Petrography and Geochemistry of Paragneisses in the Çine Submassif of the Menderes Massif, Western Anatolia

Authors : Firat Şengün, Osman Candan, O. Özcan Dora & O. Ersin Koralay

Pages : 321-342

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Publication Date : 9999-12-31

Article Type : Makaleler

Abstract :The Menderes Massif, which covers a large area in western Turkey, is made up of Pan-African basement rocks and a Palaeozoic to Early Tertiary cover sequence. The study area is located in the Dalama and Hallaçlar (Aydın) area, in the northern and central parts of the Çine submassif of the Menderes Massif. The oldest units of the Pan-African basement are metaclastics, consisting of paragneisses and mica schists that gradually and conformably overlay paragneisses. Macroscopic appearances and mineralogical and textural data indicate that paragneisses can be subdivided into four subgroups. These are: (1) black spotted, (2) white spotted, (3) massive, grey-coloured and (4) massive, purple-coloured paragneisses. Geochemical data show that the spotted and purple-coloured paragneisses are characterized by high alumina content that is consistent with high sillimanite content. Paragneisses exposed in the eastern part of the Çine submassif were partly migmatized during the last stage of the polyphase Pan-African metamorphism. Based on comparison with relics of upper amphibolite to granulite (?) facies parageneses in the Pan-African basement of the Menderes Massif, we infer that the porphyroblasts in the black-spotted paragneisses are pseudomorphs after cordierite. Considering the inferred replacement of cordierite by sillimanite + garnet + biotite, it can be concluded that former high-temperature assemblages were overprinted by almandine-amphibolite facies metamorphism. Geochemical data obtained from paragneisses and mica schists reveal that the protoliths of this metaclastic sequence were derived from a cratonic provenance. The paragneisses are intruded by 550 Ma syn- to post-orogenic orthogneisses. Based on the well-preserved the original intrusive contact relationship with the orthogneisses and the youngest detrital zircon ages in paragneisses, it can be inferred that the time of deposition of their protolith is Late Proterozoic.
Keywords : paragneiss, geochemistry, metamorphism, Menderes Massif, western Anatolia