Sulfur isotopic composition of the Bainiuchang super-large Ag polymetallic deposit, Yunnan Province, China： Implications for the source of sulfur in ore-forming fluids

• Published in: Acta geochimica Vol. 28; no. 3; pp. 284 - 292
• Main Authors: Xie, Hongjing, Zhu, Chaohui, Zhang, Qian, Wang, Dapeng, Fan, Liangwu
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science Press 01.09.2009; Springer Nature B.V; Graduate School o the Chinese Academy of Sciences, Beijing 100039, China%State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China; Scientific Research Institution of State Land Resources, Henan Province, Zhenzhou 450053, China%State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China; State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
• Subjects: Cambrian; Earth and Environmental Science; Earth Sciences; Fluids; Geochemistry; Igneous rocks; Isotopes; Ocean floor; Studies; Sulfides; Sulfur; 云南省; 成矿时代; 成矿流体; 白牛厂; 硫同位素组成; 超大型; 银多金属矿床; China; Bainiuchang Ag-polymetallic deposit; ore-forming fluid; China; Yunnan Province; sulfur isotopic composition; Yunnan Province,China
• ISSN: 1000-9426; 2096-0956; 1993-0364; 2365-7499
• DOI: 10.1007/s11631-009-0284-6

The Bainiuchang deposit in Yunnan Province, China, is located geographically between the Gejiu ore field and the Dulong ore field. In addition to 〉7000 t Ag reserves, the deposit possesses large-scale Pb, Zn, Sn reserves and a mass of dispersed elements （i.e., In, Cd, Ge, Ga, etc.）. Based on systematic studies of sulfur isotopic composition, the authors conclude： The Bainiuchang deposit experienced two epochs of metallogenesis, i.e., the Middle-Cambrian sea-floor exhalative sedimentary metallogenic epoch and the Yanshanian magmatic hydrothermal superimposition metallogenic epoch. In the two metallogenic epochs, the δ^34S values of sulfides were all near 0, showing a tendency of being enriched slightly in heavy sulfur. The δ^34S values of sulfides in the early metallogenic epoch are within the range of 2‰--5‰ with a peak value range of 2‰-3‰ and an average of 3.0‰, and those of sulfides in the/ate metallogenic epoch are within the range of 2‰--6‰ with a peak value of 3‰-4‰ and an average of 3.9‰. For the single metallogenic epoch, sulfur in the ore-forming fluids in the early epoch already reached isotopic equilibrium and was derived mainly from underneath the magma chamber or basement metamorphic igneous rocks. Sulfur in the sulfides in the late epoch was derived mainly from magmatic hydrothermal fluids formed in the process of remelting of the basement metamorphic igneous rocks.