Surface and Subsurface Structural Mapping via Airborne Magnetic and Remote Sensing Data A Study of Kachia (Sheet 166), North-Central Nigeria

Abstract

The present study utilizes airborne magnetic and Shuttle Radar Topographic Mission (SRTM) data of Kachia (Sheet 166), north-central Nigeria to elucidate the relationship between the surface and subsurface structures within the study area with the objectives of mapping the structures, ascertaining the structural density of the area and expound the areas of subsurface and surface structural overlaps that are points of structural continuation between the surface and subsurface structures. To achieve these objectives, SRTM data was processed into hillshade maps at four distinct solar elevations and merged after which the surface structures were delineated using Geomatica software. Also, the two methods used in magnetic structural delineation were the first vertical derivative (FVD) and 3D Euler deconvolution using structural index of one (SI = 1) in Oasis Montaj environment. The combined structural density map of the area revealed high structural density around the northcentral portion of the area, northeast, in the west of Gidan Bawa, around the southwest in Kazaze and the west and south of Janjala. The combined structural statistical trend analysis revealed that the area has been affected by several tectonic activities that produce structural imprints with the predominant trend being the ENE-WSW direction, followed by WNW-ESE, NE-SW, NW-SE, NNE-SSW and NNW-SSE respectively. The combined structural map also revealed areas of structural continuation between surface and subsurface structures. These are points whereby fluid (water or hydrothermal fluids) can find their way from the subsurface to the surface and were observed in areas around Kazaze and Janjala in the southwest and Gidan Bako in the North-central portion of the study area.