3D Magnetic Basement Derived from Power Spectrum of Aeromagnetic Data of Parts of Lower Benue Trough, Nigeria

Summary The basement analysis of the aeromagnetic data of parts of lower Benue Trough has been carried out using spectral analysis. The grid is windowed to 25 blocks each of length 50 km x 50 km with 50 % overlapping. Each block was processed to remove first order trend based on edge points using 10 % square maximum entropy expansion. The magnetic basement depths are calculated varying between 2 km and 5 km. In the present study, the shallow depth calculated which in most cases less than 1 km can be interpreted the depth to top of the invaded basalts within the study area. In many locations as compared to the geological map of the present study, the basalts are observed to correspond to high magnetic anomalies. The depths to top of the basalts range between 0.24 km and 1 km.