The studied area is located in the high Zagros zone and it is considered a part of the Neyriz ophiolite. In this area, the ophiolitic complex is small coloured melanges include radiolarite cherts and serpentinized ultrabasic rocks. The main lithological unit is serpen
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The studied area is located in the high Zagros zone and it is considered a part of the Neyriz ophiolite. In this area, the ophiolitic complex is small coloured melanges include radiolarite cherts and serpentinized ultrabasic rocks. The main lithological unit is serpentinized ultrabasic rocks, which have a variety of colors from dark to light brown and dark to light green. These ultrabasic rocks have composed of olivine, pyroxene, amphibole, opaque, serpentine and spinel. Olivines have been highly altered to serpentine and pyroxenes to bastite. Based on whole rock chemistry, the studied rocks are basic and ultrabasic cumulates type (lherzolite-harzburgite) with a composition close to the average composition of the mid-ocean ridge basalt (MAR). Based on mineral chemistry, pyroxenes are calcic type and in the range of diopside and augite, and amphiboles are calcic and actinolite type. Pyroxenes have crystallized under conditions of low oxygen fugacity, temperature higher than 910 °C (1100 - 1200 °C) and pressure more than 2 kbar (2 to 10 kbar). Amphiboles have crystallized at a temperature below 700 °C and a pressure less than 1 kbar. Based on the geochemical characteristics and mineral chemistry, the ultrabasic rocks in the Koopan area were formed in a subduction zone.
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