2-D Electrical Resistivity Imaging for Detecting Landslide Vulnerability of Some Tin Mine Sites in Jos South, Plateau State, North Central, Nigeria

Abstract

A possible cause of landslide is mining activity, with the problem exacerbated in areas where mining activities are uncontrolled and unregulated like the Jos-South, North-Central Nigeria. The aim of this study is to use 2-D electrical resistivity imaging as a preliminary tool to investigate landslide vulnerability of some tin mine sites in this area. The Wenner-Schlumberger configuration was used and the apparent resistivity (observed data) was iteratively subjected to inversion process using RES2DINV software, to generate the 2-D resistivity sections. The 2-D Electrical Resistivity models revealed resistivity sections with resistivity generally increasing with depth, that is overburden resistivity < granitic weathered basement resistivity < granitic basement. The exception was that of the model for Gyerro 2 (Sabongida Kanar 2), which revealed a section with overburden resistivity > granitic weathered < granitic basement resistivity.The fluid flow mechanism and weathered zone as indicated by the low resistivity values show the presence of a weak zone within the subsurface of Gyerro 2 where landslides can form. Hence, the subsurface of Gyerro 2 area is vulnerable to land sliding with a weak zone of very low resistivity (4.58 Ω -36.4 Ω) greater than 3600m2. This weak zone may comprise of high content of clayey material, cassiterite bearing alluvium and water.