Magmatic processes recorded in plagioclase and the geodynamic implications in the giant Shimensi W–Cu–Mo deposit, Dahutang ore field, South China
Magmatic processes recorded in plagioclase and the geodynamic implications in the giant Shimensi W–Cu–Mo deposit, Dahutang ore field, South China
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华南大湖塘矿田石门寺巨型瓦铜钼矿床斜长石记录的岩浆过程及其地球动力学意义
DOI：
10.1016/j.jseaes.2021.10
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发表时间：
2021-03
影响因子：
3
通讯作者：
Wu X.Y.
中科院分区：
文献类型：
--
作者：
Fan X.K.;Zhang Z.Y.;Hou Z.Q.;Mavrogenes J.;Pan X.F.;Zhang X.;Dai J.L.;Wu X.Y.
石门寺钨铜钼存款矿床是世界上最大的钨矿床之一。尽管对该区与矿有关的花岗岩进行了大量的地球化学研究，但很少有研究涉及岩浆房过程。本文通过对石门寺存款矿床中与成矿有关的中生代花岗岩中斜长石晶体的主量元素和微量元素以及花岗岩全岩Sr-Nd同位素组成的系统原位研究，探讨了钙的来源、岩浆系统动力学和成矿地球动力学背景。斜长石的原位分析表明，Au与FeO之间没有明显的正相关关系，而Sr与Ba之间存在明显的正相关关系，表明石门寺存款岩浆房可能经历了仅受热混合和/或减压作用影响的化学封闭演化，而没有与来自地幔的镁铁质岩浆发生化学混合。这一结论也得到了全岩Sr-Nd同位素特征的支持，即高（87 Sr/86 Sr）i（0.71664-0.73689）和负εNd（t）值（−9.81-−5.07）。结果表明，白钨矿成矿所需的钙主要来自高钙、大颗粒的黑云母花岗闪长岩（BG），而成矿金属主要来自双桥山群泥质岩和基性火山岩的岩浆源区，而不是镁铁质岩浆的补给。此外，应力环境的变化可能促进了地壳浅部长期稳定、体积大、演化程度高的长英质岩浆房的形成，这对石门寺钨铜钼存款的形成至关重要。
The Shimensi W–Cu–Mo deposit is one of the largest tungsten deposits in the world. Despite numerous geochemical studies conducted on ore-related granites in the district, few studies have concerned magma chambers processes. In this study, systematic in-situ major- and trace-element studies across plagioclase crystals from the ore-related Mesozoic granites as well as whole-rock Sr–Nd isotopic compositions of such granites in the Shimensi deposit were used to constrain the sources of calcium, the dynamics of the magmatic system and the metallogenic geodynamic setting. In-situ analyses of plagioclase showed no obvious positive correlations between An and FeO, while Sr was positively correlated with Ba, indicating that the magma chambers in the Shimensi deposit may have experienced chemically-closed evolution affected only by thermal mixing and/or decompression, without chemical mixing with mafic magma from the mantle. This conclusion was also supported by whole-rock Sr–Nd isotopic characteristics of high (87Sr/86Sr)i (0.71664–0.73689) and negative εNd(t) values (−9.81 to −5.07). It was found that the calcium needed for scheelite mineralization may have been predominantly provided by biotite granodiorite (BG) because of its high calcium content and large size, while oreforming metals should mainly have been derived from the magma sources of pelites and basic volcanic rocks in the Shuangqiaoshan Group instead of the recharging of mafic magma. Moreover, change of the stress environment likely facilitated the formation of long-term stable, large-volume, highly evolved felsic magma chambers in the shallow crust, which would have been critical to the formation of the giant Shimensi W–Cu–Mo deposit.
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影响因子：
3.1
作者：
Akira Tsune;A. Toramaru
通讯作者：
Akira Tsune;A. Toramaru
DOI：
10.1016/j.jvolgeores.2015.03.013
发表时间：
2015-05
影响因子：
2.9
作者：
P. Shane
通讯作者：
P. Shane
影响因子：
3.5
作者：
A. Pietranik;J. Koepke;J. Puziewicz
通讯作者：
A. Pietranik;J. Koepke;J. Puziewicz
DOI：
--
发表时间：
2007
期刊：
--
影响因子：
--
作者：
SrnpHnN T. NBr;Anr MoNrANrA
通讯作者：
SrnpHnN T. NBr;Anr MoNrANrA
影响因子：
3.5
作者：
M. Wilke;H. Behrens
通讯作者：
M. Wilke;H. Behrens