青海滩间山金矿床地质特征及其铅同位素组成的地质意义

滩间山金矿床产于中元古界蓟县系万洞沟群碳质糜棱片岩和华力西晚期侵入岩中。该金矿床天在热水沉积、区域变质和热变质预富集的基础上，与区域绿片岩相脆韧性剪切变形变质带的退化演化同步，经历了脆韧性、韧脆性和脆性剪切变形成矿阶段的演化，井遭受华力西晚期侵入岩浆活动的叠加改造而形成的。矿区地层、侵入岩、矿石及黄铁矿的铅同位素组成表现出良好的亲缘关系，较清楚地反映了地层和侵入岩浆活动对成矿物质的贡献。

GE0LOGICAL CHARACTERISTICS OF TANJIANSHAN GOLD DEPOSIT, QINGHAI AND INTERPRETATION OF ITS LEAD ISOTOPIC COMPOSITION

Locaed on the northern margin of the Qaidam Massif, the Tanjianshan gold deposit occurs in the Wandonggou Group Carbaoaceous mylonite schist of the Jixian System of the Middle Proterozoic and in the Late Varscan intrusive rocks. Hydrothermal sedimentation, regional metmorphism and thermal metamorphism led to the primary enrichment of ore-forming elements. The retrograde metamorphism of the regional greenschist facies brittle-ductile shear deformed and metamorphic zone, in conjunction with the brittle-ductile, ductile-brittle and brittle shear deformation superimposed by magma intrusiveactivity of Late Variscan resulted in the formation of the ore deposit.The lead isotopic compositions of the strata in the mining area, the intrusive rocks and the pyrites show that there is a good affinity among them. The Pb isotopic ratios of ores and pyrite lie between those of the strata in the mining area and the intrusive rocks. This dearly indicates the contribution of the strata and magma intrusive activity to the ore-forming materials.