Benthonic Foraminiferal Biostratigraphy of the Upper Cretaceous (Middle Cenomanian−Coniacian) Sequences of the Bey Dağları Carbonate Platform, Western Taurides, Turkey


Abstract: Identification of the benthonic foraminiferal assemblages from ten stratigraphic sections from the inner platform limestones of the Middle Cenomanian−Coniacian successions of the Bey Dağları carbonate platform (BDCP) allowed the recognition of one biozone and two subzones. The lower part of the platform limestones (Middle−Upper Cenomanian) is represented by relatively rich benthonic foraminiferal assemblages, while the upper part (Turonian−Coniacian) contains poor assemblages. The benthonic foraminiferal assemblages determined in the BDCP are dominated by long-ranging species. The shorter-ranging, stratigraphical index species have been selected to date the Upper Cretaceous platform limestones of the BDCP based on the distributions of the species in the circum-Mediterranean region. The Pseudolituonella reicheli-Pseudorhapydionina dubia Concurrent Range Zone is defined from the Middle−Upper Cenomanian platform limestones. The biozone includes the Cisalveolina lehneri Subzone and the Coxites zubairensis Subzone of Middle Cenomanian and Upper Cenomanian age respectively. The first occurrences of Moncharmontia apenninica-compressa and Pseudocyclammina sphaeroidea indicate the Late Turonian and the Coniacian respectively. The spread of hemipelagic limestones in the BDCP during the Coniacian shows that neritic accumulation on the BDCP persisted from the Middle Cenomanian to the Coniacian. These data indicate that the global sea level rise at the Cenomanian−Turonian boundary, which caused the general demise of many Tethyan carbonate platforms, did not result in deepening on the BDCP.

Keywords: benthonic foraminifera, biostratigraphy, Upper Cretaceous, Bey Dağları carbonate platform, western Taurides

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