Neogene sedimentary history of the Cilicia Basin, eastern Mediterranean

Abstract

The Miocene to Recent tectonic evolution of the Cilicia Basin near the present day mouth of the Goksu River is studied using 2000 km of high resolution 96-channel seismic reflection profiles collected in 2008 using the RV Koca Piri Reis of the Institute of Marine Sciences and Technology. Our project is intended to provide a history of deposition in one of the ultimate sinks: the eastern Mediterranean. We mapped the distribution of sediment deposits and delineated the structures that developed in the Cilicia Basin precisely in space and time. The focus of this research is on the basin-wide structures that developed near the Turkish continental slope and extend through the entire Cilicia Basin. -- Detailed interpretation and mapping of the seismic reflection profiles showed that during the Miocene a major south- and southeast-verging fold-thrust belt developed across the entire Cilicia Basin. The leading portion of this fold-thrust belt is well imaged in the Inner Latakia Basin, south east of the present-day Misis-Kyrenia Fault Zone. The trailing portion of the fold-thrust belt is believed to constitute the thrust panels which form the core of the central Taurus Mountains of southern Turkey. A north- and northwest-verging fold-thrust belt is locally mapped in the Outer Cilicia Basin. The belt is overprinted by smaller positive flower structures all soling into the primary thrust surface(s), and showing tip points extending to the depositional surface. This structural architecture suggests that they are developed within a transpressional regime during the Pliocene Quaternary. Seismic stratigraphic correlations with deep offshore exploration wells provided the chronology for the seismic data. A thick evaporite succession is unconformably deposited over deeper portions of the fold-thrust belt. This evaporite succession presently forms numerous salt pillows and salt rollers in Inner Cilicia Basin, and salt diapirs and salt walls in the Outer Cilicia Basin. -- Detailed mapping showed that Miocene contraction was followed by partitioned contraction and extension that is related to strike-slip fault activity along the Kozan Fault Zone, a major splay from the East Anatolian Transform Fault. Our results show that Pliocene-Quaternary extension occurs within the basin contemporaneously with the contractional or transpressional structures along the southern margin of the basin. A specific problem that is addressed in this study is to understand the relationship of contemporaneous contractional to extensional deformation in the study area.