Geology, Geochemistry and Genesis of the Dongping Manganese Deposit, Guangxi Province, China

Triassic is one of the most important manganese (Mn) metallogenic epoch, and there are many great to medium sized Mn ore deposits in South China. Dongping manganese deposit is located in the metallogenic belt of southwest Guangxi Zhuang Autonomous Region. In this paper, we discussed sources and genesis of Mn ore deposit by detailed petrographic observations using optical microscope and electron probe micro analysis (EPMA) and geochemical analysis. Based on detailed petrographic observations, we found various metal sulfides, inculding pyrite, chalcopyrite, sphalerite, galena, siegenite, cobalite and other sulfoarsenide in Dongping Mn ore deposit. The Al/(Al+Fe+Mn) and Y/Ho ratio, Fe - Mn - (Ni+Cu+Co) ×10 and lgU - lgTh graphs of Mn ores indicated that source of Mn is associated with hydrothermal activity. The positive Ce anomaly and V/(V+Ni) of Mn ores indicate that Mn was initially precipitated in oxic environment. Combining all data, we suggest that source of Mn is associated with hydrothermal activity. Manganese carbonate formed by reduction of Mn oxides derived from hydrothermal activity during the diagenesis. © 2024 China University of Geosciences. All rights reserved.