| 摘要: |
| 黑牛洞铜矿床经历了早期韧性变形-变质作用和成矿期的韧-脆性变形作用。早期韧性变形-变质作用过程中围岩可能分异出含CO2流体,并形成顺片理发育的磁黄铁矿、黄铜矿等矿化。成矿期为伴随江浪穹窿隆升的韧-脆性变形期,含矿石英脉中流体包裹体主要以富液相流体包裹体为主,次为纯气相流体包裹体。流体包裹体成分测试结果显示,富液相流体包裹体主要成分为水,含少量CO2和甲烷等烃类碳质流体;纯气相流体包裹体主要为甲烷,表明成矿流体为富水含炭质流体。流体包裹体氢、氧同位素测试结果表明,黑牛洞矿床含矿流体中的水主要来源于围岩中的变质水。燕山期花岗岩侵位,江浪穹窿隆升,韧-脆性变形形成系列滑脱断层。在此减压、降温过程中,成矿流体被活化并聚集、填充到滑脱断层内。 |
| 关键词: 黑牛洞铜矿床 流体包裹体 甲烷 滑脱断层 |
| DOI： |
| 附件 |
| 投稿时间：2011-07-04修订日期：2011-08-20 |
| 基金项目:全国危机矿山找矿办公室项目“四川里伍铜矿、泸沽铁矿床成矿规律总结研究”(编号:20089952)和中国地质调查局“云南麻栗坡矿产远景调查”(编号1212010880402)联合资助 |
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| Mineralizing fluids and genesis of the Heiniudong copper deposit in the Liwu copper orefield, Sichuan |
| CHEN Min-hua, ZHU Xiang-ping, FENG Xiao-liang, DING Jun, YAO Peng, MA Dong-fang, TANG Gao-lin |
(1. Chengdu Institute of Geology and Mineral Resources, Chengdu 610081, Sichuan, China;
2. Liwu Copper Mining Co., Ltd., Garze 626200, Sichuan, China) |
| Abstract: |
| The Heiniudong copper deposit has gone through the ductile deformation and metamorphism in the premetallogenic stages and ductile-brittle deformation in the metallogenic stages. In the pre-metallogenic stages, the CO2-bearing fluids were differentiated from the host rocks due to the ductile deformation and metamorphism, which may facilitate the formation of elongated disseminated pyrrhotite and chalcopyrite mineralization. The ductile-brittle deformation in the metallogenic stages was accompanied by the uplifting of the Jianglang metamorphic core complexes. The fluid inclusions from the ore-bearing quartz veins are dominated by the aqueous fluid inclusions, and subordinately by gaseous fluid inclusions. The former consist of water, CO2 and methane, whereas the latter mostly contain methane, implying that the ore-forming fluids are aqueous carbonaceous fluids. The water in the oreforming fluids mainly stemmed from the metamorphic water in the country rocks. The emplacement of the Yanshanian granites and the uplifting of the Jianglang metamorphic core complexes led to the formation of a series of detachment faults due to the ductile-brittle deformation. In the decompression and catathermal processes, the oreforming fluids were activiated, concentrated and filled into the detachment faults. The exsolution of CO2 and CH4 from the ore-forming fluids gave rising to the decrease of the dissolubility, precipitation and mineralization of the sulfides in the ore-bearing hydrothermal solutions, and finally to the formation of copper-rich ore bodies. |
| Key words: Heiniudong copper deposit fluid inclusion methane detachment fault |
