Infrared microthermometric and stable isotopic study of fluid inclusions in wolframite at the Xihuashan tungsten deposit, Jiangxi province, China
Infrared microthermometric and stable isotopic study of fluid inclusions in wolframite at the Xihuashan tungsten deposit, Jiangxi province, China
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DOI：
10.1007/s00126-011-0377-0
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发表时间：
2012-08
影响因子：
4.8
通讯作者：
Wen-Feng Wei;R. Hu;X. Bi;Jian‐tang Peng;W. Su;Shengqiong Song;Shaohua Shi
中科院分区：
文献类型：
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作者：
Wen-Feng Wei;R. Hu;X. Bi;Jian‐tang Peng;W. Su;Shengqiong Song;Shaohua Shi
江西西华山钨存款矿床是产于寒武系地层和中生代花岗岩体中的世界级脉状存款矿床。主要有两组近平行的含矿石英脉。矿石矿物组合为黑钨矿和黑钨岩，并含有少量毒砂、黄铜矿和黄铁矿。黑钨矿中只有两相富水包裹体，而石英中至少有三种主要类型的包裹体：两相或三相富CO2包裹体、两相纯CO2包裹体和两相水包裹体，指示沸腾作用。黑钨矿中流体包裹体具有较高的均一温度和盐度（239-380°C，3.8- 13.7wt.% NaCl当量）与石英中的那些（177-329°C，0.9-8.1重量%）相比，NaCl当量）。这些明显的差异表明，那些传统的石英显微测温数据不足以解释成矿过程。焓-盐度图显示线性关系，意味着不同来源的流体的混合。虽然沸腾作用发生在脉型成矿过程中，但在黑钨矿沉积过程中似乎可以忽略不计。混合作用是锡华山黑钨矿沉淀的主导机制。硫化物的δ 34 S值介于−1.6至+0.1‰之间，表明硫的岩浆来源。黑钨矿的δ 18 O值较均一，为+4.8‰ ~+6.3‰。沸腾和混合过程的氧同位素模拟也表明，两种不同流体的混合是黑钨矿沉淀的重要机制。
The Xihuashan tungsten deposit, Jiangxi province, China, is a world-class vein-type ore deposit hosted in Cambrian strata and Mesozoic granitic intrusions. There are two major sets of subparallel ore-bearing quartz veins. The ore mineral assemblage includes wolframite and molybdenite, with minor amounts of arsenopyrite, chalcopyrite, and pyrite. There are only two-phase aqueous-rich inclusions in wolframite but at least three major types of inclusions in quartz: two- or three-phase CO2-rich inclusions, two-phase pure CO2inclusions and two-phase aqueous inclusions, indicating boiling. Fluid inclusions in wolframite have relatively higher homogenization temperatures and salinities (239–380°C, 3.8–13.7 wt.% NaCl equiv) compared with those in quartz (177–329°C, 0.9–8.1 wt.% NaCl equiv). These distinct differences suggest that those conventional microthermometric data from quartz are not adequate to explain the ore formation process. Enthalpy–salinity plot shows a linear relationship, implying mixing of different sources of fluids. Although boiling occurred during vein-type mineralization, it seems negligible for wolframite deposition. Mixing is the dominant mechanism of wolframite precipitation in Xihuashan. δ34S values of the sulfides range from −1.6 to +0.1‰, indicative of a magmatic source of sulfur. δ18O values of wolframite are relatively homogeneous, ranging from +4.8‰ to +6.3‰. Oxygen isotope modeling of boiling and mixing processes also indicates that mixing of two different fluids was an important mechanism in the precipitation of wolframite.