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Cretaceous Research 26 (2005) 329e341
Palaeontological, diagenetic and faciescharacteristics of Cretaceous/Paleogene boundary
sediments in the Ordu, Yavuzlu andUzunisa areas, Eastern Pontides, NE Turkey
Aysxegul Yıldıza,*, Ali Gurelb
aNig�de University, Aksaray Engineering Faculty, Department of Geological Engineering, 68100 Aksaray, TurkeybNig�de University, Engineering Faculty, Department of Geological Engineering, Nig�de, Turkey
Received 1 December 2003; accepted in revised form 24 January 2005
Available online 24 March 2005
Abstract
The region discussed in this paper is located in the eastern part of the Pontide tectonic unit in north-east Turkey. From north to
south it comprises the Ordu, Yavuzlu and Uzunisa areas, which form part of the Pontide fore-arc basin. The region shows differentfacies developments through the Upper Cretaceous to the Eocene, and the K/Pg boundary section is represented by limestones,sandstones, and glauconitic sandstones. While investigating the palaeontological, diagenetic and facies characteristics of theboundary sediments, it was observed that the Maastrichtian age is represented by thicker successions than the Paleocene in the
northern and southern parts of the study area. By contrast, in the centre, the Paleocene epoch is represented by a thicker sequence. Itwas also determined that the area has become deeper from north to south, owing to rifting during the MaastrichtianePaleocene anduplift to the north.
� 2005 Elsevier Ltd. All rights reserved.
Keywords: Diagenesis; Eastern Pontides; Facies; K/Pg boundary; Turkey; Palaeontology
1. Introduction
The Black Sea Region was named the PontideTectonic Unit by Ketin (1966). The Pontides are aneastewest oriented orogenic belt, representing anamalgamated tectonic entity in which three tectonos-tratigraphically different sectors can be distinguished:the Western, Central and Eastern Pontides (Yılmazet al., 1997). The region investigated in this paper islocated in the Eastern Pontides, which are representedby the following eastewest-orientated tectonic zones:
* Corresponding author.
E-mail address: ayildiz@nigde.edu.tr (A. Yıldız).
0195-6671/$ - see front matter � 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.cretres.2005.01.003
a volcanic belt, a fore-arc basin fill, a belt of meta-morphic massif, an ophiolitic suture zone, and a remnantbasin fill (Yılmaz et al., 1997). The study area is on thenorthern margin of the fore-arc basin fill (Fig. 1).Previous geological studies in this region and nearbyinclude those reported by Dewey et al. (1973), Adamiaet al. (1977), Tokel (1983), Bektasx (1983, 1986), Goruret al. (1983), Yılmaz (1993a,b), Korkmaz and Yılmaz(1994), Demir (1995), Korkmaz et al. (1995), Yılmazand Bektasx (1996), Arslan et al. (1997), Kandemir andKorkmaz (1997), Yılmaz et al. (1997), and Yıldız et al.(1998). Studies on MaastrichtianePaleocene outcrops inthe Eastern Pontides have been limited to the southernpart of the region; none has been made previously in thearea considered herein.
330 A. Yıldız, A. Gurel / Cretaceous Research 26 (2005) 329e341
Fig. 1. Maps showing the location of the study area and the measured sections.
The main objectives of our paper are to: (1) presentpalaeontological, diagenetic, and facies characteristicsof the Cretaceous/Paleogene (K/Pg) boundary sedi-ments; (2) evaluate depositional environments basedon fossil associations and lithological features; and (3)determine changes in facies in the region during theMaastrichtianePaleocene period.
2. Material and methods
Our paper is based on an analysis of 60 samplescollected from three measured sections in the Ordu,Yavuzlu, and Uzunisa areas. These range from 10 to15 m in thickness and comprise limestones and sand-stones, some of the latter containing glauconite.
331A. Yıldız, A. Gurel / Cretaceous Research 26 (2005) 329e341
Fig. 2. Generalised stratigraphic section of the study area.
