| 西藏雄村斑岩型铜金矿红柱石成因矿物学特征 |
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| 引用本文：黄勇,丁俊,唐菊兴,张丽,郎兴海.2012.西藏雄村斑岩型铜金矿红柱石成因矿物学特征[J].地球学报,33(4):510-518. |
| DOI：10.3975/cagsb.2012.04.11 |
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| 基金项目:自然科学基金(编号: 41172077);国家973项目(编号: 2011CB403103);青藏专项(编号: 1212010012005);西藏大型矿床成矿专属性研究(编号: 1212011221073) |
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| 中文摘要:雄村斑岩铜金矿中广泛分布有红柱石, 红柱石主要呈三种产出状态: ①石英-钾长石-白云母/绢云母-红柱石组合; ②红柱石-石英-绢云母/白云母组合; ③石英-红柱石-硫化物脉。矿物组合关系、红柱石结构和成分等特征均表明红柱石属热液成因。早期钾硅酸盐化带中的石英-钾长石-白云母/绢云母-红柱石组合形成于高温(大于550℃)、低+K/+H比值环境。随着热液体系温压降低, 热液体系+K/+H比值升高, 早期钾硅酸盐化被黄铁绢英岩化强烈交代, 形成相对较低温环境的红柱石-石英-绢云母/白云母组合, 黄铁绢英岩化交代早期钾硅酸盐化过程可能伴随有大量循环大气降水进入崩塌的热液体系。石英-红柱石-硫化物脉分布较少, 且只分布在黄铁绢英岩化外围, 硫化物以黄铁矿为主, 脉体两侧见有较为宽广的绢云母蚀变晕, 形成于相对低温环境的高+K/+H比值环境。雄村斑岩铜金矿中的热液成因红柱石特征与智利的El Salvador斑岩矿床中热液红柱石特征类似, 富含Al2O3的火山岩/侵入岩为红柱石提供了良好的物质条件, 同时广泛分布的热液红柱石重塑了岩浆-热液过程中的P-T条件。 |
| 中文关键词:红柱石 斑岩铜金矿床 雄村 西藏 |
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| Genetic Mineralogy of Andalusite in Xiongcun Porphyry Copper-Gold Oredeposit, Tibet |
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| Abstract:There are abundant andalusites in the Xiongcun porphyry copper-gold deposit. Three major assemblages are recognized, i.e., quartz–K-feldspar-muscovite/sericite-andalusite assemblage, andalusite–quartz-sericite/
muscovite assemblage, and quartz – andalusite – sulfide veins. The mineral association, texture and composition of andalusites indicate that the andalusites are of hydrothermal type. The quartz-K-feldspar-muscovite/
sericite-andalusite assemblage in early K-silicate alteration zone was formed under the conditions of fairly high temperatures (above 550℃) and relatively low +K/+H ratios. Early K-silicate alteration was replaced by later phyllic/sericitic alteration under lower P-T and higher +K/+H conditions, and meteoric water probably entered the collapsed hydrothermal system during this period. Quartz-andalusite-sulfide veins with sericite alteration envelope occur rather rarely and are only observed within the phyllic alteration zone. This assemblage was formed under lower P-T and higher +K/+H condition. Andalusite assemblages are similar to the El Salvador porphyry copper deposit in Chile. Volcanic tuff and porphyry stock had rich Al2O3, which was favorable for the formation of andalusite. The andalusite within different assemblages helps reconstruct the P-T condition of the magmatic-hydrothermal process. |
| keywords:andalusite porphyry copper-gold deposit Xiongcun Tibet |
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