羊坪湾金矿地质特征及成矿模式  

Geological Features and Metallogenic Model of Yangpingwan Gold Deposit

作　　者：任小华 高航校 李福让 李鑫 李希 

机构地区：[1]西北有色地质勘查局,陕西西安710068

出　　处：《西北地质》2015年第1期127-136,共10页Northwestern Geology

基　　金："十二五"国家科技支撑计划项目(2011BAB04B05)

摘　　要：羊坪湾金矿床地处南秦岭南部逆冲推覆系前缘,在该区域已经发现多个金矿床,显示出巨大的找矿潜力。羊坪湾金矿床矿体主要分布在下志留统梅子垭岩组中,控矿围岩为逆冲推覆剪切带内劈理、裂隙发育的含碳二云母石英片岩及二云母片岩。矿石类型主要为含碳二云母(石英)片岩型。围岩蚀变主要有硅化、黄铁矿化、褐铁矿化、黑云母化和绿泥石化。包裹体中流体成分显示成矿是以H2O-CO2-NaCl为主的热液体系。氢、氧同位素特征表明成矿热液中的水介质是原始地层水,硫同位素特征说明黄铁矿、磁黄铁矿中34S来源于地层。矿源层为志留系梅子垭岩组,燕山期逆冲推覆构造控制本区金矿形成。综合上述方面的研究,建立了羊坪湾金矿床成矿模式。Yangpingwan gold deposit is located in the frontier of the southern thrust nappe of south Qinling. Many gold deposits have been found in this region of great prospecting potential. Yangpingwan gold deposit is distributed in Meiziya formation of early Silurian, the ore-control- ling wall rock is carbon-bearing two-mica quartz schist and two-mica schist with developed cleav age and fissure in thrust nappe shear zone. The type of ore is mainly carbon-bearing two-mica quartz schist and two-mica schist. Wall rock alteration is associated with silicification, pyritiza tion, limonitization, biotitization and chloritization. The composition of fluid inclusions shows that the mineralization system is H20-CO2-NaC1 hydrothermal system. The characteristics of iso- tope of hydrogen and oxygen show that the water medium of ore-forming fluids is the original for mation water. Sulfur isotopic characteristics show that the 348 in the pyrite and pyrrhotite is de rived from the strata. Meiziya formation of early Silurian is the source bed, the gold ore forming in Yangpingwan gold deposit is controlled by Yanshanian thrust nappe shear zone. Through com- prehensive study of these aspects, this paper established the metallogenic model of Yangpingwan gold deposit.

关 键 词：成矿模式 成矿物质来源 燕山期逆冲推覆剪切构造 羊坪湾金矿 

分 类 号：P618.51[天文地球—矿床学]