Geochemistry of the Hujiawan–Zhangmuyan Mn Deposit, South China: Implications for the Origin of Datangpo‐Type Mineralization and Depositional Environment

The Nanhuan Datangpo‐type manganese (Mn) deposits represent one of the most important manganese resources in South China. However, the mechanisms responsible for the formation of these deposits remain controversial, and the relationships between climate shift during the Datangpo period and manganese metallogenesis remain poorly understood. In this contribution, new drill cores from the Hujiawan–Zhangmuyan manganese deposits were investigated to evaluate the controls of paleoclimate, sedimentary environment, and ore‐forming material sources on large‐scale manganese deposition in the Changyang area. Major and trace element geochemistry, rare earth elements (REEs) distributions, and C–O isotopic compositions were analysed and compared with those of other Datangpo‐type deposits in the Yangtze Block. The results indicate that the Datangpo‐type manganese deposits in the Yangtze region formed within an oxic–suboxic water column under warm and humid climatic environments. Ore‐forming materials were predominantly derived from deep‐seated hydrothermal fluids, with minor additions from terrigenous input, exhibiting a multi‐source exogenic metallogenic system. Manganese oxides were precipitated initially in oxygenated seawater and then converted into manganese carbonates during the early‐stage diagenesis. In contrast to other coeval deposits along the southeastern margin of the Yangtze Block, where organic matter degradation provided the main carbon source, seawater dissolved inorganic carbon (DIC) served as the primary carbon source in the Changyang area. This study provides new insights into the metallogenic processes of Nanhuan manganese deposits and provides additional geochemical evidence for the coupling relationship between Neoproterozoic manganese mineralization in South China and extreme climatic events.