Mineralogy, geochemistry of spinels in chromitites and host peridotites in Nehbandan Ophiolitic Complex, eastern Iran

In the Chesmeh-anjir, Bandan and Zolfaqari of Nehbandan ophiolitic complex areas, host peridotites of chromitites are of harzburgite type. These harzbogites are composed of olivine, orthopyroxene, clinopyroxene, and spinel. The spinel from Chesmeh-anjir and Bandan aera peridotites is chrome-spinel and in Zulfaqari aera of Al-chromite type, nd the spinel found in the chromitites of Chesmeh-anjir, Bandan and Zolfaqari are all of Cr-spinel type. Only a few samples of Bandan are of Al-chromite type. The chromitites of these areas are alpine type. According to the geochemical studies and determining the tectonic setting, the spinels in the harzburgites of the Zolfaqari aera show a high degree of depletion and partial melting and are of the SSZ type. Spinels in harzburgites of Bandan area have a low degree of depletion and partial melting and are N-MORB type. In the peridotites of Chesmeh-anjir aera, they show the transition state between the two. The spinels in the chromitites of Bandan aera are also SSZ type and have higher Cr. The spinels in the chromitites of Chesmeh-anjir and Zulfaqari are of N-MORB type, nevertheless, they are very similar to SSZ type. In the chromitites of Chesmeh-anjir and Zolfaqari aeras, the amount of Al is higher than in those from the chromitites of Bandan aera.