Typomorphic Characteristics Of Pyrite And Deep Prognosis Of Kangguer Gold Deposit In Eastern Tianshan Of Xinjiang

Kangguer gold deposit is located in the Kangguer-Tage gold-mineralization belt of Eastern Tianshan mountains, Xinjiang, strictly controlled by the huge Qiugemingtashi-Huangshan ductile shear belt. The outcropped strata are calcalkaline volcanic and pyroclastic rocks of Lower Carboniferous Yamansu Formation. Subvolcanic rocks occur extensively as well. On the basis of the study of pyrite typomophic characteristics and previous researches, genetic mineralogy and mineral prospecting mineralogy were applied in the systematic study of pyrite in the eastern part of L2-2 gold vein of Kangguer gold deposit and deep and peripheral prospecting prediction was undertaken.The deposit is characterized by multiperiodic and multistage mineralization with Au, pb, Zn enriched in the upper part and Cu enriched in the lower part. Alteration zoning is observed with chloritization-silicification-pyritization-magnetite mineralization, beresitization-sericitization, propylitization from the center to sides of orebodies.The pyrite related to mineralization tend to be brassy yellow and dark yellow with weak metallic luster and fine grains of 0.05-0.5mm particle size. Besides,they are likely to be anhedral and occur in pyritohedron, cube and combination mode in general. The occurrence probability of P-type pyrite, ratios of pyritohedron and gold-containing amount of pyrite in different mineralization stages are positively correlated. Their values in the main stages are the highest.The decrepitation temperatures of pyrite manifest the law of rise â†' fall â†' rise â†' fall from the early mineralization stage to the late one. The decrepitation curves of pyrite in the main mineralizations exhibit several decrepitation peaks. The initial decrepitation temperature is less than 200℃, and the decrepitation temperatures have a wide range. The pyrite with a high cell parameter has a relatively better quality to contain gold.The w(As) of pyrite averages 1757×10-6, between the metamorphic hydrothermal gold deposit type(846.9×10-6) and the magmatic hydrothermal gold deposit type(4016.9×10-6). In addition, The Co/Ni ratios of pyrite range from 0.5 to 5.7, averaging 2.7, indicating the superimposed mineralization characteristics of magmatic and metamorphic hydrotherm. The rare earth elements characteristics show negative Eu anomaly at first and then positive Eu anomaly, indicating the variation from the early redcing environment to late oxidation environment. The CO2 content of ore-forming fluid decreaces from the early stage to the later stage, implying that strong crust-mantle interaction between ore-forming fluid and country rocks which results in the interfusion of crustal materials into the primitive mantle-derived mineralization system.The deep ore prospecting prediction shows that there are preferential exploration prospects in both the No. 22 exploration line and No. 14 exploration line under the 400 m level. Besides, there are more favorable exploration prospects in the west of No.22 exploration line than those in its east.