins [50], Cawthorn and Mcarthy [51], Cawthorn[52], Duchesne [53], Zhou et al., [54, 55], Pang et al. [56],Zhong et al. [57], Hou et al.[58], Dong et al., [59], Gross[60], Thy [61].Variable genetic models have been proposed for the V-Timagnetite deposits associated with Bushveld (S. Africa),Duluth (USA), Rogaland (Norway), Ulvno (Sweden), Luc-du-Pin-Rouge (Canada), Gusevogorsk and Pervouraisk(Russia), Panzhihua, Hongge, Xinjie, Baima and Taihelayered complexes (southeast China) and a number ofother mafic-ultramafic complexes in the world. The oldermodels acknowledge the existence of genetic connectionwith the host complexes. They either invoke separation

535


Table 4C. REE analyses (in ppm) of representative Ti-V- bearing & Cr-magnetite ore samples from HPB.

1 2 3 4 5 6 7 8 9 10Samp Nos. M2 M5 M11 M84 M99 M105 M93 M103 M6 M181La 0.22 0.30 -0.05 -0.05 -0.05 -0.05 0.07 0.06 -0.05 0.82Ce 0.40 0.70 0.30 -0.10 -0.10 -0.10 0.20 -0.10 -0.10 2.70Pr 0.04 0.10 0.04 -0.02 -0.02 0.03 0.03 -0.02 -0.02 2.70Nd 0.20 0.43 0.24 -0.05 -0.05 0.18 0.18 0.07 0.39 3.39Sm -0.02 0.07 0.04 -0.02 0.03 -0.02 0.06 -0.02 0.02 1.48Eu -0.01 0.02 0.01 -0.01 0.01 -0.01 0.01 -0.01 0.03 0.71Gd 0.02 0.04 0.04 -0.02 -0.02 -0.02 0.05 -0.02 0.38 1.96Tb -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 0.09 0.39Dy -0.02 0.03 0.05 -0.02 0.04 -0.02 0.06 0.02 0.72 2.67Ho -0.01 -0.01 0.01 -0.01 -0.01 -0.01 0.02 -0.01 0.15 0.54Er -0.01 0.01 0.03 -0.01 0.02 -0.01 0.03 0.02 0.41 1.52Tm -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 -0.01 0.07 0.20Yb 0.01 0.02 0.04 -0.01 0.03 0.02 0.04 0.04 0.38 1.21Lu 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.01 0.05 0.18ΣREE 0.89 1.73 0.81 0.00 0.13 0.02 0.76 0.22 2.89 18.29

ICPMS analyses using Li-metaborate/ tetrabore fusions, Actlabs, Canada: -ve value indicatesbelow this detection limit.1-6: PGE mineralized fine-grained ultramafite with ferriferous chromite & chlorite, 7:Chromiferous magnetite 8: V-Ti magnetite, 8 & 9: Coarse-grained ultramafite from east-ern side of the block

Figure 10. Primitive mantle normalize REE patterns for Ti-V bearingMagnetite, Cr-magnetite, FUM and CUM of HPB.

Figure 11. Binary discrimination diagram based on Ni/Pd Vs Cu/Ptmetal ratios of PGE mineralized chromiferous units ofHPB (fiels after Barnes et al., 1987).

and accumulation of Fe-Ti crystals to form layers or pos-tulate existence of Fe-Ti oxide liquids from which theores crystallized [45, 46, 49, 62–65]. The newer mod-els invoke mechanisms whereby episodic increase in oxy-gen fugacity triggers the crystallization of enough quan-tities of Ti-Fe oxides for the development of ore rich lay-ers [47, 54, 55, 58, 59, 66–68]. This interpretation hasbeen supported by the results of experimental studies on

synthetic Fe-bearing systems [47, 69, 70], which have in-dicated that oxygen fugacity is an important factor inthe crystallization of magnetite and Fe-bearing mineralphases. These studies have established that Fe2O3/FeOratios of magmas are to a large extent dependent on oxy-gen fugacity and that magnetite precipitation would beenhanced by an increase in the amount of Fe3+ in themelt.

536


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Figure 12. Variation diagrams for the average compositions of V-Ti magnetite and Cr-magnetite units in CMUC. In all the plots presented, theV-Ti magnetites show well defined trends while the single average of Cr-magnetite plots markedly away, which is inferred to reflect thedifference in lineage for the two magnetite varieties.