Petrographic characters of the samples were examinedunder an Ortholux polarizing microscope. Limestonethin-sections were analysed according to the methods ofDunham (1962) and Embry and Klovan (1971), andsandstones were determined according the classificationof Folk (1968). The definitions of the lithofacies arebased on Wilson (1975), Wilson and Jordan (1983) andFlugel (1992), and those of the biofacies on Sartorioand Verturini (1988). Estimated sea-level fluctuationsand interpretations of depositional environment weredetermined by comparing the distribution of lithofaciesand biofacies associations and diagenetic features.
3. Stratigraphy
The oldest rock units in the study area are LateCretaceous sandstones and mudstones interbedded withbasaltic lavas and pyroclastics, a succession that isapproximately 1000 m thick. These rocks are overlainby 750 mofLateCretaceous brown, grey-white, greenish-and pinkish-grey trachyandesite-andesite lavas and py-roclastics. This unit is overlain by 750 m of an alternatingsuccession of limestones, marls, mudrocks, sandstones,
conglomerates and tuffs of Late CretaceouseEocene age.In general this unit is grey-white to grey-green in colour. Itis in turn overlain by Eocene sandstones, mudstones,marls, andesite, basalt lava and pyroclastic accumula-tions more than 1000 m thick. All of these volcanic andsedimentary rocks have been cut by Late Cretaceous andTertiary intrusions. The succession is topped by Quater-nary alluvium (Figs. 1, 2).
4. Lithofacies and biofacies features
of K/Pg sediments
The thickness of the K/Pg boundary sediments rangesbetween 10 and 15 m in the area studied. Based onlithological features and fossil associations in limestonesthe following four facies were identified: (a), packstoneswith miliolid foraminifera and algae; (b), boundstonesand packstones with corals and algae; (c), rudstones andpackstones with orbitoid foraminifera and Siderolites;(d), packstones with planktonic foraminifera (Figs. 3e7,10, 11A).
Fig. 3. Lithological log of K/Pg boundary strata, facies and distribution of fossils, Ordu section.
Fig. 4. Lithological log of K/Pg boundary strata, facies and distribution of fossils, Yavuzlu section.
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Fig. 5. Lithological log of K/Pg boundary strata, facies and distribution of fossils, Uzunisa section.
4.1. Facies a
This facies represents an inner shelf (SF8) environment(Wilson, 1975; Wilson and Jordan, 1983; Sartorio andVerturini, 1988). It is composed of packstones thatgenerally contain green algae, miliolids, peloids, ostra-cods, and gastropod fragments. In commonwith Facies c,it was encountered at the bottom and around the middleof the Yavuzlu section (Paleocene: DanianeSelandian) inthe YK-2eYK-8 limestone samples collected frombetween 0.93 and 11.81 m (Figs. 4, 6B, 7, 10A, B).
4.2. Facies b
This facies represents an outer shelf (SF5e6) environ-ment (Wilson, 1975; Wilson and Jordan, 1983; Sartorioand Verturini, 1988). It is composed of boundstonesand packstones that contain mainly coral fragments(Actinacis sp.) and red algae (Ethelya alba Pfender), andoccasionally, benthonic foraminifera (Anomalina sp.,miliolids, Textularia sp.) bryozoan, echinoderm andgastropod fragments, ostracods and green algae. Thefacies was encountered at the top of the Ordu section inthe ORK-1 and ORDU limestone samples of Paleoceneage collected from between 10.31 and 11.5 m, and in theYavuzlu section in the YK-9e10 limestone samples fromPaleocene (DanianeSelandian) levels between 11.81 and15 m, as for Facies c (Figs. 3, 4, 6B, 7, 10C).
