地质学报2026，Vol.100Issue(2)：524-536,13.DOI:10.19762/j.cnki.dizhixuebao.2025298
桂西平果那端矿区沉积型铝土矿地球化学特征与成矿机制研究
Research on the geochemical characteristics and mineralization mechanism of sedimentary bauxite deposits in the Naduan mining area,Pingguo,western Guangxi
摘要
Abstract
Long-standing controversies regarding the provenance of ore-forming materials,the paleo-sedimentary environments,and the metallogenesis of sedimentary bauxite in western Guangxi have restricted a deeper understanding of their formation mechanisms and constrained targeted exploration efforts.In this study,we performed a systematic geochemical analysis of major and trace elements within the ore-bearing sequence from the Naduan mining area,Pinguo.The geochemical data reveal significant negative correlations of Al2O3 with Fe2O3 and SiO2,alongside a strong positive correlation with TiO2;these patterns indicate the depletion of iron and silica coupled with the residual enrichment of aluminum and titanium during the bauxitization process.Furthermore,low Si/Al ratios and high chemical index of alteration(CIA)values reflect a warm,humid paleoclimate characterized by intense chemical weathering and leaching.Trace element signatures suggest a freshwater depositional environment within a terrestrial to marine-terrestrial transitional facies,occurring under redox conditions ranging from oxic to suboxic.Building on this evidence,this paper proposes a three-stage metallogenic model for the Naduan sedimentary bauxite deposit:formation of the host basin,accumulation of precursor materials,and mineralization during marine transgression.In this model,the ore-forming materials were predominantly derived from island arc-related acidic volcanic ash.Within a transitional marine-terrestrial setting,these precursors underwent intense weathering,leaching,and hydrodynamic processes(e.g.,tidal sorting)that ultimately led to the enrichment of bauxite.This study provides new geochemical evidence for understanding the metallogenic evolution of sedimentary bauxite in the Pinguo region and serves as a valuable reference for investigating the regional genesis of such deposits throughout western Guangxi.关键词
沉积型铝土矿/地球化学特征/成矿机制/桂西/平果Key words
sedimentary bauxite deposit/geochemical characteristics/mineralization mechanism/western Guangxi/Pingguo引用本文复制引用
唐沫岚,范博伦,姚双秋,卢光辉..桂西平果那端矿区沉积型铝土矿地球化学特征与成矿机制研究[J].地质学报,2026,100(2):524-536,13.基金项目
本文为国家重点研发计划课题(编号 2022YFC2903405)、广西科学院基本科研业务费资助项目(编号 2024YWF2120)、广西壮族自治区自然资源厅项目(编号 桂自然资函[2023]1486号)和广西青苗人才计划(编号 2024QMJH-1912)联合资助的成果. （编号 2022YFC2903405）
