Gradio-magnetic and Resistivity Exploration for Groundwater in Wuro Yakubu Song Area, Hawal Basement Complex, Northeastern Nigeria

Abstract

This research demonstrates the integrated use of magnetic-gradiometric and resistivity methods in mapping subsurface structural features to explore for ground water bearing zones in Wuro Yakubu area, Song Adamawa State in northeastern Nigeria. The research was carried out between March 2010 and December 2010. Acquisition of ground magnetic data was achieved using G-856-MagTM Proton Precision Magnetometer in the gradiometric mode, while resistivity measurements were done using ABEM SAS 1000c terrameter. Interpretation of ground magnetic and resistivity data were carried out using WinGlink and IX1D resistivity softwares respectively. Vertical magnetic gradient results in the study area revealed anomaly as high as 10 nT/m, while results of resistivity survey revealed three to four geo-electrical layers, with layer resistivity ranging from a minimum of 9.11 Ω-m to a maximum of 2329.6 Ω-m. Layer thickness ranges from 0.51 m to 35.62 m. Qualitative analysis of total magnetic intensity and the vertical gradient maps shows a prominent belt of anomalies striking in NW-SE direction and was interpreted to be due to the presence of fault, fracture or shear zones. Resistivity work across this zones shows that the third geo-electrical layer comprising of fractured/weathered basement with a resistivity range of 100.17-531.21 Ω-m, and thickness 27.29-35.62 m is a promising zone for ground water accumulation.