摘要
李坝式金矿床是位于西秦岭礼岷金成矿带中川印支—燕山早期岩体外接触带微细粒浸染型金矿类型,其成矿与岩体、构造等关系密切,含矿围岩为成矿提供了矿质来源,金矿(化)体与围岩具有相似的稀土元素地球化学特征,中川岩体为成矿提供了热动力。氢氧同位素研究表明,由岩浆水、地层水、大气降水等共同组成了成矿热液,热液沿构造带上升的过程中萃取了容矿围岩中的成矿物质,在地壳浅部由于物化条件的改变在容矿构造中富集成矿,形成金矿体,并形成了特定的围岩蚀变,因而属地下热卤水溶滤型浅成中低温充填—交代型金矿床。在此基础上建立了西秦岭礼岷金成矿带岩体(岩脉)、地化异常、构造、蚀变四位一体的综合找矿模式,热接触变质作用形成的黑云母带(Ⅱ带)是区域找矿的有利部位。
Liba type gold ore is a micro-disseminated type deposit, lies in outside of contacting zone of Zhongohuan Indosinian to early Yanshanian rocks in the Li-Ming gold mineralizing belt, western Qinling. Gold mineralization has important relation with rock body and tectonic. Mineralizing rocks supply ore source and have the similar rare element character with ore body. Zhongchuan rock body supplies hot force. Hydrogen and oxygen isotope data indicate that hydrothermal fluids are composed of magmatic, stratum and meteoric water. The fluids extract ore materials from wallrocks while rising up along the tectonic belt, and precipitate to form ore bodies in the hosting tectonic of shallow Crust when the physical and chemical conditions change. Specif- ic wallrock alterations are formed in the adjacent rocks at the same time. This type deposits belong to middle to low temperature hydrothermal fluid fillingreplacement gold ores. A mineralizing model of pluton, geochemistry abnormity, tectonic and wallrock alteration is constructed. Biotite belt formed by thermal contacting metamorphism is the key belt for ore exploration.
出处
《地质与勘探》
CAS
CSCD
北大核心
2008年第6期1-7,共7页
Geology and Exploration
基金
国土资源部中国地质调查局国土资源调查评价项目(编号:1212010630505)资助
关键词
李坝式金矿床
地球化学
找矿方向
西秦岭
Liba type gold deposit, geochemistry, ore exploration, western Qinling
