Seismic stratigraphy and depositional history of the Buyukcekmece Bay since Latest Pleistocene, Marmara Sea, Turkey

Abstract

High-resolution seismic data shed light on latest Pleistocene and Holocene sedimentation beneath the Buyukcekmece Bay, northern shelf area of the Marmara Sea, Turkey. Discontinuous fluvio-marine and marine deposits overlying the erosional truncation surface of Oligocene-Lower Miocene deposits are as thick as 30 m and preserved preferentially within the incised valleys that were controlled by some old faults. A series of prograding shoreline, laterally passing to the latest Pleistocene-Holocene valley-fill deposits, are thought to have accumulated mainly during times of shoreline transgression and sea-level rise. The overall morphology and stratigraphic setting observed in the Buyukcekmece Bay and at the southern outlet of the Bosphorus Strait have nearly same characteristics, implying that similar hydrodynamic conditions, erosional and depositional processes were mainly under the control of strong northerly flows during the Late Quaternary. These flows were less powerful in the Buyukcekmece region with decreased sediment input and smaller accommodation space.