关键词: 柏梓山铝土矿, 地质特征, 成矿作用, 找矿标志

Abstract: In order to clarify the geological characteristics，metallogenic mechanism and prospecting direction of Baizishan bauxite deposit in southeastern Chongqing，and enrich the metallogenic theory of re⁃ gional sedimentary bauxite deposit，this paper takes Baizishan bauxite deposit in Nanchuan as the research object，and systematically studies its deposit characteristics，ore composition，mineralization and prospect⁃ ing criteria by means of field exploration，indoor microscopic identification and geochemical analysis. The study shows that the deposit is located in the Yangtze paraplatform，and the ore-bearing horizon is the Li⁃ angshan Formation（P2l）of the lower Permian system. The bauxite occurs in the middle and upper part of the ore-bearing rock series，and No.III and No.II ore bodies are developed from north to south，which are layered and irregular，and are controlled by strata and structures. The ore is mainly diaspore，which is di⁃ vided into three types of dense，clastic and porous. The chemical components are mainly Al2O3，SiO2， Fe2O3 and TiO2. The content of Al2O3 is 40.45%~77.68%. The average contents of No.III and No.II ore bod⁃ ies are 61.56% and 53.35% respectively，and the average Si/Al ratios are 3.43 and 4.22 respectively. The deposit is a paleo-weathering crust sedimentary transformation type，and the source is derived from the Si⁃ lurian Hanjiadian Formation silty shale weathering crust. The mineralization is divided into three stages(lat⁃erization，sedimentary mineralization and later transformation). Sedimentary intermittent lithology，syn⁃ cline axis and other structures，cliff bottom landform and Liangshan formation thickness >3 m are the main prospecting indicators.

Key words: Baizishan bauxite deposit, geological characteristics, metallogenesis, prospecting indica? tors