University of Isfahan Petrological Journal 2228-5210 11 1 2020 04 20 The study of mineral chemistry of the Harzburgite in the Noorabad-Harsin ophiolite complex: Evidence from the evolution of partial melting of mantle peridotite from the deep ocean to the subduction zone The study of mineral chemistry of the Harzburgite in the Noorabad-Harsin ophiolite complex: Evidence from the evolution of partial melting of mantle peridotite from the deep ocean to the subduction zone 1 28 23995 10.22108/ijp.2019.116059.1125 FA Samaneh Falah Department of Geology, Faculty of Science, Lorestan University Ahmad Ahamadi Khalaji Department of Geology, Faculty of Science, Lorestan University Ayoub Veisinia Department of Geology, Zanjan University, Zanjan, Iran Zahra Tahmasbi Department of Geology, Faculty of Science, Lorestan University Ahman Rahimzade Department of Geology, Faculty of Earth Science, Shahid Beheshti University Journal Article 2019 03 14 The Noorabad-Harsin ophiolite complex as part of the Kermanshah ophiolite is located in the high Zagros zone. The ophiolitic complex from the lower part to upper part is composed of serpentinized peridotites, layered gabbro, isotropic gabbro, plagiogranite, sheeted dike complex, basaltic lava, andesite and sedimentary rocks, respectively. The structure such as orientation and elongation of crystals in these rocks show that Noorabad-Harsin peridotites have been formed in the upper mantle and then emplaced in the crust. The detailed electron microprobe study olivine composition is forsterite with Fo (91-93). The composition of pyroxenes is diopside and ‌enstatite with low contents of TiO2 and Al2O3. The study of chrome spinels has high Cr # (57-80), Mg # (61-89) and very low TiO2 content which indicate the ophiolitic and depleted mantle origin. The serpentines have Al2O3 content in the range of 0.01 to 10.42 wt. % with SiO2 content between 36.75 to 41.08 wt. percent and are chrysotile and lizardite. Low modal of clinopyroxene, Mg rich olivines and high Cr# content and Cr/Al ratio of chromian spinel from ultramafic cumulates indicate that dunites and harzburgitic rocks have formed by high degrees of partial melting. The chemical compositions of different minerals show different petrogenesis for ultramafic rocks of the Noorabad- Harsin ophiolite complex and show characteristics of the abyssal environment to supra-subduction zone. It seems these peridotites have derived by high degree partial melting of the depleted and sub-oceanic mantle in a supra-subduction zone-Fore arc and have same properties with residual mantle peridotites. The Noorabad-Harsin ophiolite complex as part of the Kermanshah ophiolite is located in the high Zagros zone. The ophiolitic complex from the lower part to upper part is composed of serpentinized peridotites, layered gabbro, isotropic gabbro, plagiogranite, sheeted dike complex, basaltic lava, andesite and sedimentary rocks, respectively. The structure such as orientation and elongation of crystals in these rocks show that Noorabad-Harsin peridotites have been formed in the upper mantle and then emplaced in the crust. The detailed electron microprobe study olivine composition is forsterite with Fo (91-93). The composition of pyroxenes is diopside and ‌enstatite with low contents of TiO2 and Al2O3. The study of chrome spinels has high Cr # (57-80), Mg # (61-89) and very low TiO2 content which indicate the ophiolitic and depleted mantle origin. The serpentines have Al2O3 content in the range of 0.01 to 10.42 wt. % with SiO2 content between 36.75 to 41.08 wt. percent and are chrysotile and lizardite. Low modal of clinopyroxene, Mg rich olivines and high Cr# content and Cr/Al ratio of chromian spinel from ultramafic cumulates indicate that dunites and harzburgitic rocks have formed by high degrees of partial melting. The chemical compositions of different minerals show different petrogenesis for ultramafic rocks of the Noorabad- Harsin ophiolite complex and show characteristics of the abyssal environment to supra-subduction zone. It seems these peridotites have derived by high degree partial melting of the depleted and sub-oceanic mantle in a supra-subduction zone-Fore arc and have same properties with residual mantle peridotites. https://ijp.ui.ac.ir/article_23995_3e471c5843e6471d1781e82005659be6.pdf