Metamorphism of Palaeozoic Schists in the Southern Menderes Massif: Field, Petrographic, Textural and Microstructural Evidence

The Menderes Massif is a large-scale metamophic core-complex in western Anatolia and forms the western of two large metamorphic culminations in the Turkish Alpide orogen. Within the Southern Menderes Massif on the southern side of the Beßparmak Mountain north of Selimiye (Milas-MuÛla), two distinct lithologic groups are recognized on the basis of their lithology and structural position: the late Oligocene granitoid rocks now in the form of mylonitic augen gneiss and the structurally overlying sequence of Palaeozoic metasediments where the former display intrusive boundary relationships with the latter. In this part of the massif, three metamorphic phases (M1, M2, M4) have been, distinguished in the metasediments on the basis of field, fabric, textural and petrographic data. The earliest episode (M1) is a regional Barrovian-type metamorphism that reached upper amphibolite facies at structurally lower levels of the metasediments and gradually decreases southwards to greenschist facies at upper levels (main Menderes metamorphism). High temperatures during the climax of M1 facilitated crustal anatexis at depth, and produced a granitic melt which was emplaced concordantly into the metasediments. The intrusion has resulted in the M2 contact metamorphism. A last retrograde metamorphism (M4) was the manifestation of the uplift, unroofing and consequent cooling of the metasediments.