Abstract: Evolution of Western Black Sea Region, Turkey

Sami A. Derman

Sedimentary record in western Black Sea region indicates a number of erosional unconformities which bear important data on the geological evolution of the western Black Sea region. The first erosional unconformity is recorded above the Carboniferous sediments. The oldest unit covering this unconformity are continental clastics of Triassic age. They are exposed east of the town of Amasra. Another Triassic exposure occur in Gebze, near Istanbul. The first Mesozoic marine transgression began in Bajocian, continued into Bathonian. The westernmost limit of these sediments are observed south of Kurucasile town. Overlying this marine sequence are continental clastics of probably Callovian age.

The second transgression began in the late Oxfordian. This transgression resulted in extensive carbonate deposition which continued into Berriasian time. Block faulting associated with the opening of the Black Sea created irregular topography controlling the facies development.

The Early Cretaceous transgression began in Barremian time, covering a wider area than the Jurassic time. Local highs were sites of beach sands and shallow water sediments whereas turbiditic sediments were deposited in local low areas. In the middle Cretaceous, island arc volcanism was initiated. The highs controlled distribution and thickness of the volcanoclastic sedimentation. The last transgression began in late Campanian covering all of the present-day Black Sea region. The onshore Black Sea area experienced differential uplift and erosional event, but the offshore western Black Sea subsided continuously.

AAPG Search and Discovery Article #90956©1995 AAPG International Convention and Exposition Meeting, Nice, France