The Shizhuyuan ore deposit in southern Hunan Province is a world-class W-Sn-Bi-Mo occurrence hosted by Devonian limestone in the thermal aureole of the Qianlishan granite. Mineralization coincided with intrusion of the granite pluton during Mesozoic crustal extension in South China. We present new He and Ar isotope data for volatiles released from pyrite in the Shizhuyuan deposit. Concentrations of ⁴⁰Ar range from 0.21 to 2.38x10-6cm3 STP ⁴⁰Ar/g, and ⁴He concentrations range from 0.8 to 65.1x10-6cm3 STP ⁴He/g. 3He/4He ratios vary from 0.06 to 1.66Ra (where Ra is the ³He/⁴He ratio of air=1.39x10-6) and ⁴⁰Ar/³⁶Ar ratios range from 293 to 1072. The isotopic compositions of He and Ar indicate that the ore-forming fluids were mantle-derived, modified by air-saturated crustal fluids. Shallow-level boiling increased ³He concentrations, whereas crustal contamination decreased ³He/⁴He ratios in the magmatic fluids. The occurrence of mantle-derived components in the magmatic fluid indicates that the associated Qianlishan granite is not a typical S-type pluton that formed entirely by crustal melting. We propose that the mineralization was related to mantle upwelling and Mesozoic lithosphere extension of the South China Block.

Publication name	INTERNATIONAL GEOLOGY REVIEW　　Volume: 53　　Issue: 5-6　　Special Issue: Sp. Iss. SI　　Pages: 677-690　　Published: 2011
Author(s)	Wu, Li-Yan; Hu, Rui-Zhong; Peng, Jian-Tang; Bi, Xian-Wu; Jiang, Guo-Hao; Chen, Hong-Wei; Wang, Qiao-Yun; Liu, Ya-Ying
Corresponding author	HU, Rui-Zhong  huruizhong@vip.gyig.ac.cn  Chinese Acad Sci, Inst Geochem, State Key Lab Ore Deposit Geochem, Guiyang 550002, Peoples R China