| 其他摘要 | Tengchong area of Yunnan is located in the most leading edge of the Eurasian plate and Indian plate collision, with strong structural deformation, and frequent intermediate-acid magmatic intrusion, providing excellent conditions for the tungsten tin rubidium polymetallic mineralization. The Xinqi tungsten tin rubidium polymetallic deposit of Tengchong, Yunnan procince was selected as the object of study, carried out systematic geological, mineralogical, geochemical, isotopic geochemical and chronological studies of regional granite rock and ore deposit, based on investigations of the relationship between regional granite and tungsten-tin mineralization, the geological and geochemical characteristics of tungsten, tin and rubidium polymetallic deposit, the sources of ore-forming minerals, the mineralization age, the physical and chemical conditions of ore-forming system, try to explore the ore-forming mechanism of this deposit. The main and preliminary findings obtained by this study were listed as follows: 1. The Xinqi granites mostly are biotitic granites, muscovitic granite, monzonitic granite and potassium granite. The characteristics of main and trace elements of granite show that the Xinqi granite has the characteristics of high silicon and potassium, rich calcium alkaline, weak aluminum – per-aluminous. They are relatively enriched of Rb, U, Th, Ta, Yb, lack of Sr, Ba and slightly lack of La, Ce, Zr elements. Also they have similar trace elements spider variation, rare earth distribution patterns differ slightly, which suggest that the Xinqi rock mass and the Guyong rock mass should have similar or the same material source. And that they has a relatively low Nb, Ta, Zr/Hf and relatively high Rb/Nb, Rb/Sr ratio, Rb/Ba, Rb/Sr ratio, which reflect that the original material was crust rich clayey sandstone, it is possible that they are with the same source, but different periods, experienced diverse crystallization evolution processes. 2. Systematic mineralogy and detailed electron probe research show that the tungsten tin ores in Xinqi area, are mainly of quartz vein type and greisen type, the tungsten mainly exists in the form of wolframite, tin mainly exists in the form of cassiterite and the associated minerals are mainly molybdenite, pyrite, chalcopyrite, pyrrhotite, sphalerite (iron), bismuth, almandine and bismuthinite, fluorite, etc. Rare polymetallic deposits, including niobium thallium rubidium cesium mainly occur in the altered potassium granite, albite granite and monzonitic granite. 3. Fluid inclusion studies have shown that: the mineralization of tungsten tin type of quartz vein are mainly divided into two phases: the early silicate - oxide phase, the homogenization temperature of inclusion is 270 ~ 290 ℃, it’s salinity ranges from4.96 to 9.47 wt %, mainly concentrated in 6 ~ 6.5 wt %, there has the main minerals such as cassiterite, wolframite, molybdenite, topaz and so on; and the late sulfide stage, the homogenization temperature of inclusion is 200 ~ 220 ℃, it’s salinity ranges from 2.07 to 8.81 wt %, mainly concentrated in 4 ~ 4.5 wt % , there has the main minerals such as pyrite, chalcopyrite, pyrrhotite, sphalerite, etc. Its temperature and salinity diagram show that the magmatic fluid is mainly of low salinity in the region.The fact that magma, from early to late, that with lower temperature has less salinity, maybe also shows the existence of atmospheric water mixing action in the process of magma evolution. 4. The range of sulfur isotope is relatively narrow in Xinqi area, mainly in the 3.77 ‰ ~ 8.19 ‰, with a mean of 5.98 ‰. Slightly higher than the sulfur isotopic composition of sulfide from deep magmatism（δ34S=0±3‰）, which shows that the source of sulfur is unitary, combining previous data, it can be known that the sulfur isotope ratio reflects that it was derived from the earth’s crust or with a small amount of mantle source material contamination. 5. There are Guyong and Xinqi granite rock bodies |
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