Hydrothermal Alteration Distribution Model of the Jiama(Gyama) Copper-Polymetallic Deposit Based on Shortwave Technique
基于短波红外勘查技术的西藏甲玛铜多金属矿热液蚀变矿物分布模型研究

The Jiama(Gyama) copper-polymetallic ore deposit is a superlarge ore deposit in the eastern part of central Gangdise. The hydrothermal alteration minerals of the ore body mainly include muscovite, chlorite, biotite, anhydrite, kaolinite, dickite, topaz and calcite, as identified by short wave infrared measurement. The muscovite has close relations with copper polymetallic mineralization, and the thickness of the ore body has the positive correlation with the sample number of aluminum-poor muscovite. The distribution trend of biotite represents potassic alteration, which suggests that the heat center of Jiama(Gyama) ore body lies in the north of exploration line ZK2416-ZK3216. Magnesium-rich chlorite is distributed outside of the aluminum- poor muscovite. In addition, magnesium- rich chlorite and aluminum-poor chlorite have the same significance of heat center. The distribution model, short of phengite, shows that the heat center is quite deep in the mining area. Therefore, the Jiama(Gyama) porphyry system with low denudation extent must have high ore potential in its periphery.