| 斑岩-浅成低温热液型Cu-Au矿H2O-Cl-S流体性质和演化方式对成矿的制约 |
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| 引用本文： | 胡庆成,闫浩,吴春明.斑岩-浅成低温热液型Cu-Au矿H2O-Cl-S流体性质和演化方式对成矿的制约[J].地质论评,2014,60(3):601-610. |
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| 作者姓名： | 胡庆成 闫浩 吴春明 |
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| 作者单位： | 中国地质大学(武汉)资源学院，武汉, 430074;中国地质大学(武汉)资源学院，武汉, 430074;中国地质大学(武汉)地质调查研究院，武汉, 430074 |
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| 基金项目： | 本文为中央高校基本科研业务费专项资金（编号CUGL120296）资助的成果。 |
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| 摘 要： | 斑岩—浅成低温热液型Cu—Au成矿流体最具代表性的是H2O—Cl—S流体。流体的性质强烈控制着Cu、Au的成矿行为,包括溶解性、迁移形式和气—液分配。流体的氧逸度和流体中Cl、S物种相对含量决定金属在流体中的溶解形式,高氧逸度的高温高盐度流体中Cu、Au主要和Cl络合,S-3也可能是促进Au溶解的重要S物种形式。而过量的S有利于Cu、Au等元素以含S离子络合物进入液相流体,与含S中性络合物配分进入气相流体并迁移Au至浅成低温热液环境形成矿床。岩浆需要经历充分的分异,出溶成分和性质有利于金属迁移的流体,形成高品位的斑岩型Cu、Au矿体;上覆叠加浅成低温热液型Au矿体可能需要初始的成矿流体状态进入NaCl—H2O的超临界区、有效的演化方式、良好的流体缓冲环境和有利的Au沉淀场所。相分离和流体—流体反应是沉淀斑岩—浅成低温热液型Cu—Au矿体最重要的流体演化方式。气相流体具有独特的流体性质和演化方式,可能成为十分重要的成矿流体。
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| 关 键 词： | 斑岩—浅成低温热液 成矿流体 流体性质 演化方式 气相流体 |
| 收稿时间： | 8/3/2013 12:00:00 AM |
| 修稿时间： | 2013/12/24 0:00:00 |
Constrains of Properties and Evolution Patterns of H2O-Cl-S Fluid
on Forming of Porphyry-Epithermal Cu-Au Deposit |
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| Institution: | Faculty of Mineral Resources, China University of Geosciences, Wuhan, 430074;Faculty of Mineral Resources, China University of Geosciences, Wuhan, 430074;Geological Survey Institute, China University of Geosciences, Wuhan, 430074 |
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| Abstract: | The fluid system H2O-Cl-S is the most typical representative of porphyry-epithermal-Cu-Au ore forming fluids. The properties of fluids of interest dominate the behavior of Cu, Au in the fluids, including solubility, spicies, and liquid-fluid partition. The species formed responsible for dissolving and transporting metals are determined by oxygen fugacity and Cl/S ratio of the fluids. High temperature, salinity and oxygen fugacity favor Cu-Cl and Au-Cl complexes in the fluids, where S-3 is likely to serving as an important S bearing species for dissolving Au. Excessive amount of S with respect to Fe and Cu is benifical to distributing Cu and Au by the form of charged ionic and neutral complexes in liquid like and vapor like fluids, respectively, the latter of which would migirate Au as far as epithermal enviroment. The source magama ought to experience adequate fractionation to exsolute fluids with components and properties that are so good for transportation of metals that high grade porphyry Cu, Au could form. Especially in the case of space-time related epithermal Au over the porphyry system, it is required that initial state of the fluids is in the supercritical region of the referential binary system of NaCl-H2O; efficient fluid evolution patterns, favorable buffering surroundings and suitable sites for precipitation of Au are encouraged as well. Phase separation and fluid-fluid reaction are the two most important manners determining the precipitation of porphyry-epithermal Cu-Au. Vapor like fluids have characteristic properties and evolving pattern, which should be considered as an important ore forming fluid. |
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| Keywords: | porphyry-epithermal ore forming fluids fluid properties evolution patterns vapor like fluids |
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