Authors: ALİ RIZA ÇOLAKOĞLU
Abstract: The Sarıçimen Fe-Ni laterite ore is located 15 km east of Çaldıran County, northeast of Lake Van. This area is situated in the eastern Anatolia accretionary complex of Turkey, close to the Iran boundary. It is the first transported Fe-Ni rich laterite to be described from this area. This paper concentrates on the mineralogical and textural features of the ore minerals and the transported Fe-Ni laterite zone. These transported laterites are very inhomogeneous and contain very abundant zoned chromite grains, which have been altered to magnetite. SEM/probe investigations indicate that Fe-Ni is depleted in the core chromite and increases in the magnetite rim. A sedimentary transported laterite zone exhibits a high proportion of silcretes and ferruginous materials and chemically contains 29-61wt% SiO_2 and 11.8-48.7 wt% Fe_2O_3. The average contents of Al_2O_3, TiO_2, MnO and P are 4.81, 0.37, 0.32, and 0.03 (all in wt%) respectively. The highest Ni value obtained from the transported lateritic ferruginous zone is 1.16 wt%. The Pt and Pd concentrations are low, ranging from 39 ppb to 6 ppb and 21 ppb to 5 ppb, respectively. The Au value reaches up to 3 ppb. The diversity in chemical compositions of transported laterites is related to fracturing, erosion, corrosion, transportation, quantity of clastic material with different alteration history and diagenesis.
Keywords: Van, ophiolite, Fe-Ni laterite, eastern Anatolia, Turkey
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