Identification and dating of tephra layers from Quaternary sedimentary sequences of Inner Anatolia, Turkey

Results presented here are part of a research programme to investigate the environmental evolution in central Anatolia during the Pleistocene. In this study, tephra are used as chronostratigraphical markers between lacustrine sequences studied in cores or in sections surrounding eruptive centres of the Central Anatolian Province. At different locations in the Konya Plain and Cappadocia, tephra have been identified, characterized and linked to eruptions of the nearby volcanoes. Seven different tephra have been clearly identified in lacustrine sequences of the Konya Plain. 14C dates on shells or organic matter, as well as 230Th/234U ages on gypsum, give a chronological framework to the tephra layers. In addition, the study of the sediment fill of the Eski Acigöl maar near Nevsehir has allowed the recognition of several eruptions during Late Glacial and Holocene in the vicinity of Acigöl. The results show the first tephra to be identified in lacustrine sequences of Anatolia; they also show the Cappadocian volcanism to be very young (≤35 ka). This young volcanism is often of a basaltic type and does not include thick differenciated pyroclastic deposits.