Molybdenite Re-Os Geochronology and S, Pb Isotopic Characteristics of Banchang Copper Polymetallic Deposit in Neixiang, Henan Province
Zeng Wei
Xu Yawen
Sun Fengyue
Zhang Feng
Lian Shipo
Li Shengli
Yu Reng'an
Hao Shuang
Ao Cong
Abstract：A great breakthrough has been achieved in prospecting in Banchang copper polymetallic deposit, East Qinling orogenic belt in recent years, which is characterized by obvious mineralization zoning in the mining area.The Cu, Pb, Zn and Ag mineralizations are developed in the upper part, and the Cu and Mo mineralizations are located in the lower part of the mining area.With Re-Os isotopic dating of molybdenite, LA-ICP-MS zircon U-Pb dating of granite rocks, sulfur and lead isotopic tracing of metal sulfide, the metallogenic time, ore genesis and metallogenic dynamic setting of the deposit are discussed in this study.Re-Os model ages of six molybdenite samples are 149.8±2.4Ma to 151.5±2.3Ma, with the weighted average age of 150.7±1.9Ma and isochron age of 151.0±4.6 Ma, indicating that the metallogenic epoch was Late Jurassic.The zircon U-Pb age of Zhifanggou granite porphyry which is located to the south of Banchang deposit is 148±1Ma, indicating that magmatic activities occurred during the metallogenic period.Elevenδ34SV-CDTvalues for sulfides range from-1.2‰to+1.2‰, and the values are interpreted to reflect a deep magmatic source of the sulfur.In addition, the results show that 206Pb/204Pb values range from17.178to 17.709, 207Pb/204Pb values range from 15.430to 15.528and 208Pb/204Pb values range from 37.476to 37.847, which are similar to lead isotope values of Yanshan Period granites in North Qinling and the crustal basement of South Qinling but very different from lead isotope values of the North Qinling strata.It is concluded that Banchang copper polymetallic deposit belongs to skarn-like type-hydrothermal vein type deposit which is related to Yanshannian magmatic activity, and it formed in the lithospheric thinning setting of East Qinling.
Keywords：Yanshannian Periodmagmatic hydrothermalstable isotopeBanchang copper polymetallic depositEast Qinling orogenic beltgechronology
Publication Date：2019-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：14( 109-122 )