stratigraphy and larger foraminifera of the eocene shallow ... · 77 k u s o g n t r. 34...
TRANSCRIPT
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Stratigraphy and Larger Foraminifera of the EoceneShallow-marine and Olistostromal Units of the Southern
Part of the Thrace Basin, NW Turkey
ERCAN ÖZCAN1, GYÖRGY LESS2, ARAL I. OKAY3, MÁRIA BÁLDI-BEKE4,KATALIN KOLLÁNYI4 & İ. ÖMER YILMAZ5
1 İstanbul Technical University, Faculty of Mines, Department of Geology, Maslak, TR−34469 İstanbul, Turkey(E-mail: [email protected])
2 University of Miskolc, Department of Geology and Mineral Resources, H−3515 Miskolc-Egyetemváros, Hungary3 İstanbul Technical University, Eurasia Institute of Earth Sciences, Maslak, TR−34469 İstanbul, Turkey
4 Geological Institute of Hungary H-1143, Budapest, Stefánia út 14, Hungary5 Middle East Technical University, Department of Geological Engineering, TR−06531 Ankara, Turkey
Received 03 February 2009; revised typescript receipt 10 April 2009; accepted 10 April 2009
Abstract: The Eocene marine sequence in the southern part of the Thrace Basin (NW Turkey) involves a variety ofplatform and deep-marine olistostromal units, the stratigraphy of which have been vigorously debated in the past. Adetailed analysis of larger foraminifera in these either foraminifera or foraminifera-coral-coralline algae-dominatedplatform and associated comparatively deeper-marine units permits us to establish a high-resolution biostratigraphy inthe context of shallow benthic zonation (with SBZ zones) of Tethyan Paleogene. The oldest zone (SBZ 5, correspondingto the basal Ypresian) was observed only in olistoliths. An old erosional remnant of a transgressive shallow-marine tobasinal sequence (Dişbudak series; late Ypresian−? middle Eocene) was recognized below the regionally mostwidespread carbonate platform unit, the Soğucak Formation. The Dişbudak sequence, previously considered to belongto the Soğucak Formation and formally introduced recently, contains larger foraminifera, such as orthophragmines,nummulitids and alveolinids in its shallow-marine package referred to SBZ 10 (late Ypresian). The Soğucak Formation,which often exhibits patch reef developments, contains a rich and diverse assemblage of orthophragmines(Discocyclina, Orbitoclypeus and Asterocyclina), nummulitids (reticulate and other Nummulites, Assilina, Operculina,Heterostegina and Spiroclypeus), and other benthic taxa (Silvestriella, Pellatispira, Chapmanina, Orbitolina, Linderina,Gyroidinella, Fabiania, Halkyardia, Eoannularia, Sphaerogypsina, Asterigerina, Planorbulina and Peneroplis). Theirassemblages, referred to SBZ 15/16, 17, 18, 19 and 20 Zones, provide a precise tool for recording the history of marineevents which resulted in the deposition of the Soğucak Formation during four main periods. Their spatial distribution,recorded as late Lutetian, early Bartonian, late Bartonian and Priabonian, suggests a marine transgression from WSWto ENE. The Çengelli flysch sequence overlying the Soğucak Formation in a limited area to the east of the GeliboluPeninsula, contains benthic foraminifera, mainly from limestone olistoliths mostly derived from the SoğucakFormation, and also in the turbiditic strata. The assemblages in the olistoliths reveal the existence of various shallowmarine limestone sequences ranging in age from late Bartonian to early Priabonian.
Key Words: southern Thrace, benthic foraminifera, biometry, taxonomy, biostratigraphy
Trakya Havzası Güneyi Eosen Sığ-Denizel ve Olistostromal BirimlerininStratigrafisi ve Bentik Foraminiferleri (KB Türkiye)
Özet: Trakya Havzası (KB Türkiye) güneyindeki denizel Eosen birimleri stratigrafik konumları tartışmalı platform vederin-denizel türbiditik ve olistostromal istifleri ile temsil edilir. Havzanın güneyinde, foraminifer ve/veya foraminifer-mercan-kırmızı alg bakımından zengin birimlerde yaptığımız çalışmalar ilk kez bu birimler için yüksek çözünürlübiyostratigrafik bir sistemin oluşturulmasına imkan sağlamıştır. Paleontolojik veriler ve arazi gözlemleri ışığındastratigrafik olarak Soğucak Formasyonu’nun altında daha önce Trakya’da tanımlanmamış erken Geç İpreziyen−? Orta
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Turkish Journal of Earth Sciences (Turkish J. Earth Sci.), Vol. 19, 2010, pp. 27–77. Copyright ©TÜBİTAKdoi:10.3906/yer-0902-11 First published online 09 October 2009
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Eosen yaşlı sığ- ve derin-denizel bir istifin, Dişbudak istifi, varlığı ortaya konmuştur. Önceki çalışmalarda SoğucakFormasyonu içinde değerlendirilen, bu birimin sığ-denizel kısmı SBZ 10’u (erken Geç İpreziyen) temsil edenorthophragmines, nummulitid ve alveolinid grupları içerir. Yama resifi düzeylerinin yaygın olarak gözlendiği SoğucakFormasyonu orthophragmines (Discocyclina, Orbitoclypeus ve Asterocyclina), nummulitid (retikule ve diğerNummulites grupları, Assilina, Operculina, Heterostegina ve Spiroclypeus) ve diğer bentik foraminifer grupları(Silvestriella, Pellatispira, Chapmanina, Orbitolina, Linderina, Gyroidinella, Fabiania, Halkyardia, Eoannularia,Sphaerogypsina, Asterigerina, Planorbulina ve Peneroplis) içerir. SBZ 15/16, 17, 18, 19 ve 20 sığ bentik zonları temsileden bu topluluklar birimin çökelimi ile ilgili denizel olayların kronolojisinin oluşturulmasını sağlamış olup dörtönemli dönem; Geç Lütesiyen, Erken Bartoniyen, Geç Bartoniyen ve Priaboniyen transgresyon dönemleri ortayakonmuştur. Çengelli fliş istifinin yaygın kireçtaşı olistolitleri (çoğunluğu Soğucak Formasyonu’ndan aktarılma) vekısmen türbiditik seviyelerinde ise (geç) Bartoniyen ve Priaboniyen grupları tanımlanmıştır.
Anahtar Sözcükler: güney Trakya, bentik foraminifer, biyometri, taksonomi, biyostratigrafi
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EOCENE FORAMINIFERA OF THE THRACE BASIN
IntroductionEocene units, represented mainly by platformcarbonates and a flysch sequence containingolistoliths of varying dimensions, can be traced indiscontinuous outcrops across the southern part ofthe Thrace Basin (Figures 1−3). In previous studies,the Eocene platform units were recognized at twostratigraphic levels. The stratigraphically older one,the Başaoğlu carbonates of the Karaağaç Formation,crops out in a single locality in the northern part ofthe Gelibolu Peninsula. The younger and regionallymore widespread Soğucak Formation is traceablethroughout the Thrace Basin (Saner 1985; Önal1986; Sümengen & Terlemez 1991; Siyako & Huvaz2007) (Figure 4). In this study, we have recognisedanother shallow marine transgressive sequencebelow the Soğucak Formation north-east of Şarköynear Doluca Hill. This unit, named the Dişbudakseries by Okay et al. (2010), is a carbonate-clasticsequence and is quite different from the carbonateblocks of the Çengelli Formation and lithologies ofthe Soğucak Formation in containing a substantialproportion of clastics. The upper part of thesequence is represented by basinal fine clasticscontaining a badly preserved pelagic fauna and flora.The Çengelli Formation has not been differentiatedand mapped in previous studies and was treated aspart of the Soğucak Formation (Şentürk et al. 1998b)before Okay et al. (2010) provided a detailed mapand description of the unit.
The Soğucak Formation is a widely recognizedforaminifera- and coral-dominated platform unitand, owing to its well-developed patchy reefs, is a
potential reservoir throughout Thrace (Siyako et al.1989; Siyako & Huvaz 2007). Despite its economicpotential, a complex biostratigraphic study andinformation about the correlation of its isolatedsurface outcrops are completely missing. Moststudies were concerned with faunal assemblages inlocal sections and were far from revealing a basinscale evaluation. Widespread shallow marinelimestone outcrops of the Soğucak Formationaround Şarköy (Doluca Hill) (Figure 3) werepreviously considered either to represent theSoğucak Formation, or were regarded as olistoliths inthe Çengelli Formation (Saner 1985; Okay & Tansel1992; Özcan et al. 2007a). Recently, Okay et al.(2010) have shown that both in situ SoğucakFormation (Doluca Hill sequence) and limestonesrepresenting the blocks of the Çengelli Formationoccur in the same region. The relationship of theselimestone outcrops with the surrounding clasticrocks cannot be judged with certainty in all casesmainly due to Miocene cover or tectoniccomplications. Previous views considering therelationship between the olistostromal unit and thelimestone outcrops are discussed in Okay et al.(2010).
The olistostromal unit, the Çengelli Formation,formerly investigated under differentlithostratigraphic names such as the Korudağ(Sümengen & Terlemez 1991; Şentürk et al. 1998b),Ceylan (Siyako 2006) or Çengelli Formation (Okay etal. 2010), is made up of turbidite beds with arhythmic alternation of sandstone and shale anddebris flow horizons and olistostromes. Clasts in themass flows mainly include serpentinite and
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MEC
TAYBESN
10 km
Çanakkale
Mecidiye
SAROS BAY
Çanakk
ale str
ait
Gelibo
lu Peni
nsula
Biga Peninsula
Gelibolu
B
Tayfur
Beşyol
SAZ
Aegean Sea
Lapseki
Bolayır
Marmara Sea
Çanakkale
İstanbulMecidiye
Greece
A
Aegean Sea
Thrace BasinPIR
Pırnar KorudağSample CEL.13
Çeltik
Gökçeada
GİZ.A
GİZ.B
N5 km
C
4 5
1 2 3
6 7 8 9
Gökçeada
Figure 1. Geological map of the Gelibolu Peninsula (B) and Gökçeada (C) in the southern part of the Thrace Basin(A) and location of stratigraphic sections. Geological maps simplified from Temel & Çiftci (2002),Türkecan & Yurtsever (2002) and Siyako & Huvaz (2007). 1− Ophiolitic units, 2− Lört Limestone, 3−Karaağaç Formation, 4− Fıçıtepe Formation, 5− Soğucak Formation, 6− Keşan and/or Ceylan formations,7− undifferentiated Miocene and younger units (partly include Oligocene), 8− volcanics, 9− alluvium.
