Re–Os and Pb isotope features of pyrite in the Shihangli graphite deposit: implications of coal-generated graphite mineralization in central Hunan, South China
Re–Os and Pb isotope features of pyrite in the Shihangli graphite deposit: implications of coal-generated graphite mineralization in central Hunan, South China
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DOI：
10.1007/s11631-023-00618-6
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发表时间：
2023-06
期刊：
影响因子：
1.6
通讯作者：
Yong Zhang;D. Ma;Jian-Feng Gao;Jiayong Pan;Xupeng Lv;Guoqi Liu;Fujun Zhong;Xiaotian Zhang;Y. Liu
中科院分区：
文献类型：
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作者：
Yong Zhang;D. Ma;Jian-Feng Gao;Jiayong Pan;Xupeng Lv;Guoqi Liu;Fujun Zhong;Xiaotian Zhang;Y. Liu
湘中煤变质作用提供了有关热液活动和水岩反应的重要信息。学习如何收集热液流体系统的年龄数据对于理解大型煤成石墨矿床的历史和成因机制是必要的。石行里石墨存款矿床是湘中地区最具特色的石墨矿床，其成因主要为硅质热液蚀变作用。石行里石墨存款矿床中黄铁矿的Re-Os定年结果表明，煤成石墨成矿年龄为127.6 ± 3.8Ma。通过对石行里石墨存款热液黄铁矿的原位矿物学分析，发现黄铁矿主要富集Sb、As、Au、W、Ag、Cu、Pb和Zn。根据黄铁矿Re-Os等时线，黄铁矿的初始（187Os/188Os）值为1.03 ± 0.24，Os（t）值为571.8~755.1。石行里石墨存款矿床黄铁矿的铅同位素组成与锡矿山锑存款矿床麻底驿组块状岩和辉锑矿的铅同位素组成相似。根据湘中石墨、锑矿床中硫化物的Re-Os、Sr、S、Pb同位素组成，麻底驿组可能是成矿元素（Sb、Au、As）的主要来源。黄铁矿的Re-Os和Pb同位素组成最有可能反映湘中地区大规模流体运移和煤成石墨成矿的时代。
The coal metamorphism in Central Hunan provides valuable information about hydrothermal activity and water/rock reactions. Learning how to collect age data on hydrothermal fluid systems is necessary for understanding the history and genetic mechanisms of large-scale coal-generated graphite deposits. The Shihangli graphite deposit, formed by significant siliceous hydrothermal alteration, is the most distinctive in Central Hunan. Re–Os dating of pyrite from the Shihangli graphite deposit demonstrates that the coal-generated graphite mineralization age is ~ 127.6 ± 3.8 Ma. Based onin-situmineral analysis, the hydrothermal pyrite in the Shihangli graphite deposit is mostly enriched in Sb, As, Au, W, Ag, Cu, Pb, and Zn. Based on the pyrite Re–Os isochron, the initial (187Os/188Os) values of pyrite were 1.03 ± 0.24 and the Os(t) values varied from 571.8 to 755.1. Pyrite from the Shihangli graphite deposit comprises a Pb isotope composition similar to that of the Madiyi Formation bulk rock and stibnite from the Xikuangshan Sb deposit. Based on the Re–Os, Sr, S, and Pb isotopic compositions of sulfides in the graphite and Sb deposits in Central Hunan, the Madiyi Formation was likely the primary source of ore-forming elements (Sb, Au, and As). The Re–Os and Pb isotope compositions of pyrite most likely reflect when large-scale fluid migration and coal-generated graphite mineralization occurred in Central Hunan.