Separation of Regional-Residual Anomaly Using Least Square Polynomial Fitting Method

Abstract

This paper presents quantitative application of Least-Square Polynomial fitting method in regional-residual separation. The study area covered geographical coordinate between latitude 8˚06΄70˝N and 8˚06΄98.7’’north and longitude 4˚14΄28.2˝E and 4˚14΄56.9˝ east of the Aeromagnetic maps of the region. The data were obtained by digitizing the maps of the above areas, picking the Total magnetic values along the profile line, processed and analyzed. The result of the residual separation revealed that the area is underlain by a NE-SW regional trend, characterized by basement complex with a weak amplitude of approximately – 85.73l nT. The regional magnetic anomaly map shows that the southern part of the map is suspected to be sedimentary basin, which is W-E trending, an indication of smoother magnetic field and it masked off the effects of the stronger magnetic basement. The basement complex underlies between the north and south of the study area comprises of broader area of outcrops.

Keywords: Aeromagnetic map, Regional and Residual fields, basement complex, Polynomial fitting