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E. ÖZCAN ET AL.
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18
Şarköy
78
Kızılcaterzi
KocaaliŞenköy
Şarköyreservoir
Sarıkaya T.
Gölcük
Ortaköy-1
Yeniköy
Sofuköy
Çokal
Yüllüce
Al
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Al
Tm
Tm
Tm
Teç
Tek
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Tek
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Şarköy-1
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Teç
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lp
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g
Quaternary alluviumAl
Miocene sandstone, conglomerate
Keşan Fm. - sandstone, shaleEocene
UpperEocene(Priabonian)
sandstone, shale, massflows, olistostromes:s, serpentinite;l, Eocenelimestone; p, pelagiclimestone; g, granitoid;gb, gabbro
Tm
Teklimestone
serpentinite, metadiabaseblueschist, granitoid
sbedding horizontal bedding overturned bedding
stratigraphic contact
strike-slip fault
bl
gb
gb
77
Ku
So
gn
t r.
34
27°00'00'' 27°07'30''
40°37'30''
27°00'00''
transpressive fault hydrocarbon exploration well
SoğucakLimestone
YEN7-9
SAR 2007BYEN1-4
SAR.4
YEN10
TEKE
202
172
183
2B
649
Şarköy
Mürefte
Marmara Sea
Saros Bay
616
SAR.17
Cinbasarkale H.
Figure 2. Geological map of the region north and west of Şarköy and location of samples and stratigraphic sections(small boxes). Geological map from Okay et al. (2010).
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EOCENE FORAMINIFERA OF THE THRACE BASIN
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Figure 3. Geological map of the Doluca Hill region northwest of Mürefte and location of samples and stratigraphic sections(small boxes). Geological map from Okay et al. (2010).
MürefteAl
A. Kalamış85
Gölcük
Al
Şarköy
Marmara Sea
0 4 km2
N
DolucaHill
66
2410
Mursallı
Yaya
58
38
Tek
Tek
Tm
Tm
Tm
Tm
18
55
Araplı
Tepeköy
Y. Kalamış
Çınarlı
Kirazlı
Çengelli25
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13
24
18
14
14 5040
Eriklice
Quaternary alluviumAl
Miocene sandstone,conglomerate
Keşan Formationsandstone, shaleEocene
UpperEocene(Priabonian)
LowerEocene
Tek
Tm
Gedik
yol
Teç
s
sandstone, shale, mass flows,olistoliths: s, serpentinite;l, Eocene limestone; p, pelagiclimestone; gb, gabbro
18
31
35
18
3228
2332
18
26
12
19
s
Çengelli stream
gb
Çengelli Formation
Soğucak Formation
Dışbudak Series
Yörgüç
27°15'00''
40°37'30''
27°07'30''
CEN 2, 428,564
DeveHill
bedding
stratigraphic contactstrike-slip fault transtensional fault
1900, 1901
1907
1902
Tes
Ted
Ganos F
ault
Özcan 2007aet al.
DOL1-2MÜF-B
MÜF-C
MÜF-A
638
ŞAR10-13
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E. ÖZCAN ET AL.
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Lutetian
Ypresian
lowerBartonian
upperBartonian
lowerPriabonian
upperPriabonian
lowerOligocene
Gökçeada North of Saros Bay Tayfur Doluca Hill Teke
?
?
?
?
A
B
DE
C
F
G
I
H
J
K
Özcan et al. 2007a
Lört Limestone
Karaağaç Fm. / Başaoğlu member
Dişbudak series
Fıçıtepe Fm.
Soğucak Fm.
Keşan/ Ceylan/Mezardere fms.
Çengelli Fm.
ophiolitic melangemetamorphics
non-deposition orerosion
?
?
Figure 4. Stratigraphic relations of shallow marine Eocene units in the southern Thrace Basin based on the present study. Barsindicate the stratigraphic intervals of the studied sections/samples; A− SAZ (Sazlimanı), B− MÜF (Mürefte) A, C−GİZ (Gizliliman) A and B, D− TAY (Tayfur), E− BEŞ (Beşyol), F− TEKE (Teke Hill), G−MÜF (Mürefte) B, H− PIR(Pırnar), I− MEC (Mecidiye), J− MÜF (Mürefte) C and YEN (Yeniköy), K− ÇEL (Çeltik). The Lower Priabonian partof the Soğucak Formation studied earlier near Doluca Hill by Özcan et al. (2007a) is shown by an arrow.
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EOCENE FORAMINIFERA OF THE THRACE BASIN
foraminifera- and coral-dominated limestone (Okayet al. 2010). Larger foraminifera occur both in thelimestone blocks and in the turbiditic sandstones.
This study is part of the revision of largerforaminifera in the Paleogene shallow marine units
in the Thrace Basin. We present here our data fromEocene shallow-marine and associated turbiditic andolistostromal units exposed in the southern part ofthe Thrace Basin. The description of largerforaminifera and their biostratigraphy from the
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33
E. ÖZCAN ET AL.
northern and eastern part of the basin is given in asubsequent paper (Less et al. in review). Theforaminiferal information on these units is eithercompletely lacking as in the Dişbudak series andÇengelli Formation, or is very poor and includesdeterminations usually at generic level, thus notpermitting a high-resolution biostratigraphicframework (Sümengen & Terlemez 1991; Çağlayan& Yurtsever 1998; Şentürk et al. 1998a, b) for theSoğucak Formation. Among these foraminifera,nummulitids (Nummulites, Heterostegina andSpiroclypeus) and some orthophragminid taxa areparticularly important since their recently-proposedevolutionary features allow us to subdivide somemiddle to late Eocene shallow benthic foraminiferalzones into sub-zones (Özcan et al. 2007a; Less et al.2008; Less & Özcan 2008). Description of most of thetaxa is based on the study of isolated specimens ofthe above groups recovered from some argillaceouscarbonate levels and from thin-sections.
Figured specimens prefixed by ‘O/’ are stored inthe Özcan collection of the Department of Geology,İstanbul Technical University, while those marked by‘E.’ are in the Eocene collection of the GeologicalInstitute of Hungary (Budapest).
Abbreviations for biozones: NP− Paleogenecalcareous nannoplankton zones by Martini (1971);OZ− Orthophragminid zones for the MediterraneanPaleocene and Eocene (Less 1998a) with correlationto the SBZ zones; P− Paleogene plankticforaminiferal zones by Blow (1969), updated byBerggren et al. (1995); SBZ− shallow benthicforaminiferal zones for the Tethyan Paleocene andEocene (Serra-Kiel et al. 1998, with additional sub-zones for SBZ 18 and 19 by Less et al. 2008) withcorrelations to the planktonic and magnetic polarityzones. The correlation of these zonations is shown inFigure 5.
Stratigraphy and Palaeontological Background ofthe Shallow-marine and Olistostromal EoceneUnits in the Southern ThraceThe most complete Eocene sequence in southernThrace Basin crops out in the northern part ofGelibolu Peninsula along the southern shore of SarosBay (Figure 4). The lowest observable part of the
sequence includes a deep-marine argillaceouscarbonate unit containing Late Cretaceous and EarlyPaleocene planktonic foraminifera (Önal 1986). Thestratigraphic position of this unit, just exposed in alimited area, is not clear and it is overlain by asequence of massive deep-marine marls representingthe lower part of the Karaağaç Formation. Anoutcrop of a 3−5-m-thick shallow marine carbonatesequence (Başaoğlu member of Karaağaç Formation)with a limited lateral extent (about 100−150 m) wasobserved just above the lower marls of the KaraağaçFormation. This unit, containing a very richassemblage of nummulitidae and orthophragmines,has been considered to mark an early Eocenetransgression. The field observations show a sharpcontact between carbonates and marls below andabove, suggesting that it is an olistolith in theKaraağaç Formation. The finding of a smallerolistolith in the same area also supports this view.The age of Başaoğlu member was considered to beearly Eocene (Önal 1986) and early−middle Eocene(Temel & Çiftci 2002).
Our knowledge about the faunal composition andchronology of the transgressive Eocene sequencescomes mainly from the Soğucak Formation, tracedin continuous and widespread outcrops across thenorthern part of the Thrace Basin (Konak 2002;Siyako 2006). The Soğucak Formation can also betraced in discontinuous outcrops in the southernpart of the basin in the Biga Peninsula (Siyako et al.1989), in the Gelibolu Peninsula (Önal 1986; Siyakoet al. 1989; Sümengen & Terlemez 1991; Siyako &Huvaz 2007) and in the islands of Gökçeada andBozcaada (Temel & Çiftçi 2002; Siyako & Huvaz2007). It is a platform carbonate unit containing arich association of benthic foraminifera and otherfossil groups, such as corals, molluscs, bryozoans,echinoids and coralline red algae (Daci 1951; Keskin1966, 1971; Önal 1986; Şentürk et al. 1998a, b; Temel& Çiftci 2002). Unlike the lower Eocene unitsdescribed from Bozcaada in the Aegean Sea (Varol etal. 2007) and the Armutlu peninsula (Özgörüş et al.2009), patch-reef carbonates constitute a prominentpart of the platform succession. Our data suggestthat most shallow marine limestone olistoliths in theÇengelli Formation originated from this unit.Previous studies on the fossil composition of the
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Figure 5. Correlation of orthophragminid biozones with late Paleocene and Eocene planktonic foraminiferal, calcareousnannoplankton and shallow benthic biozones, based on Less et al. (2007, 2008) and on Özcan et al. (2007a, b), slightlymodified. Time scale based on Graciansky et al. (1999).
