西藏多不杂矿集区斑岩铜矿地球化学指标研究

多不杂矿集区位于西藏改则县北部,是近些年发现的超大型斑岩型铜矿床,在以多不杂为中心,东西长约30km,南北宽约10km的范围内,包括多不杂、波龙、色那、拿顿、拿若、尕尔勤和铁格龙7个矿区。本文在前人工作的基础上,通过对矿集区钻孔岩芯样品地球化学数据进行旋转正交因子处理和成矿元素Cu与稀土元素La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y、微量元素U、Th的相关性分析,发现轻重稀土元素均在Cu矿(化)体部位相对富集。另外微量元素U、Th(尤其是Th),与金属元素Cu含量随深度的变化也存在一定的对应关系,在Cu矿化部位相对富集。研究表明稀土元素La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y与微量元素U、Th可能是一种潜在有效的矿产勘查地球化学指标。

Geochemical Indicators of Porphyry Copper Deposits in the Dobzha Ore Concentration Area, Tibet

The Dobzha ore-concentration area in northern Geize County of Tibet is composed of superlarge porphyry copper deposits discovered in recent years. In an area 30 km long in EW direction and 10 km wide in NS direction with Dobzha as the center, there are seven copper deposits, i.e., Dobzha, Bolong, Sena, Nadun, Naruo, Gaerqin and Tiegelong. On the basis of previous work and through the rotating orthogonal factor analysis of geochemical data of the core rock samples and the correlation analysis between the metallogenic elements such as Cu and rare earth elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y and trace elements U and Th, the authors have found that LREE and HREE show relative enrichment in the position of Cu ore (mineralization) body, so do trace elements U and Th , especially Th, which show some positive correlation with Cu with the increasing drilling depth. It can be inferred that the rare earth elements and trace elements U and Th might serve as potentially effective geochemical indicators in mineral exploration.