石湖金矿流体包裹体特征及成因意义  

Characteristics and genetic significance of fluid inclusions in Shihu gold deposit

作　　者：门文辉 MEN Wen-hui(Xi’an Northwest Geological Institute of Nonferrous Metals Co.,Ltd.,Xi’an 710054,China)

机构地区：[1]西安西北有色地质研究院有限公司,陕西西安710054

出　　处：《世界有色金属》2022年第9期91-93,共3页World Nonferrous Metals

摘　　要：石湖金矿是太行山地区一超大型石英脉型金矿床。本文对石英脉中流体包裹体进行岩相学观察及激光拉曼光谱分析显示:矿区石英脉中流体包裹体可分为三种类型:①H_(2)O+CO_(2)包裹体,②富CO_(2)包裹体,③H_(2)O溶液包裹体。其中成矿早期乳白色石英脉发育原生H_(2)O+CO_(2)包裹体;主成矿期黄铁矿石英脉中主要发育富CO_(2)包裹体,少量H_(2)O溶液包裹体;成矿晚期石英-碳酸盐阶段发育原生H_(2)O溶液包裹体。各成矿阶段包裹体完全均一温度为:成矿早期H_(2)O-CO_(2)包裹体254.3℃~424.5℃;主成矿期富CO_(2)包裹体261.2℃~440.2℃,同期H_(2)O包裹体289.3℃~323.5℃;成矿晚期H_(2)O包裹体115.3℃~260.2℃。成矿流体属低盐度的CO_(2)-H_(2)O-NaCl体系。构造体质转换引起流体减压沸腾可能是金沉淀成矿的控制因素。Shihu gold deposit is a super large quartz vein type gold deposit in Taihang Mountain area.Fluid inclusion studies shows that there are three types of fluid inclusions in the gold ores of shihu gold deposit at various ore-forming stages,which are H_(2)O-CO_(2) inclusions,rich CO_(2) inclusions and H_(2)O solution inclusions.There are different inclusions in different mineralization stages.Primary H_(2)O-CO_(2) inclusions are mainly developed in quartz in the early mineralization stage,which often exist as gas-liquid two-phase;The primary CO_(2)-rich inclusions are mainly developed in the pyrite quartz veins in the main metallogenic period,and H_(2)O solution inclusions appear in some quartz veins.The complete homogenization temperatures of the two are similar,indicating the characteristics of insoluble fluid combination;Primary H_(2)O solution inclusions in late quartz-carbonate stage.Microscopic temperature measurement shows Phase I homogenization temperature of H_(2)O-CO_(2) inclusions(Th,TOT homogenization to liquid phase)is 254.3℃~424.5℃;the homogenization temperatures of CO_(2)-rich inclusions in stage II and III were 261.2℃~440.2℃,and those of H_(2)O solution inclusions were 289.3℃~323.5℃in the same period.Phase IV homogenization temperature of H_(2)O solution inclusions 115.3℃~260.2℃.The ore-forming fluid is a low salinity CO_(2)-H_(2)O-NaCl system.The stress field changes caused by structural constitution transformation may lead to fluid decompression boiling,which may be the main factors for gold precipitation mineralization.

关 键 词：石湖 流体包裹体 金矿床 

分 类 号：P618.51[天文地球—矿床学]