538


Figure 12. Continued.

CMUC is not a compact and well defined layered intru-sion comparable to Bushveld, Duluth, Rogaland, Panzhi-hua and other well known complexes. It consists of narrowsegments occupying interdomal troughs of the basementgranitoids and the contacts between the basement rockand younger formations. An attempt is made here to re-construct the evolution of the complex. This has been donebased on the best of information gathered for Hanumala-pur block of the Tavarekere segment, which not only in-cludes an association of V-Ti- and Cr-magnetite ore bod-ies but also (ore level) PGE mineralization [23, 25]. TheHPB shows the largest variation recorded in the complexand encompasses within it a fuller history of the complex.Our study has revealed the following:

1. The complex consists of two major cycles and twodistinctly different phases of mafic-ultramafic mag-matism.

2. The first phase of the first cycle, which is largely inthe range of melagabbro-gabbro, occupies south-eastern portion and so far no V-Ti magnetite orother mineralization is recorded in this part of thecomplex.

3. The second phase of the first cycle is a ferriferoussuit, which occupies north-eastern portion of thecomplex and includes several V-Ti magnetite seams.This is the phase which makes up the entire westernside and the eastern border zone of the HPB.

4. Following the emplacement of the second phase ofthe first cycle of essentially ferrogabbroic magma,along the western margins of HPB, there wassill-like intrusion of diorite with tholeiite basalt-andesite affinity (Table 5). This has been identifiedonly in (deeper) drill core samples and apparentlyoccupies the base of the complex.

5. The second cycle, which occupies the eastern sideof HPB consists of a suit of chromiferous rocks.This cycle appears to have wedged through almostcentre of the previously formed mafic-ultramafic se-quence (named at para 3) of HPB. It also has em-placed over a period of time in differentiated frac-tions, which accrued eastwards.

6. The coarse-grained ultramafite, which occurs en-closed within eastern side of HPB, is chemicallyheterogenous, comprising of high Al, Mg and Fe-

539


rich units (Table 5). Besides, as compared to sur-rounding chromiferous suit (Table 5) it is contrast-ingly low in Cr, high in V and Ti, and bears noevidence of PGE mineralization.

7. Mafic-ultramafic rocks of the two phases of the firstcycle, constituting the bulk of CMUC, were derivedessentially from the same mantle region, but, thesecond phase was more fractionated/ evolved andenriched in Fe, Ti V, and Al. The second cycle aswell as the two other magmatic phases identifiedby us in the HPB, are different from one anotherand genetically unrelated. Formation of the PGEmineralized chromiferous suit from the deeper man-tle derived ferropicritic magma for the chromiferoussuit, deep crustal generation of diorite, and mantlederivation of coarse-grained ultramafite as residualphase are inferred.

8. Our interpretation of the evolution of CMUC givenhere needs back-up of isotopic age determination.Easterly dip of all the litho units in HPB and ab-sence of chilled margins/ apophyses and other pri-mary features due to pervasive alteration sufferedby the whole complex do not permit an entirely fieldbased interpretation of the history of the complex.

9. The association of ferriferous suit, hosting Cr-poor V-Ti-magnetite and chromiferous suit (picritic)hosting Cr-rich magnetite is rather unusual. Theonly analogue is recorded in Xinjie intrusion inPanxi region, SW China [59, 71]. However, in theXinjie intrusion, the Cr-rich magnetite, in keep-ing with its early formation, occurs at lower strati-graphic level as compared to Cr-poor Ti-magnetite.In the HPB of CMUC the situation is different. Bothferriferous and chromiferous suites of the block, aspointed out earlier, dip at angles of 55◦ – 65◦ Eand the latter overlies the former. On the basisof the said observation, we have invoked later em-placement of chromiferous suit from deeper man-tle region. Although, sill-like and layered, CMUCdoes not constitute a flat-lying layered complexor lopolithic body as described from Panzhihua[54, 55], Baima and Taihe [58], Xinjie [59], Hongge[72], intrusions of the Emeishan large igneous com-plex, Sichuan Province, SW China.

