Journal Article

Geophysical Interpretation of Ground Magnetic Data over some Northern parts of the Bida Basin, North Central Nigeria

Abstract

Total magnetic field intensity data was acquired on the ground using the G5 Proton precession magnetometer in seventeen different locations on at least, four E-W or N-S traverses at station spacing of between 9.0m and 90m along each traverse. Diurnal correction was first applied, after which the Savitzky-Golay smoothing and filtering techniques were applied to smoothen and filter unwanted signals. Regional Magnetic Field Intensity was also calculated for each of the surveyed areas using the World Magnetic Model calculator and then removed from the smoothed data to obtain the residual magnetic field. The raw data, diurnal corrected data and the diurnal corrected-filtered data as well as the residual magnetic anomaly were plotted as contour maps for a qualitative interpretation while the residual anomalies were plotted against the distances traversed on each profile for a qualitative interpretation. The results of these interpretations revealed the residual magnetic intensity values ranging from -277.59 in Batati to 165.84nT in Babban Rami. The negative magnetic values were attributed to thick overburden while the positive values were ascribed to shallow overburdens except where magnetic ironstones were responsible for such high values.The depths to basement rocks varied from 0.0012km in Sakpe to 2.545km in Enagi with an average depth of 135m..

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