Electrical Resistivity Imaging of a Coal Deposit at Tai Area of Gombe State, North Eastern Nigeria

Abstract

A 2-D electrical resistivity imaging of some parts of Tai in Akko Local Government area of Gombe State, northeastern Nigeria was carried out. Tai is located 28 km from Pindiga and lies between latitudes 10⁰ 00′00″ and 10⁰ 06′00″N and longitudes 10⁰ 40′ 00″E and 10⁰45′00″E. This study was prompted by a report that in the course of siting a hand-dug well and hand-pump borehole in Tai, coal seam was intercepted. The aim of this geoelectrical investigation is to image the survey area for possible location and future exploitation of coal seam found in the area. The survey was targeted at determining the lateral extent of the coal seam, resistivity values associated with the coal seam and depth to the coal seam. ABEM Terrameter SAS 1000 was used to acquire the data in this survey. The protocol chosen was the Wenner-Schlumberger array because of its sensitivity to both horizontal and vertical structures. Data processing was done using RES2DINV software. The results show that the resistivity values range from 3Ωm to 2033 Ωm. The top layer has resistivity ranges of about 66 Ωm to 2033 Ωm. Below this, is a layer of low resistivity ranging from 3 Ωm to 57 Ωm probably saturated with water. The layer with resistivity range of about 250 Ωm to 900 Ωm is probably the host of the coal seams. It can be concluded that the occurrence of the coal seam is probably more at the Northwest of the survey area and the coal seam is suspected to have resistivity values ranging from about 250 Ωm to 900 Ωm and depth varying from 3 m to 17.2 m.

Keywords: Coal Seam, Lateral Extent, Electrical Resistivity Imaging