نویسنده
دانشیار گروه زمین شناسی، دانشکده علوم پایه، دانشگاه ارومیه، ارومیه، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسنده [English]
In this manuscript, we focused on the Silvana ophiolite-related gabbro, south of Urmia. The essential aim is studying constituent minerals classification and understanding formation conditions of this rock type based on the mineral chemistry. The mentioned gabbro was intruded in the serpentinized ultramafic unit in the area and outcropped along the Asbi Bunar fault as colored mélange accompanied by other ophiolitic members. Abundant rock types are gabbro and hornblende gabbro with clinopyroxene, amphibole, plagioclase, and ore minerals as major minerals. Additionally, some biotite, calcite and apatite as minor or accessory phases exist. Clinopyroxenes composition in these rocks is diopsidic, amphiboles are parasitic-kaersutite, plagioclases are anorthite-rich, opaque minerals are ilmenite and biotites are phlogopitic, based on the EPMA analyses. Mineral chemistry of both amphibole and clinopyroxene in the studied gabbro, shows a supra subduction zone/fore-arc setting for them. Also, the oxygen/water fugacity of the parent magma was high. The crystallization temperature of 800-1000 ⁰C at the 5-8 kbar pressure using amphibole composition and 1150 ⁰C at low pressure by clinopyroxene are evaluated.
کلیدواژهها [English]
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