Arabian-Anatolian Plate Movements and Related Trends in Southeast Turkey's Oilfields

Abstract

Two important tectonic phases generated by African and Arabian plate movements influenced the evolution of trends in SE Turkey's oilfields. The main phase occurred during the late Cretaceous (Maastrichtian) time, while the second phase reactivated the existing trends in Miocene. Paleogeological evolutions reveal that SE Turkey was tectonically stable from Paleozoic up to the end of Cretaceous, during which the structural trends were oriented in a WSW-ENE direction, contrarily, under the influence of opening of the Red Sea area, the existing trends rotated in a counterclockwise direction and oriented in a SW-NE direction. This rotational tectonic event is evidenced by SW-NE alignments of SE Turkey's oilfields in subsurface and Karacadag basaltic expensions and appearence of major faults, like the Dead Sea fault, Adiyaman fault, and Akcakale fault, on surface. Subsurface interpretations indicate that, contrarily to the previous works, which considered the Dead Sea fault and Adiyaman fault separate tectonic features from each other and also attached them to the East Anatolian fault, the Adiyaman fault is the continuity of the Dead Sea fault through the Adiyaman, Diyarbakir and Selmo areas. The Akcakale fault, which generated the Karacadag basaltic flows, is another tectonic element and has influenced the exploration activities in SE Turkey. Moreover, detailed interpretations of well data reveal that the SW-NE structural trends also improved reservoir conditions by creating fractures and dolomitizations in reservoir rocks, and the high geothermal and potential (piezometric) gradients and porosity trends are also aligned in the same direction.