4.3. Facies c
This facies consists of rudstones and packstones thatcommonly contain red algae (Ethelya alba Pfender),hippuritid fragments, Orbitoides sp. and Siderolites sp.,and occasionally, benthonic foraminifera and othermicrofossils [Anomalina sp., Kathina sp., Marssonellasp., Marssonella oxycona (Reus), Pithonella ovalis(Kaufmann), Rotalia sp., Selimina cf. spinalis _Inan,Textularia sp.], bryozoan, echinoderm and bivalvefragments, planktonic foraminifera [Globotruncana sp.,Globigerina sp., Morozovella angulata (White), Planor-otalites sp., Subbotina pseudobulloides (Plummer)] andgreen algae. The facies represents a slope (SF3e4)environment (Wilson, 1975; Wilson and Jordan, 1983;Sartorio and Verturini, 1988). It was encountered inthe O-1e13 limestone samples of Maastrichtian agebetween 0 and 10.31 m in the Ordu section, andthroughout the MaastrichtianePaleocene (DanianeSelandian) Yavuzlu section (Figs. 3, 4, 6A, B, 7, 10D).
4.4. Facies d
This facies represents a basin (SF1e2) environment(Wilson, 1975; Wilson and Jordan, 1983; Dario Sartorioand Verturini, 1988). It is composed of pack-stones that contain abundant planktonic foraminifera
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Fig. 6. Schematic representation of the distribution of lithofacies and biofacies for the Maastrichtian (A) and Paleocene (B) within the study area
(modified from Wilson, 1975; Wilson and Jordan, 1983; Sartorio and Verturini, 1988).
[Globigerinelloides sp., Globotruncana sp., Contusotrun-cana contusa (Cushman), Hedbergella sp., Heterohelixsp., Planorotalites compressa (Plummer), Planorotalitespseudomenardii (Bolli)] and, occasionally, benthonicforaminifera [Larrazetia chartacea (des Moulins), Pla-norbulina sp., Sulcoperculina dikersoni (Palmer)]. It wasrecognized in numerous U-4e1 samples of Maastrich-tianePaleocene (DanianeSelandian) age taken fromlimestones in the Uzunisa section (Figs. 5e7, 10E).
5. Palaeontological features
The Ordu section consists of 11.5 m of limestones.The association of Globotruncana sp., Lepidorbitoides
sp., Marssonella oxycona (Reus), Marssonella sp.,Orbitoides apiculatus Schlumberger, Orbitoides medius(d’Archiac), Orbitoides tissoti Schlumberger, Orbitoidessp., Orbitoidiformis sp., Pithonella ovalis (Kaufmann),Pseudosiderolites vidoli (Douville), Pseudosiderolites sp.,Selimina cf. spinalis _Inan, Siderolites calcitropoidesLamarck, Siderolites denticulatus Douville, Siderolitessp. and hippuritid fragments from the bottom ofthe section to 10.31 m indicate a Maastrichtian age.The uppermost 1.19 m of the section (i.e. 10.31e11.5 m)is dated as Paleocene (DanianeSelandian) on the basisof the presence of Anomalina sp., coral fragments(Actinacis sp.) and Textularia sp. (Figs. 3, 9A, B, DeH).
The Yavuzlu section consists of 15 m of limestones.The age of the lowest part, between 0 and 0.93 m, is
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Fig. 7. Correlation of the lithofacies and biofacies of the K/Pg boundary interval in the study area.
determined as Maastrichtian, based on the occurrence ofOrbitoides sp., Siderolites sp. and hippuritid fragments.The overlying deposits to the top of the section are datedas Paleocene (DanianeSelandian) owing to the occur-rence of Anomalina sp., Globigerina sp., Kathina sp., thered alga Ethelya alba Pfender, Morozovella angulata(White), Planorotalites sp., Rotalia sp. and Subbotinapseudobulloides (Plummer) (Figs. 4, 8AeF).
The Uzunisa section consists of 10 m of alternatingsandstone and clayey limestone. Within the latter,assemblages of Contusotruncana contusa (Cushman),Globigerinelloides sp., Globotruncana sp., Hedbergellasp., Heterohelix sp., Planomalina sp. and Sulcoperculinadikersoni (Palmer) indicate that the section up to7.69 m is Maastrichtian in age. Within this part of thesection, specimens of Pseudolituonella reicheli Marieand Valvulinidae have also been found. They arereworked CenomanianeTuronian forms. The sectionabove 7.69 m is considered to be Paleocene (DanianeSelandian), based on assemblages of Planorotalitescompressa (Plummer) and Planorotalites pseudomenardii(Bolli). In addition, Globigerinelloides sp., Globotruncana
contusa (Cushman), Hedbergella sp., Heterohelix sp.,Larrazetia chartacea (des Moulins), Pseudolituonellareicheli Marie and Sulcoperculina obesa de Cizancourtwere also encountered; all are reworked Late Cretaceoustaxa (Figs. 5, 8E, 9C).