10. The geochemical data from the drill core samplesof HPB (representative of CMUC) show that: i)in terms of total alkali-silica binary discriminationdiagram [after [73, 74] with alkaline-sub-alkalinedividing line of [75]] the complex is made up ofboth alkaline picritic basalt–basanite-tephrite and

Figure 13. Total alkali vs Silica binary plot for drill core samples ofHPB (after Le Bas, 2000, Le Maitre 2002). Alkaline-Sub-alkaline divide line is from Irvine and Baragar (1971).

sub-alkaline picritic-basalt to andesitic rocks; ii)the diorite on the western border of HPB is en-tirely subalkaline basalt and the ferrogabbros areentirely in the range of picrite–basanite–tephrite(Fig. 13). Similar mixed affinity of the com-plex to tholeiite–komatiitic-basalt–komatiite is in-dicated by plot of the data in CaO-MgO-Al2O3 [af-ter [42, 43]] and Al-Fe+Ti-Mg diagrams [41, 42](Figs. 14 & 15).

11. Pervasive chloritization recorded in ferriferous aswell as in chromiferous suits further suggests un-usual enrichment of deuteric liquids in water andvolatiles (CO2, etc.,) in both the magmas. Possibil-ity of such an enrichment is substantiated by exper-imental work of Xing et.al., [76], who have demon-strated by using step-heating mass spectrometerthe presence of H2O + CO2 at much higher levels(e.g., 0.6%) in titanomagnetite of Hongge. This sup-ports the earlier work of Zhang [77] who had shownthat the volatiles are present in the crystal structureof the minerals as fluid inclusions and they are re-leased from the mineral in substantial quantities at400◦–800◦ C temperature intervals. Further, Zhanget.al [57] have opined that water + CO2 are gen-erally incompatible during magmatic evolution andtend to be trapped in minerals such as (Cr-poor)titanomagnetite.

AcknowledgementsA large part of the data presented here for the magnetitedeposit of CMUC was generated incidentally in our effortsto gather the best of information about PGE mineraliza-tion. Our study over a prolonged period received substan-

540


Figure 14. CaO-MgO-Al2O3 ternary discrimination diagram for thedrill core analyses of HPB (after Vilijoen et al., 1982).

Figure 15. Al-Fe+Ti-Mg cation ternary discrimination diagram plot-ted for drill core analyses (about 550) of various lithounitsof HPB.

tial support of the Finnish Academy grants through itsaward to late Prof. Alapieti and supplemented by grantsawarded to TCD by Department of Science & Technol-ogy, Government of India. We gratefully remember theencouragement of late Mr. B.A.Lalgondar, Additional Di-rector (Minerals), Department of Mines & Geology, Gov-ernment of Karnataka by way of arranging exploratorydrilling in support of our investigation. We are also highlythankful to Prof. M. Raith, former Director, Mineralogisch-Petrologisches Institut, Univesitat Bonn, Germany, for al-lowing BS and TCD to use EPMA facility of the instituteto analyse a set of samples collected by KRJ, and Mr.Seppo Sivonen, Director, Institute of Electron Optics, Uni-versity of Oulu, Finland, for permitting unrestricted use ofEPMA and XRF to analyse a large number of samplescollected by TCD, TTA and TLS. The lab work at Oulu

Table 5. Chemical analyses of representative ferro-gabbro (1 & 2),coarse-grained ultramafite (3 & 4) & average diorite (5)

1 2 3 4 5Sample DHi1-147.9 DH3-151 M:181:97 M:89:97 Av of 32SiO2 35.18 30.17 38.29 34.98 52.29TiO2 3.39 4.62 3.51 0.12 1.50Al2O3 3.87 4.17 3.63 14.03 12.50Fe2O3 31.49 35.67 28.41 18.80 13.04MnO 0.19 0.20 0.17 0.13 0.17MgO 14.08 13.72 13.35 21.75 7.40CaO 12.49 10.51 9.70 4.45 7.57Na2O 0.23 0.16 0.21 0.23 2.71K2O 0.02 0.02 0.04 bld 0.60P2O5 0.01 0.01 0.01 0.02 0.19S 0.70 0.38 0.07F 0.05 0.06 bld 0.05LOI 1.54 6.88

