Spectral Analysis of Magnetic Data over Jalingo and Environs North - Eastern Nigeria

Two - dimensional techniques for spectral analysis and Hilbert transformation of aeromagnetic data over Jalingo and environs were carried out in order to estimate the average depth to magnetic sources. The result from spectral analysis conducted indicates two source depths. The deeper magnetic source varies between 437 m to 2617 m. While the shallow magnetic source ranges between 123 m to 436 m. The result of Hilbert transform, which was used to delineate lineaments from analytical signal map are presented in terms of azimuth from Rose diagram, which trend NE-SW, NNE-SSW, ENE-WSW, NW-SE, NNW-SSE, WNW-ESE, N-S and E-W. These lineaments are in line with Pan-African and pre-Pan - African deformational episode on North - Eastern basement complex and are potential site for secondary mineralization. This study also involves estimating the Curie point depth and Heat flow. The Curie point depth obtained varies between 24 to 28km and the geothermal gradient varies between 21 and 23 OCkm-1, while the heat flow values range between 53 to 61 mWm-2. These results are consistent with the existing geothermal and geotectonic regime in the area. Spectral analysis of the data in conjunction with heat flow values revealed an almost inverse linear relationship between heat flow and Curie depths. However, the study has shown possibility for moderate geothermal resources to exist in the study area.