Delta formation at the southern entrance of Istanbul Strait (Marmara sea, Turkey): a new interpretation based on high-resolution seismic stratigraphy

Abstract

A detailed stratigraphic investigation based on high-resolution seismic profiles revealed that the delta at the southern entrance of the Istanbul Strait consists of three parasequence sets. The lowermost parasequence shows a sea-level stillstand at the beginning of the lowstand systems tract, possibly at 11,000 +/- 1,100 a b.p., whereas the upper two parasequences reflect deposition at lowstand and during the subsequent transgression. A maximum flooding surface may be developing on the delta at present. The delta is located on the eastern side of the Istanbul Strait canyon, with east-west prograding parasequences. The development of the delta is clearly associated with the Kurbagali Stream on the east coast, and not with the Black Sea outflow through the strait. The geometry of the delta indicates a radial architecture arranged from northeast to southwest.