LAUSR

Abstract The Mardin Group strata, as a product of the Cretaceous carbonate platform developed in the northern margin of the Arabian Platform, consists of a thick sedimentary sequence composed mostly of carbonates with subordinate clastic sediments. In this study, three stratigraphic sections Turkoglu, Derik and Inisdere addressing this sequence have been investigated in terms of lithostratigraphy and biostratigraphy combined with microfacies analysis and sequence stratigraphic interpretation. A comprehensive examination of both benthic and planktonic foraminifers in thin sections has revealed that the age of the Mardin Group ranges from early Aptian to Santonian. The lower Aptian and Cenomanian deposits are characterized by benthic foraminifers, whereas the planktonic foraminifers predominate in the upper Albian, Turonian, Coniacian and Santonian. Following a detailed microfacies analysis, a wide depositional environment ranging from inner to outer ramp have been recognized in the Mardin Group carbonates. A sequence stratigraphic analysis has been carried out in order to trace the signals of global sea—level changes during the deposition of Areban, Sabunsuyu and Derdere formations of the Mardin Group. Twenty one depositional sequences are recognized in the interval from lower Aptian to upper Turonian and, under the control of paleontological data, sequence boundaries are correlated with the cycle boundaries of global charts. Eustatic signals enable to recognize several time lines within the Aptian, Albian, Cenomanian and Turonian stages and some important eustatic events like mid—Aptian sea—level fall and the onset of a more accentuated sea—level rise starting from the early Albian.