Bey dağları otoktonu (Batı Toroslar, Türkiye) üst kretase istiflerinin foraminifer-rudist biyostratigrafisi, Sr-C-izotop stratigrafisi ve mikrofasiyes analizi

The Upper Cretaceous sequences of the Bey Daları autochthon (Western Taurides) are divided into three geographical areas (southern, northern and eastern areas), which present important biotic and facies changes and include sedimentary breaks related to the evolution and drowning of the platform. The Bey Daları Formation in the northern part of the autochthon can be divided into two parts. Approximately 700-m-thick Middle Cenomanian-?Coniacian neritic carbonates form the basal part and are gradationally overlain by the 26-m-thick Coniacian-Santonian hemipelagic limestones. The 100-m-thick Late Campanian-Late Maastrichtian Akda Formation comprises planktonic foraminifera-bearing pelagic limestones and disconformably overlies the different stratigraphic levels of the Bey Daları Formation along a prominent hardground or erosional surface. The Palaeogene pelagic marls disconformably rest over the different stratigraphic levels of the Upper Cretaceous sequence. The neritic limestones of the autochthon mainly deposited in a platform interior environment (from peritidal to platform edge) include four main rudist associations, which are caprinid lithosome, hippuritid lithosome, hippuritid-radiolitid lithosome and Joufia-Gorjanovicia lithosome corresponding to the Middle Cenomanian, Upper Turonian, Santonian-Campanian and Upper Campanian-Maastrichtian respectively. The Late Turonian age was obtained by Sr-isotope analysis. The C-isotope stratigraphy permitted fixing the Cenomanian-Turonian boundary in the neritic limestones. Benthonic foraminifera assemblages identified from the neritic limestones yields five biozones. Two of the biozones, `level with Ovalveolina maccagnoi? and `level vi with Orbitolina (Conicorbitolina) conica? have been defined from the Middle Cenomanian. The younger three biozones namely `level with Coxites cf. zubairensis?, `level with Assemblage-A? and `level with Pseudocyclammina sphaeroidea? correspond to the Upper Cenomanian, Upper Cenomanian-?lowermost Turonian and Middle Turonian-?Coniacian respectively. Analysis of the fifty planktonic foraminiferal species belonging to twelve genera have yielded six biozones such as Dicarinella concavata IZ, Dicarinella asymetrica TRZ (from the Coniacian-Santonian hemipelagic limestones), Radotruncana calcarata TRZ, Globotruncana falsostuarti PRZ, Gansserina gansseri IZ and Abathomphalus mayaroensis IZ (from the Late Campanian-Late Maastrichtian pelagic limestones). The two hiatuses corresponding to the Lower-Middle Campanian and uppermost Maastrichtian-Middle Palaeocene and the drowning of the platform after the Late Turonian may have been related to the regional tectonics as the easternmost Mediterranean area was subjected to the important tectonic events during the Late Cretaceous. Keywords: Upper Cretaceous, Planktonic Foraminifera, Benthonic Foraminifera, Rudist, Biostratigraphy, Sr-isotope stratigraphy, C-isotope stratigraphy, Bey Daları Carbonate Platform, Western Taurides