Mesozoic Mo-W-Ag-Pb-Zn mineralization in the Nannihu area, western Henan Province, China

Abstract

There are many Mesozoic hydrothermal Mo-W-Ag-Pb-Zn deposits in the Nannihu area, west Henan Province, which is located in the eastern part of the Jinduicheng-Nannihu Mo-W polymetallic metallogenic belt of the southern margin of the North China Craton. Deposit types in the Nannihu area include porphyry-skarn Mo-W deposits, skarn polymetallic pyrite deposits, and structurally-hosted, altered-rock Ag-Pb-Zn deposits. These deposits show a consistent spatial-temporal association with Late Jurassic magmatism. Sulfur and lead isotopic compositions indicate that ore was mainly derived from the lower crust. Hydrogen-oxygen isotope compositions indicate that ore fluids were derived from primary magmatic water in the early stages, and a mixture of magmatic and meteoric water in the later stage. During a period of tectonic regime transitions in eastern China in the Late Jurassic, underplating of mafic magma, partly remelting of the lower crust, and intrusion of acid magmas developed successively, resulting in extensive mineralization in the area.