地质学报2026，Vol.100Issue(2)：553-568,16.DOI:10.19762/j.cnki.dizhixuebao.2025203
华北克拉通南缘巩义地区铝(黏)土矿矿物学特征及成因演化
Genesis and supergene modification of bauxitic(clay)deposits in the Gongyi area,southern North China Craton
摘要
Abstract
The North China Craton hosts extensive Late Carboniferous karst-type bauxite deposits;however,the mechanisms governing their spatial differentiation and the genetic relationships between bauxite and claystone remain controversial.This study investigates the Nangoucun deposit in the Gongyi area of western H enan Province,integrating multi-scale mineralogical analyses and paleoenvironmental reconstruction to elucidate the metallogenic evolution of these bauxite(clay)deposits.Field investigations reveal a characteristic karst-type bauxite sequence,which consists,from bottom to top,of a ferruginous weathering crust,ferruginous clay rock,and aluminous clay rock/bauxite.Results from X-ray diffraction(XRD)and electron probe microanalysis(EPMA)indicate that the bauxite(clay)deposits are predominantly composed of kaolinite,illite,goethite,hematite,anatase,rutile,and quartz.Stratigraphic variations in alkaline-environment indicators(e.g.,illite,diaspore,chlorite)and acidic-environment indicators(e.g.,kaolinite)across different layers collectively suggest a complex spatiotemporal evolution involving weathering,transportation,mineralization,and reworking.Notably,diaspore in oolitic bauxite is preserved only as micron-scale oolitic relics,with widespread kaolinization observed throughout mineral assemblages.This layer is also enriched in cubic hematite and weathering-resistant anatase.These features collectively indicate intense supergene weathering and acidic leaching,which drove the selective dissolution of primary aluminum hydroxides and the subsequent transformation of clay minerals.These findings therefore provide critical mineralogical insights into deciphering the multi-stage phase transformation mechanisms of aluminosilicates within paleokarst systems.关键词
华北克拉通/巩义地区/铝(黏)土矿/黏土矿物/高岭石化Key words
North China Craton/Gongyi area/bauxite(clay)ore/clay minerals/kaolinization引用本文复制引用
侯思远,左鹏飞,张慧明,刘学飞..华北克拉通南缘巩义地区铝(黏)土矿矿物学特征及成因演化[J].地质学报,2026,100(2):553-568,16.基金项目
本文由国家重点研发计划项目(编号 2022YFC2903402)和河南省自然科学基金(编号 242300421146)联合资助的成果. （编号 2022YFC2903402）
