优选向上延拓技术在鞍山—本溪示范区航磁应用

The application of preferential upward continuation to aeromagnetic survey in Anshan-Benxi area

优选向上延拓技术可以保持深源低频信号基本不变的同时,使浅部高频信号衰减,能够较为准确地提取区域异常,进而分离出局部异常;避免了传统向上延拓浅源高频信号与深源低频信号同时衰减。笔者利用优选向上延拓技术处理鞍山—本溪示范区航磁资料,实现了深部区域异常的增强和分离,获得了较好的效果;并进一步对西鞍山铁矿床航磁异常进行三维反演,初步推断了西鞍山铁矿体空间形态和规模,为后期资料的成果解释提供了重要的参考依据。

The advantage of preferential upward continuation method lies in the fact that, when it is used for upward continuation, the low frequent signal is not attenuated excessively and it can retain as much information on geological features as possible, so it can accurately separate regional anomaly and local anomaly. However, in conventional methods both high and low frequent signals are attenuated simultaneously for upward continuation. The preferential upward continuation breaks up the restrictions of the conventional upward continuation. So the preferential upward continuation is a method that has the capability for self-adaptive qualitative enhancing and separating the aeromagnetic anomalies. In this paper, the aeromagnetic anomaly in Anshan-Benxi area was processed using the preferential upward continuation to realize the enhancement and separation of the anomaly in the deep source field, with a good effect obtained. Furthermore, the authors studied 3D inversion of typical Xianshan iron ore deposit and inferred the distribution of underground lithologic boundaries and the spatial morphology of the Xianshan iron ore deposit. The results provide an important reference for the qualitative interpretation of the aeromagnetic anomaly.