Mineral Chemistry–thermobarometry and Petrography of Metamorphic Sole Rocks of Kömürhan Ophiolite (SE Turkey): Constraints to Evolution and Emplacement

Abstract

This paper presents the generation of metamorphic sole rocks through the detailed geochemical and petrographical analysis of field work carried out on the Kömürhan ophiolite. The metamorphic sole rocks of Kömürhan ophiolite are defined as amphibo-lite (Pl+Mg–Hbl+Ttn±Ap) plagioclase–amphibole schist (Pl+Mg–Hbl+Cpx+Ttn±Zrn±Ap), plagioclase–clinopyroxene–amphibole schist (Pl+Di+Mg–Hbl+Ttn±Ap), and epidote–plagioclase amphibole schist (Ep+Pl+Mg–Hbl+Ttn±Ap±Qtz±Zrn). This research mainly reports comprehensive petrography and mineral chemistry analyses of metamorphic sole rocks of Kömürhan ophiolite of SAOB (Southeast Anatolian Orogenic Belt) together with a goal of presenting geothermobarometric examination and unravelling the mineral sys-tematics. The metamorphic sole rocks have been observed as a thin slice and these rocks are seen at the base of the tectonites, metamorphosed in amphibolites facies throughout the intra–oceanic supra-subduction geodynamic environment. The Kömürhan ophiolite includes from the top to bottom volcanics, sheeted dike complex, isotropic gabbros cumulates, and tectonites and shows a complete oceanic lithospheric fragments. Analyses of mineral chemistry and petrography of metamorphic sole rocks have been used to exhibit the metamorphic processes of these rocks. Mineral chemistry analyses of pyroxene phenocrysts in the metamorphic sole rocks of Kömürhan ophiolite present similarities island arc tholeiite (IAT), proposing that protolith of the sole rocks was related to the supra-subduction geodynamic environment. The amphibolites were occurred by metamorphism of island arc tholeiite–type volcanics that separated from the front of the obducted ophiolite (Kömürhan ophiolite) and after that underplated.