基于GIS的证据权重法在小兴安岭北段金成矿预测中的应用

摘要

The condition of gold geological mineralization in the Xunke⁃Jiayin⁃Luobei area of northern Xiao Hinggan Mountains is very favorable.Because of the heavy surface coverage,geological work in the area has made no breakthrough in recent years.To accel⁃erate the process of gold ore prospecting, the authors,based on probing into the relationship of geological,geophysical and geochemi⁃cal information to lead⁃gold mineralization in northern Xiao Hinggan Mountains,extracted and constructed 14 evidence layers,such as fracture buffer,Early Yanshanian intrusive rocks buffer,Late Yanshanian intrusive rocks buffer,alteration remote sensing anomaly,ge⁃ochemical anomaly and magnetic anomaly through a spatial analysis of the GIS system.Gold potential was calculated by the evidence weight model.According to the prediction,nine classⅠprospective areas,nine classⅡprospective areas and fourteen classⅢprospec⁃tive areas were delineated finally.The prospective areas have almost covered all known gold deposits.The results achieved by the au⁃thors have some indication significance for further ore⁃prospecting work in this area.%小兴安岭北部逊克—嘉荫—萝北一带金成矿地质条件优越，由于地表覆盖较厚，近年来一直未有突破性进展。为加速该区金矿找矿进程，在对小兴安岭北段地质、物探、化探、遥感等金成矿信息深入分析的基础上，依托GIS平台空间分析功能，对区内成控矿要素进行定量化，提取了断裂 buffer、燕山早期岩体 buffer、燕山晚期岩体buffer、航磁异常、遥感蚀变异常、化探异常等在内的14个证据图层；利用证据权重法对研究区金矿进行预测，圈定了三级成矿远景区，其中Ⅰ级成矿远景区9个，Ⅱ级成矿远景区9个，Ⅲ级成矿远景区14个，所预测成矿远景区覆盖了大多数金矿床（点），预测结果为该区进一步找矿指明了方向。