Late quarternary depositional environments on the outhern Marmara shelf

Late quarternary depositional environments on the southern Marmara shelf

Mustafa Ergin, Nizamettin Kazancı, Baki Varol, Özden Ileri, Levent Karadenizli

Ankara University, Faculty of Sciences, Department of Geological Engineering, Tandoğan, 06100 Ankara, TURKEY

Abstract

In this study, 182 surficial sediment samples have been used to investigate the characteristics of sedimentary depositional environments on the southern Marmara shelf. Grain size analyses revealed the presence of, at least, three distinct depositional zones where sediments contained relatively high sand and gravel components partly derived from the remains of benthic organisms. Zone 1 extends from the Bozburun Peninsula in the east to the west off Imralı Island in the west. Zone 2 extends from the east off Marmara Island to the east off Kapıdağ Peninsula. Zone 3 extends from west of Marmara Island towards southwest. The sediments of these three zones grade into fine-grained mud both in nearshore and offshore directions. The presence of ridge-like and high bottom reliefs, based on bathymetric profiles, further suggest that these zones could be relict features such as former shorelines resulted from the last sea-level changes. Due to lack of data, possible influences of neotectonics remain questionable. Zone 3 seems to be controlled by a complex of mechanisms. Further investigations are underway.

Keywords: Sediment, southern Marmara shelf, carbonat contents, grain size