Quaternary sedimentary history of Adana, Cilicia and Iskenderun basins: northeast Mediterranean Sea

Abstract

Detailed single-channel airgun and 3.5 kHz profiles from the northeastern Mediterranean Sea show that the continental shelf is formed by superimposed deltaic successions (depositional sequences), separated by major erosional unconformities. Each depositional sequence is composed of a sigmoid prograding package overlain by an oblique prograding package, representing respectively delta progradation during high and low sea levels of interglacial and subsequent glacial stages. During the glacio-eustatic lowstands of sea level, deltas prograded seaward. The present-day shelf break denotes the topset to forest transition at maximum progradation during the last glacial period. During post-glacial transgressions, the deltas initially lost their dynamic equilibrium with the environment and rapidly retreated landward, leading to the deposition of a thin veneer of sediments originating from reworking of formerly coastal sediments. At the highstand position the deltas were re-established in the ancestral Adana Bay and foreset progradation started. Chronology suggests that the Cilicia and Iskenderum Basins are subsiding at rates of 0.38 m 1000 yr −1 and 0.33 m 1000 yr −1, respectively. Seismic reflection profiling shows that delta architecture in the Adana, Cilicia and Iskenderun Basins is mainly controlled by glacio-eustatic sea-level fluctuations and continuous basin subsidence.