Rare metal deposits in South China: Types, characteristics, distribution and tectonic setting

South China is an important strategic mineral resource base in China. It is famous for the occurrences of multi-stages granite and related large scale Mesozoic Cu-Mo-W-Sn-Nb-Ta-Be-REE mineralization. The mineralization of rare metals (W-Sn-Nb-Ta-Be) in the area is closely related to highly differentiated granites, and is obviously controlled by regional faults. The distribution of rare metal deposits in South China is mainly concentrated in Nanling area and the close to and the both sides of the Qin-Hang fault. The main metallogenic types are composed of granite-type, pegmatite-type, quartz-vein-type, volcanic-hosted-type and replacement-type (including the skarn-type and ribbon rock-type). Granite-type deposits are mainly distributed along both sides of Qin-Hang fault; Pegmatite-deposits are mainly distributed outside of Qin-Hang fault as well as between Shaowu-Heyuan fault and Zhenghe-Dapu fault; The replacement-type deposits are mainly distributed in the Nanling area in the east-west direction, while the quartz-vein-type deposits are genetically related to the quartz-vein type tungsten deposits in Nanling; The volcanic-hosted-type deposits are mainly distributed in the southeastern coastal volcanic area to the east of Zhenghe-Dapu fault. The metallogenic epoch of the rare metal deposits in South China can be divided into seven periods: Silurian (424 similar to 420Ma), Early Triassic (248 similar to 244Ma), Late Triassic (220 similar to 214Ma), Later Jurassic (160 similar to 150Ma), Late Jurassic-Early Cretaceous (150 similar to 140Ma), Early Cretaceous (135 similar to 125Ma) and Early Cretaceous-Late Cretaceous (105 similar to 90Ma). They are quite difference in the metallogenic intensity and the metallogenic scale. However, the large-scale mineralization is mainly concentrated in the Early Cretaceous. On the ore field scale, rare metal mineralization has obvious metal zoning, and has experienced obvious genetic relationship with non-ferrous metal mineralization; Rare metal deposits with different metal assemblages have different longer magmatic-hydrothermal evolution history. Partial melting of crustal materials, continuous energy supply and large-scale extension favorable for magma differentiation and evolution, they are the key factors for the formation of large-scale rare metal deposits. The paper concluded that the Early Cretaceous (135 similar to 125Ma) is a key period for large-scale rare metals mineralization in South China, which not only has the highest intensity of mineralization, but also has various types of mineralization, representing the peak period of large-scale thinning or disintegration of the continental lithosphere in Mesozoic in South China.