重磁异常精细正反演在梅山铁矿接替资源找矿中的应用

Application of fine forward and inversion of the gravity and magnetic anomalies in the exploration of succeeding resources in the Meishan iron deposit

对于地面实测的重磁异常剖面,在准确知晓其对应地质剖面中地质体的密度及磁化强度等物性的前提下,结合区域地质条件、区内地质背景及剖面上(周边)钻探(坑道开采)资料,建立初始地质剖面模型,利用重磁异常精细正反演,可较准确地确定剖面上的地层、岩矿等地质体界线。对于已开采的(磁)铁矿,可以通过正演,计算出磁异常并与实测异常进行比较,确定是否有剩余异常存在,从而判定是否有(磁)铁矿体存在。以梅山铁矿为例,对其重磁异常资料重新进行数据处理及精细正反演计算,结合地质及物性资料进行地质解释,利用其成果布设钻孔,取得了明显的地质找矿效果。

Based on precise knowledge of the density of geological body and magnetization of the target section, an initial geologic section model of actual gravity and magnetic anomalies section can be built by drawing on the data of regional geological conditions, geological background, and drilling and/or tunnels exploration along and/or around the section. Fine forward and inversion of the gravity and magnetic anomalies can help specify the geological borderlines of strata, rocks and ores in the section. As to the extracted （ magnetic） iron deposits, magnetic anomaly calculated by forward can be used to compare with the those discovered by actual exploration to ensure whether the residual anomaly exists, by which to determine the existence of （magnetic） iron orebodies. Taking the Meishan iron deposit as an example, its gravity and magnetic anomalies data is reprocessed with fine forward and inversion and interpreted with geological and physical data. The results are used to help drilling layout with obvious prospecting achievements.