DELINEATION OF FAULTS AND CAVITIES USING GRAVITY TECHNIQUES: AN IMPLICATION FOR ROAD CONSTRUCTION, SOUTH-SOUTH NIGERIA
Journal: Malaysian Journal of Geosciences (MJG)
Author: Johnson C. Ibout, Mfoniso U. Aka, Amarachukwu A. Ibe, Bethrand E. Oguama, Azuanamibebi D. Osu
This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
This study was carried out using five digitized aerogravity data to delineate near-surface structural faults, cavities, low-density zones and estimate the mass balance unit in foundations. Qualitative and quantitative analysis were performed in order to examines the depths to anomalous bodies, density/mass and stratigraphic features such as faults and cavities. The techniques employed were: Source parameter imaging (SPI), 3D Euler deconvolution, forward and inverse modeling. The results of the SPI shallow values range from -5.62 to -53.74 m and deep values range from 3.33 to 120 m. The 3D Euler deconvolution results range from -1892.2 to -1278.3 m for obscure and -12264 to 644.6 m for superficial formations. The forward and inverse modeling result shows the values of depth ranging from 2.5 to 4.8 km, density/mass range from (0.7 to 2.4) x 10-3 kg/m3 and (27 to 133) x 1010 kg of three profiles which is the parameter contrast of the gravity surveys. This shows sequential depths and density/mass contrast between the body of interest and the surrounding material which depicts the presents of faults, sedimentary basins and rock bearing minerals of shale/marble which comprises of air, water and sediment-filled formations. The information from this study has revealed the true nature of the subsurface and this will serve as a guide during road construction.