The study of multiple generations of olivine in metaperidotites of ShasatPich region using EMPA and Raman spectroscopy

Shesat Pich region hosts an ophiolitic complex located in the south of Kerman, southeast of Iran. This ophiolitic complex is composed of lherzolite, harzburgite and dunite. Olivine is one of the important minerals found in these rocks, which is observed along with pyroxene (orthopyroxene and clinopyroxene) and spinel in the rocks of the region. The combined range of olivines in the region is in the forsterite range of 84 to 92% and ranges from forsterite to chrysolite. NiO with an average amount of about 0.38% by weight and MnO with an average of 0.14% by weight in olivines show the range related to abyssal peridotites. In addition to serpentinization as a general change in the ultramifics of the region, petrographic studies show evidence of metamorphism in the olivines of some harzburgites along with recrystallized antigorite crystals, which indicate a phase of thermal metamorphism in this harzburgite. These results have been confirmed in mineral chemistry studies too. Metamorphic olivines have an abnormality compared to magmatic olivines with a decrease in calcium. In chemical mineralogical studies, the amounts of forsterite and olivines show a regular increase from lherzolite to harzburgite and dunite. Raman spectroscopy studies on the studied olivines show the relationship between the peak shift of 854 waves/cm and forsterite values of olivine minerals in the region.