101.70 99.69 99.43 101.41 98.09Trace elements (ppm)Ba 5 56 62Rb 1 4 bld 23Sr 25 6 5 11 157Cr 575 300 3898 137 369Ni 527 392 487 832 151V 1184 1501 1354 102 314Cu 839 517 9093 255 90Zn 115 179 146 135 110Cl 48 5 11 57 142Sc 58 64 78 8 30Ga 20 18 16 22(ppb)Pd 3 51 103 11 4Pt 2 20 25 10 2Au 3 11 57 2 3NOTE: All samples are from HPB

was mostly carried out by RJK. Dr. D.B.Nadagouda hasextended valuable help in preparing the final soft copy.We are indebted to the anonymous reviewers for theirmany constructive comments, which have been of consid-erable help in improving the presentation. Finally, weexpress our appreciation to Drs. Kirtikumar Randive andL.G. Gwalani for asking us to contribute this article forinclusion in the present publication brought out in honourof Prof. P.C. Chiaramonti.

Appendix I: Methods of studyOverall mapping of the study area, which is 700 km2, andwhich includes almost the whole of CMUC has been car-ried out in 1:25,000 and 1:12,500 scale (Figure 2). Thesouthern about 2 km strike length of 3.5 km long HPB,which bears evidence of PGE mineralization, has beenmapped on 1:2000 scale (Figure 3) employing plane tablesurvey. Exploratory drilling with the support of the Kar-

541


nataka State Department of Mines and Geology and geo-physical profiling based on magnetic measurements withthe support of Centre for Exploration Geophysics, Osma-nia University, Hyderabad, have also been carried out forthe same southern portion of HPB.

Most microscopic study was performed at the Departmentof Studies in Geology, Karnatak University, Dharwad,using Leica DMLP Microscope and modal analysis withJames Swift point counter.

Electron probe analysis of minerals was done jointly byDr. Beate Spiering and TCD at the Mineralogisch Petrol-ogisches Institut, University of Bonn, Germany. CamecaCamebax Electron Microprobe was employed under stan-dard operating conditions using natural and syntheticmineral standards. Data processing was performed withthe PAP correction procedure. Samples collected jointlyby TCD and TTA were analysed by RJK at the labs of De-partment of Electron Optics employing JEOL SuperprobeJXA-733 equipped with LINK AN10,000 Wavelength Dis-persive Spectrometer. The analytical conditions were 15kV accelerating voltage, 15 µA sample current and a largeelectron beam of ∼10 microns. Both natural and syntheticstandards were used. ZAF-4 program was adopted tomake necessary (online) corrections for overlapping peaksof different elements.

17 of the 52 whole rock chemical analyses given here weredone by KRJ at the AMSE Chemical Labs, Geological Sur-vey of India, Bangalore using AAS Varian Spectra AA30and Perkin Elmer-403. FeO was determined titrimetri-cally after digesting the sample in H2SO4 + HF mixture.Major and a few select trace elements of some of the sam-ples were also analysed employing PW-140 Philips X-raySpectrometry System at the AMSE, PPOD labs, Geolog-ical Survey of India, Bangalore. Analysis of the remainingsamples collected by TCD, TTA and TLS presented herewas done at the Department of Electron Optics, Univer-sity of Oulu, employing Seimens SRS-303 XRF analyserand using pressed powder pellets. All the REE and a setof 20 other trace elements were analyzed at the Activa-tion labs, Anacaster, Canada, using lithium metaborate/tetraborate fusion of samples. Analysis of all the PGEand Au was done at the Activation labs, Anacaster em-ploying INAA techniques. Partial analysis, exclusively forPt, Pd and Au was done for most of the samples at theRuvaneimi labs, Geological Survey of Finland, employinga combination of Ni sulfide-lead fire assay and ICPMStechniques.

The high totals reported in a good number of analyses aremainly due to non determination of FeO and low totalsof some of the analyses reflect non estimation of loss onignition.

Appendix II: Chemical analyses ofrepresentative V-Ti bearing & Cr-magnetite ore samples from Channa-giri mafic-ultramafic complex (CMUC)See Table 1A, Table -2A and Table -3A.

References

[1] Smeeth W.F and Sampath Iyengar P., Mineral re-sources of Mysore, Bull Mysore. Geol. Dept. 7, 1916.

