A critical review of Early Paleozoic W and Cu mineralized and barren granitoids in Southeast China: Magmatic differentiation, oxygen fugacity, and magmatic sources

Abstract

In Southeast China, large-scale W and Cu mineralization is traditionally thought to be related to the Late Mesozoic granitoids. However, recent studies have revealed that the Early Paleozoic granitoids have great potentials for exploration of W and Cu deposits. A critical review of magmatic differentiation, oxygen fugacity and sources of major Early Paleozoic W and Cu-mineralized and barren granitoids demonstrates that the magmatic sources were important factors controlling W and Cu mineralization. In contract to Early Paleozoic ore barren granitoids east of the Chenzhou-Linwu fault (CLF), coeval W and Cu-mineralized granitoids to the west of this fault were derived from relatively fertile sources rich in W and Cu. Specifically, the W-mineralized granitoids were originated mainly from the partial melting of W-rich crustal materials of the basement rocks in the Jiangnan Orogen affinity. The sources of the Early Paleozoic Cu-mineralized granitoids may have been added Cu-rich Neoproterozoic arc-derived materials as evidenced by decoupled Nd-Hf isotopic compositions. Considering that the Precambrian basements in the Jiangnan Orogen have much higher W and Cu contents than those in the Cathaysia Block, we propose that the Early Paleozoic granitoids west of the CLF have greater W and Cu metallogenic potential than those to the east of this fault.