6. Diagenetic features
Fibrous calcite cement, which reflects reef-relatedmarine diagenesis, was observed in the Ordu samples.This indicates that concurrent in situ sedimentation,marine cementation, and bioerosion have long been themost important factors controlling the nature of earlymarine lithification within the reef environment (Davies,1977; Petta, 1977; Walls et al., 1979; Mazzullo, 1980;James and Klappa, 1983; James and Choquette, 1983;Walls and Burrowes, 1985; Schroeder and Purser, 1986;Kerans et al., 1986; Rabat et al., 1986). Drusy cement,which coats most sedimentary grains in a thin fibrouslayer, cements them together. In nearly all cases theearly cements are abruptly overlain by sparry calcite
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Fig. 8. A, Actinacis sp., Yavuzlu sample YK-10. B, Kathina sp., Yavuzlu sample YK-6. C, Miscellenea sp., Yavuzlu sample YK-4. D, Paraketete
aspavati Pia, Yavuzlu sample YK-1. E, Planorotalites compressa (Plummer), Uzunisa sample U-1. F, Rotalia sp., Yavuzlu sample YK-4. Scale bars
represent 0.2 mm.
cement, which fills the bulk of the intergranular spaces.The syn-sedimentary druse has two forms.1. Short, closely packed, fibrous cement. Sedimentarygrains may be coated with a single thin layer of closelypacked calcite crystals. Most crystals are the samelength, giving the drusy layer a remarkably isopachouscement. Adjacent crystals are in contact throughout thegreater part of their length, being closely packed, andare terminated by obtusely pointed faces. Short, fibrouscalcite cement is the most common type of early cementin the grainy MaastrichtianePaleocene limestones of theOrdu area. The first short calcite isopachous cement isrich in inclusions and generally overlain by a younger,sparry calcite that sometimes does not contain inclu-sions. The contact between the early and later cement isgenerally sharp, and there is no transition between theshort fibrous cement and the overlying coarser sparrycalcite (Fig. 11B).2. Micro-stalactic cement. Coarse-grained packstonesand boundstones occasionally exhibit cement that is
asymmetrically distributed around the grain, beingconstantly thicker on the underside of the particles. Indetail, the cement consists of a finely laminated layerenveloping individual grains, the laminae being con-stantly thicker and more numerous on the lowersurfaces of grains. This drusy mosaic is asymmetrical.On the underside of grains, where the layer of druse maybe several millimetres thick, it grades from the smallestcrystals at the top to the largest at the bottom.Asymmetrical cementation is interpreted as being dueto alternate wetting and drying of these coarse sediments(Fig. 11C).
A meteoric, phreatic cementation model, in responseto sea-level fluctuations, is inferred from samples fromthe Yavuzlu section. It is reasonable to expect thicksedimentary sequences to be diagenetically altered bymoving the meteoric lens up or down in response torising or falling sea levels (Wagner and Matthews, 1982;Humphrey et al., 1986; Matthews, 1987). Meteoric,phreatic pore-fill cements generally occur in a more
337A. Yıldız, A. Gurel / Cretaceous Research 26 (2005) 329e341
Fig. 9. A, Globotruncana sp., Ordu sample O-7. B, hippuritid fragments, Ordu sample O-2. C, Globigerinelloides sp., and Heterohelix sp., Uzunisa
sample U-3. D, Lepidorbitoides sp., Ordu sample O-13. E, Orbitoides sp., Ordu sample O-3. F, Siderolites calcitropoides Lamarck, Ordu sample O-12.
