PRELIMINARY ESTIMATE OF GYPSUM DEPOSIT BASED ON WENNER AND SCHLUMBERGER ELECTRICAL RESISTIVITY METHODS AT IKPESHI, EDO STATE, NIGERIA

Abstract

The Wenner and Schlumberger electrical resistivity methods were employed at spread lengths of a=1m, a=3m, a=6m and a=9m across the entire area, after which a total of twelve vertical electrical sounding (VES) points were sounded at appropriate locations with a maximum spread of 100 meters in the area at Ikpeshi, Etsako Local Government Area of Edo State, with the aim of locating and estimating the quantity of some possible deposits of gypsum. Just like any other solid mineral, it is uniquely difficult to locate gypsum in isolation, however, gypsum could possibly be found in association with some other geological formations. The common formation identified in this work was limestone, which possess a very wide range in resistivity values (1 – 104 Ω-m).The surveyed area shows the presence of some traces/crystals of gypsum at depths of between 3m and 9mand a resistivity range of 1 to 3000Ω-mspread around the investigated area. The gypsum reserve deposit was estimated to be about seventeen million tons.