青海省果洛龙洼金矿多因复成成矿作用  

Polygenetic compound mineralization of Guoluolongwa gold deposit in Qinghai Province, China

作　　者：赖健清[1,2] 鞠培姣 周凤[1,2] 

机构地区：[1]中南大学有色金属成矿预测与地质环境监测教育部重点实验室,长沙410083 [2]中南大学地球科学与信息物理学院,长沙410083

出　　处：《中国有色金属学报》2016年第2期402-414,共13页The Chinese Journal of Nonferrous Metals

基　　金：中南大学"创新驱动项目"(2015CX008);国家"十一五"科技支撑计划(2006BAA01B06)~~

摘　　要：果洛龙洼金矿位于东昆仑造山带东段,华力西.印支期是最重要的成矿期。矿体受近东西向断裂控制,地-层为矿源层和隔挡层,对矿质进行圈闭,变质热液及岩浆提供热源和物质。成矿作用分为变质热液期和岩浆热液期,前者包括乳白色石英脉阶段（A）和含金石英黄铁矿阶段（B）,为主成矿期,后者对应石英硫化物再富集阶段（C）,起叠加改造作用。综合稳定同位素及包裹体的特征,从多因复成的角度探讨其成矿作用。稳定同位素反映成矿物质及流体为多来源。包裹体研究表明：B、C阶段发育3种包裹体：Ⅰ型水溶液包裹体、Ⅱ型水溶液-CO_2包裹体、Ⅲ型纯CO_2包裹体。B阶段发育的3种包裹体温度集中于260~360℃,Ⅰ型、Ⅱ型包裹体盐度分别为10.70%~22.69%和3.52%~12.42%,流体可能来源于变质热液,属变质热液期。C阶段发育Ⅰ型包裹体及少量Ⅱ型包裹体,温度集中于160~320℃,Ⅰ型、Ⅱ型包裹体盐度分别为15.90%~23.32%和10.62%~13.57%,成矿热液可能主要来源于岩浆热液,为岩浆热液期。矿床在变质热液期成矿,后期受到岩浆热液叠加改造,矿质进行再富集。因此,矿床具多大地构造阶段、多控矿因素、多成矿物质来源、多成矿作用及多成因类型,属多因复成矿床。The Guoluolongwa gold deposit is located at the eastern part of east Kunlun orogenic belt. The Variscan- Indosinian period is the most important mineralization period in this region. EW trending faults take a significant control of the ore bodies, the formation is the ore source, and acts as a barrier to trap the ore-forming minerals, besides, metamorphic hydrothermal and magmatic activity play a role in providing materials and heat for mineralization. Mineralization can be classified into metamorphic hydrothermal episode and magmatic hydrothermal episode. The former is the main mineralization episode, which consists of milky quartz vein stage （A） and gold-bearing quartz pyrite stage （B）, and the latter corresponds to quartz sulfide enrichment stage （C）. Polygenesis of the deposit was discussed according to study of S--Pb isotope, fluid inclusion microthermometry and H--O isotope. S--Pb isotope and H--O isotope analysis show multiple origins of ore-forming materials and fluids. Based on fluid inclusion petrography, three types of fluid inclusions are identified in B and C stages： aqueous inclusion （type I）, CO2-aqueous inclusion （type II） and pure CO2 inclusion （type III）. All three types of inclusions are present in stage B, having homogenization temperatures at 260- 360℃, and salinities ranging from 10.70% to 22.69% for type I and 3.52%-12.42% for type II, showing that ore-forming fluid maybe derived from metamorphic fluids and this stage belongs to metamorphic hydrothermal episode. Type I and a small amount of type II inclusions are developed in stage C, with homogenization temperatures concentrating from 160℃ to 320℃, and salinities ranging from 15.90%-23.32% for type I and 10.62%-13.57% for type II, indicating that mineralization fluid maybe magmatic hydrothermal and this stage belongs to magmatic hydrothermal episode. Gold mineralization mainly occurs in metamorphic hydrothermal episode, and superposition of magmatic hydrothermal in the late leads to re-enrichment of ore-form

关 键 词：成矿作用 多因复成 果洛龙洼金矿 

分 类 号：P611.1[天文地球—矿床学]