基于成矿过程数值模拟的隐伏矿双向预测研究

A two-way forecasting method based on numerical simulation of mineralization process for the prediction of concealed ore deposits

在三维建模及定量预测的基础上,利用数值模拟开展成矿过程研究,通过数值模拟获取可用于隐伏矿预测的参数,据此建立一套完整的基于矿床学成矿过程研究和矿产勘查学综合信息找矿研究的隐伏矿双向预测评价方法和流程。结合甘肃以地南金矿探讨大比例尺隐伏矿体三维地质建模过程、三维定量预测、成矿过程数值模拟和双向预测评价的方法体系。采用三维定量预测理论和数值模拟双向预测的方法在示范区综合圈定7个预测靶区,在三维定量预测评价过程中分别采用证据权重和信息量的方法计算单元块体的找矿概率,在成矿过程数值模拟过程中分别利用块体的空隙压力值(pp值)和体积应变值(vsr值)圈定有利成矿部位。应用实例表明采用基于成矿过程数值模拟的隐伏矿双向预测方法开展深部隐伏矿的预测评价可有效降低矿产预测过程中的不确定性,实现对矿产资源的“定位-定量-定概率”预测评价。

In this paper,we propose a two-way forecasting method for locating blind orebodies based on numerical simulation of mineralization process and 3D quantitative predication.The parameters used in predicting blind orebodies were obtained by numerical simulation,and the methodology involves 3D geological modeling of large-scale blind orebodies,3D quantitative prediction,numerical simulation,and two-way forecast and evaluation.Using this novel forecasting method,we established seven favorable prospective targets in a project test zone of the Yidinan gold deposit in Gansu Province.In the 3D quantitative prediction,we calculated the ore-forming probabilities of prospective blocks using the techniques of weigh of evidence and information value;by numerical simulation of mineralization process,we delineated the metallogenic favorable area based on the simulated distributions of prospective blocks with favorable pore pressures(pp values)and volumetric strain rates(vsr values).These application results show that using the two-way forecasting method can effectively reduce prediction uncertainty in the deep blind orebody prediction and evaluation.