Lead Isotope Geochemistry of the Jilongshan Skarn-Host Au-Cu Deposit, Hubei Province, China

Abstract

Jilongshan Au-Cu deposit is a typical skarn deposit in the southeastern Hubei metallographic province of the Middle-Lower Yangtze River Fe-Cu metallogenic belt. But little study of ore-forming material source has been made in Jilongshan Au-Cu deposit. Therefore, we discussed the ore-forming material source by analyzing 15 lead geochemistry samples collected in Jilongshan deposit. The ranges of the Pb isotopic compositions are from 17.358 to 18.589 for 206Pb/204Pb, 15.414 to 15.745 for 207Pb/204Pb and 37.956 to 39.094 for 208Pb/204Pb, which are anomalous and their single-stage model ages cannot be used as a criterion for metallogenic epoch. However, the distributing characteristics of the single-stage model ages suggest that the ore Pb have mixing sources. The linear distribution of Pb isotope in tectonic model diagram suggests that the consistent relation of granodiorite porphyry, skarn, marble and ore, which is also a good proof that the ore-forming materials are partly from magma.