Melt recharge, f O2-T conditions, and metal fertility of felsic magmas: zircon trace element chemistry of Cu-Au porphyries in the Sanjiang orogenic belt, southwest China

The magmatic hydrothermal Pulang Cu deposit (Triassic) and the Beiya Au-Cu deposits (Eocene) are located in the Sanjiang copper porphyry belt, southwest China. Zircon chemistry was used to constrain the magmatic evolution and oxidation state of the porphyries. The results show that porphyries of the Beiya district formed from an early oxidized melt and a later relatively reduced and more evolved magma, whereas Pulang experienced a normal Cu...