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EOCENE FORAMINIFERA OF THE THRACE BASIN
Soğucak Formation in the basinal scale reported richand diverse foraminiferal taxa belonging toNummulites, Discocyclina, Heterostegina,Spiroclypeus, Operculina, Assilina, Glomalveolina,Pellatispira, Chapmanina, Linderina, Silvestriella,Orbitolites, Halkyardia, Gyroidinella, Fabiania,Eoannularia and Asterigerina (Daci 1951; Önal 1986;Şentürk et al. 1998a, b). The most comprehensiveand systematic foraminiferal data from the SoğucakFormation were presented by Daci (1951), whoassigned a Lutetian−Priabonian age to the unitwidely exposed west of İstanbul, and by Özcan et al.(2007a), who described from the Şarköy section(corresponding to the upper part of the SoğucakFormation from the southern slope of Doluca Hill)an assemblage of early Priabonian largerforaminifera belonging to Discocyclina, Nemkovella,Asterocyclina, Orbitoclypeus, Nummulites,Heterostegina, Spiroclypeus, Assilina and Operculina.
In most studies the Soğucak Formation wasregarded as of ‘middle’ Eocene age without a highresolution perspective, although different parts ofthe unit were referred either to the Lutetian, orPriabonian mainly based on larger foraminifera,molluscs and corals (Keskin 1966, 1971; Önal 1986;Sümengen & Terlemez 1991; İslamoğlu & Taner1995; Çağlayan & Yurtsever 1998; Şentürk et al.1998a, b; Temel & Çiftci 2002; Siyako & Huvaz 2007).A transgressive shallow marine successioncontaining Ypresian alveolinids and nummulitidshas lately been considered to represent the SoğucakFormation on Bozcaada island by Varol et al. (2007).We believe that this marks a much older marinetransgression and that the Alveolina-dominated‘Soğucak’ Formation of the authors cannot becorrelated with the coral-foraminiferal-algalSoğucak Formation marking a younger inundation
event in Thrace. Our data suggest that the unitdescribed from this island may be comparable withthe Dişbudak series of Okay et al. (2010).
The larger foraminiferal composition of theolistostromal unit, the Çengelli Formation, is notknown. In most previous studies, the age of the unit(commonly referred to as the Ceylan or KorudağFormation) was reported to be late Eocene(Sümengen & Terlemez 1991; Toker & Erkan 1984)or late Eocene−early Oligocene (Çağlayan &Yurtsever 1998). These ages were obtained fromcorrelative units in southern or northern Thrace. Inthe study area larger foraminifera occur either inturbiditic levels or in the limestone olistoliths of theÇengelli Formation. Okay & Tansel (1992) describedsome pelagic limestone blocks containing bothupper Cretaceous and Paleocene planktonicforaminifera.
Description of the Eocene Shallow-marine andOlistostromal Units and Their PalaeontologicalContentBaşaoğlu Member of Karaağaç FormationSection SAZ (Sazlimanı). This is a limestone unitabout 5 m thick exposed only between Saz Limanıand Karaağaç, north of Tayfur village (Section SAZ,UTM coordinates: 0452324, 4475992, Figure 1B). Itrepresents an olistolith in the late Paleocene−earlyEocene basinal sequence of the Karaağaç Formationand comprises a rich assemblage of genusNummulites (undetermined in species level) andrare orthophragmines. These (identified only insample SAZ 46) are represented by Discocyclinaseunesi karabuekensis, Nemkovella stockari,Orbitoclypeus schopeni neumannae, O. munieri cf.
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ponticus, O. bayani cf. bayani. The first two taxa arecharacteristic for the OZ 2 Zone while the third onetypifies the OZ 3 Zone, although biometrically (Table2) it is very close to O. schopeni ramaraoi, thepylogenetic ancestor, whose range ends in OZ 2.Since Orbitoclypeus bayani bayani also starts in OZ 3,the age of the above assemblage can be determined asOZ 2-3, corresponding to the SBZ 4-7 zones.However, since genus Nummulites first appears onlyin the SBZ 5 Zone, the age of this olistolith is thoughtto cover the SBZ 5-7 Zones, which corresponds toearly–middle Ilerdian. Formerly (Serra-Kiel et al.1998) the early Ilerdian was correlated with the lateThanetian. However, the base of the Ilerdian and ofthe Ypresian proved to be coeval (Pujalte et al.(2009a, b), and hence the Sazlimani olistolith is ofearliest Ypresian age.
Dişbudak SequenceSection MÜF (Mürefte) A. The section is a clastic-carbonate sequence about 30 metres thick, exposeddue east of Doluca Hill, north-east of Şarköy (SectionMÜF.A, UTM coordinates: 0517151, 4505041)(Figures 3 & 6). The lowest part of this highlyfossiliferous rock sequence comprises conglomeratesand sandstones with a wealth of oysters at its base.This passes upwards into sandstones withintercalated conglomerate horizons, that grade intolimy sandstone and/or sandy limestones containing arich assemblage of Nummulites, Orbitolina andalveolinids. These levels are almost devoid oforthophragmines and are interpreted to have beendeposited in an inner shelf environment. The top ofthe profile (sample MÜF A 10) is characterized by anodular limestone containing a diverse assemblageof nummulitids [among which Assilina placentula(Deshayes) predominates], orthophragmines andvery sporadic tests of corals (Figure 7) andrepresenting a middle/outer shelf environment. A10-m-thick siltstone-marl succession was observedto overlie these nodular limestones although therelation between them is not yet fully clear. It is mostlikely that these fine clastics record a deepening inthe depositional environment following thedeposition of nodular carbonates. Based on theassemblage presented in Figure 7, the carbonatesuccession is regarded as early late Ypresian (early
Cuisian) in age (SBZ 10), although the presence of D.archiaci ex. interc. staroseliensis-archiaci suggests atransitional position between lower and upperYpresian (SBZ 9 and 10). Two samples (MÜF A 11and 1909) representing the fine clastics overlying thenodular limestone have been analysed for calcareousnannoplakton and planktonic foraminifera. SampleMÜF A 11 yielded a calcareous nannoplanktonassemblage (Figure 7) among which Discoasterlodoensis has the shortest stratigraphic range (NP 12-14) corresponding to a late Ypresian−earliestLutetian time span. This sample also containsreworked Campanian forms, such as Eiffellithusturriseiffelli, E. eximius, Watznaueria barnesae,Arkhangelskiella cymbiformis, Broinsonia parca s. l.,Bukryaster hayi and Cretarhabdus sp. Planktonicforaminifera in this sample are quite rare and areonly represented by badly preserved Acarininaprimitiva, which indicates a general early−middleEocene age. Age data from sample 1909 near DolucaHill (Figure 3) are controversial. The planktonicforaminiferal assemblage of Globorotalia bullbrooki,G. cerroazulensis cerroazulensis, Morozovellaspinulosa, Globigerina eocaena, G. linaperta, G. senni
MÜF.A1
10
MÜF.B 210
Doluca Hill
MÜF.A 11
upper Bartonian limestone
Figure 6. Overview of the Dişbudak sequence (section Mürefte− MÜF.A; upper Ypresian) and the overlying SoğucakFormation (section Mürefte − MÜF.B; upperBartonian) east of Doluca Hill, looking south from theÇengelli flysch sequence. Limestone lenses denote thenodular limestone level in MÜF.A and coralline algal-coral facies in MÜF.B. Sample MÜF A 11 representsthe basinal fine clastics overlying the upper Ypresiannodular limestone of Dişbudak sequence in thedownthrown block. Numbers refer to samples.
35
E. ÖZCAN ET AL.
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8
12 6 5
5 2
9 4
18 m �10
Disc
ocyc
lina
forti
si fo
rtisi
D. a
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ci ex
. inter
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is-ar
chiac
iD.
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ssp.
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rgen
sisNu
mm
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ina p
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tula
Assil
inasp
.Al
veoli
nasp
.Or
bitoli
tess
p.Ro
talid
foram
inifer
a
Ortho
phra
gmine
sMi
liolid
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xtular
idsBr
yozo
ans
Cora
lsGa
strop
ods
Echin
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Biva
lves
Disc
olith
ina m
ultipo
raCy
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olith
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usCy
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10
SBZ
SECTION MÜF.A & SAMPLE 1894
2.5 1
STAG
Elow
er up
per Y
PRES
IAN
7
3
15 9
Nummulites Orthophragmines CoralsGastropodsAssilina Alveolinidae
sample 1894
NP
11
12-1
3/ 14
10luY
Oysters
Figure 7. Distribution of benthic foraminifera and other fossil groups in section MÜF (Mürefte) A and sample 1894(Dişbudak sequence). luY− lower upper Ypresian.
36
EOCENE FORAMINIFERA OF THE THRACE BASIN
and Heterolepa dutemplei is characteristic (based onthe appearance of muricate Globorotalia) of the earlymiddle Eocene (P 10-12) or, less probably, theyoungest (P 9) Ypresian zone. Meanwhile thecalcareous nannoplankton (Coccolithus pelagicus,Cruciplacolithus tenuis, Chiasmolithus sp.,Zygrhablithus bijugatus, Discoaster multiradiatus, D.binodosus, D. barbadiensis, Sphenolithus moriformis)indicate the NP 9-10 zones around thePaleocene/Eocene boundary. This sample alsocontains reworked Cretaceous forms such asZeugrhabdotus embergeri, Eiffellithus turriseiffeli,Cribrosphaerella ehrenbergii, Watznaueria barnesae,Arkhangelskiella cymbiformis and Microrhabdulus sp.In view of the much younger age given by planktonicforaminifera we think that all the nannoflora ofsample 1909 is reworked.
Sample 1894. A spot sample was collected from theshallow marine part of the Dişbudak seriesimmediately east of Doluca Hill (Sample 1894, UTMcoordinates: 0516027, 4504475) (Figure 3). It alsoconsisted of argillaceous carbonates and containedalmost the same assemblage of nummulitids (withthe same predominance of Assilina placentula) andorthophragmines as sample MÜF A 10, but alsoincluded Discocyclina archiaci archiaci (Figure 7),indicating an early late Ypresian (early Cuisian) age(SBZ 10 Zone).
