青海三江北段雀莫错铅锌矿床地质特征及成因

在分析研究区成矿地质背景的基础上,对位于青海三江北段成矿带沱沱河地区的雀莫错铅锌矿床地质、地球化学特征进行了研究,结果表明:1矿床赋矿围岩主要为二叠纪拉卜查日组碳酸盐岩,是铅锌矿的有利源层,相对富集Pb、Ag、Zn、As、Sb、Cd等成矿元素;2矿体明显受控于断裂构造,次级断裂构造与矿化关系密切,伴有硅化、重晶石化和碳酸盐化;3成矿流体具有低温、中低盐度和低密度等特征,矿区地质特征及矿石同位素特征反映出成矿流体有岩浆热液活动的参与;4目前所发现的8个铅锌矿体中,Pb品位为1.65%~7.17%,Zn品位为1.13%~5.7%,Pb+Zn(334)金属量为18.88万t,矿床达中型规模,具有较好的找矿前景。结合区域地质背景、矿床地质和地球化学特征,对区内成矿物质来源、控矿因素、矿床成因进行了探讨,认为矿床属于浅成低温热液型铅锌矿床,并从地层、构造、蚀变、矿化、地球物理和地球化学特征等方面总结了找矿标志。上述研究成果对于区内铅锌矿的找矿工作具有一定的参考价值。

Geological Characteristics and Genesis of Quemocuo Pb-Zn Deposit in the Northern Segment of Sanjiang Belt,Qinghai Province

Based on analyzing the geological background of mineralization in the research area，the geological and geochemical characteristics of Quemocuo Pb-Zn deposit，which is located in northern section of Sanjiang metallogenic belt，Tuotuo river area，Qinghai province are discussed，the results show that：①the deposit of ore rock is mainly Permian Labuchari group carbonate，which is the advantageous source layer of lead-zinc mine and relatively enriched with the ore-forming elements such as Pb，Ag，Zn，As，Sb，Cd; ②the ore-body is obviously controlled by fracture structure with secondary fault structure closely related to mineralization，which is also accompanied with silicification，baratization and carbonatization; ③the ore-forming fluid has the characteristics of low temperature，low salinity，low density and so on，the geological characteristics of mining area and isotopic characteristics reflect the participation of magmatic hydrothermal activity in ore-forming fluid; ④until now，among eight Pb-Zn ore-bodies found，lead grade is 1.65%~7.17%，zinc grade is 1.13%~5.7% and Pb+Zn(334) metal capacity is 188 800 t，the metal ore deposit is in medium size，and the prospecting prospective of the deposit is good.Combining with the regional geological background，geological and geochemical characteristics of ore deposit，the source of ore-forming materials，ore-controlling factors，and metallogenic factors are discussed.The results show that the ore deposit belongs to the hypabyssal low temperature and hydrothermal type Pb-Zn deposits，besides that，the prospecting marks are summarized based on the characteristics of strata，tectonic，alteration，mineralization，geophysical and geochemical feature.The above research results can provide some reference for the prospecting work in the research area.