沱沱河盆地江仓南铅锌矿地质特征及找矿方向

Geological Characteristics and Prospecting Direction of Jiangcangnan Pb-Zn Deposit in Tuotuo River Region

江仓南铅锌矿床位于青海南部沱沱河地区,隶属于青藏高原东北缘的＂三江＂多金属成矿带北延部分。经野外地质调查,在江仓南地区发现了7个较大规模的铅锌矿物探异常,显示出该地区具有较强的铅锌矿成矿潜力,进一步分析表明：1二叠纪九十道班组等灰岩中Pb、Zn等元素相对富集,为江仓南铅锌矿体赋存有利的围岩;2已圈定的7个矿化带主要分布于断裂构造交汇、地层不整合接触面等裂缝发育部位附近,以NW、近EW走向为主,显示出构造对矿床具有较强的控制作用;3该铅锌矿体中Pb品位0.53%~5.45%,Zn品位0.91%~4.67%,预计Zn资源量约1.45×105t,矿床达中型规模,具有较好的找矿前景。结合区域地质背景、矿床地质特征、矿体特征,对区内控矿因素、矿床成因以及找矿标志进行了探讨,认为江仓南地区铅锌矿为受构造控制的中—低温热液矿床,呈红、褐、灰绿等氧化色条带的裂缝发育构造是矿床发育的重要标志。上述研究成果可为沱沱河地区其他铅锌矿体的勘探工作提供参考。

Jiangcangnan Pb-Zn deposit is located in the southern section of Tuotuo river area,which is the northern extension of Sanjiang polymetallic metallogenic belt in the northeastern margin of the Tibetan Plateau. Based on the field investigation,7 large-scale Pb-Zn geophysical anomalies are found and the strong Pb-Zn mineralization potential is presented in the research area. The further analysis results of the above geophysical anomalies show that： 1the limestone in the Permian ninety team is the main surrounding rock with high contents of the elements such as Pb,Zn,etc; 2the selected 7 mineralization zone mentioned above is located in the fracture development geological structure area,such as in the intersection of faults,unconformity interface of formation and so on,they are mainly NW-direction and nearly EW-direction,it indicated the evidence that one of the important controlling factors of Pb-Zn deposit is the geological structure in the research area; 3the Pb grade is from0. 53% to 5. 45%,the Zn grade is from 0. 91% to 4. 67% in the orebody of the Pb-Zn deposit,the Pb metal capacity is almost1. 45 × 105 t,it means that the metal ore deposit is the medium size and shows a good potential for exploring mineral resource. Based on analyzing the geological background of mineralization,ore deposit geological characteristics,orebody geological characteristics in the research area,the ore-controlling factors,ore deposit genesis and prospecting indicators in the research area are also studied in depth,it concluded that the Jiangcangnan Pb-Zn deposit is a middle-low-temperature hydrothermal deposit with the significantly structure controlling the oxide strips with the red,brown,gray and other colors in or nearby the fracture development geological structure area is the obvious sign of the development of Pb-Zn deposit. The above research results can provide the reference for the further exploration and exploitation work of the other Pb-Zn deposit in Tuotuo river area.