Soğucak FormationExposures of the Soğucak Formation can beobserved around Gökçeada, Gelibolu Peninsula(Tayfur, Beşyol villages and around Tepe Hill atSarıkaya Sliver), Şarköy (Doluca Hill) and north of
-
Saros Bay (Pırnar and Mecidiye villages) (Figures1−3).
Gökçeada Island (sections GİZ.A and GİZ.B). TheSoğucak Formation only crops out in a limited areawest of Gökçeada. Two sections, GİZ.A (UTMcoordinates: 0386973, 4442620; 0387037, 4442588,Figure 1C) and GİZ.B (UTM coordinates: 0387448,4443239; 0387011, 4442533, Figure 1C) weresampled near Gizliliman. The lower part of a 47-m-thick section of carbonates in the stratigraphicallylower section, GİZ.B, is represented below bycoralline red algae and coral-dominated strata, andby foraminifera and coralline algae-dominatedhorizons at higher levels. Nummulitids occur only inthe upper part of the section. The distribution offoraminifera and other fauna and flora is shown inFigure 8. With the absence of diagnostic Bartonianforms, such as O. ex. gr. gomezi and reticulateNummulites, and its position below the well-described Bartonian part in section GİZ.A, thissection is considered to be of late Lutetian age (SBZ15-16). Section GİZ.A stratigraphically overlyingsection GİZ.B is represented by a 66-m-thicksequence of limy siltstones, sandstones andlimestone beds with abundant larger foraminiferaand represents a more distal depositional settingthan section GİZ.B. Foraminifera are abundant anddiverse at numerous levels. Corals are sporadic andtransported. These carbonates are overlain by pelagicmarls, but their relationships were not observedbecause of a fault between the carbonates andoverlying marls (Figure 1C). The lower part of thesection (samples GİZ A 4-8) is regarded to be of lateLutetian (SBZ 15-16) age, based on the assemblage(Figure 9), containing Discocyclina prattimontfortensis, Asterocyclina stellata adourensis andlacking Operculina ex. gr. gomezi. The upper part(samples GİZ A 9-14) of the section is assigned anearly Bartonian (SBZ 17) age, based on the firstoccurrence of O. ex. gr. gomezi and the presence ofcharacteristic Bartonian taxa such as Orbitoclypeusdouvillei malatyaensis and O. haynesi. The basinalmarls of the Ceylan Formation are very rich incalcareous nannoplankton and planktonicforaminifera. A sample (GİZ B 15; UTM coordinates0388056, 4442442) collected close to section GİZ.B
(but separated very probably by a fault from theplatform carbonates) yielded a calcareousnannoplankton assemblage of Discolithinamultipora, Isthmolithus recurvus, Cyclicargolithusfloridanus, Reticulofenestra placomorpha, R. bisecta,Chiasmolithus oamaruensis, Coccolithus pelagicus,Cyclococcolithus formosus, Discoaster sp.,Sphenolithus moriformis and S. predistentus. Thecoexistence of Chiasmolithus oamaruensis,Isthmolithus recurvus and Cyclococcolithus formosussuggests a late Eocene (NP 19-20, Priabonian) age forthis sample. The same sample yielded a planktonicforaminiferal assemblage of Globigerinacryptomphala, Globigerina eocaena, andGlobigerinatheka index tropicalis, suggesting itprobably belongs to the lower Upper EoceneGlobigerinatheka semiinvoluta (P 15) Zone.
Section TAY (Tayfur). This is a clastic-carbonatesequence about 15 metres thick, exposed due southof Tayfur (Section TAY, UTM coordinates: 0455404,4472526) (Figure 1B). The section is represented byalgae and foraminifera (mainly nummulitids,alveolinids and orthophragmines)-dominated
GİZLİLİMAN (GİZ.B)
SO
ĞU
CA
K F
OR
MAT
ION
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er L
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ian
15-1
6
N. ex
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ratu
s Nu
mm
ulite
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Gyro
idine
lla m
agna
Fabia
nia ca
ssis
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tula
Spha
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rina
sp.
Gyps
ina sp
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inifer
aOr
thoph
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ines
Alve
olinid
sMi
liolid
sTe
xtular
idsBr
yozo
ans
Cora
lline r
ed al
gae
Cora
lsCr
inoids
Biva
lves
47 m 1945 1843 17
36 1433 13
27 11
19 8
39 16
18 7
13 510 46 32 20 1
10
38 15
6
9
30 12
?
? ?
FIÇ
ITE
PE
SBZ
STAG
E
UNIT
Figure 8. Distribution of benthic foraminifera and other fossilgroups in section GİZ (Gizliliman) B (SoğucakFormation).
37
E. ÖZCAN ET AL.
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GİZLİLİMAN (GİZ.A) S
OĞ
UC
AK
FO
RM
ATIO
N lo
wer B
arton
ian17
5.5 �3
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21 5
2.3 2
8.5 �4
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39 �942 �1044.8 �1152 �1260.7 �1366 m 14
Disc
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. mala
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mm
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N.ex
. gr. p
erfo
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Linde
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ed al
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Cora
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Biva
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15-1
6up
per L
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SBZ
STAG
E
UNIT
Figure 9. Distribution of benthic foraminifera and other fossil groups in section GİZ (Gizliliman) A(Soğucak Formation).
38
EOCENE FORAMINIFERA OF THE THRACE BASIN
carbonate levels of the Soğucak Formation and iscompletely devoid of corals, suggesting an inner shelfdepositional setting. These carbonates are in tectoniccontact with the overlying pelagic marls. Fossilassemblages (Figure 10), including Operculina ex. gr.gomezi, but lacking the genus Heterostegina, indicatean early Bartonian (SBZ 17) age. Some other largerforaminiferal components, such as Nummulitesbiedai, suggest a somewhat younger age, while others(Orbitoclypeus varians roberti) indicate a slightlyolder age. In summary, the upper part of the Tayfursection most probably belongs to the SBZ 17 Zone.
Section BEŞ (Beşyol). This clastic-carbonate sequenceof the Soğucak and Ceylan Formations, about 88metres thick, is exposed due east of Beşyol village(Section BEŞ, UTM coordinates: 0445329, 4468144,Figure 1B). The lower part of the Soğucak carbonatesequence comprises limestones with bivalves,sporadic nummulitids and corals: their relationshipwith the clastics of the underlying Fıçıtepe
Formation is poorly exposed. The SoğucakFormation is rich in large Nummulites biedai (sampleBEŞ 8) in the middle and upper parts of the section.The shallow marine carbonates pass upwards into afine clastic silty-marly sequence with sandstoneintercalations containing pelagic fauna and flora.Larger foraminifera occur abundantly only at thetransition (sample BEŞ 19) between the carbonatesand the overlying fine clastics. The fine clasticsyielded a calcareous nannoplankton assemblage ofCyclicargolithus floridanus, Reticulofenestra bisecta,Coccolithus pelagicus, C. eopelagicus, Cyclicoccolithusformosus, Braarudosphaera bigelowi, Pemma sp. andSphenolithus moriformis in sample BEŞ 21,suggesting a middle Eocene age for this part of thesection. In these beds planktonic foraminifera arevery scarce. The basinal clastics are almost devoid ofbenthic foraminifera. The top of the profile (samplesBEŞ 26 and 27) is characterized by a limestonehorizon containing a diverse assemblage ofnummulitids and other benthics. This 3-m-thick
-
limestone horizon is in turn overlain by more basinalclastics devoid of larger foraminifera. Based on thisassemblage (Figure 11), the age of the lowercarbonate succession should be similar to that of theshallow marine part of the Tayfur section (seeabove), i.e. it belongs to the upper part of the SBZ 17Zone (late early Bartonian). Heterostegina (cf.armenica) occurs in the upper carbonate level(sample BEŞ 27) suggesting a late Bartonian age (SBZ18) for it.
Section Teke. This Soğucak Formation carbonatesuccession approximately 50 metres thick isinterpreted as resting unconformably upon theserpentinite of the Sarıkaya sliver (Okay et al. 2010).An exposure due west of Teke Hill has been sampled(UTM coordinates: 94978, 91904; 94860, 91959,Figures 2 & 12). The distribution of largerforaminifera (their richest assemblage can be foundin sample TEKE 6) and other fossil groups is shown
in Figure 13. The abundant occurrence ofPlanorbulina, not recorded in Bartonian blocks inthe study area, in the lower to middle parts ofsequence, is noteworthy. This part of the carbonatesalso contains miliolids, bryozoans, echinoids, corals,bivalves and coralline algae. The foraminiferalassemblage (mainly based on the occurrence ofHeterostegina reticulata mossanensis, Spiroclypeussirottii and Nummulites fabianii) confidentlyindicates the SBZ 19A Sub-zone, and implies anearliest Priabonian age for the Soğucak Formation.
Section MÜF (Mürefte) B. A 19-metres-thick sectionrepresenting the basal part of Soğucak Formationwas measured east of Doluca Hill (MÜF.B, UTMlocation: 0517306, 4505174, Figure 3). This locality isclose to the Dişbudak series (MÜF.A) (Okay et al.2010). The basal part of the profile consists of 11-metre-thick limestones (samples MÜF B 2 to 6)containing an association (Figure 14) in whichmiliolids are the most common foraminifera. Thisassemblage indicates an inner shelf depositionalenvironment for the lower part of the sequence. Theoverlying horizons (samples MÜF B 7-10) contain amore diverse association with different species ofNummulites. The single Heterostegina reticulataspecimen in sample MÜF B 9 has about 9 undividedpost-embryonic operculinid chambers, suggestingthat it may belong to H. r. multifida. Miliolids arerarely identified. The uppermost part of the sectionis represented by coralline red algae and corallimestone facies containing mainly tests of corals,coralline red algae and scarce miliolids. Theaforementioned associations indicate an inner tomiddle shelf depositional environment for thecarbonates. The foraminiferal assemblages just belowthe coral-algal limestone levels can be assigned to theSBZ 18 Zone (late Bartonian), based on the jointoccurrence of Nummulites biedai, N. hormoensis,highly advanced N. striatus and relatively primitiveH. reticulata.
