The tephra record from the Sea of Marmara for the last ca. 70Â ka and its palaeoceanographic implications

Based on the radiocarbon and tephra-integrated age model the marine transgression at 12.55 ± 0.35 cal ka BP was followed by the deposition of the main lower Holocene sapropel between ca. 12.3 and 5.7 cal ka BP, and in the shallow shelf areas (<~100 m depth) such as the Gemlik Gulf, by the formation of the upper Holocene sapropel between ca. 5.4 and 2.7 cal ka BP.