ABSTRACT
Mineral exploration is a complete sequence of activities. It ranges between searching for a new mineral prospect (reconnaissance) and evaluation of the property for economic mining (feasibility study). It also includes augmentation of additional ore reserves and resources in the mine and total mining district.Most people in the Western World are environmentalists at heart whether engaged in the mineral exploration or extraction industries or not. The mining and quarrying companies are simply responding to Society’s desire and demand for houses, washing machines, cars with roads on which to drive them, and so on. Two stark facts that the majority of ordinary people understand are first that ore bodies are wasting assets (that is, once an ore body is being exploited it has become a wasting asset and one day there will be no ore, no mine, and no further cash flow) and second that they are not evenly distributed throughout the Earth’s crust.
Recent development in the electrical exploration methods have resulted in a lot of contributions in providing accurate subsurface information. One of the most important is the increasing widespread use of two dimensional (2-D) resistivity surveys (Loke and Dahlin, 2002). The most commonly used arrays in the 2-D electrical imaging surveys are conventional arrays such as the Wenner, Schlumberger or Dipole-Dipole arrays. These arrays are often well understood in terms of their depths of investigations, lateral and vertical resolution, and signal – to – noise ratios (Dahlin and Zhou, 2004).
Application of Subsurface Imaging for Lithological Studies at Owanoba Community in Edo State, Nigeria Using Werner Array along UWANOBA Community in Ikpoba-Okha, Local Government Area of Edo State. The survey area is located within longitudes 005° 40' 12.0" E to 005° 40' 19.2" E, latitudes 06° 07' 11.2" N to 06° 07'18.7" N in UWANOBA. The research engaged Application of Subsurface Imaging for Lithological Studies at Owanoba Community in Edo State, Nigeria to investigate the subsurface stratification in the vertical and horizontal direction at UWANOBA community. The electrical resistivity data collected in parallel and orthogonal equidistant lines was processed into geo-electric models using Res2Dinv and the survey data collated. The study of the 2D structures reveal three to four geo-electric layers or subsurface zones in UWANOBA area, the 2D structures reveal two to three geo-electric layers/subsurface zones which are symptomatic of the topsoil, clayey sand, dry to loose sand, dry sand, sand (partially saturated) and sand (saturated). At UWANOBA area, the resistivity of the topsoil varies from 1309 - 5377 Ωm, dry sand (2154 – 5377 Ωm), partially saturated sand (1309 – 1912 Ωm) and saturated sand (341 – 512 Ωm).
These are the low resistivity material with average apparent resistivity value below 1675 Ωm interpreted to be clayey sand/ shalely sand, the medium (median) resistivity material with average apparent resistivity values between 1675 Ωm and 3500 Ωm which depicts coastal plain sand, and the high apparent resistivity material above 3500Ωm on the average interpreted to be coarse dry sand. The estimated volumes of coarse dry sand, coastal plain sand, and clayey sand in the study area at Obayantor are,and respectively.