G, Pseudosiderolites sp., Ordu sample O-9. H, green algae, Ordu sample O-5. Scale bars represent 0.2 mm.
homogeneous distribution pattern than their vadosecounterparts. Isopachous rims, consisting of equantrhombohedral calcite crystals, are the normal fabric.Crystal size varies, but phreatic cement crystals can bea little larger than those of vadose cements (Halley andHarris, 1979; Longman, 1980; James and Choquette,1984; Saller, 1984). In the rudstone textural limestonesamples from the Yavuzlu section sparry calcite is thedominant cement. Diagenesis of calcite has occurred
in two phases. At first, dog-tooth calcite cementprecipitated vertical to the surfaces of the grains. Drusemosaic calcite then formed mostly around the dog-toothcement. It has a pore-fill shape as the crystals grew largefrom the pore-membrane to the centre. Large quartz(O20 mm) cement has been observed together withdiagenetic sparry calcite in the limestone samples. Theseare idiomorphic, xenomorph crystals that from place toplace replace sparry calcite in the pore cavities. It is
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Fig. 10. A, packstone with miliolid and algae, Yavuzlu sample YK-5, facies a. B, peloids, Yavuzlu sample YK-1, facies a. C, packstone with coral and
algae, Yavuzlu sample YK-10, facies b. D, packstone with orbitoids and Siderolites, Ordu sample O-9, facies c. E, packstone with planktonic
foraminifera, Uzunisa sample U-2, facies d. F, sandstone with glauconite, Uzunisa sample U-5. Scale bar represents 1 mm.
presumed that the quartz cement arose from amorphoussilica in the sediments, or from dissolved quartz androck fragments in the rock (Fig. 11D).
Micritic cement, which reflects diagenesis in thedeep-marine environment, was observed in samplesfrom the Uzunisa section. Open marine waters, distantfrom carbonate shelves and platforms, support adominantly calcite planktonic community of coccolithsand planktonic foraminifera. Abyssal plains are,
therefore, generally covered with calcite-dominatedpelagic sediments (Scholle et al., 1983). Fine-grained,metastable carbonates originating in the shallowwaters of the platform are commonly swept off itand deposited as peri-platform ooze (Berner et al.,1976). In the Uzunisa samples they exhibit a micro-crystalline matrix. This matrix often overlies the earlyovergrowth cement and closely resembles a fine in-tergranular muddy matrix, giving the rock a packstone
339A. Yıldız, A. Gurel / Cretaceous Research 26 (2005) 329e341
texture. These samples also contain sedimentary mudesilt-sized intergranular microcrystalline calcite and clayminerals, which may, however, be distinguished fromdiagenetic microcrystalline matrix by its less homoge-neous texture, owing to the presence of fine skeletaldebris. Their distribution as a crust below the bioclastsclearly indicates that their main origin is syn-sedimen-tary (Fig. 11E).
7. Discussion
The area under investigation represents the northernmargin of the fore-arc basin in the volcanic belt of theEastern Pontides. During the Mesozoic Era, the EasternPontide Tectonic Unit was broken up by rifting, and
deeper depositional environments developed as riftingcontinued during the Cenozoic.
Limestones, sandstones and glauconitic sandstoneswithin the Upper CretaceouseEocene volcanic andsedimentary succession that crops out in the study areainclude the K/Pg boundary. Both the fossils and thelithologies recorded from the sections examined indicatethat in the most northern (Ordu) and most southern(Uzunisa) parts of region the Maastrichtian successionwas thicker than that of the Paleocene. The reverse istrue in the central (Yavuzlu) part. During the Maas-trichtian, the Ordu and Yavuzlu areas were situated ona slope whereas the deposits of the Uzunisa area havea basinal character, the sediments that accumulatedcontaining fossils and glauconitic sandstones that werereworked from shallower and older deposits into the
Fig. 11. A, rudstone, Yavuzlu sample YK-2. B, fibrous calcite cement, Ordu sample O-6, (a) bioclast grain (red algae), (b) short fibrous cement, (c)
overlain by sparry calcite. C, micro-stalactic cement, Ordu sample O-7, (a) asymmetrically graded drusy mosaic, (b) smallest crystals, (c) and (d)
coarser crystals. D, meteoric phreatic cementation, Yavuzlu sample YK-9, (a) bioclast, (b) dog-tooth cement, (c) overlain by druse calcite, (d) coarse-
grained siliceouse cement. E, micritic cement, Uzunisa sample U-2. Scale bar represents 0.5 mm.