[2] Vasudev V.N and Ranganathan N., Vanadium and sul-phide bearing titaniferous magnetite bodies in West-ern Dharwar Craton, In Geokarnataka: Ravindra B.Mand Ranganathan N., (Eds) Karnataka Asst. Geolo-gist Association, Bangalore, 1994, 168–181

[3] IBM, Indian Minerals Yearbook 2011, Part II, 50thEd., Vanadium, 2012, 77-1-5, State review. 11–14,1–16

[4] Dry R.J., Bates C.P and Price D.P., HIsmelt-the futurein direct iron making, Proc 58th Iron making Confer-ence, Chicago, 21-24 March, 1999, 361 p

[5] Forge Resources: Qtly Rep. for the period 1 July-30Sept 2012, Bolla Bolla V-Ti-magnetite project aidedat producing (1) pig iron, (2) ferrovanadium and (3)titanium slag.

[6] Pilote J., HIsmelt, Adapted technology for Ti/V mag-netite: Non-blast furnace forum in Panzhihua City,Nov 2010.

[7] Pilote J., Future of HIsmelt In India: Appropriatetechnology for the available resource of the country,2010.

[8] Ziguo H., Hongcai F., Lian L. and Turner S., Compre-hensive utilization of vanadium-titanium magnetitedeposits in China has come to the new level, ActaGeologica Sinica, 2012, 87, 286-287

[9] Slater H.K., Report on the geological survey of por-tions of Tarikere, Channagiri and Shimoga taluks dur-ing the field season 1904-05, Rec. Mysore Geol.Dept., 1905, 6, 5-27

[10] Slater H.K., Report on survey work in Holalkere, Da-vangere and Channagiri taluks, Mysore Geol. Dept.,Rec., 1912, 12, 1–44

[11] Jayaram B., Note on revision of survey in partsof Kadur, Shimoga and Channagiri taluks., Rec.Mysore. Geol. Dept., 1915, 14, 16–107

[12] Channappa B.G. and Subramanya M., Vanadiumbearing titaniferous magnetite ores of Ubrani area,Shimoga district, Dept of Mines and Geology, Govt.of Karnataka, Geological studies 1973, 62, 11

542


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12

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369

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59.3

263

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470

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975

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817

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[13] Chayapathi N., Geology and ore reserves of Vanid-iferous magnetite deposits in Channagiri taluk, Shi-moga district, Karnataka, Proc. Symp. Geol. etc. ofFerrous and Ferro-alloy minerals, Bangalore, 1976,55–60

[14] Chayapathi N., Investigations for Vanadiferroustitanomagnetite and associated copper in theMasanikere, Taverekere and Magyathahalli areas,Channagire taluk, Shimoga district, Karnataka, Geol.Surv. India, Progress Report for the field season,1984, 74–79

[15] Ramiengar A.S and Chayapathi N., Vanadiferousmagnetite deposit near Masanikere, Channagiritaluk, Shimoga district, Karnataka, Indian Minerals,1977, 31, 1–5

[16] Ramiengar A.S., Chayapathi N., Raghunandan K.Rand Rao M.S., Mineralogy and geochemistry ofthe vanadiferous titanomagnetite deposit and asso-ciated copper mineralization in gabbro-anorthositenear Masanikere, Shimoga district, Karnataka, India,In: Archaean Geochemistry: Proceedings of the sym-posium on Archaean geochemistry, Hyderabad, 1978,395–406

[17] Channappa B.G. and Subramanya M., Vanadiumbearing titaniferous magnetite ore of Taverekere andGourapur areas, Channagiri taluk, Shimoga district,Dept. of Mines and Geology, Govt. of Karnataka, Ge-ological studies No. 129, 1979, 9p

[18] Jayaraj K.R., V-Ti-Fe deposits of Ubrani, Tavarekere,Masanikere, Devaranarsipur (Shimoga district) andMulemane (North Kanara district) areas, Karnataka,Ph.D thesis submitted to Karnatak University, Dhar-wad, Karnataka, India (Unpublished), 1992, 103p

[19] Jayaraj K.R., Khanadali S.D., Devaraju T.C and Spier-ing B., A study of Hogbomite in the V-Ti-Fe depositsof Karnataka, Jour. Geol. Soc. India, 1995, 45, 57–64

[20] Jayaraj K.R., Khanadali S.D., Devaraju T.C and Spier-ing B., A study of Chromiferous Magnetite and Ti-tanomagmetite in the V-Ti Magnetite deposits ofMagyatahalli, Shimoga district, Karnataka, IndianMineralogist, 1996, 30, 59–66