Section PIR (Pırnar). This is a 108-metres-thicksection of carbonates (UTM coordinates: 0470000,4506590; 0469790, 4506743, Figure 1B) from theSoğucak Formation and overlying deep-marine units
TAYFUR (TAY)
SO
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er B
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nian
17
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Disc
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mm
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culin
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F. F
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FM.
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STAG
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IT
Figure 10. Distribution of benthic foraminifera and other fossilgroups in section TAY (Tayfur, Soğucak Formation).
39
E. ÖZCAN ET AL.
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BEŞYOL (BEŞ)
Orbit
oclyp
eus z
itteli
O. va
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ex. in
terc.
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12.5 �8
88 m 2785 26
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Figure 11. Distribution of benthic foraminifera and other fossil groups in section BEŞ (Beşyol, SoğucakFormation).
40
EOCENE FORAMINIFERA OF THE THRACE BASIN
(Ceylan/Keşan Formation) exposed close to Pırnarvillage. The underlying rocks and the lower part ofthe Soğucak Formation are not exposed in theregion. The shallow-marine carbonate sequence isrepresented throughout the section by foraminifera,coralline algae-foraminifera or coralline algae-coraldominated levels (Figure 15). Miliolids are abundantat some levels in the lower and middle part of the
sequence, whereas coral-dominated limestone levelsmore frequently occur in the upper levels. Largerforaminifera (except for the uppermost levels, wherethey are the main biogenic contributors) occur onlyat certain horizons and are mainly represented byNummulites. This part of the section is interpreted tohave been deposited in an inner to middle shelfenvironment. The uppermost part of the section
-
contains more clastic material and largerforaminifera in rock-forming abundance at somelevels. Orthophragmines are more abundant in thispart of the section and are accompanied mostly bynummulitids, suggesting more distal platformconditions than the lower part of the section. Basedon its assemblage (Figure 15), most of the carbonatesuccession is regarded as late Bartonian in age,although the lower part of the section with nomarker forms may still be early Bartonian. The
evolution of the Heterostegina armenica lineage, amarker taxon for the early and middle lateBartonian, is nicely observed in the upper part of thesection. Based on these, most of the sequence with H.armenica armenica but lacking H. reticulata can beassigned to an early late Bartonian age (SBZ 18A).The uppermost part of the carbonates, containing H.armenica tigrisensis and H. reticulata cf. tronensis,can already be attributed to the middle lateBartonian (SBZ 18B). Nummulites lyelli with largetests of B-forms also occurs here.
The carbonate levels pass up into pelagic marls ofthe Ceylan/Keşan Formation. A sample (PIR 48A)from the lowest part of these basinal clastics containsa calcareous nannoplankton assemblage ofCyclicargolithus floridanus, Reticulofenestra bisecta,R. cf. placomorpha, Coccolithus pelagicus,Cyclococcolithus formosus, ?Lanternithus minutus,Braarudosphaera bigelowi, Discoaster barbadiensis,D. cf. tani, Sphenolithus moriformis and S. radians,suggesting a middle Eocene age (NP 16-17).
TEKE 6TEKE 10
Figure 12. Overview of the section TEKE (lower Priabonian)from the transgressive Soğucak Formation west ofTeke Hill. The locations of two samples are shown.
7
50 m 10
5
3 2
9
Disc
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ti pra
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. cf. d
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xtular
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ed al
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idsBi
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thick.(app.)
SBZ
SECTION TEKE
lower
PRI
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UNIT
Figure 13. Distribution of benthic foraminifera and other fossil groups in shallow marine carbonates of the SoğucakFormation in section TEKE (Teke Hill).
41
E. ÖZCAN ET AL.
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13 �7
19m 10
8
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15 �9
Orbit
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idine
lla m
agna
Silve
striel
la te
traed
raCh
apm
anina
gas
sinen
sisFa
biania
cass
isEo
annu
laria
eoce
nica
Aste
riger
ina ro
tula
Spha
erog
ypsin
a glo
bula
Halky
ardia
sp.
Orbit
olite
ssp.
Pene
ropli
ssp.
Gyps
inasp
.Ro
talia
sp.
Ortho
phra
gmine
sMi
liolid
sTe
xtular
idsBr
yozo
ans
Cora
lline r
ed al
gae
Dasy
clada
cean
alga
eCo
rals
Gastr
opod
sEc
hinoid
sCr
inoids
Biva
lves
SBZ
18
sample
SBZ
SECTION MÜF.B
STAG
Eup
per
BART
ONIA
N
Nummulites Orthophragmines Heterostegina Corals GastropodsDiş budaksequence
SOĞU
CAK
FM.
UNIT
Figure 14. Distribution of benthic foraminifera and other fossil groups in section MÜF.(Mürefte) B (Soğucak Formation).
42
EOCENE FORAMINIFERA OF THE THRACE BASIN
Samples from Mecidiye Region. The most widespreadoutcrops of the Soğucak Formation north of SarosBay are found around Mecidiye (Figure 1B). Thisunit unconformably overlies the clastics of theFıçıtepe Formation, which unconformably rests onmetamorphic units (Figure 16). The carbonatesuccession is mainly represented by foraminifera,coralline algae and coral-dominated limestones,suggesting a variety of depositional settings betweeninner and outer shelf environments. A set of samplesfrom these carbonates were collected from itswidespread outcrops near Mecidiye. The commonestlarger foraminifera are represented byorthophragmines and heterosteginids (Figure 17).Nummulites are very sporadic. Two samples, onecollected from the basal part of the SoğucakFormation (sample MEC 40) and the other (sampleMEC 41) from the upper part, where the carbonatesgrade into clastics of the Keşan/Ceylan formation,have yielded free tests of larger foraminifera. SampleMEC 40 contains Spiroclypeus carpaticus, adiagnostic late Priabonian (SBZ 20) taxon, although
Heterostegina reticulata is represented by H. r. cf.mossanensis (based on few specimens), a marker forthe early Priabonian (Figure 17). All samplescollected from the lowest part of the section justsouth of Mecidiye (samples MEC 15-24) containHeterostegina gracilis, a good marker for the latePriabonian (SBZ 20) (Figure 23). Thus, even thelower part of the Soğucak Formation belongs to thelate Priabonian. Sample MEC 41 also contains H.gracilis, indicating that the upper part of the unit isalso of late Priabonian age.
Samples from Doluca Tepe (Şarköy). The outcrops ofthe Soğucak Formation are widely seen aroundDoluca Hill, north of Şarköy (Figure 3). AlthoughÖzcan et al. (2007a) interpreted this large limestonebody as a huge olistolith, it has since beenreinterpreted as an in situ deposit (Okay et al. 2010)of the Soğucak Formation, transgressively overlyingthe lower (−middle) Eocene Dişbudak series. Thetopmost part of this limestone (samples ŞAR 2, 4 &
-
0 1
12 �10
PIRNAR (PIR)
72 37
59 3158 3054 29
52 2748 2645 2541 2437 23 2236 20
28 1825 17
18 1416 1315 12
11
11 9
21 16
8 88 77 66 54 41 3 2
�15
�21
�28
61 32
3564 34
77 4075 3973 38
�33
�36
104 49
93 47
85 44
84 4279 41
�43
90 �4591 �46
99 �48
108 50
?
?
?
�41A
�47A
48ADi
scoc
yclin
a au
gusta
eD.
aug
usta
e oli
anae
D. a
ugus
tae
olian
ae-a
ugus
tae
D. d
ispan
sa d
ispan
saD.
radia
ns in
det s
sp.
D. ra
dians
cf. la
batla
nsis
D. tr
abay
ensis
Orbit
oclyp
eus v
arian
s sca
laris
O. zi
tteli
Aste
rocy
clina
stell
ata
stella
risA.
stell
ata
buek
kens
isA.
stell
a ste
llaNu
mm
ulite
s hor
moe
nsis
N. st
riatu
sN.
lyell
iN.
bied
aiNu
mm
ulite
s sp.
Assil
ina ex
. gr. a
lpina
Oper
culin
a ex
. gr. g
omez
iOp
ercu
lina
sp.
Hete
roste
gina
arm
enica
arm
enica
H. a
rmen
ica tig
risen
sisH.
retic
ulata
tron
ensis
Hete
roste
gina
sp.
Gyro
idine
lla m
agna
Fabia
nia ca
ssis
Aste
riger
ina ro
tula
Spha
erog
ypsin
a glo
bula
Silve
striel
la te
traed
raCh
apm
anina
gas
sinen
sisEo
annu
laria
eoce
nica
Halky
ardia
sp.
Orbit
olite
s sp.
Linde
rina
sp.
Gyps
ina sp
.pla
nkton
ic for
amini
fera
Ortho
phra
gmine
sAl
veoli
nids
Milio
lids
Textu
larids
Bryo
zoan
sCo
rallin
e red
alga
eCo
rals
Gastr
opod
sEc
hinoid
sCr
inoids
Biva
lves
SO
ĞU
CA
K F
OR
MAT
ION
uppe
r Bar
toni
an18
B18
A
Ceyla
n F
m.
SBZ
STAG
EUN
IT
? ?
Figuer 15. Distribution of benthic foraminifera and other fossil groups in section PIR (Pırnar, Soğucak Formation).
43
E. ÖZCAN ET AL.
9), gradually passing into the Çengelli Formation,was dated as early Priabonian (SBZ 19A Zone)(Özcan et al. 2007a). Two samples from thestratigraphically lower parts of the Doluca Hilllimestone (DOL 1 & 2) contain mainly small
Nummulites, orthophragmines and coralline redalgae, suggesting an inner to middle shelfdepositional environment, unlike the uppermostpart of the sequence, which is dominated by fore-reeftalus. The foraminiferal assemblage of the Soğucak
-
17
14
23
40
33
11
8
7
İbrice Limanı
Saros Bay13
Mecid
iye
B. Derin Dere
K. Derin Dere24
1
234-5
6-12
1413
15-23
28-32
25-27
34
35
3637
38-39
40-40A
N 1 km
2 31
4 5
33
41
Figure 16. The geological map of Mecidiye region and location of samples. 1− metamorfics, 2− Fıçıtepe Formation, 3−Soğucak Formation, 4− Miocene units, 5− aluvium.
