Compositional Trend in the Specks of Tantalite, Tourmaline and Beryl Hosted within Complex Basement Rocks Using Geophysical and Geochemical Methods of Exploration

Abstract

Vertical Electrical Sounding (VES) using Schlumberger array was employed in data collection. Data acquisition was carried out along Oyan river bank with a total of twenty-three (23) soundings. This location was divided into two zones: VES 01 -09 and VES 10 -23. Rock samples hosting specks of tantalite, tourmaline and beryl were collected from the artisan pits within the study area and taken for geochemical analysis in the laboratory. The result of geochemical analyses revealed the quality of the solid minerals in terms of mineral compositions (major, trace and rare earth elements) while geophysical field measurement revealed the resistivity values, vertical and lateral distributions and depth of the solid minerals. The range of electrical resistivity values of these solid minerals as revealed by laboratory measurement is 19.4 - 31.1Ωm while that of the host rock is 10.0 - 100.0Ωm as obtained from field measurements. Specks of tantalite, tourmaline and beryl were suspected to be sparsely distributed in other VES locations except at VES02 and 09, where vast deposits were suspected. Two litho-facies changes were observed and this revealed the economic values of these solid minerals. Black tourmalines, beryl and tantalite samples collected as specks within the study area were of low quality while pink tourmaline is of moderate quality on the basis of the chemical constituents contained.