Electrical resistivity investigation of sub- surface topography of Rafin Bareda Drainage Basin as a tool for cassiterite-columbite exploration in Dutsen-Wai, Nigeria

Abstract

Geophysical investigation has been undertaken at Rafin-Bareda drainage basin with the aim of identifying suitable points of high Cassiterite potential for the study area. The people around such drainage basin exploit these cassiterite and columbite deposits by trial and error method.The trial and error process of mining is dangerous to the lives of the miners.Hence, a Schlumberger array with half current electrode spacing ranging 1-100m was used. A total of 36 vertical electrical sounding (VES) stations were equally spaced at 20 m interval along eight profiles in the area using Ohmega terrameter. The field data were interpreted using IPI2WINsoftware. The results obtained from the obtained VES data were applied to produce the geoelectric sections of the study area, which indicate a 2-4 range of geoelectrical layers. The corresponding geologic section comprises of sandy clay soil, weathered and fresh laterite, weathered and fresh basement as the main rock types. The 3D surface of the basement topography of the study area shows the undulating nature of the bedrock subsurface with the position of the various VES points. These enabled us to determine zones with high cassiterite potential and the best location for drilling productive cassiterite in the area. The depth to the basement rock, resistivity and thickness values ranged from 4.50-36.40m, 59-1724Ωm and 1.12-36.40m, respectively. Thus, the geoelectric sections suggest that the point of high depression on the basement rock represents a promising area for Cassiterite-Columbite. The Cassiterite mineralization map identifies the VES points with high cassiterite  potential.

Keyword: Geological profiles, Vertical electric sounding (VES), Cassiterite-Columbite,Dutsen-wai drainage