新疆叶城县叉路口铅锌矿床地质特征及矿床成因讨论

新疆叶城叉路口铅锌矿是喀喇昆仑北麓的叶尔羌河上游的一处中型铅锌矿床。铅锌矿体产于神仙湾二叠-三叠纪边缘裂陷带的中-下二叠统神仙湾组上段中,矿体的围岩有碎裂状的粉砂质板岩、白云质大理岩、泥晶灰岩,以及构造角砾岩等,铅锌矿体受断裂及碎裂化岩石的控制,矿体主要呈层状、似层状或大透镜状,但也有小型脉状含矿石英脉穿切层理,矿石构造有条纹-条带状、块状构造、团块状、斑点状、浸染状构造,矿物组合显示简单硫化物组合特点,围岩蚀变主要有硅化、绿泥石化和碳酸盐化,蚀变强度较弱。铅锌矿床特征既反映出沉积成矿的某些特点,也显示出后期热液成矿的许多特征,在综合对比区域铅锌矿成矿规律之后认为,叉路口铅锌矿的矿床成因为沉积-热液改造型铅锌矿床,属于复因-后成矿床范畴。

Discussion on geological characteristics and genesis of Chalukou lead-zinc deposit in Yecheng county, Xinjiang

The Chalukou lead-zinc deposit in Yecheng county of Xinjiang is a medium-sized Pb-Zn deposit at the northern foot of Karakoram mountain in the upper reaches of the Yarkand river. Ore body are layered or lenticular located in the Upper member of the Mid-Lower Permian Shenxianwan formation in Shenxianwan Permian-Triassic marginal rift zone and hosted by fractured silty slate,dolomitic marble,micritic limestone and fault breccia and controlled by faulted and fractured rocks. There are also small mineralized quartz vein cutting stratification of stratum. The ore is in laminated-banded, massive, lumpy, spotted and disseminated structure. Mineralogy is characterized by simple sulphide combination. Wall rock alteration is relatively weak dominated by silicification,chloritization and carbonatization. The Chalukou Pb-Zn deposit shows both sedimentary and late hydrothermal fluid rework characteristics. Compared with the regional Pb-Zn deposits it is considered to be a sedimentary-hydrothermal reworked Pb-Zn deposit.