非洲下刚果盆地布谷马西钾矿区南部矿段沉积旋回研究OA

To finely characterize the evaporite deposition features and mineralization patterns in the southern mining section of the Mboukoumassi area in the Congo Basin,this study conducts high-resolution sedimentary cycle research based on core,lithology,and thickness data from 15 boreholes,contour maps,sedimentological analysis,and halite fluid inclusion thermometry.The results show that sedimentary cycles Ⅱ-Ⅺ,totaling 10 sedimentary cycles,are developed in the study area,with the regional cycle Ⅰ missing;Cycles Ⅳ-Ⅶ are favorable sections for potassium-magnesium salt enrichment,characterized by the development of halite sylvite langbeinite assemblages.The migration of their sedimentary centers reveals that the sedimentary process is controlled by syn-sedimentary structures and paleotopography.Halite fluid inclusion thermometry indicates that the homogenization temperatures of paleobrines are concentrated between 25～45℃ range,significantly higher than the ambient temperature,revealing an abnormal thermal background during the salt formation period.This study preliminarily establishes the sedimentary model of the research area,enriches the understanding of regional potash mineralization mechanisms,and provides direct geological evidence and theoretical basis for subsequent mineral exploration in the mining area and surrounding regions.