Late Holocene sea-level changes on the western Anatolian coast

Abstract

Late Holocene sea level changes in two widely separated parts (Datça and Çanakkale) of the western coast of Anatolia have been studied. Geomorphic features were mapped and subsurface depositional environments were interpreted from the evidence obtained from bore-holes in Holocene coastal sedimentary deposits. In addition, geomorphological reconstructions of the former shorelines and related sea-level changes are established on the basis of archaeological data. There are important parallels between the sea-level changes observed in these two distant coastal areas and in other coastal parts of Western Anatolia. The sea-level curve for the Dalacak area shows that sea level rose rapidly to the present position or a little (about 50 cm) higher and rias or estuaries formed at the principal river mouths and coastal embayments about 6000-5000 yr ago. However, some geomorphological and archaeological evidence show that sea level descended about two meters during the 4th millennium B.P. after the first rising stage. Archaeological evidence related to the Dorians who settled on Dalacak and built their city Old Knidos, imply that the sea level was rising but still it was a little lower than the present when the first harbours of the city were being built. Since 3000 B.P. sea level has risen to the present position generally. A precise sea level curve has not been drawn for the Beşige area separately yet because of some dating problems. However, there is quite a parallel between Dalacak and Beşige on the Late Holocene sea level changes. This implies that the sea level has risen along the western coast of Anatolia in the similar order generally, in spite of recent tectonic formation and the block faulted structure of the region. However, more detailed local studies are necessary to confirm this conclusion.