贵州三都——丹寨地区铀矿床地质特征及控矿因素

Geological Characteristics and Ore-controlling Factors of the Uranium Deposit in Sandu-Danzhai Area in Guizhou Province

贵州三都—丹寨地区位于黔中—湘西北成矿远景带的丹寨—三都—独山碳硅泥岩型、煤岩型铀成矿远景带上,大地构造位置地处扬子准地台黔南台陷与华南褶皱带西缘的结合部位,著名的三(都)—丹(寨)汞金锑铅锌多金属成矿带也位于其中,具有较好的铀矿找矿潜力。通过对区域成矿地质背景和典型铀矿床地质特征的分析,结果表明:(1)区内铀成矿受地层、岩性、构造、岩相古地理等多重因素控制;(2)U异常浓集中心及高异常带、伽马高异常带、黄铁矿化围岩蚀变、富含有机质(碳质)的夹层或断层破碎带等为有利的找矿标志;(3)在黑色岩系地层中富含有机质(碳质)和黄铁矿的夹层、碳酸盐岩地层中富含有机质(碳质)的断层角砾岩等部位进行找矿,特别是在黄铁矿化、硅化等蚀变叠加部位,有望实现找矿突破。

Sandu-Danzhai area in Guizhou Province is located in Danzhai-Sandu-Dushan carbonite- silica mudstone type and coal-rock type uranium metallogenic prospective zone of the metallogenic pro- spective zone of Central Guizhou Province and Northwest Hunan Province. The geotectonic position of Sandu-Danzhai area is distributed in the contact area of Qiannan Depression of Yangzi Quasi Plafform and west margin of South China Fold Belt, the famous Sandu-Danzhai polymetallic metallogenic belt of Hg, Au, Sb, Pb and Zn is also distributed in the contact area. Prospecting potential of Uranium deposit in San- du-Danzhai area is good. The comprehensive analysis of regional metallogenic geological background, and geological characteristics of the typical uranium deposits in the area are done. The study results indicated that ： ①the metallogenic activity of uranium deposit is mainly controlled by strata, lithology, structure and lithofacies paleogeographical environment;②the favorable prospecting indicators of the area can be sum- marized as U concentration center and high anomaly belt, Gamma high anomaly belt, surrxounding rock al- teration （pyritization） and the interlayers of fault belts with high contents of organic matter （carbona- ceous） ;③ideal prospecting breakthrough can be acquired in the interlayers with high contents of organic matter （carbonaceous） and pyrite in black rock formtion and the fault breccia with high contents of or- ganic matter （carbonaceous） in carbonate formation, especially for the alteration stacking area of pyritiza-tion and silicification.