Stratigraphy and Structural Geology of the Eastern Part of the Büyük Menderes Graben, Western Turkey Based on 2-D Seismic Reflection Profiles

Abstract

The Alasehir and Büyük Menderes Grabens are two main east-west trending extensional basins located in the central part of Western Anatolia extended terrane, Turkey. These basins are formed during the Cenozoic extension in the region. Although structural development of the Alasehir Graben was studied in detail in recent years, the Büyük Menderes Graben (BMG) has remained relatively unstudied. We have constructed structural cross-sections in the BMG based on our interpretation of the 2D seismic reflection profiles of the Turkish Petroleum Corporation (TPAO) and a wildcat well, Nazilli-1, drilled by the same company. We have delineated stratigraphy of the Miocene to recent sedimentary section and the structural geometry of the extensional features in the eastern BMG. We are also comparing them to published stratigraphic sections and structural cross-sections in the Alasehir graben (AG). Our interpretation of the available seismic and well data together with the depth-conversion conducted by us suggests that the south dipping main boundary fault on the northern side of the BMG has been active during the Miocene sedimentation in the basin. This is evidenced by the wedge-shaped growth strata adjacent to the main boundary fault. Syn-sedimentary extension in the graben has also formed the rollover structure and associate extensional folds and faults. However, these structures are not as well developed as the ones in the AG. This is demonstrated by the very broad nature of the rollover folds and high angle non-rotational nature of the extensional faults within the basinal sediments in the BMG. This suggests that the intensity of the extensional features in the BMG is lesser than the AG. Therefore, although the AG and BMG may have started to form simultaneously, they may have experienced different rates and amounts of extension and they do not contain symmetrical structural features.

AAPG Datapages/Search and Discovery Article #90216 ©2015 AAPG Annual Convention and Exhibition, Denver, CO., May 31 - June 3, 2015