金沙江-红河富碱侵入岩带斑岩型铜、金矿床的成矿流体研究  

Study of Ore-forming Fluid Associated with Alkali-rich Porphyries in the Jinshajiang-Red River in Continental Tectonic Setting

作　　者：王蝶[1,2] 毕献武[1] 卢焕章[1,3] 刘张荣 

机构地区：[1]中国科学院地球化学研究所,矿床地球化学国家重点实验室,贵州贵阳550002 [2]昆明理工大学国土资源工程学院,云南昆明650093 [3]魁北克大学,加拿大魁北克G7H2B1 [4]鹤庆北衙矿业有限公司,云南大理671507

出　　处：《大地构造与成矿学》2017年第1期91-107,共17页Geotectonica et Metallogenia

基　　金：国家自然科学基金重点项目(41130423);国家自然科学基金青年项目(41502087);云南省人才培养项目(KKSY201421029)联合资助

摘　　要：对金沙江–红河富碱侵入岩带内的玉龙、北衙、铜厂–长安冲三个斑岩型铜、金矿床的流体包裹体进行了详细研究。三个矿床成矿阶段的流体包裹体类型主要有H_2O-NaCl气液两相包裹体,含钠盐、钾盐/方解石、金属子晶多相包裹体以及H_2O-CO_2包裹体。成矿期流体均一温度多在250~500℃之间,高者可达650℃及以上,盐度多在10%~50%NaCleq之间,成矿流体都具有高温、高盐度、富K、富CO_2的特点,显示典型的岩浆热液特征。并且,单个流体包裹体的成分分析也显示流体中除含有较高的成矿元素Cu、Mo、Pb、Zn等外,还含较高的K、Rb、Sr等元素,进一步证明成矿流体源自岩浆分异流体,且经历过从高温高盐度到高温中低盐度的演化。结合该区流体包裹体中广泛存在沸腾包裹体群的事实,进一步证实沸腾作用在斑岩型矿床中的普遍存在,并且说明其很可能是这些矿床金属元素沉淀的重要机制。The Jinshajiang-Red River alkali-rich intrusive belt and the abundant associated porphyry Cu-Au deposits is a representative belt of magamatic ore mineralization in continental tectonic setting. Petrographic observation, microthermometry, and Laser Raman Microprobe analyses were carried out on fluid inclusions in phenocryst quartz and quartz vein in the Yulong, Beiya and Tongchang-Chang＇anchong deposits in the belt. Different kinds of inclusions were observed in three deposits, including two phase H20-NaC1 fluid inclusions and multi-phase fluid inclusions with daughter minerals, and rich in CO2 fluid inclusions. The ore forming fluids in quartz associated with porphyry copper mineralization belong to the H20-NaC1-KCl^CO2 system with high temperature （250-500 ~C） and high salinity （10%-50%NaCleq）, indicative of typical magmatic hydrothermal origin. In addition, the SR-XRF test of single fluid inclusion showed that the fluids are enriched in K, Rb, Sr, which is also consistent with the characteristics of magmatic hydrothermal fluid. Furthermore, the fluid inclusion petrography and microscopic temperature measurement indicate that boiling and phase-separation are common in the porphyry copper deposits, which demonstrated that boiling and phase-separation may have played important roles in the transport and deposition of copper.

关 键 词：金沙江–红河富碱侵入岩带 斑岩矿床 流体包裹体 成矿流体 

分 类 号：P612[天文地球—矿床学]