Tilt-depth方法适用性研究及其应用

Applicability of tilt-depth method and its application

Tilt-depth方法是一种可以快速反演磁源上顶深度的新兴方法。二维、三维模型试验表明,tiltdepth法反演误差与地质体的上顶埋深、厚度及水平尺度均有关,同时叠加异常也会对反演结果产生影响。实例中,将tilt-depth法应用于广东省下庄矿田航磁数据反演中,tilt梯度图上展示出了两条明显的近东西走向条带异常,推断为浅部基性辉绿岩脉在深部汇聚形成,并反演了两条高磁异常带上11个位置的磁源上顶埋深。反演结果揭示了下庄矿区内北侧高磁性体深度较浅,且具有南浅北深的构造特征,而南侧高磁性体规模较大,且埋深较厚,为该区深部矿产勘查提供了有利依据。

Tilt-depth method is a new inversion method for fast estimation of the top depths of magnetic bodies. Two- and three-dimensional model tests show that the inversion error of tilt-depth method is related to the top depth, thickness and horizontal scale of geological body. In addition, superimposed anomaly also has an effect on the inversion results. Tilt-depth method is applied to the aeromagnetic data over Xiazhuang ore field in Guang-dong, and the authors find that two near EW-trending anomaly zones on tilt map are produced from deep ultrabasic diabase. Tilt-depth method is used to invert top depths of 11 inversion points on the two high magnetic anomaly zones in the tilt map. Based on the inversion results, the authors found that the depth of magnetic body located in the north of the Xiazhuang ore field is relatively shallow and is getting deeper from south to north, whereas the mag-netic body in the south of the Xiazhuang ore field is relatively deeper and with larger scale. This important informa-tion is very useful for the deep mineral exploration.