Seismic Refraction Investigation of the Subsurface Structure at Ahmadu Bahago Senior Secondary School, Minna, Nigeria

Abstract

A refraction survey was conducted over an area of 1⁄2 km x 1⁄2 km at the Ahmadu Bahago Senior Secondary School, Minna, in order to study the nature of the geological features and to determine possible aquifer locations. A total of thirty-six points were shot, and analysis of the recorded data was based on the study of velocity pattern from the time-distance graph obtained from the field data. Usually, high-velocity values correspond to high-density materials at increasing depths. Two layers were identified, the first having velocities ranging from 714.29 ms to 1666.6 ms1 and the second having velocities ranging from 3267.97 ms to 7500 ms. The refractor is situated at a depth ranging from 3.33m to 9.63m. The refractor velocities are likely associated with granite- granodiorite and granite-gneiss rocks.