Inferring the Subsurface Basement Depth and the Contact Locations from Aeromagnetic Data over Loum-Minta Area (Centre-East Cameroon)

Abstract

The present study aims to estimate the basement depth and contact locations, deduced from the available aeromagnetic data. The total intensity aeromag-netic (TMI) map was first corrected by the application of the reduction to equator technique. Different edge detection processes, for example, tilt angle derivative (TDR) and its total horizontal derivative (HD_TDR) as well as 3D-Euler deconvolution can determine the edges of these sources. These techniques were carried out on the aeromagnetic data of Minta region (the study area). A correlation was noticed between these techniques indicating that both of them can be attributed in delineating the general structural framework of the area. The aeromagnetic data analysis enables to highlight many deeply-seated structural features trending in the E-W, ENE-WSW and NE-SW directions in this region. The E-W trend is more strongly developed than the other identified trends. Moreover that, two depth methods were applied: analytic signal (AS) and source parameter imaging (SPI). They reflected similar results for estimating the basement depths. From both of them the depth ranges from 150 to 2800 m. Five methods (TDR, HD_TDR, 3D-Euler deconvolution, AS and SPI) for locating magnetic sources indicated that the depth of the basement rocks ranged between 150 and 3000 m as the average range. Also, the comparative study among the 2D magnetic modeling was established by one profile constructing.