基岩区寻找隐伏矿的地球化学方法:构造地球化学测量  

A geochemical method for finding concealed ore deposits in bedrock outcrop area:Application of tectono-geochemical survey

作　　者：程志中[1] 袁慧香 彭琳琳[2] 卢国安 贾祥祥 邴明明 林成贵 CHENG Zhizhong;YUAN Huixiang;PENG Linlin;LU Guo an;JIA Xiangxiang;BING Mingming;LIN Chenggui(Development and Research Center of China Geological Survey,Beijing 100037,China;South Jiangxi Geological Survey Team,JBGMED,Ganzhou 341000,China;No.1 Institute of Geology and Mineral Exploration,GBGMED,Tianshui 741020,China)

机构地区：[1]中国地质调查局发展研究中心,北京100037 [2]江西省地质矿产勘查开发局,赣南地质调查大队,江西赣州341000 [3]甘肃省地质矿产勘查开发局第一地质矿产勘查院,甘肃天水741020

出　　处：《地学前缘》2021年第3期328-337,共10页Earth Science Frontiers

基　　金：国家重点研发计划项目(2017YFC0601506);中国地质调查项目(DD2016052,DD20190570,DD20160050,DD20190159,DD20190166)。

摘　　要：构造地球化学测量是在基岩出露区发现深部矿化信息的一种较为有效的方法。本文介绍了构造地球化学的一些基本概念和构造地球化学测量方法的发展历程。为解决岩石样(构造岩样)的代表性和均匀性,提出了方格采样法,即在每个采样网格内多点采样组合分析采样方法,采集以构造破碎带物质、裂隙充填物、蚀变岩石、矿化岩石等为主的能反映深部矿化信息的样品。利用该方法在甘肃西和地区进行了1∶50000构造地球化学测量试验,采用500 m×500 m的采样网格,在每个采样单元中采集6~8个子样组合,分析了其中的Au、Ag、Pb、Zn等19种元素,圈定了较好的金地球化学异常,经查证发现了金矿体。在江西岩背锡矿外围开展1∶10000的构造地球化学测量试验,采用100 m×100 m的网格,采集构造裂隙样品,圈定了Sn等元素的地球化学异常,对圈定的Sn地球化学异常进行钻探验证,发现深部隐伏Sn矿体。不同比例尺的构造地球化学测量试验表明,构造地球化学测量在基岩出露区能有效发现深部矿化信息,在寻找隐伏矿工作中具有较好的应用前景,在中国黔西南地区寻找卡林型金矿和东南沿海地区火山岩覆盖区找矿中能发挥一定的作用。Tectono-geochemical survey is effective for collecting information on deep mineralization in bedrock outcrop area.In this article,the basic concepts and the development of tectono-geochemistry are systematically introduced.We propose a multi-point sampling method particularly useful for collecting rock(tectonic rock)samples associated with deep mineralization to ensure proper sample representation and data uniformity.Specifically,within each sampling unit of a survey grid,multiple“sub-samples”are collected mainly from fracture zones,fissures,altered rocks and mineralized rocks,and combined into one sample.For example,in a 1∶50000 tectono-geochemical survey carried out in the Xihe area of Gansu Province,6-8“sub-samples”were collected in each 500 m×500 m sampling unit and altogether 2967 samples were obtained from the survey grid.In the final analysis,19 elements were analyzed,including Au,Ag,Pb and Zn,and the location of Au geochemical anomaly was more accurately determined.The Au orebodies were subsequently discovered through exploration.In another 1∶10000 survey in the periphery of the Jiangxi Yanbei tin(Sn)deposit,we collected 4620 sub-samples from fracture and fissure,using 100 m×100 m grid sampling unit,which resulted in 934 samples for the final analysis to delineate the geochemical anomalies of Sn and other elements.The delineated Sn geological anomaly was verified by drilling and the deep conceal tin orebodies were found.The above results show that the tectono-geochemical survey of different scales can have fruitful application in the discovery of concealed deposits in the bedrock outcrop area,such as in finding Carlin type gold deposits in Southeast Yunnan and volcanic rock covered deposits in the southeast coastal region.

关 键 词：基岩覆盖 隐伏矿 构造地球化学 裂隙采样 

分 类 号：P612[天文地球—矿床学] P632.2[天文地球—地质学]