青海同仁德合龙洼铜金矿床石英包裹体地球化学特征  

Geochemical Characteristics of Inclusions of Quartz in the Dehelongwa Copper-Gold Deposit,Tongren,Qinghai Province

作　　者：康亚龙[1,2] 刘继顺[1] 曹勇华[1] 

机构地区：[1]中南大学地球科学与信息物理学院,湖南长沙410083 [2]西部矿业股份有限公司,青海西宁810001

出　　处：《西北地质》2013年第3期98-108,共11页Northwestern Geology

基　　金：青海省德合龙洼矿区地质综合研究及找矿预测;湖南省自然科学基金(07JJ6071)资助

摘　　要：德合龙洼铜金矿床是西秦岭成矿带内重要的斑岩型铜金矿,主要产于断裂破碎带中。通过对石英流体包裹体研究,表明流体包裹体主要有3种类型:富H2O包裹体、富CO2包裹体、含盐类子矿物包裹体。显微测温结果显示,成矿前为岩浆流体,富含Na+、K+等组分,为强力上侵的流体;成矿期为NaC1不饱和流体,为高温、高盐度的岩浆流体,具沸腾特征;成矿后为中高温、中低盐度、低密度的H2O-NaCl-KCl体系。温度、盐度、压力变化,构造的开放性和氧逸度的增强、溶液pH值的降低可能是矿区铜金沉淀成矿的主要原因。Dehelongwa copper-gold deposit is a typical porphyry-type copper-gold deposit in the west Qinling mineralization belt, occurring mainly in fracture zone. Studies on quartz fluid inclusions show three main types of inclusions, namely H2 O-rich, COe-rich and saline daughter mineral inclusions. Microthermometry data suggests that prior to mineralization, the inclusion is powerful intrusion magmatic fluid, rich in Na＋ , K＋ and so on. In the metallogenic period, the inclusion is NaC1 unsaturated magmatie fluid of high temperature and high salinity, with a boiling feature. After mineralizaion, the inclusion is a HzO-NaC1-KC1 system with moderate temperature, medium-low salinity and low density. The study shows that the ore-forming of copper and gold is mainly caused by the changes in temperature, salinity and pressure, the open formation, the increasing oxygen fugacity, and the declining fluid pH value.

关 键 词：包裹体 地球化学 德合龙洼铜金矿床 青海 

分 类 号：P599[天文地球—地球化学]