340 A. Yıldız, A. Gurel / Cretaceous Research 26 (2005) 329e341
basin. Typically, glauconite occurs in the Uzunisa areaas bright green and rounded pellets in the silt to sand-size range. Magmatic grains of glauconitic facies occurmainly deeper than 50e80 m, and are most abundantbetween depths of 150 and 300 m. At greater depths,they are often considered to be reworked from shallowerdeposits. Their occurrence indicates that during theMaastrichtian, the Uzunisa area was in a tectonicallyactive region (Figs. 3e7).
During the Paleocene, the Ordu area was elevated,the depositional environment becoming an outer shelf,whereas conditions in the Yavuzlu and Uzunisa areasremained largely unaltered. The Uzunisa section againcontains fossils and glauconitic sandstones that wereoriginally deposited in older and shallower environ-ments. These data suggest that tectonic activity contin-ued during the Paleocene. It is concluded that the studyarea deepened from north to south as a result ofMaastrichtianePaleocene rifting (Figs. 3e7).
Fibrous calcite druse that reflects reef-related marinediagenesis was observed in Ordu samples. Meteoric,phreatic cementation, in response to sea level fluctua-tions, was determined from Yavuzlu samples. Micro-crystalline calcite cement, which reflects diagenesis in thedeep-marine environment, distant from carbonateshelves and platforms, was observed in Uzunisasamples, and interpretation supported by the occurrenceof a dominantly planktonic assemblage of coccolithsand foraminifera in this section (Fig. 11).
References
Adamia, Sh., Lordkipanidze, M., Zakariadze, G., 1977. Evolution of
active continental margin as exemplified by the Alpine history of
the Caucasus. Tectonophysics 40, 183e199.
Arslan, M., Tuysuz, N., Korkmaz, S., Kurt, H., 1997. Geochemistry
and petrogenesis of the Eastern Pontide volcanic rocks, NE-
Turkey. Chemie der Erde, Geochemistry 57, 157e187.
Bektasx, O., 1983. I type granites and their geotectonic situations in the
magmatic arc of north-eastern Pontides. TJK 37th Geological
Congress of Turkey, Abstracts, pp. 49e50.
Bektasx, O., 1986. The distribution of palaeostress and great period of
time rifting in the back-arc regions of the eastern Pontides. Bulletin
of Mineral Research and Exploration in Turkey 103/104, 114e120(in Turkish).
Berner, R.A., Berner, E.K., Keir, R.S., 1976. Aragonite dissolution
on the Bermuda pedestal: its depth and geochemical significance.
Earth and Planetary Science Letters 30, 169e178.
Davies, G.R., 1977. Former magnesian calcite and aragonite sub-
marine cements in Upper Paleozoic reefs of the Canadian Arctic:
a summary. Geology 5, 11e15.Demir, O., 1995. Stratigraphic differentiation between north and south
directions and hydrocarbon possibility of the region between _Ispir-
Yusufeli and Tortum Lake. Black Sea Technical University,
Trabzon, 30th Anniversary Symposium of the Geology Depart-
ment, Abstracts, pp. 115e116.
Dewey, J.F., Pitman, W.C., Ryan, W.B.F., Bonnin, J., 1973. Plate
tectonics and evolution of the Alpine system. American Associa-
tion of Petroleum Geologists, Bulletin 84, 3137e3180.
Dunham, R.J., 1962. Classification of carbonate rocks according
to depositional texture. In: Classification of Carbonate Rocks.
