Mapping magnetic lineaments and subsurface basement beneath parts of Lower Benue Trough (LBT), Nigeria: Insights from integrating gravity, magnetic and geologic data

Abstract

In this study, we present the analysis of the aeromagnetic data of parts of the Lower Benue Trough. Lineament analysis of the aeromagnetic data demonstrated four tectonic trends of the basement terrain. The lineaments are in the northeast to southwest (NE–SW), east, northeast to west, southwest (ENE–WSW), north to south (N–S), and east, southeast to west, northwest (ESE–WNW) directions. The NE–SW and ENE–WSW are the most dominant whereas the N–S and ESE–WNW are the minor trends. The estimated magnetic basement using spectral analysis vary between 3.5 and 5 km and the shallow magnetic sources (depth to top of intrusions) vary between 0.24 and 1.2 km. The result of the basement estimation from the magnetic data is comparable with the previous results from other studies as well as with the basement depth estimated from the gravity data of part of the present study area are incorporated in the study. From the gravity data, we identified sub-basin around Makurdi and basement of the sedimentary basin (5 km) is estimated using GPSO algorithm and Oasis Montaj (Geosoft).