铝土矿地质与成因研究进展

摘 要]我国铝土矿矿产时空分布广,类型多样,铝土矿地质与成因研究对促进铝土矿地质学发展有重要意义。本文从铝土矿矿床分类、铝土矿的矿体形态与内部结构、矿体层序、物质组成、物质来源、成矿环境和成因机制等方面,综述了国内外铝土矿地质学的研究进展,阐释了我国铝土矿的部分特征,提出了近年我国铝土矿研究的部分新方法与观点;应用铝土矿中碎屑锆石U-Pb 和Lu-Hf 同位素特征, 判识了多个喀斯特型铝土矿集中区的物质来源,提出多数喀斯特型铝土矿多具有异源特征,与区域重大地质事件具有成因联系,是洋陆俯冲、大陆漂移以及集中风化等多因耦合的结果。提出了我国喀斯特型铝土矿迁移机制,认为华北板内铝土矿(山西、河南) 成因机制主体为“离子结晶与碎屑沉积冶综合成因;而华南铝土矿(贵州、广西)成因机制主体为“离子结晶冶成因。

Review on Research of Bauxite Geology and Genesis in China

Bauxite deposits in China are characterized by widespread temporal-spatial distribution and a broad spectrum of types with various genetic mechanisms.Researches of their geological features and genesis are of considerable significance for bauxite geology.In this paper,we reviewed research of bauxite geology from the aspects of deposit classification,orebody morphology and structures,mineral composition,source rocks,ore-forming environments and mechanisms.Some features of the bauxite deposits in China are also illustrated,and new research methods and opinions obtained in recent years are further presented.The source rocks of kasrtic bauxite areas can be distinguished by utilizing the U-Pb and Lu-Hf isotopes of the detrital zircons in the bauxite ores.Most source materials of the China’s karstic bauxites are allochthonous,and their formation has an intimate genetic relationship with regional geological events.The formation of the bauxite in China was resulted from the a serial of ocean-continent subduction,continental drift,source rock weathering and weathered remnants transportation.The transportation mechanism of the karstic bauxites in China is regionally varied.In the North China Block,the Carboniferous ores were formed via both ion crystallization and clastic deposition,while the Permian karstic bauxite in the South China Block was dominated by ion crystallization in generation.