Structural investigation of Zungeru-Kalangai fault zone and its environ, Nigeria using aeromagnetic and remote sensing data

A.B Arogundade,M.O Awoyemi,O.S Hammed,S.C Falade,O.D Ajama

doi:10.1016/j.heliyon.2022.e09055

Abstract

This study analysed aeromagnetic and satellite imagery data over parts of northern Nigeria to delineate magnetic and surface lineaments associated with fault system trends. The aeromagnetic data were analysed using the Fast Fourier transform technique for reduction-to-equator, total horizontal derivative, analytic signal amplitude and Euler deconvolution. Landsat-8 OLI and SRTM data have been enhanced using spatial filtering and hill-shading techniques for the delineation of lineament features. The extracted surface lineaments are denser on the satellite imageries than on the HRAD because the datasets respond to different physical properties of the geological units and features. The location and orientation of the Zungeru/Kalangai fault zone, which extends about 245 km from the Bida Basin Basement to the northern part of Nigeria, correlate with the existing fault on the published geological map and form a conjugate pair with a fault around Kaya. The derived maps revealed the presence of several previously undetected geological lineaments corresponding to faults and folded dyke, striking predominantly N–S, NNE-SSW, NE-SW and NW-SE lacking in previous geological maps. The application of 2D forward modelling revealed the 2D image of the nature of the subsurface, magnetic susceptibilities of rocks and the block boundaries coinciding with the geological lineaments.

Highlights

The Earth is a dynamic and changing system that is divided into several rigid blocks known as tectonic plates
The Landsat-8 OLI lineament map clearly shows that the NE-SW trending lineaments from Zungeru to Birnin Gwari areas enclosed with Zungeru mylonites are dense (Kolawole and Anifowose, 2011)
The extracted lineaments from Landsat-8 show N–S, NNE-SSW, NW-SE, NNW-SSE, ENE-WSW and NE-SW trending lineaments while the lineaments extracted from the Shuttle Radar Topography and Mapping mission (SRTM)-DEM's shaded-relief maps are prominent in the N–S, NNE–SSW and NW-SE directions

Summary

Introduction

The Earth is a dynamic and changing system that is divided into several rigid blocks known as tectonic plates. Previous studies have shown that there is an inland extension of the oceanic fracture zones after offsetting the Mid-Atlantic Ridge and manifest as fault zones in the Nigerian Basement Complex (Wright, 1976; Whiteman, 1982; Binks and Fairhead, 1992; Adepelumi et al, 2008; Ajama et al, 2021). These fracture zones are believed to have created some megastructures (such as Ifewara and Zungeru-Kalangai fault zones) that serve as weaknesses zones within the Nigeria Basement (Anifowose et al, 2006; Kolawole and Anifowose, 2011; Awoyemi et al, 2017a)

Methods

Results

Discussion

Conclusion