隐伏矿体立体预测的体元模型及其磁法正演模型

摘要

针对隐伏矿体立体定量预测结果的可靠性问题,以及磁法正反演模型一直存在的地质依据不足和多解性问题,提出隐伏矿体立体预测体元模型与磁法正演模型在定量层面上相结合的新方法.利用体元模型的特点,结合磁荷面积分公式,推导出基于隐伏矿体立体预测体元模型的总磁场异常的数学模型,并进行算法设计和软件开发.以福建省尤溪县丁家山铅锌矿床为实例,计算得到研究区域的总磁场异常,绘制基于已知矿化体、预测矿化体及已知矿化体总体的理论总磁场异常等值线图,分别与实测等值线图进行比较分析.研究结果表明:以体元模型为纽带,可实现隐伏矿体立体定量预测结果与磁性体正演结果的耦合与互补,检验隐伏矿体立体定量预测结果的正确性,有效地降低隐伏矿体立体定量预测的风险.%Aiming at the problem of reliability in stereoscopic quantitative prediction of concealed ore body, and the problem of geological basis shortage and multi-solutions in magnetic forward and inverse models, a new method combining the voxel model of stereoscopic prediction of concealed ore body with magnetic forward model at the quantitative level was put forward. By use of the voxel model and the formula for magnetic charge surface integral, the mathematical model of the total magnetic field anomalies based on the voxel model of stereoscopic prediction of concealed ore bodies was deduced, the algorithm and software for solving the model were designed and developed. A case study was performed in Dingjiashan lead-zinc deposit in Youxi County, Fujian Province, China. The total magnetic field anomalies of the study area were achieved, the contour maps about theoretical total magnetic field anomalies were drawn on the basis of the known mineralization bodies, the amalgam of the predictive mineralization bodies and the known mineralization bodies, and the comparison analysis between the theoretical contour maps and the actual contour maps was made. The results show that this method, taking the voxel model as the link bridge, can achieve the coupling and complementarities of the stereoscopic quantitative prediction results of concealed ore bodies with the magnetic body forward results, and test the accuracy of the prediction results, and effectively lower the risk of the prediction of concealed ore bodies.