The Pliocene–Quaternary tectonic evolution of the Cilicia and Adana basins, eastern Mediterranean: Special reference to the development of the Kozan Fault zone

• We distinguished deltas derived from Göksu River from those sourced by Seyhan, Ceyhan, Tarsus Rivers.
• We showed that Pliocene-Quaternary deltas were systematically displaced toward the southwest.
• We argued that Göksu River is the only source that could create the observed sediment accumulations.
• We suggested that 20-35 km lateral displacement must have occurred along a northeast-southwest line.
• We suggested a conservative estimate of 0.43-0.75 cm/yr sinistral strike slip for the Kozan Fault Zone.

A grid of high-resolution multi-channel seismic reflection profiles allows the detailed mapping of the Kozan Fault zone in the Cilicia and Adana basins. The zone is delineated by an arcuate zone consisting of several ENE–WSW and NNE–SSW striking, closely-spaced high-angle extensional faults which define an ~ 300 km long and 15–20 km-wide “lazy-S” shaped structure along the southeastern fringes of the Taurus Mountain and along the northwestern margins of the Cilicia and Adana basins. In the Cilicia Basin the zone consists of several high-angle faults which exhibit small dip separations on the M-reflector and have tip points situated mainly in the lower and middle portion of the Pliocene–Quaternary succession. In the Adana Basin a family of northeast-striking and southeast dipping extensional faults occurs along the western and northwestern margin of the basin. The faults cut down with relatively steep dip into the ~ 700 ms thick Tortonian and older Miocene successions.Multi-channel seismic reflection profiles show that three prominent seismic markers divide the uppermost Messinian–Recent successions in the Cilicia and Adana basins into three subunits: the uppermost Messinian–Lower Pliocene subunit 1C between the M- and A-reflectors, the Upper Pliocene subunit 1B between the A- and P-reflectors and the Quaternary subunit 1A between the P-reflector and the seafloor. Prominent delta lobes are identified in the seismic profiles that are correlated with the ancestral Göksu River. Isopach maps constructed using depth-converted seismic reflection profiles show clear temporal and spatial variations of the delta lobes of the Göksu River during the latest Messinian–Recent. The uppermost Messinian–Lower Pliocene delta lobe is situated furthest to the northeast whereas the youngest Quaternary lobe is situated furthest to the southwest, with 20–35 km displacement along a northeast–southwest line, which suggests a conservative estimate of 0.43–0.75 cm/yr sinistral slip for the Kozan Fault zone.