山东焦家金矿田锶、铅同位素特征及其地质意义

焦家金矿田是胶西北地区重要的金矿产地，金矿类型以破碎带蚀变岩型为主，其成矿物质来源及成矿地质体尚存争议。采取了焦家金矿田深部样品，分析其同位素特征，研究成矿物质来源，探讨金矿成矿地质体。焦家金矿田金矿石黄铁矿⁸⁷Sr/⁸⁶Sr=0.711 653～0.732 45,按焦家金矿田平均成矿年龄120 Ma返算的(⁸⁷Sr/⁸⁶Sr)_i的值，其范围0.710 752～0.711 986,与郭家岭花岗岩较为接近。焦家金矿田金矿石黄铁矿²⁰⁸Pb/²⁰⁴Pb=37.683～38.103,²⁰⁷Pb/²⁰⁴Pb=15.43～15.547,²⁰⁶Pb/²⁰⁴Pb=17.04～17.44。焦家金矿田金矿体铅为地幔和下地壳的混合源。郭家岭型花岗岩与焦家金矿田金矿形成时间相近，分布空间相依，与金矿体同位素组成接近，成因上有密切联系，是金矿的成矿地质体。

Sr and Pb Isotopic Characteristics and Geological Significance of Jiaojia Gold Field, Shandong Province

Jiaojia gold field is an important gold producing area in Northwest Jiaotong. The type of gold deposit is mainly fracture zone altered rock type, and its source of ore-forming materials and metallogenic geological body are still controversial. The research results take the deep samples of Jiaojia gold deposit, analyze its isotopic characteristics, study the source of ore-forming materials, and explore the geological body of gold mineralization. The gold ore pyrite of Jiaojia gold field is 87Sr/86Sr=0.711905~0.73245. The value of (87Sr/86Sr)i calculated back according to the average metallogenic age of Jiaojia gold field is 120M, which ranges from 0.710441~0.711986, which is close to guojialing granite. Gold ore pyrite in Jiaojia gold field 208Pb/204Pb = 37.683~38.103, 207pb / 204Pb=15.43~15.547, 206pb/204Pb=17.04~17.44. The lead in the gold ore body of Jiaojia gold field is a mixed source of mantle and lower crust. The guojialing type granite is close to the gold deposit in Jiaojia gold field in formation time, distribution space, isotopic composition and genesis. It is a metallogenic geological body of gold deposit.