云南镇沅嘎里河铜矿地质特征及矿床成因

Geological features and ore genesis of Galihe Copper Deposit in Zhenyuan County,Yunnan Province

嘎里河铜矿位于"三江特提斯"构造域澜沧江火山弧内,受区域构造的影响,变质作用、岩浆岩活动及构造运动较强烈,成矿条件优越,为嘎里河铜矿的形成提供了丰富的物质来源。矿床主要赋矿层位为三叠系上统小定西组第四段,含矿岩性为安山岩、安山玄武岩及蚀变安山岩,矿体呈层状、似层状及透镜状产出,在空间上受控于地层及NE向、NW向断裂构造,矿化与较强的褐铁矿化、硅化及方解石化等蚀变关系密切。本文对矿床的成矿地质特征及矿化规律进行了总结,结果表明,矿化沿水平方向变化较大,而沿厚度方向上较稳定,验证了矿床同生成矿作用及后期热液改造作用的叠加,属于与火山—岩浆侵入作用有关的中—低温热液型铜矿。

The Galihe Copper Deposit is located in the Lancangjiang volcanic arc of ＂Sanjiang Tethyan＂ tectonic domain. This mining area is characterized by the strong metamorphism, magmatic activity and the strong tectonic movement, where has the superior metallogenic condition. This special geological environment provides rich ore-forming material source to the Galihe Copper Deposit. The main ore-bearing stratum is the upper Triassic Xiaodingxi Formation, and the ore-bearing rock include the andesite, andesitic basalt and altered andesite. The ore bodies occur as stratified, stratiform-like and lenticular, which are controlled by NE-and-NW trend structural frac- ture. There are positive correlations between the mineralization and limonitization, silicification, calcilization. This paper summarize the metallogenic geological characteristics and mineralization law. The results show that the mineralization has obvious variation along the horizontal direction but the stability along the thickness direction. This research indicates that the Galihe Copper Deposit has gone through the early syngenetic ore-forming process and the later hydrothermal-superimposition. Therefore, the genesis of deposit has been determined as a medium-low temperature hydrothermal copper deposit related to volcanic-magmatic intrusion.