Geochronology and Physical-Chemical Conditions of Skarns in Chengmenshan Cu Deposit,Northwestern of Jiangxi Province,Eastern China
Zhong Hao
Xu Yaoming
Xiao Juwei
Kong Fanbin
Abstract：In the purpose of understanding formation time and physical-chemical conditions of skarn in Chengmenshan Cu deposit of northwestern Jiangxi Province,we use garnet to do U-Pb isotopic dating,EPMA major elements analyze and LA-ICPMS trace elements analyze,combined with TIMA automated mineral analyze,the skarn forming age of 146.2±1.1 Ma is acquired,and the mineral composition is mainly garnet(Andradite with And value average 95%),LREE elements are enriched and HREE elements are depleted,and Eu show obviously positive anomalies.Therefore we conclude that Chengmenshan Cu deposit own two times of skarn forming respectively corresponding to the formation of granodiorite porphyry and quartz porphyry.Strong oxidized,acidic,high salinity and advective metasomatism conditions are the environment of skarn forming,and magmatic fluids is the major source of these skarns.The physical-chemical conditions like f O2,pH,Cl-concentration varied systematically with the change of W/R ratio during the formation process of Chengmenshan skarns.
Keywords：Middle-Lower Yangtze River Metallogenic BeltChengmenshanskarngeochronologyphysical-chemical conditionsgeochemistry
Publication Date：2025-02-14
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：13( 596-608 )