证据权重法在黑龙江省三合屯地区三维金矿远景区建模中的应用

Application of weight of evidence model in 3D gold mineral prospectivity modeling in the Sanhetun area,Heilongjiang Province

矿床的分布具有明显的群聚性,成矿过程是由多方面因素共同作用的结果,因此从三维地学模型中准确地识别具有成矿前景的信息是一项重要且具有挑战性的任务。证据权重法引入成矿有利度量化矿床与三维证据因子之间的空间关系,并确定最优正负权重;以单元格成矿后验概率值为基础进行成矿远景建模,并结合约登指数确定成矿概率临界值以圈定成矿靶区。本文利用三维地质和地球物理模型对黑龙江省三合屯地区的热液型金矿进行了成矿远景建模,圈定出3个找矿靶区。研究表明,证据权重法用于三维成矿预测中具有预测可靠性高、简单易实现等特点,并为探测地下隐伏矿体提供可靠的支持。

The deposits show a clear clustered distribution,and the metallogenic process is the result of multi-factor combination.Therefore,accurately identifying prospective information from 3D geoscience models is an important and challenging task.The weight of evidence(WoFE)method introduces the concept of metallogenic favorability to quantify the spatial relationship between the deposit and 3D evidence factors and determines the optimal positive and negative weights.The voxel metallogenic posterior probability values are used as the basis for mineral prospectivity modeling,and the Jorden index is combined to determine the threshold of metallogenic probability to delineate the prospecting targets.We implemented the mineral prospectivity modeling of hydrothermal gold deposit based on 3D geological and geophysical models in the Sanhetun area of Heilongjiang Province.By analyzing the posterior probability,three prospecting targets were delineated at the metallogenic probability threshold of 0.001.The study shows that the WoFE method for 3D mineral prospectivity modeling has high prediction reliability and simple implementation and provides reliable supports for predicting subsurface concealed ore bodies.