MAPPING THE SUBSURFACE STRUCTURES AND SEDIMENTARY THICKNESSES IN PARTS OF MIDDLE BENUE TROUGH, NIGERIA USING INTERPRETATION OF AEROMAGNETIC DATA

Abstract

The study aimed at mapping the subsurface structures and sedimentary thicknesses in parts of Middle Benue Trough, Nigeria using interpretation of aeromagnetic data. Four aeromagnetic data acquired from Nigerian Geological Survey Agency were merged, displayed and analyzed using various standard techniques including spectral analysis. The result depicts that the study area possess variable magnetic intensity ranging 8480 nT to 8630 nT for total magnetic intensity and -100 nT to 140 nT for residual anomalies. The visual inception of the derivative and lineament maps along with the Rose diagram indicate that the area is intensely fractured with major structures trending in the NE-SW direction while the minor structures trend in E-W and NW-SE path. The spectral analysis result depicts two ranges of sedimentary thicknesses, namely; the shallower thicknesses which vary from 0.52 km to 1.90 km and the deeper thicknesses which vary from 2.00 km to 6.82 km. The results also show the variability of the sedimentary thickness with an average of 3.73 km in the study area being part of Middle Benue Trough depicting a sub-basin configuration. The study concludes that the existence of subsurface lineament structure systems and high sedimentary thicknesses could serve as huge boost for possible hydrocarbon accumulation within the study area.