Outcrop Scale Sequence Stratigraphy of the Derdere and Karababa Formations in the Adiyaman Area, Southeastern Turkey
The upper Cenomanian-lower Turonian Derdere Formation and upper Coniacian-lower Campanian Karababa Formation are two of the most important petroleum reservoirs and source rock units in the Adiyaman area, Southeastern Turkey. The two formations were deposited on the shelf-to intrashelf part of a passive continental margin of the Arabian plate. The Derdere Formation is composed of limestone and dolomite. The Karababa Formation is divided into three members: Karababa-A, composed mainly of limestone containing planktonic foraminifera, Karababa-B, consisting of distinctive features such as dolomitic carbonate, and Karababa-C, characterized by mollusk and echinoid microfacies. We have conducted an outcrop scale sequence stratigraphic study of the two formations to determine their lithofacies characteristics. From our stratigraphic section measurement and petrographic study of three outcrops near the town of Adiyaman in southeastern Turkey, we have identified four major lithofacies and seven subfacies, which are interpreted to have been deposited in shallow marine conditions. Our data sugget that the Karababa and Derdere formations constitute two distinct depositional sequences separated by palaeokarst features representing a tectonically enhanced sequence boundary, which can be correlated with a world-wide sequence stratigraphic event. Each depositional sequence is composed of meter-scale shallowing-upward parasequences, and the depositional sequences are composed of transgressive (TST) and highstand (HST) systems tracts. The transgressive intervals of the sequences are dominated by organic-rich carbonates, while the regressive intervals consist of prograding units of bioclastic wackestone/packstone. We plan to carry out a study to correlate our surface findings with the available subsurface data on the Derdere and Karababa Formations in several oils fields in southeastern Turkey.
AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014