Mineralization Characteristics and Formation Mechanism of the Intrusions in Xiarihamu Magmatic Ni-Cu Sulfide Deposit, East Kunlun Orogenic Belt, Northwest China

Some mafic-ultramafic intrusions have been found in the East Kunlun Orogenic Belt, but only the Xiarihamu I intrusions produces the giant Ni deposit. The study on ore-bearing characteristics and formation mechanism of the Xiarihamu I intrusion contributes to the exploration of copper-nickel deposits in the east Kunlun area. The research work of many scholars on the Xiarihamu nickel ore deposit has been summarized in this paper. Based on the field investigation, it's found that the iron series mafic-ultramafic intrusions can form the magmatic copper-nickel ore body with economic value, but magnesia series mafic-ultramafic intrusions are unlikely to achieve copper-nickel sulfide ore bodies. Large faults provide favorable conditions for the intrusion of mantle magma. The well-differentiated mafic-ultramafic intrusions have the better potential to form a copper-nickel ore. Crystallization differentiation promotes sulfide saturation, and the crustal sulfur contamination is the key to mineralization. The intrusions with olivine and clinopyroxene have low CaO and FeO content, which is more conducive to copper-nickel ore.