【摘要】 以成矿规律研究和成矿条件分析为基础的二维成矿定量预测方法难以精确表达含矿地层的三维空间分布情况,导致其预测结果的可靠性差。本文针对矿产资源预测评价中的真三维地学分析需求,以平面地质图和图切地质剖面图为三维地质建模的数据源,按照线框架建模的技术思路,由剖面轮廓线和地面地质界线联合重构了成矿地质体的三维表面,较好地表达了桂西南地区成锰地质体在三维空间中的分布情况。同时,为了分析三维空间中锰矿资源量的分布情况,本文采用规则体元将研究区的三维地质空间分割为连续场,并结合区域锰矿二维成矿定量预测的成果,获得了研究区1 000m以浅含锰地层中锰矿资源量的三维空间分布:研究区锰矿资源量主要集中在上泥盆统(以五指山组为主,5 036万t)和下三叠统北泗组(3 447万t);而下石炭统大塘组资源量仅为566万t,以前的二维预测对该地层内赋存的锰矿资源量估计偏高。三维预测较好地反映了含锰地层三维形态对锰矿分布的控制作用,为研究区锰矿定量预测提供了新的技术手段。更多还原

【Abstract】 The 2Dquantitative mineral prediction based on the study of metallogenic laws and the analysis of metallogenic conditions cannot precisely deseribe the 3Dspatial distribution of ore bearing strata,and results in the unreliability of prediction.Aiming at the real 3Dgeosciences analysis needs of the prediction and evaluation of mineral resources,taking planar geological map and geological crosssections as the data source of 3Dgeological modeling,a wire frame modeling method is presented to reconstruct 3Dsurface of geological bodies according to profiles on cross-sections and planar map,and applied to describe the 3Dspatial distribution of manganese geological bodies in southwestern Guangxi.Meanwhile,in order to analyze the 3Dspatial distribution of manganese ore resources,the 3Dgeological space of the study area is divided into continuous field by regular voxels,and the 3Dspatial distribution of manganese ore resources in the manganese bearing strata from 1 000 meters to the shallow is obtained on the basis of the regional manganese metallogenic 2Dquantitative prediction results.The manganese ore resources in the study area are mainly concentrated in Upper Devonian(mainly in the Wuzhishan Group),50 360 kiloton,and in the Beisi group of Lower Triassic,34 470 kiloton,while the resource in the Datang Group of Lower Carboniferous is only 5 660 kiloton,which was over-estimated in the 2D prediction.The 3D geological modeling improves the reliability of the quantitative prediction of the manganese ore,and better reflects the controlling effect of the manganese bearing strata on the distribution of manganese ore.更多还原