Linking the Cryogenian Manganese Metallogenic Process in the Southeast Margin of Yangtze Block to Break-up of Rodinia Supercontinent and Sturtian Glaciation

The metallogenic process of Cryogenian Datangpo-type manganese deposit in the southeast margin of Yangtze Block is closely related to the development of Nanhua Rift Basin and Sturtian glaciations interglaciation.Accompanying with the break-up of Rodinia supercontinent,the Nanhua Rift Basin distributed in NEE trend,it can be divided into graben and horst and each graben can be further divided into subgraben and subhorst.The manganese deposit formed in the subgrabens within the graben area.After the Sturtian glaciation,cold events disturbed the warming process and both cold and oxidized freshwater came from the melted glacier.Cold and oxidized seawater generated from cold events could lead to the oxidation of the bottom water in the basin.Dissolved Mn²⁺ in the bottom water was then oxidized to Mn oxides and hydroxides and precipitated into the sediments.In early diagenesis stage,the organic materials reacted with Mn oxides and hydroxides and formed rhodochrosite.We suggest that methane leaking in post-glaciation accelerated this metallogenic process.The Mn metallogenic process in the Southeast margin of Yangtze Block is controlled by the original rift basin structure and paleoclimatic fluctuations in Sturtian glaciation and post-glaciation.