Late Cretaceous-Eocene Geological Evolution of the Pontides Based on New Stratigraphic and Palaeontologic Data Between the Black Sea Coast and Bursa (NW Turkey)

Ozcan, Zahide
Okay, Aral
Özcan, Ercan
Hakyemez, Aynur
Altıner, Sevinç
The Late Cretaceous-Eocene geological evolution of northwest Turkey between the Black Sea and Bursa was studied through detailed biostratigraphic characterization of eleven stratigraphic sections. The Upper Cretaceous sequence in the region starts with a major marine transgression and lies unconformably on a basement of Palaeozoic and Triassic rocks in the north (Istanbul-type basement) and on metamorphic rocks and Jurassic sedimentary rocks in the south (Sakarya-type basement). Four megasequences have been differentiated in the Late Cretaceous-Eocene interval. The first one, of Turonian to Late Campanian age, is represented by volcanic and volcanoclastic rocks in the north along the Black Sea coast, and by siliciclastic turbidites and intercalated calcarenites in the south, corresponding to magmatic arc basin and fore-arc basin, respectively. A major ridge along the present southern margin of the Kocaeli Peninsula separated these two realms. In the Late Campanian, volcanism and clastic sedimentation gave way to the widespread deposition of the pelagic limestone and marl of the Akveren Formation; only in the extreme south near Bursa are the pelagic micrites of the Akveren Formation replaced by calciturbidites and siliciclastic turbidites. The age of the Akveren Formation ranges from Late Campanian to Late Palaeocene. The third megasequence is a thick flysch wedge of Early Eocene age, which extends from north of Bursa to the Black Sea coast. The base of the Lower Eocene flysch is marked by a major unconformity. The flysch wedge marks the collision between the Pontides and the Anatolide-Tauride Block. The fourth megasequence is a thick volcanic and volcaniclastic series of late Early to Middle Eocene age, which extends from north of Bursa to the northern margin of the Armutlu Peninsula. The coherent Upper Cretaceous-Eocene stratigraphy, the laterally traceable facies belts, absence of ophiolitic slices and high pressure metamorphic rocks in the Upper Cretaceous-Tertiary series in the region between the Black Sea and Bursa indicate pre-Santonian juxtaposition of the Istanbul and Sakarya zones.


Upper Cretaceous volcaniclastic complexes and calcareous plankton biostratigraphy in the Western Pontides, NW Turkey
Boehm, Katharina; Wagreich, Michael; Wolfgring, Erik; Tuysuz, Okan; Gier, Susanne; Yılmaz, İsmail Ömer (2019-01-01)
This study describes and interprets Upper Cretaceous volcaniclastics interbedded with hemipelagic to pelagic limestones, marls, and turbidites from the Western Pontides, northwestern Turkey. The Derekey Formation, the Unaz Formation (red pelagic limestone unit), and the Cambu Formation can be distinguished, overlain by the turbiditic Akveren Formation. Biostratigraphic ages from the predominantly volcaniclastic Derekoy Formation indicate Turonian (Dicarinella concavata planktonic foraminifera zone, CC13/UC8...
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Altıner, Sevinç (1999-01-01)
Planktonic and larger benthonic foraminifers of the Upper Cretaceous (Santonian-Maastrichtian)-Lower Tertiary (Danian) rock units from north, northwest and central Anatolian fore-are basins have been investigated in order to improve the biostratigraphic resolution of this time interval. Total abundance and diversity of planktonic foraminifers vary from rare (the sequence from the Haymana region) to high (the sequences from the Cide, Caycuma, Hanonu and Yenikonak regions) and preservation is poor to moderate...
Late Campanian Maastrichtian evolution of orbitoidal foraminifera in Haymana Basin succession Ankara Central Turkey
Özcan, Ercan; Altıner, Sevinç (1997-01-01)
In Central Anatolia, a thick sedimentary succession composed of deep-water turbiditic units represented by marl-shale, sandstone, olistostromal horizons and carbonates crops out. This succession constitutes the lower part of so-called Haymana Basin spanning the Santonian (?)/Campanian-Eocene time interval. Evolution of Lepidorbitoides and Orbitoides concerning embryonic features and the initial chamber arrangement has been investigated in the Late Cretaceous part of this succession. Previously unrecognized ...
Middle Jurassic Lower Cretaceous biostratigraphy in the Central Pontides (Turkey): Remarks on paleogeography and tectonic evolution
Rojay, Fuat Bora; Altıner, Demir (1998-08-01)
The deposition of Jurassic-Lower Cretaceous carbonates in the Pontides was controlled mainly by the evolution of an Atlantic-type continental margin in the Tethys. The study of several stratigraphic sections from allochthonous slices and blocks of the North Anatolian Ophiolitic Melange provided insight into the Middle Jurassic-Early Cretaceous paleogeographic evolution of the Central Pontide Belt. The Callovian-Aptian successions span the Globuligerina gr. oxfordiana, Clypeina jurassica (equivalent of the T...
Late Permian (Tatarian) fluvio-lacustrine successions in NW Anatolia (Zonguldak Terrane, Turkey): palaeogeographic implications
OKUYUCU, CENGİZ; Dimitrova, Tatyana K.; Göncüoğlu, Mehmet Cemal; Gedik, Ibrahim (2017-09-01)
Late Permian fluvio-lacustrine successions of the Cakraz Formation in the Zonguldak Terrane between the regions of Akcakoca and Ereli were investigated in order to describe the litho- and biostratigraphic properties and explain the depositional environment. The studied succession with black, dark-grey to greenish-grey shales, siltstones and limestones is named the Alapl Member to distinguish it from the classical red clastic successions, which are tentatively named the Ereli Member of the Cakraz Formation. ...
Citation Formats
Z. Ozcan, A. Okay, E. Özcan, A. Hakyemez, and S. Altıner, “Late Cretaceous-Eocene Geological Evolution of the Pontides Based on New Stratigraphic and Palaeontologic Data Between the Black Sea Coast and Bursa (NW Turkey),” TURKISH JOURNAL OF EARTH SCIENCES, pp. 933–960, 2012, Accessed: 00, 2020. [Online]. Available: