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滇东南丘北地区上二叠统吴家坪阶主要为一套含铝土矿的碎屑岩系。根据区内实测剖面的沉积特征以及区域地质资料分析,认为研究区吴家坪早期为低能淤泥质海岸到局限浅海的沉积环境。在对54条剖面的岩性、厚度、沉积特征等资料定性、定量分析的基础上,采用单因素分析、多因素综合作图法编制了丘北地区吴家坪早期的岩相古地理图,分析了其沉积相分布和演化特征。吴家坪早期,丘北地区总体表现为潮坪-局限浅海的沉积环境,铝土矿主要发育在吴家坪阶下部的第一个三级层序中。通过对区内已知矿点与古地理关系的研究,认为铝土矿成矿的最有利沉积环境是潮下带-浅海上部。
The Upper Permian Wujiaping Formation in Qiu Bei area of southeastern Yunnan is mainly composed of clastic rocks containing bauxite. According to the sedimentary characteristics of the measured sections in the area and the analysis of the regional geological data, it is considered that the Wujiaping area in the study area was the depositional environment of the low-lying muddy coast to the confined shallow sea in the early stage. Based on the qualitative and quantitative analysis of the lithology, thickness and sedimentary characteristics of 54 sections, the lithofacies paleogeographic map of Wujiaping in Qiu Bei area was developed by using single factor analysis and multi-factor comprehensive mapping. Its sedimentary facies distribution and evolution characteristics. In the early stage of Wujiaping, the Qiu Bei region generally showed a sedimentary environment of tidal flat-limited shallow sea. The bauxite mainly developed in the first third-order sequence of the lower part of the Wujiaping. By studying the relationship between the known mineral deposits and palaeogeography in the area, it is considered that the most favorable sedimentary environment for bauxite mineralization is the subtidal-shallow sea upper part.