[21] Alapieti T.T., Halkoaho T.A.A., Devaraju T.C.,Chromite-hosted PGE mineralization in the Channa-giri area, Karnataka State, India, VIIth InternationalPlatinum Symposium, 1994, 1-4 Aug 1994, Moscow(Abstract), 3–4

[22] Devaraju T.C., Alapieti T.T., Halkoaho T.A.A., JayarajK.R., Khanadali S.D., Evidence of PGE mineralizationin the Channagiri mafic complex, Shimoga district,Karnataka, Jour. Geol. Soc. India, 1994, 43, 317–318

[23] Alapieti T.T., Devaraju T.C and Kaukonen R.J., PGEmineralization in the late Archaean iron-rich mafic-

ultramafic Hanumalapur Complex, Karnataka, India,Mineral & Petrol., 2008, 92, 99–128

[24] Devaraju T.C., Investigations of Archaean layeredmafic-ultramafic complexes of Shimoga Schist belt ofKarnataka with special reference to evidence of Plat-inum mineralization. Report (unpublished) submittedto Department of Science and Technology, Govt. ofIndia, 2000, 66p

[25] Devaraju T.C., Alapieti T.T., Kaukonen R.J and Sud-hakara T.C., Petrological and PGE mineralizationstudy of the Channagiri mafic-ultramafic complex,Shimoga Supracrustal belt, Karnataka, Jour. Geol.Soc. India, 2007, 70, 535–556

[26] Chadwick B., Vasudev V.N. & Jayaram S., Stratigra-phy and structure of late Archaean Dharwar volcanicand sedimentary rocks and their basement in a part ofShimoga basin east of Bhadravathi, Karnataka, Jour.Geol. Soc. India, 1988, 32, 1–19

[27] Devaraju T.C., Alapieti T.T., Kaukonen R.J., Geo-chemistry of ultramafic lenses in the granitoids ofthe southeastern flanks of Shimoga supracrustalbelt (Karnataka) with a note on the distribution ofplatinum-group elements and minerals. Jour. Geol.Soc. India, 2004, 63, 371–386

[28] Taylor P.N., Chadwick B., Moorbath S., Ramakrish-nan M and Vishwanatha M.N., Petrology, chemistryand isotopic ages of Peninsular gneiss, Dharwar acidvolcanic rocks and the Chitradurga granite with spe-cial reference to the late Archaean evolution of theKarnataka craton, Southern India, Precamb. Res.,1984, 23, 349–375

[29] Wager L.R and Brown G.M., Layered Igneous rocks,Oliver and Boyd, 1968, 588p

[30] Stevens R.E., Compositions of some chromites of thewestern hemisphere, Am. Mineral., 1944, 29, 1–34

[31] Roach T.A., Roeder P.L., and Hulbert L.J., Compositionof chromite in the upper chromitite, Muskox layeredintrusion, Northwest territories, Can. Mineralogist,1998, 36, 117–135

[32] Yong Z, Jian-xing L, Gonf-Jin C, Zhang-Gen L, Man-sheng C, Xian-xin X, Experiment study on sinter-ing process optimization of high chromium vanadium-titanium magnetite (Abstract- p363) In: Characteri-zation of minerals, metals and materials, 2013, Wiley

[33] Himmilberg G.R and Ford A.B., Iron-Titanium oxidesof the Dufek intrusion, Antartica, Am. Mineral, 1977,62, 623–633

[34] Mathison C.I., Magnetites and ilmenites in the Som-erset Dam layered basic intrusion, SoutheasternQueensland, Lithos, 1975, 8, 93–111

[35] Neumann E.R., The distribution of Mn2+ and Fe 2+between ilmenites and magnetites in igneous rocks,

546


Am. Jour. Sci., 1974, 274, 1074–1088[36] Friedman G.M., Study of Hogbomite. Am. Mineral,

1952, 37, 600–608[37] Zakrzewski M.A., Hogbomite from the Fe-Ti deposit

of Liganga (Tanzania). Neues Jahrb Mineral Monatsh,1977, H8, 373-380

[38] Coolen J.J.M.M.M., Hogbomite and aluminium spinelfrom some metamorphic rocks and Fe-Ti ores, NeuesJahrbuch fur Mineralogie Monatshifte, 1981, 373-384

