Metallogenic Model of Sedimentary Bauxite in Western Guangxi, China: Insights from Ore Genesis, Material Sources, and Depositional Environments

Western Guangxi is one of the principal bauxite-producing regions in China; however, its metallogenic model remains unclear. Building on previous studies, this paper systematically examines the ore-forming materials, sedimentary setting, ore genesis, mineral assemblages, diaspore formation, and pisoid (ooid) development of sedimentary bauxite deposits in western Guangxi. Based on this synthesis, a comprehensive metallogenic model is proposed to clarify the formation processes of these deposits. Metallogenic evolution is interpreted to involve five successive stages: weathering, leaching and alteration, deposition, post-depositional modification, and capping–sealing. Ore-forming materials are derived from volcanic ash supplied by the Emeishan Large Igneous Province and the Permian magmatic arc of the Paleo-Tethys. These materials are transported to isolated carbonate platforms and subsequently subjected to intense chemical weathering. During the early stages of ore formation, bauxite undergoes leaching and alteration, and variations in leaching intensity lead to the development of distinct ore types. Future work should focus on the genesis of diaspores, the formation of pisoids (ooids), and ore-forming mechanisms, while also addressing the coupling relationships among deep-time paleoclimate, major geological events, and sedimentary bauxite formation. Such efforts are essential for advancing a comprehensive metallogenic framework for sedimentary bauxites.