ISSN: 1003-6326
CN: 43-1239/TG

Vol. 27    No. 6    June 2017

Geochemical characteristics of auriferous pyrite in Longtoushan gold deposit, Guangxi Province, China
TAO Shi-long1, LAI Jian-qing1, ZHANG Jian-dong1, QIAN Li-hua1, HU Li-fang1, CAO Rong1, YOU Fei1, HUANG Chong2, LI Liao-hui2, HUANG Rui2, LIANG Chong-gao2
(1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, Ministry of Education, School of Geosciences and Infophysics, Central South University, Changsha 410083, China;
2. Guigang Jindi Mining Co., Ltd., Guigang 537100, China
Abstract: The Longtoushan gold deposit, located in southern Qinhang metallogenic belt, is one of the important deposits in the Dayaoshan region, different stages of pyrite were found in the deposit. According to the characteristics of occurrence, pyrites are divided into 5 types, corresponding to 5 stages: tourmaline-quartz-sulfide stage (Ⅰ), quartz-pyrite-chalcopyrite stage (Ⅱ), quartz-polymetallic sulfide stage (Ⅲ), quartz-pyrite-sphalerite stage (Ⅳ) and quartz-pyrite stage (Ⅴ). REE and trace element analysis data of pyrites show that the ore-forming fluid of gold mineralization is mainly magmatic hydrothermal with medium-high temperature and reducing, and the fluid is characterized by rich Cl- and poor F-. Au mainly is migrated by the way (AuCl2)- complexes. δ34SCDT values of pyrites range from +1.29×10-3 to +2.01×10-3, showing that ore-forming materials is derived from deep magma. Values of μ and Th/U are 9.63-9.84 and 3.87-4.00, respectively. The narrow range of Th/U shows the characteristics of stable lead isotope. Based on the above analysis, ore-forming materials are from deep magma caused by basement crust remelting and the ore-forming fluid is mainly post-magmatic hydrothermal.
Key words: pyrite; rare earth element; trace element; S isotope; Pb isotope; ore-forming fluid; ore-forming material
Superintended by The China Association for Science and Technology (CAST)
Sponsored by The Nonferrous Metals Society of China (NFSOC)
Managed by Central South University (CSU)