A new insight on economic evaluation of nain ophiolite, central Iran

Nain ophiolite mélange is a partial of Nain-Dehshir-Baft ophiolite belt and located in Norh of Nain. The rocks units of Nain ophiolite mélange is contains peridotite, serpentinite, listvenite, gabbro, diabase dikes, pillow lava and sedimentary rocks. Therewith geodynamic emphasis of ophiolites, existence of chromite deposits, volcanic massif sulfide deposits of base elements, platinum group elements, gold and huntite are characteristics that gives economic valence to Iran ophiolites. The Nain ophiolite chromites are rich of chromium and values less than 0.25 percent of TiO2 in them representative ophiolite genesis. According to studies the chromium has high positive correlation to platinum group elements (Iridium, Palladium and Platinum). The comparative concentration of platinum group elements in chromites of study area can be Justifies economic evaluation of them. Upper cretaceous manganese deposits such as Benvid manganese deposit occurred in volcano sedimentary formations of colored mélange zones of Iran ophiolite belt. The Benvid manganese deposit is one of the high tonnage reserves in Nain district. The listvenites to form brown rocks and vein and grid structure with prominent morphology have observed in several faults zones of Nain ophiolite. These rocks have economic importance from elements such as gold and frequency of elements such as arsenic, mercury, sulfur and …, emphasis the necessity of environmental impacts of them. In the Nain ophiolite complex, central Iran, off white cotton-ball assemblages are disseminated within an earthy serpentinite groundmass. The nodular Mg-rich carbonates occur in tectonically disturbed, strongly weathered zones of the ultrabasics. XRD, SEM and DTA/TG analysis revealed that the Mg-rich carbonate mineralogy is varying in each location, as ten distinct modes of paragenesis have found, namely: hydromagnesite- pyraurite [the most common], hydromagnesitemanasseite, hydromagnesite- pyraurite- manasseite, hydromagnesite- pyraurite- brugnatellite, hydromagnesitehydrotalcite, hydromagnesitepyraurite- aragonite, hydromagnesite- huntite, huntite, magnesite, magnesite-calcitedolomite. It is crucial to note that huntite occur far from the hydromagnesite-rich cotton ball assemblages and magnesitecalcite dolomite or single magnesite have found on soils, above the serpentinized ultrabasics. To attention great extension of ultramafic rocks in Nain ophiolite, there was occurrence of Nickel laterite deposit in this zone possibility.