Time-Space Distribution of Tin/Tungsten Deposits in South China and Controlling Factors of Mineralization
The abundant tin and tungsten deposits in South China were formed in different geologic ages. They began to appear in the late Protereozoic, and reached their paramount development during the Yenshanian period. In regional distribution the W deposits tend to occur in the eastern part of this region, mostly in post-Caledonian uplifts, while the Sn deposits tend to occur in the western part, mostly in Hercynian-Indosinian depressions. Both of them are found either within the middle-late Pro-terozoic and lower Paleozoic basemental structure, or adjacent to the basement rocks. Genetically, they are mainly associated with continental crustal anatectic granitoids. The following factors are considered to be most important in controlling the time-space distribution of Sn/W deposits: regional existence of ore source beds of middle-late Proterozoic and early Paleozoic ages; crustal mechanism in the generation of multi-cyclic granitoids and their evolution; activities of ore-bearing hydrothermal solutions; and localization of Sn/W mineralization in close relation to structural environment and wall rock properties.