Olivine chemistry as a petrogenetic indicator for origin and formation conditions of Sargaz-Abshur ultramafic-mafic intrusion, SE Baft, Kerman

The alpine ultramafic-mafic Sargaz-Abshour complex in the SW of Baft, as a part of the ultramafic-mafic/ophiolitic intrusives of the Hajiabad-Esfandagheh region, comprises of tectonite units (foliated harzburgite and porphyroclastic dunite), layered ultramafic-mafics, large isotropic gabbro bodies and scattered microgabroic-diabase dykes. In this complex, olivines are the main mafic residual phase in porphyroclastic dunites and harzburgites, as well as magmatic cumulate phase in chromitites, ultramafic and layered mafics. In most cases, composition of olivine is chrysolite and in chromitite is forsterite. Their compositions are consistent with mantle peridotites, abyssal peridotites, alpine massives and magmatic cumulative series. Due to the refractory nature in porphyroclastic dunites and primitive crystal phases in chromite and layered cumulative dunites, percentage of forsterite content is high, and will reduced with the progress of differentiation in the mafic layered rocks. These changes may indicate the residual nature of olivine and evolution of Mg-rich mantle-derived magma. Different source and origin of magmas  have been compareable with other ultramafic-mafic complexes of Esfandagheh region and alpine ultramafic-mafic intrusions which distinct from ophiolites.