An Albian–Turonian shallow-marine carbonate succession of the Bey Dağları (Western Taurides, Turkey): biostratigraphy and a new benthic foraminifera Fleuryana gediki sp. nov.

Abstract

The studied Cretaceous succession is exposed at the Toçak Mountain in the southeastern part of the Bey Dağları Carbonate Platform (BDCP). The Alakır outcrop section presents seemingly continuous shallow-marine carbonate sedimentation during the Albian–Turonian times which is known from very few parts of the peri-Mediterranean platforms. Approximately 550 m thick platform carbonate succession is unconformably overlain by carbonate breccia/conglomerate and pelagic limestones of Campanian age. A benthic foraminiferal biostratigraphic zonation scheme is presented. The biozones are tentatively placed into the stages, without chronostratigraphic calibration, based on stratigraphic distribution of common benthic foraminifera in the peri-Mediterranean platforms. Protochrysalidina elongata–Cuneolina pavonia assemblage zone and Coskinolinella bariensis taxon range subzone are assigned to the upper Albian. In the conformably overlying limestones, Sellialveolina gr. viallii taxon range zone (lower–middle Cenomanian), Pseudorhipidionina casertana assemblage zone (upper Cenomanian), Pseudorhapydionina dubia–Pseudolituonella reicheli assemblage zone (uppermost Cenomanian) and Pseudocyclammina sphaeroidea assemblage zone (Turonian) have been distinguished. Two-step pattern of extinction of benthic foraminifera across the Cenomanian–Turonian boundary interval, which was first recorded from the Apennine Carbonate Platform, has been documented also from the BDCP. The tentative Cenomanian–Turonian Boundary is constrained into an interval of one meter between the last occurrence of the Cenomanian larger foraminifera and the first occurrence of the Turonian benthic foraminiferal assemblage comprising morphologically-simple and less-known taxa and other taxa left in open nomenclature. Fleuryana gediki sp. nov. is described from the Turonian.