The cause of N-S extensional tectonics in western Turkey: Tectonic escape vs back-arc spreading vs orogenic collapse

It is proposed that Late Cenozoic N-S extensional tectonics in western Turkey began in the latest Oligocene-Early Miocene (similar to 24-20 Ma) and has been related to the spreading and thinning of an over-thickened crust (i.e. orogenic collapse) created by an earlier Palaeogene (similar to 65-22 Ma) compressional regime. The occurrence of N-S extension immediately after the cessation of the compressional regime is attributed to hot lithosphere in western Turkey as indicated by pre- and syn-extensional magmatic activity. This early start for N-S extensional tectonics in western Turkey in the latest Oligocene-Early Miocene is inconsistent with the tectonic escape and back-are spreading models. Those models cannot explain this early beginning of extension because their triggering events, that is the collision of Eurasia/Arabia in Middle Miocene (similar to 14 Ma) and inception of the roll-back process in the Aegean in Middle-Late Miocene (similar to 12 Ma), are too young. Copyright (C) 1996 Published by Elsevier Science