HEAT FLOW PARAMETERS OF ISANLU (SHEET 225) NIGERIA OBTAINED FROM THE RADIALLY AVERAGED POWER SPECTRUM (RAPS) OF ITS MAGNETIC FIELD

The Curie point depth of Isanlu and it environ has been investigated from the spectral analysis of aeromagnetic data. Data enhancement was carried out to delineate residual features relative to the strong regional gradients and the more intense anomalies due to basement features and igneous intrusives. Structural features identified in the study area from both the regional and residual maps revealed two principal trend directions. The result of the radially averaged power spectrum analysis shows that the Curie point varies from the lowest to the highest value which is 5.91 to 24.81 km. The value of geothermal gradient was found to vary between the minimum value of 23.38°C/km in the north eastern part of the study area (FS02) and a maximum of 57.48°C/km in the south eastern sector of the study area (FS10). This trend is similar for Heat flow values which vary between the lowest value of 42.08 mWm-2 in the north eastern sector to a maximum heat flow value of 103.48 mWm-2 in the south eastern sector.