十五里桥地区位于大兴安岭北部漠河前陆盆地东南部,属典型森林沼泽浅覆盖区,直接获取地质信息难度大.在1∶5 万磁法数据综合解译的基础上,结合地质矿产、化探等信息,建立区域成矿预测模型、圈定成矿预测区,为十五里桥地区找矿等工作提供必要的小比例尺物探信息.综合分析结果表明,十五里桥地区各类地质单元磁场区分明显,火山岩地层表现为高磁化率、高剩余磁场强度,早白垩世侵入岩次之,沉积岩地层表现为低磁化率、低剩余磁场强度;高磁异常梯度带为成矿有利部位,沉积岩区磁异常值为20~80 nT,火山岩区磁异常值为120~180 nT;圈定Ⅱ级成矿预测区3 处,Ⅲ级成矿预测区5 处.其中,Ⅱ级成矿预测区成矿地质条件较好,综合信息强度高,找矿潜力较大.
The Shiwuliqiao Area is located in the southeastern part of the Mohe foreland basin in the northern Greater Khingan Mountains.It is a typical forest swamp shallow-covered area,making it difficult to directly obtain geological information.Based on the comprehensive interpretation of 1:50 000 magnetic survey data,combined with geological,mineralization,and geochemical prospecting information,a regional metallogenic prediction model is estab-lished to delineate metallogenic prediction areas.This provides necessary small-scale geophysical information for mineral prospecting in the Shiwuliqiao Area.The comprehensive analysis indicates that different geological units in the Shiwuliqiao Area exhibit distinct magnetic field characteristics.Volcanic rock strata show high magnetic susceptibility and residual magnetic field intensity,followed by early Cretaceous intrusive rocks,while sedimentary rock strata show low magnetic susceptibility and residual magnetic field intensity.The high magnetic anomaly gradient zone is considered favorable for mineralization,with magnetic anomaly values ranging from 20 to 80 nT in sedimentary rock areas,and 120 to 180 nT in voleanic rock areas.3 areas are delineated as level Ⅱ metallogenic prediction zones,and 5 areas as level Ⅲ metallogenic prediction zones.Among them,level Ⅱ metallogenic prediction zones have favorable mineralization geological conditions,high comprehensive information intensity,and great prospecting potental.