广西大黎地区地球化学特征及找矿远景预测

Regional geochemistry and prospecting prediction of Dali area, Guangxi, China

广西大黎地区位于钦杭成矿带西南端大瑶山金多金属成矿带上。1∶5万水系沉积物测量成果表明该区Au、Ag、As、Hg、Sb、Pb、Cu、Sn、Mo、Bi等元素含量明显高于全国水系沉积物元素含量水平,Au、Ag、As、Pb、Cu、Sn、Bi、Mo等元素高于广西区背景含量;异常元素主要沿凭祥-大黎深大断裂和苍梧-大黎隐伏基底断裂呈近E-W和NW向带状展布,主要异常区均分布在凭祥-大黎深大断裂与近S-N向断裂交汇处。大黎矿区具铜、钼、银、金、铅、锌等多种矿化类型,由岩体往外,次生晕异常在平面上具Mo-Cu-Au、Ag、Pb、Zn、As分带特征。通过对化探异常进行综合评价,结合成矿地质条件及矿化富集规律,提出了六岑、大黎和陈塘～桃花3个Ⅰ级找矿远景区,马练和六练顶2个Ⅱ级找矿远景区及同和1个Ⅲ级找矿远景区,作为下一步矿产勘查工作的靶区。

Dali area, Guangxi province is located in the southwestern tip of Dayaoshan gold polymetallic metallogenic area in Qinzhou-Hangzhou metallogenic belt. 1：50000 stream sediment survey results show that the Au, Ag, As, Hg, Sb, Pb, Cu, Sn, Mo, Bi and other elements were significantly higher than the national level elements in stream sediments of this area; and the Au, Ag, As, Pb, Cu, Sn, Bi, Mo and other elements are above background levels in Guangxi Zhuang Autonomous Region; abnormal elements are mainly zonal distributed along Pingxiang - Dali deep faults and Cangwu - Dali buried basement fault E-W- and NW-trending, major anomalies are localed in convergence zone among Pingxiang-Dali deep fault with nearly north-south trending faults. Dali deposit with copper, molybdenum, silver, gold, lead, zinc and other types of mineralization has got zonation characteristics of secondary halo anomalies of Mo-Cu-Au, Ag, Pb, Zn, As from intrusion to outwards. Through a comprehensive e- valuation of geochemical anomaly, combined with geological conditions and mineralization regularity analysis, prospecting areas of Dali area are subdivided： grade Ⅰ prospecting area of Liueen, Dali and Chentang-Taohua; grade Ⅱ prospecting area of Malian and Liulianding; grade Ⅲ prospecting area of Tonghe.