Mineralogy and petrogenesis of chromian - spinel in Rudan ultramafic body, Hormozgan Province

The studied area is located in the north of Rudan city and is a part of Kahnuj - Rudan - Minab ophiolite belt. The studied rock are harzburgite and lherzolite and are composed of olivine, orthopyroxene, clinopyroxene and chrome – spinel (as a minor). According to microprobe data, the amount of MgO in the olivines ranges between %50.17 to %50.55, so these olivines are forsterite. Clinopyroxenes are diopside and spinels contain chrome. Detail microprobe studies on the chrome - spinel of ultramafic lherzolites prove that they are high in Mg#(%71-%77) and Al2O3 (52.98 to 46.31 Wt%) ) and low in Cr# (%0.14 - %0.22). (Cr/Al) ratio in the spinel of lherzolites is 0.19. The amount of Fe3 in the chrome - spinel of ultramafic Peridotites is very low (