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 a nd Cappadocia, tephra have been identified, characterized and linked to eru ptions of the nearby volcanoes. Seven different tephra have been clearly id entified in lacustrine sequences of the Konya Plain. C-14 dates on shells o r organic matter, as well as Th-230/U-234 ages on gypsum, give a chronologi cal framework to the tephra layers. In addition, the study of the sediment fill of the Eski Acigol maar near Nevsehir has allowed the recognition of s everal eruptions during Late Glacial and Holocene in the vicinity of Acigol . The results show the first tephra to be identified in lacustrine sequence s of Anatolia; they also show the Cappadocian volcanism to be very young (l ess than or equal to 35 ka). This young volcanism is often of a basaltic ty pe and does not include thick differenciated pyroclastic deposits. (C) 1998 Elsevier Science B.V. All rights reserved.