American Association of Petroleum Geologists, Bulletin 46,
108e121.Embry, A.F., Klovan, J.E., 1971. A late Devonian reef tract on north-
eastern Banks Island Northwest Territories. Bulletin of Canadian
Petroleum Geology 19, 730e781.
Flugel, E., 1992. Microfacies analysis of limestone. First edition,
translated by K. Kristansen. Springer Verlag, Berlin, 378 pp.
Folk, R.L., 1968. Petrology of Sedimentary Rocks. University of
Texas, Publications in Geology, 370 pp.
Gorur, N., Sengor, A.M.C., Akkok, R., Yılmaz, Y., 1983. Sedimen-
tologic data on the recovery of Neotethys in the Pontides.
Geological Bulletin of Turkey 26 (1), 11e20 (in Turkish).
Halley, R.B., Harris, P.M., 1979. Fresh-water cementation of a 1,000
year-old oolite. Journal of Sedimentary Petrology 49, 969e988.
Humphrey, J.D., Ransom, K.L., Matthews, R.K., 1986. Early
meteoric diagenetic control of Upper Smackover production, Oaks
Field, Louisiana. American Association of Petroleum Geologists,
Bulletin 70, 70e85.
James, N.P., Choquette, P.W., 1983.Diagenesis 6. Limestones of the sea
floor diagenetic environment. Geoscience Canada 10, 162e179.
James, N.P., Choquette, P.W., 1984. Diagenesis 9. Limestones of the
meteoric diagenetic environment. Geoscience Canada 11, 161e194.
James, N.P., Klappa, C.F., 1983. Petrogenesis of early Cambrian reef
limestones, Labrador, Canada. Journal of Sedimentary Petrology
53, 1051e1096.Kandemir, R., Korkmaz, S., 1997. Stratigraphic and sedimentological
features of northern Tortum Lake (Erzurum). 20th Anniversary
Symposium of the Geology Department of Selcuk University,
Konya, Abstracts, pp. 122e123.
Kerans, C., Hurley, N.F., Playford, P.E., 1986. Marine diagenesis in
Devonian reef complexes of the Canning Basin, Western Australia.
In: Schroeder, J.H., Purser, B.H. (Eds.), Reef Diagenesis. Springer-
Verlag, Berlin, pp. 357e380.
Ketin, I., 1966. Tectonic units of Anatolia. Bulletin of Mineral
Research and Exploration 66, 23e34.
Korkmaz, S., Yılmaz, C., 1994. Evolution of the Pontide carbonate
platform during Upper DoggereLower Cretaceous, NE Turkey.
Perimediterranean carbonate platforms. Geologie Mediterraneenne
21, 103e104.Korkmaz, S., Tuysuz, N., Er, M., Musaog�lu, A., Keskin, I., 1995.
Stratigraphy of the Eastern Pontides. In: Erler., et al. (Ed.),
Geology of the Black Sea Region, Ankara, pp. 59e69.
Longman, M.W., 1980. Carbonate diagenetic textures from near-
surface diagenetic environments. American Association of Petro-
leum Geologists, Bulletin 64, 461e487.
Matthews, R.K., 1987. Eustatic controls on near-surface carbonate
diagenesis. In: Warme, J.E., Shanley, K.W. (Eds.), Carbonate
Depositional Environments, Modern and Ancient e Part 6:
Diagenesis. Colorado School of Mines Press, Golden. Colorado
School of Mines Quarterly, 17e40.
Mazzullo, S.J., 1980. Calcite pseudospar replacive of marine acicular
aragonite, and implications for aragonite cement diagenesis.
Journal of Sedimentary Petrology 50, 409e422.
Petta, T.J., 1977. Diagenesis and geochemistry of a Glen Rose patch
reef complex, Bandera Co., Texas. In: Bebout, D.G., Loucks, R.G.
(Eds.), Cretaceous Carbonates of Texas and Mexico; Applications
to Subsurface Exploration. Bureau of Economic Geology, Univer-
sity of Texas, Austin, Investigation Report 89, 138e167.Rabat, A.M., Negra, M.H., Purser, B.H., Sassi, S., Ben Ayed, N.,
1986. Micrite diagenesis in Senonian rudist build-ups in central
Tunisia. In: Schroeder, J.H., Purser, B.H. (Eds.), Reef Diagenesis.
