综合构造岩相学勘查技术在玻利维亚古布利达铜矿床找矿中的应用

Application of Comprehensive Tectonic Lithofacies Exploration Method in Cuprita Copper Deposit, Bolivia

古布利达铜矿床位于安第斯成矿带中段斑岩型铜金矿床和浅成低温热液型金铜-铅锌矿床集中分布区。由于地形切割大,海拔高以及自然环境恶劣,给找矿勘查增加了难度。以构造岩相学分析研究为思路,将遥感解译-构造岩相学路线观测、沟系次生晕测量、地质填图、构造岩相学解析研究等方法综合应用于古布利达铜矿床找矿。结果表明:(1)综合构造岩相学勘查技术在玻利维亚高原特殊景观区进行找矿勘查具有准确和快速高效特点;(2)通过遥感解译-构造岩相学路线观测,圈定了火山穹隆构造、断裂构造,初步建立了填图单元和对应的遥感异常色斑标志;(3)通过大比例尺地质填图,确定了含矿地层、含矿岩相和储矿构造样式,圈定了矿化蚀变带,揭示了矿化蚀变带走向和倾向,为探槽和钻孔验证提供了设计依据;(4)通过探槽揭露了浅部矿体,评价了化探异常,进一步确定了矿体产状,经钻探验证,控制到厚大铜矿体;(5)在对探槽和钻孔岩芯构造岩相学编录基础上,进行了构造岩相学解析研究,预测深部具有寻找斑岩型铜矿床的潜力。综合构造岩相学勘查技术为玻利维亚高原地区快速、高效勘查技术方法选择提供了支撑,也为境外同类型铜矿床勘查提供了借鉴。

Cuprita copper deposit is located at the middle of Andean metallogenic belt, where distribute many porphyry copper-gold deposits and epithermal gold-copper-lead-zinc deposits. Due to largely cut topography, high altitude and harsh natural environment, it is more difficult for prospecting and exploration. Based on tectonic lithofacies research and analysis, the remote sensing-tectonic lithofacies interpretation route observation, valley system secondary halo soil survey, geology mapping and tectonic lithofacies analysis were used for prospecting predictions in Cuprita copper deposit. The results are as follows.(1) Comprehensive tectonic lithofacies analysis is a fast and efficient exploration methods for minerals exploration in Bolivian plateau special scenic area.(2) Through remote sensing-tectonic lithofacies interpretation route observation, the volcanic dome faults and mineralized alteration are delineated, the mapping units and corresponding remote sensing abnormal color spot sign are established.(3) By geological mapping on a large scale ore-bearing strata, the ore-bearing lithofacies and ore-storing structural styles are determined, occurrence of mineralized alteration zone is showed in the anomaly area, the trend and tendency of mineralized alteration zone are revealed, which provides a design basis for probing trough and borehole verification.(4) Shallow ore bodies are exposed, geochemical anomalies are evaluated by probing trough, and the occurrence of ore body is further determined. Through borehole verification, it is controlled to thick and large copper ore bodies.(5) On the basis of tectonic lithofacies cataloging of probing trough and borehole cores, the analytical study of structural petrography is carried out, and it is predicted that there is a potential to search for porphyry copper deposits in the deep. Comprehensive tectonic lithofacies exploration method is fast and efficient in Bolivia plateau, meanwhile provides a reference example for exploration of the same type copper deposit abroad.