JIN Shao-rong1, CHEN Jun3, DAI De-rong1, YANG De-zhi1, ZHOU Jia-xi2,3*, HE Xiao-hu2
(1. Institute of Geophysical and Geochemical Prospecting, Bureau of Geology and Mineral Exploration and Development of Guizhou Province, Guiyang 550018, China;
2. School of Resource Environment and Earth Science, Yunnan University, Kunming 650504, China;
3. Stake Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China)
Abstract: Fluorite is a scarce strategic resource. It was previously studied as gangue mineral of other element deposits due to the small numbers of fluorite independent deposits which were limitedly studied as a deposit. The Gaoling fluorite deposit is a newly discovered independent fluorite deposit with associated weak Sb mineralization in the periphery of the Qinglong Sb deposit in southwest Guizhou. Based on the geological study of the Gaoling independent fluorite deposit, by using the micro-drill sampling technique and microwave digestion method, we have obtained the in situ analytical data of trace and rare earth elements in different colored fluorites and various positions of fluorite grains. The results show that the fluorite samples are obviously enriched in low-temperature elements such as As and Sb, but depleted in other elements in different degrees comparing to the upper crust, indicating that these fluorites have low-temperature mineralization characteristics. This is according with the measured homogenization temperature results of fluid inclusions (90-200 ℃). All fluorite samples have similar REE distribution patterns and relatively low ΣREE contents ranging from 11.4×10-6 to 105×10-6, with an average value of 46.6×10-6. The ΣREE contents of the purple fluorites are obviously higher than those of the white and light green ones. This indicates that different colored fluorites could be formed by the evolved ore-forming fluids in different stages of evolution. In addition, all fluorites have very weak Eu anomalies (δEu = 0.91-1.20, average 0.98), but have obviously negative Ce anomalies (δCe = 0.51-0.90, average 0.68), suggesting that these fluorites could be formed in a relatively reduced environment. This is consistent with the fact that there is Sb mineralization in fluorite. In summary, we have considered that the Gaoling fluorite deposit was formed in a reduced environment with characteristics of the low-temperature hydrothermal genesis. Both the Gaoling and Qinglong deposits are within the Qinglong metallogenic belt which is one of the important components of the large-area low-temperature metallogenic region in South China.
Keywords: fluorite; trace and rare earth elements; metallogenic environment; Gaoling fluorite deposit
