The southern Menderes Massif (western Turkey): geochronology and exhumation history

In the southern flank of the Menderes Massif, western Turkey, an E-W-trendi ng quartz-mica vein was recognized in the augen gneisses of the so-called ' core' series. Rb-Sr determinations of two undeformed or slightly deformed m ica books from the vein yielded Palaeocene-Early Eocene ages (c. 62-43 Ma) for the vein formation. The new data are interpreted to closely post-date t he time of major Barrovian-type High Temperature/Medium pressure (HT/MP) ma in Menderes metamorphism (MMM) and coeval crustal-scale top-to-the-N-NNE Te rtiary deformation that affected the whole Massif. Subsequent cooling occur red in the Middle Eocene (36 +/- 2 Ma Ar-Ar mica ages). Top-to-the-N-NNE structures were later overprinted by top-to-the S-SSW fabr ics within normal-sense ductile shear zone, located between the core augen gneisses in the footwall and the structurally overlying cover schists in th e hanging wall. The Massif was at the surface by the Early Miocene. Field r elations clearly demonstrate that the age of top-to-the-S-SSW deformation i s well constrained between the age of the MMM and the Early Miocene, and th at exhumation was mainly tectonically controlled. Copyright (C) 2000 John W iley & Sons, Ltd.