THE DERDERE AND KARABA FORMATIONS OF LATE CRETACEOUS MARDIN GROUP,CEMBERLITAS OIL FIELD, SOUTHEASTERN TURKEY: DEPOSITIONAL ENVIRONMENTS AND SEQUENCE STRATIGRAPHY
We have conducted a detailed study of microfacies, depositional environments and sequence stratigraphy of the Derdere (Mid-Cenomanian-Turonian) and Karababa (Coniacian-Lower Campanian) Formations in the oil field. We have recognized 8 microfacies in the Derdere and Karababa Formations in the study area; (1) fine crystalline dolomite, (2) medium-coarse crystalline dolomite, (3) bioclastic wackestone/packstone, (4) lime mudstone (5) phosphatic-glauconitic planktonic wackestone, 6) planktonic foraminiferous wackestone/packstone, (7) dolomitic planktonic wackestone, and (8) mollusk-echinoid wackestone/packstone. These microfacies suggest that the Derdere formation was deposited in lagoonal to shelf depositional environments. The microfacies also suggest that Karababa Formation was deposited in a deep to shallow marine intra shelf basin.
We have indentified, two-third-order sequence boundaries in the reservoir.These boundaries are of late Turonian and early Campanian age. Each sequence contains transgressive and highstand systems tracts.These sequences are compared with those in other regions to differentiate the local, regional and global factors that controlled sedimentation within the study area.