Akademik Veri Yönetim Sistemi
MARINE GEOLOGY, cilt.254, ss.1-17, 2008 (SCI-Expanded)
Seismic profiles show that the upper Quaternary-Recent stratigraphic architecture of the NE Aegean Sea is characterized by several vertically stacked depositional sequences which are developed within three NE-SW-trending basins. The depositional sequences are separated from one another by prominent shelf-crossing unconformities, formed during periods of falling and low sea level and reworked further during the subsequent sea-level rise by shoreface erosion. Each depositional sequence consists of a lower mainly parallel-stratified subunit, and an upper oblique to sigmoid-oblique prograded subunit. The lower subunit represents hemipelagic and prodeltaic deposition of the transgressive and early highstand systems tracts. The upper subunit represents deltas of the forced regressive systems tract. The chronology of the depositional sequences is constrained by radiocarbon and U/Th dates on cores. An average sedimentation rate of similar to 30 cm/ka is calculated for basinal muds of the region. Correlations with global sea-level curves based on oxygen-isotope stratigraphy reveal that the seaward-prograded delta sequences developed on a rapidly subsiding shelf during successive glacio-eustatic sea-level falls associated with late Quaternary glaciations. A set of paleogeographical maps shows changing basin configuration since similar to 330 ka. Volumes of the depositional sequences compare well with the volumes of sediment estimated to have been eroded from the incised valleys of the Tuzla, Karamenderes, and Dumbek rivers draining the Biga Peninsula. (C) 2008 Elsevier B.V. All rights reserved.