On Uraniferous Depositional Formation in South China

In present paper the distribution of ore - forming material and ore - forming background before forming of uranium deposits is South China are reviewed according to the forming and classification of uraniferous de-positional formations in this area. Author firstly proposes the three kinds of uraniferous depositional formation in South China, i.e. the uraniferous formation (I) of geosynclinal - type terrigenous fragment -volcanic deposit in Sinian -Cambrian periods, the uraniferous formation (II) of platform -type terrigenous fragmental deposit in Palaeozoic Era and the uraniferous formation (III) of platform - type terrigenous fragment - volcanic deposit in Mesozoic - Cenozoic Era. Most of uranium deposits in South China were controlled by those uraniferous depositional formations in space. Finally, author generalizes the principal features of uraniferous depositional formations and genetic relationship between all kinds of uranium deposits and various uraniferous depositional formations in South China. The most important features of uraniferous depositional formations include: (1) It is composed of uraniferous strata as well as non-uranlferous strata; (2) Uranium abundance in it is higher than that in the earth crust, in general several times or tens times; (3) It is rich in organic material, pyrite, carbonaceous - pelite and phosphate etc. which could intensely adsorb and reduce uranium ( VI ) ; (4) In rocks uranium element unevenly distributes, often in the condition of multipeak; (5) Uranium element mainly is in the form of adsorption in rocks; (6) Uranium -rich strata relatively are rich in elements of P. Mo, Ni, V, Zn, Cu, Pb, Ag etc. . Among three formations the uraniferous formation of geosynclinal -type terrigenous fragment -volcanic deposit in Sinian - Cambrian periods (I) is the most important for forming of uranium deposits in South China. The geosynclinal-type depositional formations in Proterozoic Era are the ancient (maybe the most ancient) uraniferous strata in South China.