Resumen de Fission-track and (U-Th)/He studies in the Aegean islands: constraining the timing of major detachments, their slip rates and their role in the exhumation of the Cycladic blueschists

S. Brichau, Uwe Ring, A. Carter, Miguel Bruno Mejías

• The main goal o f this work is to constrain the cooling history o f major extensional detachments in the Cyclades. This will allow to constrain the timing o f the detachments, the number o f detachments which operated in this area, their slip rates and hopefully the amount o f displacement. Their contribution to the exhumation ofthe blueschist will be studied and we will discuss the role o f detachment faulting above retreating subduction zones. By constraining the timing o f the detachments, in conjunction with a petrographic analysis of metamorphic detritus in conglomerates and the timing o f arc-related magmatism (from the literature), we will be able to constrain in detail how much o f the exhumation ofthe Cycladic blueschist unit occurred in a forearc position and how much is due to back-arc extension. It is commonly believed that most or all o f the extension in the Cyclades is due to back-arc extension. We hope with the fission track and U-Th/He data o f Stephanie Brichau s Ph.D. study in the Cyclades and the eastern Aegean to close the gap between western Turkey and Crete and to get a detailed map o f the cooling between the Aegean, Turkey and Crete.