RUAN Kun1,2, PAN Jia-yong2, WU Jian-yong1, XIANG Xin-kui3, LIU Wen-quan1, LI Zhong-shu1
1. No.290 Research Institute, CNNC, Shaoguan, Guangdong 512026, China;
2. National Defense Key Discipline Laboratory of Radioactive Geology and Exploration Technology, East China Institute of Technology, Nanchang 330013, China;
3. No.916 Geological Party, Jiangxi Bureau of Geology & Mineral Exploration, Jiujiang, Jiangxi 332100, China
Abstract: To explore the genesis of the Shimensi cryptoexplosive breccia type tungsten deposit in Dahutang, detailed field observation and indoor appraisal of rock ore has been carried out. Furthermore, quartz inclusions and sulfur isotope compositions of cryptoexplosion breccia type ores were tested by using micro thermometry. The results showed that δ34S values of twelve chalcopyrite samples are between -1.4‰ and -0.1‰ with an average of -0.82‰ and δ34S values of three molybdenite samples are between -0.8‰ and 0.2‰ with an average value -0.33‰. The above figures showed that sulfur mainly came from deep magma or upper mantle. In addition, the homogenization temperature is between 152.1 and 387.1℃, concentrating on 170 to 250℃. The salinity is between the range of from 4.8% to 14.9% NaCleq(wt) with an average of 10.8% NaCleq(wt), concentrating on 8% to 14% NaCleq(wt). The results showed that the ore-forming fluid belongs to the system of NaCl-H2O±CO2 with middle temperature and medium-low salinity, which has gone through the boiling mixture action by the composition of magmatic hydrothermal and atmospheric rainfall with low temperature and low salinity in the evolution process, and the boiling mixture action of fluid is the primary cause of complex decomposition and precipitation in the type of ore-fluid.
Keywords: cryptoexplosive breccia sulfur isotope fluid inclusion Shimensi tungsten deposit in Dahutang
Bulletin of Mineralogy, Petrology and Geochemistry Vol. 34, No.3, 2015, page 633-641