44
EOCENE FORAMINIFERA OF THE THRACE BASIN
Formation at Doluca Hill and its close vicinity iscomposed of taxa listed in Figure 18. These samplesare assigned to the SBZ 18 or19A Zones (lateBartonian or early Priabonian), based both on theoccurrence of Heterostegina and the early Priabonianage data from the upper part of the same sequence(Özcan et al. 2007a).
Çengelli FormationThe Çengelli Formation can be traced across thesouthern part of the Thrace Basin from south ofYeniköy in the west to Mürefte in the east (Figures 2& 3). This unit is not known further west thanYeniköy, where the Paleogene shallow to deepmarine carbonates and clastics are prominent partsof the Paleogene sequence. A short description of thestudied blocks (olistoliths), turbidite and marl beds isgiven below.
Olistoliths. The most common blocks in the ÇengelliFormation, found in virtually all outcrop areas, areBartonian−Priabonian. Unlike the mixed clastic-carbonate lithologies of the Dişbudak series, they arecomposed of white thickly bedded to massivelimestone. The sections and samples characterizingthese olistoliths are MÜF.C, YEN, 2B, 616, 638 and1902 (Figures 2 & 3).
Section MÜF (Mürefte) C. A 30-metres-thick sectionwas measured in a large block exposed north of DeveHill (Figure 3) consisting of monotonous coral andcoralline red algal limestone (MÜF.C, UTMcoordinates: 0517497, 4505958). Isolated specimensof larger foraminifera can only be obtained from asingle level (sample MÜF C 6). The only age-diagnostic group is represented by reticulateNummulites, belonging to N. hormoensis, although
-
MECİDİYE (MEC)
SAMPLES
Orbit
oclyp
eus v
arian
s sca
laris
Aste
rocy
clina
stell
ata i
ndet.
ssp.
Num
muli
tes f
abian
iiNu
mm
ulite
ssp.
Hete
roste
gina
grac
ilisH.
retic
ulata
cf. m
ossa
nens
isH.
retic
ulata
Spiro
clype
us ca
rpat
icus
Spiro
clyeu
ssp.
Gyro
idine
lla m
agna
Fabia
nia ca
ssis
Aste
riger
ina ro
tula
Spha
erog
ypsin
a glo
bula
Silve
striel
la te
traed
raCh
apm
anina
gas
sinen
sisEo
annu
laria
eoce
nica
Halky
ardia
sp.
Gyps
inasp
.Pl
anor
bulin
a sp
.Or
thoph
ragm
ines
Milio
lids
Textu
larids
Bryo
zoan
sCo
rallin
e red
alga
eCo
rals
Gastr
opod
sEc
hinoid
sCr
inoids
Biva
lves
SO
ĞU
CA
K F
OR
MAT
ION
uppe
r Pria
boni
an20
4140A40393837363534333231302928272625242322212019181716151413121110987654321
SBZ
STAG
EUN
IT
Figure 17. Distribution of benthic foraminifera and other fossilgroups in samples from Mecidiye region (samplesMEC, Soğucak Formation).
Figure 18. Distribution of benthic foraminifera and other fossilgroups in samples DOL 1 and 2 in the lower, and insamples ŞAR 2, 4, 9 (data from Özcan et al. 2007a) inthe upper part of the Soğucak Formation nearDoluca Hill (Şarköy).
Discocyclina augustae olianaeD. aff. augustaeD. trabayensis cf. elazigensisD. t. ex. interc. elazigensis-trabayensisD. dispansa umblicataD. pratti cf. prattiD. pratti ex. interc. pratti-minorD. radians indet. ssp.D. nandoriNemkovella daguiniO. varians ex. interc. scalaris-variansO. varians cf. variansO. zitteliAsterocyclina stella indet. ssp.A. stella cf. stellaA. stellata stellarisA. stellata cf. stellarisA. alticostata cf. alticostataA ferrandeziNummulites incrassatusNummulites sp.Heterostegina r. mossanensisHeterostegina sp.Spiroclypeus sirottiiOperculina ex. gr. gomeziAssilina ex. gr. alpinaSphaerogypsina globulaGyroidinella magnaPellatispira madarasziAsterigerina rotulaGypsina sp.OrthophragminesTextularidsBryozoansCoralline red algaeCorals
DOL 2
DOL 1
ŞAR.9ŞAR.4 SAMPLE
ŞAR.2
SOĞUCAK FM. low. Pri.
19A18 or 19A
upp. Bar. or low. Pri.
SBZ
STAGE
UNIT SAMPLES FROMDOLUCA TEPE &
ITS CLOSE VICINITY
45
E. ÖZCAN ET AL.
very close to N. fabianii. The foraminiferalassemblage in the lower part is more diverse andincludes taxa listed in Figure 19 (see also for otherforaminifera in sample MÜF C 6). Based on thepresence of highly advanced N. hormoensis andHeterostegina sp., the foraminiferal assemblages canbe assigned to the uppermost part of the SBZ 18 (lateBartonian) Zone, although a transitional positionbetween SBZ 18 and 19 (early Priabonian) Zonescannot be excluded either.
Samples from Other Olistolits. A set of samples werecollected from olistolith outcrops south of Yeniköy(Figure 2), represented mainly by foraminiferal(small-sized Nummulites, miliolids andorthophragmines) and coralline algal limestones.The list of foraminifera and other fossil groups fromthese olistoliths is shown in Figure 20. These groupsindicate an inner to outer shelf depositionalenvironment for these blocks.
-
�6 5
3 2
4Or
bitoc
lypeu
s var
ians i
ndet.
ssp.
Num
muli
tes h
orm
oens
isNu
mm
ulite
ssp.
Assil
inaex
. gr. a
lpina
Hete
roste
gina
sp.
Gyro
idine
lla m
agna
Silve
striel
la te
traed
raCh
apm
anina
gas
sinen
sisFa
biania
cass
isPe
llatis
pira
mad
aras
ziEo
annu
laria
eoce
nica
Glom
alveo
lina
unga
roi
Aste
riger
ina ro
tula
Spha
erog
ypsin
a glo
bula
Halky
ardia
sp.
Gyps
inasp
.
Ortho
phra
gmine
sMi
liolid
sTe
xtular
idsBr
yozo
ans
Cora
lline r
ed al
gae
Cora
lsEc
hinoid
sCr
inoids
Biva
lves
SBZ
18
sample
SBZ
SECTION MÜF.C
1
STAG
E
up
per
BAR
TONI
AN
?
ÇEN
GELL
İOL
ISTO
LITH
UNIT
Figure 19. Distribution of benthic foraminifera and other fossil groups in section MÜF (Mürefte) C (olistolithin Çengelli Formation).
46
EOCENE FORAMINIFERA OF THE THRACE BASIN
A succession 25-metres-thick (samples YEN 1-4,UTM coordinates: 0500905, 4499155, Figure 1) wasmeasured in Eocene limestones at Cinbasarkale Hill.These samples yielded foraminiferal taxa (Figure 20)and, based on the occurrence of Nummulites fabianii,Heterostegina reticulata mossanensis andAsterocyclina ferrandezi in sample YEN 2, thisolistolith was assigned to the SBZ 19A (earliestPriabonian) Sub-zone.
Another nearby olistolith (UTM coordinates:0500951, 4499494, Figure 21) is a composite blockwith pink pelagic limestone and chert overlain by 5metres of Eocene basal conglomerate and limestone.Three samples from this Eocene limestone (YEN 7-9) contain orthophragmines and small-sizedNummulites sp. as the dominant biogeniccontributors. The occurrence of Spiroclypeusconfidently establishes the age of the Eocenelimestone as Priabonian (SBZ 19–20 Zones). Theoccurrence of A. kecskemetii suggests SBZ 19 ratherthan 20.
Sample YEN 10 was taken from anotherlimestone block due south of the collecting locality ofsamples YEN 1–4. Taxa from this sample (Figure 20),and the occurrence of Spiroclypeus establish the ageof this olistolith as Priabonian (SBZ 19–20 Zones).
Sample 1902, collected due east of Doluca Hill(Figure 3) yielded an association of Discocyclina
pratti, D. dispansa, D. augustae, Orbitoclypeusvarians cf. scalaris, Heterostegina reticulata reticulata,and Pellatispira madaraszi (Figure 20). Theoccurrence of H. r. reticulata confidently establishesthe age of this olistolith as latest Bartonian (SBZ18C).
Various small olistoliths from the ÇengelliFormation were sampled (Samples 2B, 616, 638,Figures 2 & 3). Identified taxa from their faunal andfloral composition (Figure 20) do not yield a preciseage for these blocks and they can only be referred toBartonian or Priabonian.
Samples from the Turbidite Beds of the ÇengelliFormation. Some turbidite beds of the ÇengelliFormation consist of redeposited tests of largerforaminifera and other fossil groups, and do notpermit a high-resolution biostratigraphic scheme,since only a few larger foraminifera identified inthese beds have a stratigraphic range covering thewhole duration of the Bartonian and Priabonian.The distribution of fossil groups in ten levels(samples ŞAR 10, 11, 12, 13, 172, 649, 202, 183 and428) are shown in Figure 20. Sample 428,representing the uppermost part of the ÇengelliFormation (Okay et al. 2010), contains mostlycoralline red algae, bryozoans and corals and it is
-
very probable that this level is Priabonian, in view ofthe early Priabonian age data from stratigraphicallylower levels (Özcan et al. 2007a). Foraminifera in theother samples are not age-diagnostic either, but theoccurrence of Operculina ex. gr. gomezi,Chapmanina gassinensis, Heterostegina andGyroidinella magna implies a Bartonian orPriabonian age. Some of the turbidite beds of theunit contain reworked late Cretaceous pelagic fauna(mainly Globotruncanidae). Okay & Tansel (1992)presented similar evidence from blocks in theÇengelli Formation.
