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

甲玛铜多金属矿是西藏冈底斯中段东部取得找矿突破的超大型矿床。通过短波红外测量,确定了矿体中热液蚀变矿物主要有白云母、绿泥石、黑云母、硬石膏、高岭石、地开石、黄玉和方解石。白云母与铜多金属矿化的关系密切,矿体厚度与贫铝白云母的样本数具有正相关关系,代表钾化带的黑云母分布趋势显示甲玛矿体的热源中心位于ZK2416-ZK3216一线以北的位置,富镁绿泥石分布在贫铝绢云母的外侧,与贫铝绢云母具有相同的热源中心指示意义。分布模型中缺少多硅白云母,显示矿区成矿的热源中心较深,因此作为剥蚀程度比较浅的甲玛斑岩系统而言,外围找矿潜力大。

Hydrothermal Alteration Distribution Model of the Jiama(Gyama) Copper-Polymetallic Deposit Based on Shortwave Technique

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.