GUO Yu1，CHEN Deng1.2*，TANG Zi-cheng1，LIU Zhi-chen1.2.3，ZHANG Xiao-dong1
(1. 102 Geological Party，Guizhou Bureau of Geology and Mineral Exploration and Development, Zunyi 563003, China;
2. Innovation Center for Mineral Exploration Engineering Technology in the Bedrock Area of the Ministry of Natural Resources, Guiyang 550009, China;
3. School of Resources and Environment, Guizhou University, Guiyang 550009, China)
Abstract: A large number of fluorite deposits (occurrences) are distributed in the northeastern Guizhou and southeastern Chongqing. These deposits (occurrences) are mainly distributed in the NW- and NNW-trending extensional faults within limestone beds of the lower Ordovician Tongzi and Honghuayuan formations in two sides of the NE-trending regional faults. Their orebodies occurred mainly in forms of vein or lens. They are gradually pinched out in the deeply distributed lower Ordovician Tongzi Formation. The origins and material sources of fluorite deposits in this area have been controversially debated for a long time. The Jinliang fluorite deposit is a representative small-scale fluorite deposit in the Yanhe area in the northeastern Guizhou. In this paper, we have conducted REE geochemical research of fluorites in this deposit. The results show that fluorite samples have ΣREE contents, LREE/HREE, δEu and δCe values ranging from 67.4×10-6 to 90.55×10-6, from 43.98 to 78.78, from 77.07 to 94.71, and from 0.39 to 0.42 respectively. The REE distribution patterns of fluorites in the deposit are characterized with obviously right-declined curves, relatively LREE enriched patterns, obvious Eu positive and Ce negative anomalies. Combined with geological characteristics of the deposit, it is believed that the Jinliang fluorite deposit is a product of hydrothermal genesis, and its fluorite was formed by the homologous and contemporaneous hydrothermal fluid in an oxidized environment. The mineralization of fluorite could be closely related to sedimentary rocks. It is believed that the Ca could be mainly sourced from the limestone of the Lower Ordovician Honghuayuan Formation, and could be partially sourced from carbonate rocks in the depth, while the F could be mainly sourced from the high-fluorine strata of the Upper Sinian Doushantuo Formation and the Lower Cambrian Mingxinsi Formation.
Keywords: fluorite deposit; source of ore-forming materials; host rock; rare earth elements; Jinliang