Samples from the Marls of the Çengelli Formation.Seven samples collected from the marls of theÇengelli sequence to investigate their nannoflora andplanktic foraminifera (listed in Figure 22) include
Disc
ocyc
lina
augu
stae
D. p
ratti
D. d
ispan
saOr
bitoc
lypeu
s var
ians s
calar
isO.
varia
ns cf
.sca
laris
O. va
rians
O. zi
tteli
Aste
rocy
clina
keck
emet
iiAs
tero
cycli
naaff
.pria
bone
nsis
Afe
rrand
ezi
Num
muli
tes f
abian
iiNu
mm
ulite
ssp.
Hete
roste
gina
r. mos
sane
nsis
H. r.
retic
ulata
Hete
roste
gina
sp.
Spiro
clype
us sp
.Op
ercu
lina
ex. g
r. gom
ezi
Spha
erog
ypsin
a glo
bula
Gyro
idine
lla m
agna
Silve
striel
la te
traed
raCh
apm
anina
gas
sinen
sisFa
biania
cass
isPe
llatis
pira
mad
aras
ziEo
annu
laria
eoce
nica
Glom
alveo
lina
unga
roi
Aste
riger
ina ro
tula
Plan
orbu
lina
sp.
Orbit
olite
ssp.
Pene
ropli
ssp.
Gyps
inasp
.Ro
talia
sp.
Halky
ardia
sp.
Ortho
phra
gmine
sMi
liolid
sTe
xtular
idsBr
yozo
ans
Cora
lline r
ed al
gae
Dasy
clada
cean
alga
eCo
rals
Gastr
opod
sEc
hinoid
sCr
inoids
Biva
lves
YEN.4YEN.3YEN.2
SAMPLE
YEN.1
YEN.10
SAR.13
YEN.9
SAR.12
SAR.10SAR.11
YEN.8YEN.7
202649
sam
ples f
rom
the
turb
iditic
leve
ls of
Çen
gelli
F
orm
ation
sam
ples f
rom
the
limes
tone
blo
cks o
f Çen
gelli
Form
ation
2B
172
183
616638
?
?
SAMPLES FROM OLISTOLITHS & TURBIDITE LEVELS OF ÇENGELLİ FM.
PRIA
BONI
AN
STAGE
BART
ONIA
N or
PRI
ABON
IAN
428
1902 upp.
BAR.
Figure 20. Distribution of benthic foraminifera and other fossil groups in samples from the olistoliths and turbidite levelsof the Çengelli Formation.
YEN 7
YEN 9YEN 8
CB
A
Figure 21. Overview of a composite olistolith in the ÇengelliFormation south of Yeniköy. Samples YEN 7-9represent the lower part of the platform limestone(C) above a basal conglomerate (B). Theseunconformably overlie the red pelagic limestonesequence (A).
47
E. ÖZCAN ET AL.
-
Helicosphaera euphratis HaqH. compacta Bramlette & WilcoxonH. intermedia MartiniH. seminulum Bramlette & SullivanDiscolithina multipora (Kamptner)Transversopontis pulcher (Defl.)Isthmolithus recurvus Defl.Cyclicargolithus floridanus (Roth & Hay)Reticulofenestra placomorpha (Kamptner)R. callida (Perch-Nielsen)R. bisecta (Hay et al.)R. placomorpha (Kamptner)Chiasmolithus grandis (Bramlette & Riedel)C. cf. grandis (Bramlette & Riedel)Chiasmolithus sp. (older type)Coccolithus pelagicus (Wallich)C. eopelagicus (Bramlette & Riedel)Cyclococcolithus formosus KamptnerZygrhablithus bijugatus (Defl.)Lanternithus minutus StradnerBraarudosphaera bigelowi (Gran & Braarud)Micrantholithus vesper Defl.Discoaster tani Bramlette & RiedelD. cf. tani Bramlette & RiedelD. cf. binodosus MartiniD. lodoensis Bramlette & RiedelD. distinctus MartiniD. cf. distinctus MartiniD. cf. mirus Defl.D. barbadiensis TanD. deflandrei Bramlette & RiedelSphenolithus radians Defl.S. predistentus Bramlette & WilcoxonS. moriformis (Brönn. & Stradner)S. radians Defl.Blackites sp.
REWORKED NANNOFOSSILS
Eiffellithus turriseiffeli (Defl.)Eiffellithus eximius (Stover)Watznaueria barnesae (Black)Arkhangelskiella sp.
Globorotalia bullbrooki (Bolli)G. cerroazulensis frontosa (Subbotina)G. cerroazulensis cerroazulensis (Cole)G. cerroazulensis pomeroli Toumarkine et BolliG. cf. c. possagnoensis Toumarkine et BolliGlobigerina cryptomphala GlaessnerG. eocaena GümbelG. corpulenta SubbotinaG. hagni GohrbandtG. linaperta Finlay Globigerina sp.Globigerinatheka index index (Finlay)G. cf. luterbacheri BolliGlobigerinita martini martini Blow et BannerTruncorotaloides cf. rohni Broennimann et Bermudez
1907
1901 SAMPLE
1900
ÇENGELLİ FM. upper Eo.-lower Rup.
19-2216-22
Bartonian-lower Rupelian
NP
STAGE
UNIT SAMPLES FROMMARLS OF ÇENGELLİ
FORMATION
PLANKTONIC FORAMINIFERA
CALCAREOUS NANNOPLANKTON
ÇEN.2
16-21 ŞAR.4
ŞAR.17
ŞAR.2007 -B
Figure 22. Distribution of calcareous nannoplankton and planktonic foraminifera in the marlybeds of the Çengelli Formation.
48
EOCENE FORAMINIFERA OF THE THRACE BASIN
-
49
E. ÖZCAN ET AL.
four from near Doluca Hill, where the Çengelli seriesclearly overlies the Soğucak Limestone. These are(Figure 3) samples 1900, 1901 and 1907 from north-east of Doluca Hill and ÇEN.2 from west of the hill.The calcareous nannoflora from sample 1900generally indicates the Bartonian NP 16-17 Zones,but the older (lower to middle Eocene) forms such asChiasmolithus cf. grandis, Discoaster cf. tani and D.cf. binodosus are poorly preserved. Without theseforms, most other species belong to the NP 16 to NP22 Zones, i.e. from Bartonian to lower Rupelian. Theassemblage of sample 1901 represents three differentages: (i) Turonian to Campanian, based on theshortest range of Eiffellithus eximius, (ii) late Ypresianto earliest Lutetian (NP 12-14), indicated by theshortest range of Discoaster lodoensis, (iii)Priabonian to earliest Oligocene (NP 19-22)determined by the range of Isthmolithus recurvus.The other marker species for the end of NP 20 or NP21 (Discoaster barbadiensis, Cyclococcolithusformosus) may be reworked from older Eocene beds.The above assemblages of three different ages alsooccur in sample 1907. Its age (NP 19-22, Priabonianto earliest Oligocene) is defined by the range ofIsthmolithus recurvus. There are reworked olderforms from the Cretaceous (Turonian to Campanianwith Eiffellithus eximius) and from the older (lowerto middle ?) Eocene with Sphenolithus radians,Helicosphaera seminulum and Discoaster div. sp. Inthe poor nannoplankton assemblage of sampleÇEN.2 Reticulofenestra placomorpha has the shortestrange: NP 16 – NP 22, i.e. Bartonian to lowerOligocene. The age of the rather poor plankticforaminifera from samples 1900 and 1901 is middleEocene, while those of samples 1907 and ÇEN.2,containing much richer assemblages, span fromBartonian to early Priabonian (P 14-15). To sum up:The Çengelli Formation near Doluca Hill consists ofmixed planktonic assemblages, among which theyoungest forms approach most reliably the real age ofthese olistostromal deposits. Therefore, the age of theÇengelli Formation is considered to be middlePriabonian to earliest Rupelian (NP 19-22). This fitswith the youngest age (early Priabonian, Özcan et al.2007a) from the underlying Soğucak Limestone.
The other three samples (ŞAR.4, UTM: 0501126,4499536; ŞAR.17, UTM: 0500825, 4498777 andŞAR.2007B from the matrix of the olistostrome ofsamples YEN 7-9 with the same UTM co-ordinates,see above) are from near Yeniköy (Figure 2). Theyyielded poorer nannoflora, giving an age fromBartonian to earliest Rupelian (NP 16-21), whereasplanktonic foraminifera are rare and recrystallized oraltogether absent (as in sample ŞAR.17) and give avery uncertain middle Eocene age. Since thepresence of Spiroclypeus (first appearing in the upperEocene) in the olistoliths clearly indicates that thematrix cannot be older than Priabonian as well, mostof the plankton from the matrix has to be consideredas redeposited in this case, too. The upper age of theolistostrome in the Yeniköy region is given byCylococcolithus formosus, last occurring in the NP 21Zone, approximately marking the Eocene/Oligoceneboundary.
Keşan FormationLarger foraminifera occur very sporadically in thedeep marine Keşan (Ceylan) Formation. In southernThrace, a rather rich assemblage has been discoveredonly in one locality near Çeltik village (Figure 1B).This sandstone sample (ÇEL 13, UTM coordinates:06366, 03036) contains Heterostegina reticulataitalica, the most advanced stage of the species in thePriabonian, Nummulites budensis, Operculina ex. gr.gomezi and Linderina sp. This assemblage suggests amiddle to late Priabonian (SBZ 19B-20) age for thissample.
Systematic PaleontologyIn this section, systematic description ofstratigraphically important groups such asorthophragmines and nummulitids (e.g.Heterostegina, Spiroclypeus and some Nummulites) isgiven. Some comments on the occurrence of otheraccompanying benthic foraminifera identified in theÇengelli and Soğucak formations are made in thesection ‘Conclusions’. Some taxa such as Discocyclinadiscus, D. trabayensis, Nemkovella evae and N.
