Geochemical characteristics of Sinian manganese deposits in China

Sinian is one of the main periods of the formation of manganese deposits in China. Sinian manganese deposits are mainly hosted in carbon-rich black sh ale and siliceous shale formed during the Sinian interglacial period. The c omposition of manganese ore is simple. The main ore mineral is manganiferou s carbonates. The grade of manganese ore is about 16-25%, with Mn/Fe>S and P/Mn=0.006-0.14. Based on the tectonic setting and geological and geochemic al characteristics of manganese deposits, this paper discusses the process of migration and concentration of manganese and ore-forming conditions of S inian manganese deposits in China.