通过对华北地区1∶50万布格重力资料进行小波多尺度分析,得到自地表至莫霍面不同空间尺度范围内地质体产生的重力异常.讨论各阶小波变换细节特性及相应地质构造特征认为,华北裂陷盆地的隆起、坳陷与重力异常的高、低存在明显的对应关系,并给出了它们的下延深度.分析结果显示,华北裂陷盆地内深大断裂两侧岩石密度存在较大差异.采用帕克法反演得到华北地区莫霍界面深度在29～42 km范围内,在太行山与华北平原交界地区存在明显的地壳厚度变化梯级带.%Using 1∶500 000 Bouguer gravity anomalies data in north China,decomposed with the multi-scale wavelet transform method,we obtain the gravity anomaly from anomalous density bodies of varying scales between the earth surface and the upper Moho.By discussing details of wavelet transform of different orders and the corresponding geological tectonic features,we find the existence of an obvious corresponding relationship between the uplift and depression of north China rift-depression basin and gravity anomaly and present their extended depths.Analysis shows rocks on the two sides of the deep large fracture in the north China rift-depression basin vary widely in density and their fracture depth is inferred.With the method of Parker inversion in the Moho interface (29-42 km) in north China,it can be seen that there is an obvious crustal thickness gradient zone in the junction area between Taihang mountains and the north China plain.
展开▼