[39] Hey M.H., A new review of the chlorites, MineralMag., 1954, p277

[40] Barnes S.J., Boyd R., Korneliussen,A., Nillson L.P.,Opten M., Pedersen R.B., Robins B., The use ofmantle normalization and metal ratios in discrimi-nating between the effects of partial melting, crystalfractionation and sulphide segregation on platinum-group elements, gold, nickel and copper: examplesfrom Norway. In: Pichard, H.M., Potts P.J.,BowelsJ.F.W., Cabri S.J. (Eds), Geo-platinum, Amsterdam,1987, 113-143

[41] Jensen L.S., A new cation plot for classifying subalka-line volcanic rocks, Ontario Dept. Mines Misc, paperNo. 66, 1976, 22p

[42] Viljoen, M.J., Viljoen R.P., Pearton T.N., Nature anddistribution of Archaean komatiite volcanics in SouthAfrica, In: N.T. Arndt and E.G. Nisbet (Eds.) Komati-ites, Allen and Unwin, London, 1982, 53–79

[43] Viljoen, M.J., Viljoen R.P., Evidence for the existenceof mobile extrusive peridotite magma from the Komatiformation of the Onverwacht Group, Geol. Soc. S.Africa, Sec. pub. 2, Upper Mantle Project, 1969, 87–112

[44] Pearce J.A., Basalt geochemistry used to investigatepast tectonic environments, Tectonophysics, 1975,25, 41–67

[45] Hall A.L., The Bushweld Igneous complex of the cen-tral Transvaal, S. African Geol. Sur. Memoir, 1932,28, Pretoria

[46] Bateman A.M., The formation of late magmatic oxideores, Eco. Geol., 1951, 46, 404–426

[47] Osborn E.F., The role of oxygen pressure in the crys-tallization and differentiation of basaltic magma, Am.Jour. Sci., 1959, 257, 609–647

[48] Buddington A.F. and Lindsley D.H., Iron-titanium ox-ide minerals and their synthetic equivalents, Jour.Petrol, 1964, 5, 310–357

[49] Lister G.F., The composition and origin of selectediron-titanium deposits, Econ. Geol., 1966, 61, 275–310

[50] Collins L.G., Regional crystallization and the forma-tion of magnetite concentration, Dover magnetite dis-trict, New Jersey, Econ. Geol., 1969, 64, 17–33

[51] Cawthorn R.G. & Mc Carthy T.S., Bottom crystal-lization and diffusion control in layered complexes:Evidence from Cr distribution in magnetite from theBushveld Complex, Geol. Soc. S. Africa. Trans., 1981,84, 41–50

[52] Cawthorn R.G., Layered Intrusions, Elsevier, Amster-dam, 1996, 531p

[53] Duchesne J.C., Fe-Ti deposits in Rogalandanorthosites (South Norway): Geochemical Charac-teristics and problems of interpretation, MineraliumDeposita, 1999, 34, 182–194

[54] Zhou M.F., Chen W.T., Wang C.Y., Prevec S.A., Liu P.Pand Howarth G.H., Two stages of immiscible liquidseparation in the formation od Panzhihua-type Fe-Ti-V oxide deposits, SW China, Geoscience Frontiers,4, 2013, 481–502

[55] Zhou M.F., Robinson P.T., Lesher C.M., Keays R.R.,Zhang C.J. and Malpas J., Geochemistry, petrogen-esis and metallogenesis of the Panzhihua gabbroiclayered intrusion and associated Fe-Ti-V oxide de-posits, Sichuan Province, SW China, Jour. Petrol.,2005, 46, 2253

[56] Pang K.N., Zhou M.F., Lindsley D., Zhao D and Mal-pas J., Origin of Fe-Ti oxide ores in the mafic intru-sions: Evidence from the Panzhihua intrusion, SWChina, Jour. Petrol., 2008, 49, 295–313

[57] Zhang M., Niu Y., Hu P., Volatiles in the mantle litho-sphere: modes of occurrence and chemical composi-tions., In: Anderson J.E and Coates R.W (Eds.) TheLithosphere: Geochemistry, geology and geophysics,Nova Science Publishers Inc, New York, 2009, 171–212

[58] Hou T., Zheng Z., Encarnacion J and Santosh M.,Petrogenesis and metallogenesis of the Taihe gab-broic intrusion associated with Fe-Ti oxide ores inthe Panxi district, Emeishan large igneous province,Ore Geol. Review, 2012, 49, 109–127

