QUALITATIVE ANALYSIS OF AEROMAGNETIC DATA OF BASHAR AND ENVIRONS, NORTH-CENTRAL NIGERIA

Abstract

This study focuses on Qualitative Analysis of Aeromagnetic Data of Bashar and environs, North-central Nigeria. Software used for the analysis include: Oasis Montaj Version 8.4, Matlab Version R2010a, Grapher 5, SUFER 11, Georient and Microsoft Excel. The Total Magnetic Intensity (TMI) map has intensity values that range from 32876.4 to 33189.7 nT, showing significant magnetic high and low signatures. The Reduce-to-Equator (RTE) map has an intensity range of -732.6 to -405.5nT. The Upward Continuation analysis of 15 km distance which shows more of the deep regional trend with a range of -616.7nT to -457.6nT. The First Vertical Derivative (FVD) map has an intensity value ranges from -0.123 to 0.102nT/m. The magnetic high regions could be said to be regions with fresh basement outcrops while the regions with low magnetic intensity could be said to be region with old weathered outcrops. The lineaments observed were basic dykes, alpite, felsite and quartz veins which the host minerals. The dominant trend of lineament is NE-SW while minor trend of lineament is NW-SE direction. The rose diagram plot shows the lineaments trending NE-SW, NW-SE, and NNE-SSW directions, with the NE-SW being the dominant trend. The mineralization map shows positive magnetic intensity which ranges from 0.2 to 129.8. The region characterized by high magnetic anomalies intensity (36.7 - 129.8) is associated with rocks having higher content of ferromagnetic minerals and could be attributed to underlying igneous and metamorphic rocks while the region with low magnetic intensity (0.2 - 26.6) corresponds to the sedimentary bedding of sandstones, siltstones and claystone within the study area.