内蒙古满洲里地区哈拉胜大型银铅锌矿床地质特征及成矿时代

矿床产于哈拉胜火山穹隆中，成矿与火山－岩浆作用关系密切.钻探和高磁资料显示，火山基底为额尔古纳河组，穹隆核部为次火山岩体，盖层塔木兰沟组和满克头鄂博组火山－沉积岩为容矿围岩.共圈定的11条矿体分布于穹隆东北部，受近南北向张性断裂-裂隙控制，产状较陡.4条主矿体长500～1400 m，平均厚度1～3 m，延深一般500～900 m.自岩体至围岩化探异常元素组合依次为Bi（-Pb-Ag-As-Mo）→Ag-Pb-Mo-Cu→Pb-Zn-As→Ag-Pb-Zn-Sb→Ag-Pb-Zn-Sb；矿化元素组合依次为Cu（-Mo-Pb-Zn）→Pb-Zn-Ag→Pb-Ag；围岩蚀变由岩体内部向外依次为硅化－钾化－石英绢云母化→夕卡岩化→玉髓化－绿帘石化－绿泥石化－碳酸盐化.3件岩浆岩锆石U－Pb年龄为161～142 Ma，结合区域典型矿床研究成果，认为矿床成岩成矿于晚侏罗世—早白垩世，成矿年龄为142 Ma.

GEOLOGICAL CHARACTERISTICS AND METALLOGENIC AGE OF THE LARGE SILVER-LEAD-ZINC DEPOSIT IN HALASHENG OF MANZHOULI AREA,INNER MONGOLIA

This Ag-Pb-Zn deposit is occurred in the Halasheng volcanic dome, with mineralization closely related to volcano-magmatism. The drilling and high-precision magnetic data show that the volcanic basement is the Ergunahe Formation, with subvolcanic body as the core of the dome and the volcanic-sedimentary cap rocks of Tamulangou and Manketouebo formations as ore-host rocks. The delineated 11 orebodies in the northeast of the dome are controlled by the N-S-trending extensional fault/fracture with steep occurrence. The four main orebodies are 500-1400 m long with an average thickness of 1-3 m and general depths of 500-900 m. The geochemical anomaly element assemblages from the rock body to surrounding rocks are in the order of Bi(-Pb-Ag-As-Mo)→Ag-Pb-Mo-Cu→Pb-Zn-As→Ag-Pb-Zn-Sb→Ag-Pb-Zn-Sb. The mineralized element associations are Cu (-Mo-Pb-Zn)→Pb-Zn-Ag→Pb-Ag in sequence. The wallrock alterations from inside to outside of the rock body are silicification→potash feldspathization→quartz sericitization→skarnization→chalcedonization→epidotization→chloritization→ carbonation successively. The zircon U-Pb isotopic age of 3 magmatic rock samples is 161-142 Ma. Combined with the research of regional typical deposits, it is believed that the diagenesis and mineralization occurred in Late Jurassic to Early Cretaceous with a metallogenic age of 142 Ma.