三江特提斯兰坪盆地通甸地区水系沉积物地球化学特征及找矿靶区优选

通甸地区地处三江特提斯兰坪盆地铅-锌-铜-银巨型矿集区东北部,具有寻找沉积岩型铅锌矿的前景。在通甸地区开展了1∶5万水系沉积物地球化学测量,以进一步指导铅锌矿勘察工作。确定了Pb、Zn和Ag等15种单元素异常范围,揭示了不同成因类型组合元素的分布特征及规律,圈定了21处地球化学综合异常。通过化探异常查证,识别出两条铅锌矿(化)体,经分析检测,Pb含量为1.93%～2.01%,Zn含量为0.48%～12.22%。研究表明,三合洞组(T3sh)碳酸盐岩和与其上下地层接触部位是区内重要的矿源层。结合异常分布规律、异常查证结果以及成矿地质背景进行综合评价,优选AS05甲1综合异常区为最佳铅锌找矿靶区,为通甸地区深入开展矿产勘查提供参考和依据。

Geochemical characteristic of stream sediment and prospecting target optimization in the Tongdian area of Lanping Basin, Sanjiang Tethys

The Tongdian area has good prospecting prospects for sediment-hosted lead-zinc deposits, which is situated in the northeast of the giant Pb-Zn-Ag-Cu ore-concentrated area of Lanping Basin, Sanjiang Tethys. To further assist in lead-zinc deposit prospecting, a 1:50, 000 stream sediment survey was carried out in this area. It delineated fifteen single element anomalies, including Pb, Zn, Ag, and defined twenty-one comprehensive geochemical anomalies. Also, it revealed the distribution characteristics and regularities of combined elements of different genetic types. According to verified geochemical anomalies, two lead-zinc ore-mineralized bodies (w(Pb)1.93%~2.01%, w(Zn)0.48%~12.22%) were identified. The study indicates that the Sanhedong Formation and its contact with the upper and lower strata are major source beds of lead-zinc deposits. Based on the anomaly verification, regularity of anomaly distribution, and geological setting of mineralization, the AS05-A1 comprehensive anomaly was selected as the best lead-zinc prospecting target, which provides an important reference and basis for the geological prospecting in this area in the future.