-
strophiolata, are represented by one single specimenin our material and are therefore not described here.The description of the two Discocyclina species,more widely recorded from the northern part of theThrace Basin, can be found in Less et al. (in review),whereas that of the Nemkovellae is in Özcan et al.(2007b).
Since most of the taxa occurring in our materialwere described in detail in the last few years, we donot repeat their description here. The mostcomprehensive data for Western TethyanHeterostegina and Spiroclypeus, with their newlyproposed taxonomic and phylogenetic scheme, aregiven in Less et al. (2008) and Less & Özcan (2008).A synthesis of diagnostic features of Tethyanorthophragminid families and genera and theirqualitative features can be found in Less (1987,1993), Less et al. (2007), Less & Ó. Kovács (2009) andÖzcan et al. (2007a, b). Additional information withreferences to more detailed descriptions, geographicand stratigraphic ranges, and the most up-to-datesubdivision into subspecies in orthophragmines canbe found in Less (1987, 1998a), Less et al. (2007),Less & Ó. Kovács (2009), Özcan (2002), Çolakoğlu &Özcan (2003) and Özcan et al. (2007a, b). The mostup-to-date description of most orthopragminidspecies discussed below can be found in Özcan et al.(2007a); for Discocyclina archiaci, D. fortisi,Orbitoclypeus schopeni and O. munieri see Özcan etal. (2007b) while for D. seunesi, Nemkovella stockariand O. bayani see Less et al. (2007). A shorteneddescription is given for Orbitoclypeus haynesi andAsterocyclina aff. priabonensis, fully described bySamanta & Lahiri (1985) and Less (1987),respectively. A complete description is given only forO. zitteli, since this taxon is hardly mentioned sinceChecchia-Rispoli (1909). A revised stratigraphy oflate Paleocene to Priabonian orthophragmines isproposed in Less et al. (2007) and Özcan et al.(2007a, b). An updated range-chart for the above andother stratigraphically important benthic taxa thatcover the late Lutetian to early Rupelian interval isshown in Figure 23. Based on Less et al. (2008) thesubdivision of reticulate Nummulites (N. fabianiilineage), spanning from the early Bartonian to themiddle Oligocene, is shown in Figure 24.
Principles in the Determination ofOrthophragmines and NummulitidsIn the description of orthophragmines we adoptedthe principles used by Less (1987, 1993) as illustratedin Figure 25A, and explained in the header of Tables1−3. A synopsis of subspecies identification based onthe outer cross-diameter of the deuteroconch(parameter d) is shown in Figure 26. Thedetermination of Nummulites is based on both thesurface characteristics and the features of the
Oligocene
earlyLutetian Rupelian
A B C A B?
N. brongniarti-puschi-groupN. gizehensis-lyelli-groupN. millecaput-maximus-groupN. perforatus-biedai-groupN. lorioli-ptukhiani-groupN. bullatusN. garganicusN. hormoensisN. fabianiiN. fichteliN. discorbinus-beaumonti-groupN. striatus ?N. incrassatusN. chavannesiN. pulchellusN. stellatus ?N. vascus
?A. spira-groupA. exponens-groupA. schwageri ?A. alpina ?O. gomezi-groupO. complanata ?H. armenica armenicaH. armenica tigrisensisH. reticulata tronensisH. reticulata hungaricaH. reticulata multifidaH. reticulata helveticaH. reticulata reticulataH. reticulata mossanensisH. reticulata italica ?H. gracilisS. sirottiiS. carpaticus
?
Other orthophragmines (D. dispansa, D. augustae, D. radians, D. trabayensis, O.
varians, O. furcatus, A. stella, A. stellata)
20 21
Orthophragmines of Lutetian acme (D. pulcra, Orbitoclypeus douvillei)
Discocyclina discus
Orthophragmines of middle Eocene acme (D. pratti, Nemkovella strophiolata, Asterocyclina
alticostata, A. kecskemetii)Orthophragmines of Priabonian acme (D. euaensis, D. nandori, D. aspera, D. ruppi,
A. ferrandezi, A. priabonensis)
Oper-culina
H e
t e
r o s
t e g
i n
aR
etic
ulat
e N
umm
ulite
s
Shallow benthic zones (SBZ) 16 17
Spiro-clypeus
Pellatispira
Rad
iate
Num
mul
ites
Nummulites garnieri-groupGiant
AssilinaSmall
Assilina
E o c e n e
19
Alveolina
Gia
nt
Num
mul
ites
18
m i d d l e l a t ePriabonian B a r t o n i a n
Figure 23. Range-chart for some late Lutetian to early Rupelianlarger benthic foraminiferal taxa of the WesternTethys. The subdivision of the stratigraphic scale isnot time-proportional (Less et al. 2008).
50
EOCENE FORAMINIFERA OF THE THRACE BASIN
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Taxon Pmean ( m) Surface Stage SBZ zoneN. bullatus 65–100 granules, no reticulation basal Bartonian early SBZ 17
N. garganicus 100–140 heavy granules + reticulation early Bartonian to middle late Bartonianlate SBZ 17 to SBZ 18B
N. hormoensis 140–200 heavy granules + umbo + reticulation late Bartonian SBZ 18N. fabianii 200–300 heavy reticulation, weak granules + umbo Priabonian to early Rupelian SBZ 19–21N. fichteli 200–300 weak reticulation to irregular mesh late Priabonian to late Rupelian SBZ 20–22AN. bormidiensis 300–450 irregular mesh early Chattian SBZ 22B
Figure 24. Subdivision of the Nummulites fabianii-lineage in the Bartonian to early Chattian time-span (Özcanet al. 2009). SBZ 21–22B are in the sense of Cahuzac & Poignant (1997).
P
D
Md
dM
D
+++
++
++
+
+
+
+++
++ + +
++*
* * * **
**
*
***
*d
P
BApd
H
W
n
w
h
C
Figure 25. Measurement system for megalospheric larger foraminifera (parameters are explained in the headers of Tables 1to 5). The parameters for the definition of megalospheric orthophragmines (A), Nummulites (B), Heterosteginaand Spiroclypeus (C).
51
E. ÖZCAN ET AL.
equatorial section. Based on Drooger et al. (1971),Less (1999) introduced a measurement andparameter system to characterize the equatorialsection of A-forms that is slightly modified here(Figure 25B). These parameters adopted here areexplained in the header of Table 4 (also see Figure25). The description of Heterostegina andSpiroclypeus is based on the system introduced byDrooger & Roelofsen (1982) and adopted for Eocenerepresentatives of these genera (Less et al. 2008 andLess & Özcan 2008). The explanation ofmeasurements and counts executed in the equatorialsection of each megalospheric specimens (Figure25C) are given in the header of Table 5.
Biometric data are summarized in Tables 1−5.Grouped samples containing almost the sameassemblages having similar parameters are evaluated
both separately and jointly. However, the subspecificdetermination of particular species is given for thejoint samples on the basis of the total number ofspecimens. These data are marked always with boldletters. Because of limited space, a completestatistical evaluation with the number of specimens(n°), arithmetical mean and standard error (s.e.) isgiven only for deuteroconch size (d), the crucialparameter in subspecific determination. Subspeciesare determined according to the biometrical limits ofsubspecies for populations presented in thedescription of the given species. No subspecies isdetermined if only a single specimen is availablefrom joint samples. If the number of specimens istwo or three, the subspecies is determined as cf. Ifthis number is four or more, however the dmean valueof the given population is closer to the biometrical
-
Equatorial chamberlets
number width height annuli/0.5 mm width height
N W ( m) H ( m) n w ( m) h ( m)Species Sample mean range range range range range range
Discocyclina seunesi SAZ 46 6 225 – 450 341.7 ± 34.9 140 – 270 203.3 karabuekensisMÜF A 10 10 280 – 470 380.0 ± 19.2 150 – 240 197.5 17–30 35–40 45–70 11–13 35–45 80–85 staroseliensis–archiaci1894 9 380 – 650 503.3 ± 29.1 170 – 320 232.9 28–38 30–50 40–60 11–12 25–35 45–65 archiaci
D. discus GIZ A 4 1 1030.0 430.0 indet. ssp.MÜF A 10 28 530 – 1040 726.3 ± 23.7 250 – 630 379.4 51–63 30–50 55–80 6–9 35–45 65–100 fortisi1894 21 540 – 1005 723.8 ± 20.8 290 – 520 376.7 53–61 30–50 40–85 7–9 30–50 50–75 fortisiMÜF A 10 8 90 – 115 106.3 ± 2.8 55 – 85 66.3 10–11 15–35 15–25 16–21 20–25 70–85 sourbetensis1894 4 90 – 125 107.5 ± 6.7 65 – 85 76.7 10 15–20 15–20 16–20 25–30 50–55 sourbetensisGIZ A 9+11 16 130 – 215 163.1 ± 5.8 70 – 110 95.4 20 35 30 50 13 18 20 35 50 95
GIZ A 9 9 130 – 215 160.0 ± 8.3 70 – 100 92.9 20 35 30 50 13 18 20 35 50 90GIZ A 11 7 130 – 190 167.1 ± 7.7 80 – 110 98.3 30 35 35 40 15 25 30 95
GIZ A 12 7 140 – 190 160.7 ± 5.8 85 – 115 100.0 25 40 35 60 15 25 35 50 55 atlanticaPIR 46 4 195 – 240 221.3 ± 9.7 100 – 125 110.0 olianae-augustaePIR 47A+48 14 190 – 225 206.1 ± 2.9 100 – 130 116.3
PIR 47A 3 205 – 225 213.3 110 – 130 120.0PIR 48 11 190 – 225 204.1 ± 3.1 100 – 125 115.0
1902 1 210.0 100.0 indet. ssp.1894 4 170 – 250 216.3 ± 14.7 90 – 125 106.3 16–20 30–35 35–45 13–16 20–25 50–70 tauricaGIZ A 6+7 4 315 – 345 331.3 ± 6.0 150 – 160 155.0 35 55
GIZ A 6 1 345.0 160.0 55GIZ A 7 3 315 – 340 326.7 ±