Helium and argon isotope geochemistry of the Tibetan Qulong porphyry Cu-Mo deposit,China

作者：Keqiang Peng,Liyan Wu,Yong Huang,Ke Jiang

摘要：The Qulong porphyry Cu-Mo deposit,generated in the Miocene post-collisional extension environment of the Gangdese Copper(Molybdenum)Metallogenic Belt,is one of the largest porphyry Cu deposits in China.This study reports the noble gas isotopic compositions of volatiles released from fluid inclusion reserved in pyrite from the Qulong deposit.3He/4 He and 40Ar/36Ar ratios range from 0.54 to 1.015 Ra and 300-359,respectively.Concentrations of 4 He and 40Ar range from 1.77 to 2.62×10^(-8)cm^(3)STP and 1.7-34×10^(-8)cm^(3)STP,respectively.The isotopic composition of noble gases indicates that the ore-forming fluids of the Qulong Cu-Mo deposit were a mixture of fluid containing mantle component,which is exsolved from the porphyry magma,and crustal fluid characterized by atmospheric Ar and crustal radiogenic He.Theδ34S values of pyrite and molybdenite range from-0.52‰to 0.31‰,with an average of-0.12‰,indicating a magmatic origin.More mantle components were involved in the Cu-Mo deposit than in the Mo-Cu deposit in the Qulong-Jiama ore-district.

发文机构：State Key Laboratory of Ore Deposit Geochemistry University of Chinese Academy of Sciences College of Eco-Environmental Engineering

关键词：HeandArisotopesSulfurisotopeQulongCu–ModepositOre-formingfluidTibetChina

分类号： P61[天文地球—矿床学]