高精度磁法在松辽盆地北部古龙-常家围子断陷火山岩预测方面的应用

Application of High-precision Geomagnetic Method in Volcanic Rocks Prediction of Gulong-Changjiaweizi Fault-depression in North Songliao Basin

利用高精度磁力资料预测了松辽盆地北部古龙—常家围子断陷深层火山岩的分布,对采用的处理解释方法技术和应用效果进行了分析。在对岩石物性分析的基础上,指出磁异常是基底岩性及断陷火山岩所产生磁异常的综合反映,应用高精度磁异常能够进行盆地深层火山岩的预测,但存在较大的难度。滑动趋势分析及小波多尺度分解方法能够较好地分离火山岩磁异常,磁异常的解析信号及垂向导数对火山岩及其岩性有较好的识别作用。应用高精度磁异常预测火山岩所采用的方法技术对类似其他地区盆地深层火山岩的预测有重要的参考和借鉴作用。

The processing and interpretation techniques of high precision magnetic method are applied in deeplayer volcanic rocks prediction of Gulong-Changjiaweizi faulting-depression in Songliao Basin and the application results are discussed. The magnetic anomalies are produced by the superposition of basement lithology and volcanic rocks, therefore it is very difficult to predict the deep-layer volcanic rocks by applying the conventional high-precision geomagnetic method. The slide-trending and wavelet multi-scale analysis can be a powerful tool for separating the magnetic anomalies of the volcanic rocks, and the analytical signals and vertical derivatives of magnetic anomalies can indicate and identify the lithology of volcanic rocks. This technique can also be applied in the prediction of deep-layer volcanic rocks in other areas.