江西朱溪钨矿床矽卡岩矿物热红外光谱学特征研究

朱溪钨矿床白钨矿化与矽卡岩化密切相关，白钨矿多与石榴子石、透辉石等矽卡岩矿物一起产出。该研究对朱溪典型矽卡岩矿物如石榴子石、透辉石、符山石、硅灰石、阳起石等进行显微红外光谱测量和电子探针分析，探究朱溪矽卡岩矿物的热红外光谱特征及其对成矿的指示意义，并建立朱溪地区的矽卡岩矿物热红外光谱库。结果表明，朱溪钨矿床石榴子石主要为钙铝—钙铁榴石系列，在800和920 cm^-1附近存在一大一小两个吸收峰，在880 cm^-1附近存在特征吸收谷；当石榴子石成分中钙铝榴石含量大于50%时，石榴子石特征吸收谷位于880～900 cm^-1,当钙铝榴石含量小于50%时，石榴子石吸收谷位于865～875 cm^-1。随着Al₂O₃含量增加，其特征吸收谷向高波数方向移动，钙铝榴石偏向高波数，钙铁榴石偏向低波数；辉石主要为透辉石—钙铁辉石系列，在850～950 cm^-1波数范围内存在诊断式、呈阶梯状降低的吸收峰，且在1 050 cm^-1处存在吸...

A Study on the Thermal Infrared Spectroscopy Characteristics of the Skarn Minerals in Zhuxi Tungsten Deposit,Jiangxi Province

The mineralization of scheelite in the Zhuxi tungsten deposits is closely related to skarnization. Scheelite is mostly produced together with skarn minerals such as garnet and diopside. In this study, for the first time, the typical skarn minerals such as garnet, diopside, vesuvianite, wollastonite and actinolite are measured by micro infrared spectroscopy and electron probe analysis to explore the thermal infrared spectral characteristics of skarn minerals in Zhuxi and their implications for mineralization, and to establish a thermal infrared spectral library of skarn minerals in Zhuxi area. The results show that the garnet in Zhuxi tungsten deposit is mainly grossular-and radite series. There are two absorption peaks (a large and a small) near 800 and 920 cm-1, and there is a characteristic absorption valley near 880 cm-1. When the grossular content in garnet is greater than 50%, the characteristic absorption valley of garnet is located at 880~900 cm-1. When grossular content is less than 50%, the absorption valley of garnet is located at 865~875 cm-1. With the increase of Al₂O₃ content in garnet, the characteristic absorption valley moves towards the high-wavenumber direction. Grossular tends to high wavenumber while andradite tends to low wavenumber; Diopside is mainly diopside-hedenbergite series. There is a diagnostic step-shaped absorption peak in the wavenumber range of 850~950 cm-1, anabsorption peak at 1 050 cm-1 and a weak double-valley absorption at 1 000 cm-1. With the decrease of diopside content, MgO content decreases the diopside absorption peak moves to the low-wavenumber direction. The absorption peak of hedenbergite is concentrated in the low-wavenumber range compared with diopside, which is consistent with the changing law of garnet. It is speculated that the reason is that Al and Mg are more active than Fe. Vesuvianite has similar absorption peaks in the range of 850~950 cm-1 as diopside. The difference is that vesuvianite still has anabsorption peak at 800 cm-1; Wollastonite has three absorption peaks (a large and two small) near 875, 1 000 and 1 060 cm-1, and two characteristic absorption valleys near 980 and 1 040 cm-1; Actinolite has two absorption peaks (a small and a large) near 750 and 900 cm-1, and three characteristic absorption valleys near 770, 930 and 1 020 cm-1.The scheelite mineralization in the Zhuxi deposit is most closely related to garnet and diopside, and it mainly grows in veins along the boundary of garnet and diopside. Their thermal infrared spectra can be used as an indicator for searching for scheelite. The above results have theoretical and practical significance for in-depth analysis and research on the mineralogy characteristics and genetic environment of the Zhuxi tungsten deposit in Jiangxi, as well as for exploring the possibility of using thermal infrared technology to guide skarn mineral zoning and ore prospecting.