甘肃鹰嘴山金矿床地质和成矿地球化学  

GEOLOGY AND METALLOGENIC GEOCHEMISTRY OF THE YINGZUISHAN GOLD DEPOSIT,GANSU PROVINCE

作　　者：毛景文[1,2,3] 张作衡[1,2,3] 扬建民 张招崇[1,2,3] 王志良[1,2,3] 叶得金 

机构地区：[1]中国地质科学院矿床地质研究所 [2]中国地质科学院地质研究所 [3]甘肃省酒泉地质调查队

出　　处：《矿床地质》1998年第4期297-306,共10页Mineral Deposits

基　　金：国家计委科技找矿项目;地质矿产部定向科研项目;地质矿产部跨世纪人才基金

摘　　要：鹰嘴山金矿床是北祁连山西段新发现的剪切带型金矿床。赋矿围岩为粉砂质板岩、英安质碎裂岩和安山质角砾凝灰岩等，蚀变以硅化和绢云母化为特征。成矿作用分为原生成矿期和表生氧化－次生富集成矿期。原生成矿期又可以分为微晶石英岩矿化阶段和脉状石英硫化物阶段，后者为主成矿阶段，表生成矿期硫化物氧化为硫酸盐类，金除了包含在硫化物中外，还以自然金充填石英颗粒之间或石英裂隙。在原生矿化蚀变过程中，硅质、碱质、ＣＯ２和ＲＥＥ带入了成矿体系。均一法测温表明成矿主要温度为３２０～２００℃，成矿流体含有大量ＣＯ２，其氧同位素显示为岩浆水或深部流体为主。The Yingzuishan deposit,a gold deposit recently discovered in the western part of North Qilianshan Caledonian orogenic belt,is 15 km away from the Hanshan large size gold deposit.The strata in the mine are composed of volcanic,clastic and carbonate rocks of Middle Cambrian Ge'ermogou Group. The host rock for the gold mineralization mainly comprises silty slate,dacitic cataclastic breccia and andesitic tuffbreccia.Totally 11 orebodies have so far been found,of which the largest one is about 509 m long and 3 to 5 m wide with an average grades of 9 62×10 -6 .The orebodies extend 180° to 200° and dip 37° to 82°.Silicification,sericitization and ferrodolomitization are developed in the mine Mineralization in the Yingzuishan gold deposit diplays two episodes,i.e.,endogenetic and exogenetic episodes.The endogenetic episode comprises two stages of mineralization.Stage I mineralization comprises dense massive quartzite formed through replacement of ultrabasic rocks by auriferous hydrothermal solution Stage Ⅱ mineralization,the principal gold mineralization stage characterized by small auriferous sulfide quartz veins,is commonly superimposed upon stage Ⅰ mineralization.Geochemical studies of the ores and altered rock reveal that silicon,alkaline components,CO 2 and LREE were brought into the metallogenic system during mineralization and alteration. Homogenization temperature of stage Ⅱ mineralization range from 320℃ to 200℃.Raman laser spectrum analysis of single inclusions shows the existence of abundant CO 2 in the fluid.Oxygen isotope data suggest that the ore forming hydrothermal solution responsible for the gold deposit was mainly derived from the magma of the mantle.

关 键 词：金矿床 地质特征 地幔流体成矿 成矿地球化学 

分 类 号：P618.510.5[天文地球—矿床学] P618.510.4[天文地球—地质学]