山西省平陆县西山头铝土矿地质特征及成矿模式分析

西山头铝土矿区位于平陆铝土矿成矿带东部,区内本溪组为铝土矿含矿地层。通过研究区内地质特征、矿床特征,对铝土矿成矿模式进行探讨。研究结果表明：本溪组具海相地层沉积特征,为快速海侵和缓慢海退过程中的产物,自下而上划分为铁质岩段、铝质岩段、硅-碳质岩段。本溪组地层特征反应出研究区在晚石炭世经历了浅海相—潮坪相—沼泽相的沉积环境演化。矿石类型以豆鲕状、碎屑状铝土矿为主,次为致密状铝土矿,偶见粗糙状铝土矿。受淋滤作用影响,矿石品位以粗糙状铝土矿最佳,致密状铝土矿品位最差。常量元素化学特征显示原岩遭受了强红土化作用,化学性质活泼的Na、Ca、Mg等元素可能在淋滤作用下流失。西山头铝土矿成矿过程分为四个阶段：母岩风化阶段、沉积成矿阶段、成岩阶段、表生阶段。

Geological characteristics and genesis of Xishantou bauxite deposit in Pinglu County, Shanxi Province

Xishantou bauxite mining area is located in Pinglu Xiaxiantou bauxite metallogenic belt. Benxi Formation is ore-bearing strata, mainly formed in marine sedimentary environment, and can be divided into ferruginous rock section, aluminous rock section and silicon (carbon) rock section from bottom to top. The bauxite ore deposit are layered, stratoid, funnel-form and lenticular. They occur on the Ordovician paleo-weathering crust. Under the background of Late Carboniferous transgression, the aluminum rich materials in the aluminosilicate weathering crust of Zhongtiao old land were transported to the favorable metallogenic zones such as funnel and thaw-depression, and formed in tidal flat environment. The ore-forming process of Xishantou bauxite deposit can be divided into four stages: Weathering stage of parent rock, sedimentary metallogenic stage, diagenetic stage and epigenetic stage.