Geology, fluid inclusions, isotope geochemistry, and geochronology of the Paishanlou shear zone-hosted Gold Deposit, North China Craton

The well-defined Ar/Ar plateau age (126.6 ± 1.1 Ma) of biotite from the NNE ductile shear zone provides a possible temporal link between Au mineralization, magmatism and deformation at the Paishanlou deposit. The concordance of the biotite age with other well-constrained mineralization ages for the deposit, and the intrusion age of the granite, suggests that Au mineralization was essentially contemporaneous with late Mesozoic granitic magmatism and the second stage of mylonitization. In terms of its genetic linkage with the subduction process at the leading northern edge of the North China Craton, the Paishanlou deposit can be favored as an orogenic gold deposit. Its formation benefited from the combined action of protracted activity of ductile fault zones, hydrothermal circulation associated with granitoid intrusion and preferred structural setting favoring gold deposition. The major geodynamic switch towards generalized extensional tectonics that occurred during uplift, and thinning of the upper crust after the collisional stages in the northern edge of the North China Craton, may be the key factors controlling Au concentration and enrichment in the Paishanlou deposit.