University of Isfahan Petrological Journal 2228-5210 9 3 2018 11 22 Mineral chemistry and geothermobarometry of gabbroic dykes ‎of the Garmab Ophiolite sequence ‎‎(Northeast of Kamyaran)‎ Mineral chemistry and geothermobarometry of gabbroic dykes ‎of the Garmab Ophiolite sequence ‎‎(Northeast of Kamyaran)‎ 121 146 22984 10.22108/ijp.2018.108462.1063 FA Shahryar Mahmoudi Assistant professor-geochemistry department- Faculty of earth sciences-kharazmi university Tehran - Iran Ayob Vaisy Nya Msc petrology-Department of petrology - Faculty of geology - zanjan university-Zanjan-Iran Mir Ali Asghar Mokhtari Assistant professor in petrology-Department of petrology - Faculty of geology - zanjan university-Zanjan-Iran 0009-0005-1226-5254 Journal Article 2017 12 12 The Garmab ophiolite complex, a part of the Ophiolite-Radiolithic zone of Kermanshah, is located in the northeast of Kamyaran. In view of the Iranian geo-structural zones, this complex is situated between the Sanandaj-Sirjan Zone and the Zagros thrust Zone. Field studies demonstrate that the dykes with gabbro (pegmatoidic gabbro, microgabbro and gabbronorite) and diabasic composition have crosscut the peridotites of the ophiolite complex. The main minerals of gabbroic rocks include plagioclase (andesine and occasionally anorthite in pegmatoidic gabbros and oligoclase to andesine in microgabbros) and clinopyroxene (diopside-augite). The amphiboles belong to calcic amphiboles group (magnesio-hornblende and actinolite). Mineralogical and geothermometry studies of the clinopyroxene, amphibole and the plagioclase from the pegmatoidic gabbro reveal that these rocks have originated at 800 to 1200 ^OC. Moreover, geobarometric measurements, based on aluminum content within the amphiboles, indicate pressures between 5 to 7 kbar for the final equilibrium of the minerals studied.  The chemical compositions of the clinopyroxene and the amphiboles indicate that the aforementioned minerals have crystallized from a sub-alkaline magma in an island arc or volcanic arc (IAT) tectonomagmatic setting. In addition, the gabbroic dikes formed from a mantle source in a subduction zone. The Garmab ophiolite complex, a part of the Ophiolite-Radiolithic zone of Kermanshah, is located in the northeast of Kamyaran. In view of the Iranian geo-structural zones, this complex is situated between the Sanandaj-Sirjan Zone and the Zagros thrust Zone. Field studies demonstrate that the dykes with gabbro (pegmatoidic gabbro, microgabbro and gabbronorite) and diabasic composition have crosscut the peridotites of the ophiolite complex. The main minerals of gabbroic rocks include plagioclase (andesine and occasionally anorthite in pegmatoidic gabbros and oligoclase to andesine in microgabbros) and clinopyroxene (diopside-augite). The amphiboles belong to calcic amphiboles group (magnesio-hornblende and actinolite). Mineralogical and geothermometry studies of the clinopyroxene, amphibole and the plagioclase from the pegmatoidic gabbro reveal that these rocks have originated at 800 to 1200 ^OC. Moreover, geobarometric measurements, based on aluminum content within the amphiboles, indicate pressures between 5 to 7 kbar for the final equilibrium of the minerals studied.  The chemical compositions of the clinopyroxene and the amphiboles indicate that the aforementioned minerals have crystallized from a sub-alkaline magma in an island arc or volcanic arc (IAT) tectonomagmatic setting. In addition, the gabbroic dikes formed from a mantle source in a subduction zone. https://ijp.ui.ac.ir/article_22984_aecda98c742f74300ada92f33455e403.pdf