摘要
马家窑金矿是产在胶东群古老变质岩中的含金黄铁矿石英脉型金矿床.它是胶东地区有代表性的重要金矿类型之一.本文论述了马家窑金矿的地质特征、矿物组合、微量元素、稳定同位素地球化学和矿物包体学特征等,探讨了金矿的物质来源、金矿成因和成矿时代,指出了金矿的演化和最后定位于燕山期.
Majiayao is a quartz vein-typed gold deposit. It is a representative of such kind of gold deposit in the East Shandong Province, China.This paper deals with geolgical, geochemical, paragenetic, microelement and isotope characteristics of the deposit and physiochemical condition of the ore-forming process. Co/Ni ratios of pyrite are in the range of 0.29～13.2 which falls in the fields of metamorphic and magmatic hydrothermal gold ore in the triangle plot of Co, Ni and As.Homogenization temperatures of quartz inclusion from ore veins are 110℃～370℃ with oreforming Tem. of 150℃～330℃. The average salinity value is 12.03 wt%. Accotding to the composition of inclusions ore fluid is weak acidic.S-isotope somposition of ore is similar to Linglong Granite and the metamorphic rocks of Jiaodong Grotp with value range of + 6.3 ～ + 13.91%. Pb-isotope is stable similar to that of hornblend - plagioclase gneiss of Jiaodong Goroup belonging to normal Pb. Model age range is 1051～1250 Ma. Majiayao gold deposit is slightly lower in μ value and slightly higher in w and Th/U velue indicating a U - depletion source area of ore materials. Both Jiaodong Group and upper mantle supply materials for the metallogeny.C, O isotope composition of carbonate minerals from the deposit falls about the boundary between the fields of carbonatite fluid and Linglong Granite fluid, furtherly indicating ore fluid may be derived from melting magma in the deep crust. Ore was formed in Yanshanian Period.
出处
《地质找矿论丛》
CAS
CSCD
1990年第3期36-48,共13页
Contributions to Geology and Mineral Resources Research