[59] Dong H., Xing C and Wang C.Y., Textures and min-eral compositions of the Xinjie layered intrusions,SW China: Implications for the origin of magnetitefractionation process of Fe-Ti-rich basaltic magmas,Frontiers, 2013, 4, 503–515

[60] Gross G.A., Grower C.F and Lefebure D.V., MagmaticTi-Fe ± V oxide deposits, British Columbia Geol.Surv. Geol .Field work Mo4, 1997, 241-1, 241–3

[61] Thy P., Jakobsen N.N. and Wilson J.R., Fine-scalegraded layers in the Fongen-Hyllingen gabbroic com-plex, Norway, Can. Mineral., 1988, 26, 235–243

[62] Dunn J.A and Dey A.K., Vanadium bearing titanifer-ous iron ores in Singhbhum and Mayurbhanj, India.Trans. Min. Geol. Inst. India, 1937, 31, p30

[63] Kolker A, Mineralogy and geochemistry of Fe-Ti ox-

547


ide and apatite (nelsonite) deposits and evaluationof liquid immiscibility hypothesis, Econ. Geol., 1982,77, 1146–1158

[64] Philpotts A.R., Origin of certain iron-titanium oxideand apatite rocks, Econ. Geol., 1967, 62, 303–315

[65] Reynolds I.M., The nature and origin of titanifer-ous magnetite-rich layers on the upper zone of theBushveld complex: A review and synthesis, Econ.Geol., 1985, 80, 1089–1108

[66] Hill R and Roeder P., The crystallization of spinelfrom basaltic liquids as a function of oxygen fugacity,Jour. Geol., 1974, 82, 709–729

[67] Irvine T.N., Crystallization sequence in the Musox in-trusion and other layered intrusions – II. Origin ofchromitite layers and similar deposits of other mag-matic ores. Geochem. Cosmochem. Acta, 1975, 39,991–1020

[68] Molyneux T.G., The geology of the area in the vicin-ity of Magnet Heights, east Transvaal, with specialreference to the magnetic iron ore, Mineral. Mag.,1972, 38, 863–871

[69] Muan A., Osborn E.F., Phase equlibria at liquidustemperatures in the system MgO-FeO-Fe2O3-SiO2,Am. Ceramic Soc. Jour., 1956, 39, 121–140

[70] Roeder P.L and Osborn E.F., Experimental data forthe system MgO-FeO-Fe2O3-CaAl2Si2O2 and theirpetrologic implications, Am. J. Sci., 1966, 264, 428–480

[71] Mei Y., Zhou M.F., Wang C.Y., Pang K.N., Origin of

giant magmatic Fe-Ti-V oxide deposits hosted in lay-ered intrusions in the Pan-Xi area, Sichuan Province,SW China, Mineral deposits research: Meeting theGlobal Challenge, 2005, 458–461

[72] Zhong H., Zhou X.H., Zhou M.F., Sun M and Liu B.G.,Platinum group element geochemistry of the HonggeFe-V-Ti deposit in the Pan Xi area, southwesternChina, Mineral. Deposita, 2002, 37, 226–239

[73] Le Bass M.J., IUGS reclassification of the high-Mgand picritic volcanic rocks, Jour. Petrol., 2000, 41,1467–1470

[74] Le Maitre R.W., Igneous rocks: A classification andglossary of terms, 2nd Ed. Cambridge UniversityPress, 2002, 236p

[75] Irvine T.N and Barager W.R.A., A guide to the chemi-cal classification of the common volcanic rocks, Cana-dian J. Earth Sci., 1971, 8, 523–548

[76] Xing C.M., Wang C.Y., Zhang M., Volatile and C-H-Oisotope composition of a giant Fe-Ti-V oxide depositin the Panxi region and their implications for sourceof volatiles and the origin of Fe-Ti oxide ores, ScienceChina Earth, China, 2012, http//dz.dn.org/10.10007/s11430-012-4468-2

[77] Zhang M, Niu Y, Su.S., Chemical and stable isotopicconstraints on the nature and origin of volatiles in thesub-continental lithospheric mantle beneath China,Lithos, 2007, 96, 55–56

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Mineralogy, geochemistry and petrogenesis of the V-Ti-bearing and chromiferous magnetite deposits...

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