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The late Neoproterozoic poly-metamorphic basement of the Menderes Massif can be divided into two units (Bozdeğ Unit and Birgi Unit) with distinct metamorphic and magmatic histories. Birgi Unit consists of high-grade paragneiss - schist intercalation and (meta) acidic – basic intrusions. Granulite facies metamorphism has been preserved only in a few localities and is characterized by the orthopyroxe relics. Pelitic granulites and hypersthene orthogneisses (charnockites) form the main lithologies. The zircons in charnockites contain featureless overgrowth and rim textures representing metamorphic growth on magmatic cores and inherited grains. The protolith of the charnockites, yielded a crystallization age of ~ 590 Ma. U/Pb SHRIMP and LA-ICP-MS zircon and monazite ages from granulitic rocks gave an age of ca. ~580 Ma, which is interpreted as the time of granulite-facies metamorphism in the basement of the Menderes Massif. These data indicate that the Menderes Massif experienced acidic magmatic activity and granulite-facies metamorphism in Ediacaran. Furthermore, the basement rocks have been overprinted by a Barrovian-type Alpine metamorphism in Eocene (~ 42 Ma). The granulite-facies metamorphism in the Menderes Massif can be attributed to the orogenic event (600-500 Ma; Malagasy orogeny) causing the final amalgamation processes for the northern part of the Gondwana. |