Springer-Verlag, Berlin, pp. 210e223.Saller, A.H., 1984. Diagenesis of Cenozoic limestones on Enewetak
Atoll. Unpublished PhD dissertation, Louisiana State University,
Baton Rouge, 363 pp.
341A. Yıldız, A. Gurel / Cretaceous Research 26 (2005) 329e341
Sartorio, D., Verturini, S., 1988. Southern Tethys Biofacies. Agip
Stratigraphic Department, Milan, pp. 224e225.
Scholle, P.A., Bebout, D.G., Moore, C.H. (Eds.), 1983. Carbonate
depositional environments. American Association of Petroleum
Geologists, Memoir 33, 708 pp.
Schroeder, J.H., Purser, B.H., 1986. Reef diagenesis: introduction. In:
Schroeder, J.H., Purser, B.H. (Eds.), Reef Diagenesis. Springer-
Verlag, Berlin, pp. 1e5.Tokel, S., 1983. Distribution of the Lias volcanites in north Anatolia
and importance, as was revealed by the evolution of north Tethys
Island-arc system. Geological Congress of Turkey, Ankara,
Abstracts, pp. 42e43.Wagner, P.D., Matthews, R.K., 1982. Porosity preservation in the
upper Smackover (Jurassic) carbonate grainstone, Walker Creek
Field, Arkansas: response of paleophreatic lenses to burial
processes. Journal of Sedimentary Petrology 52, 3e18.Walls, R.A., Burrowes, G., 1985. The role of cementation in the
diagenetic history of Devonian reefs, western Canada. In:
Schneidermann, N., Harris, P.M. (Eds.), Carbonate cements.
Society of economic palaeontologists and mineralogists, special
publication 36, 185e220.
Walls, R.A., Mountjoy, E.W., Fritz, P., 1979. Isotopic composition and
diagenetichistoryof carbonate cements inDevonianGoldenSpike reef,
Alberta,Canada.Geological Society ofAmerica,Bulletin 90, 963e982.
Wilson, J.L., 1975. Carbonate facies in geological history. Springer-
Verlag, Berlin, 471 pp.
Wilson, J.L., Jordan, C., 1983. Middle shelf environment. In:
Scholle., P.A., Bebout, D.G., Moore, C.H. (Eds.), Carbonate
depositional environments. American association of petroleum
geologists, Memoir 33, 298e343.
Yıldız, A., Yıldız, M., Atabey, E., 1998. Age, lithofacies and biofacies
features of Beyyurdu Formation in the Akdag�madeni (Yozgat)-
Ag�cakısxla (Sivas) area, Turkiye. 12th International Petroleum
Congress and Exhibition of Turkey, Ankara, October 12e15,
Proceedings, pp. 181e202.
Yılmaz, C., 1993a. Accumulation rates of JurassiceLower Cretaceous
sediments in the southern zone of eastern Pontides (NE Turkey).
Geologia 55 (2), 131e145.Yılmaz, C., 1993b. Stratigraphic correlation and paleogeographic
evolution of the south zone of the eastern Pontides. (NE Turkey).
Bulletin of the Mediterranean University, Engineering Faculty of
Isparta, 199e204 (in Turkish).
Yılmaz C., Bektasx O., 1996. Platform, slope and basin facies at
the Cretaceous interval in the Eastern Pontides (NE Turkey).
Black Sea Technical University, Trabzon, 30th Anniversary
Symposium of the Geology Department, Proceedings 2, pp.
602e609.
Yılmaz, Y., Tuysuz, O., Yig�itbasx, E., Genc, S.C., Sengor, A.M.C.,
1997. Geology and tectonic evolution of the Pontides. In:
Robinson, A. (Ed.), Regional and Petroleum Geology of the Black
Sea and Surrounding Region. American Association of Petroleum
Geologists, Bulletin 81, 183e226.