SEISMIC REFRACTION INVESTIGATION OF GROUNDWATER POTENTIAL IN PARTS OF THE OBAN MASSIF, SOUTH-EASTERN NIGERIA

A seismic refraction survey was conducted in parts of the Akampka Basement Region of the Oban Massif, South-Eastern Nigeria, using a portable MOD. S79 3- channel digital type signal enhancement seismograph. The objectives were to determine the depth to the water table, the thickness of the saturated overburden, and the depth to basement, for purposes of groundwater development. The result showed that for the three selected areas, the average depth to the basement was 16.4m, the average aquifer thickness was 10.6m, and the average velocities of 492m/s, 969m/s, 1811m/s and 3759m/s for the first, second, saturated aquifer and bedrock respectively were obtained. The mean depth to the water table was determined to be 8.7m at Aiyebam 10.1m at Awi and 1.7m at Mbarakom. There was a good correlation between seismic interpretation and borehole lithologic section within the study area. With a considerable saturated thickness, areas of good potential aquifers for groundwater development abound in the study area. KeyWords: Seismic refraction, groundwater development, basement, Oban Massif, South-eastern Nigeria. [Global Jnl Geol. Sci. Vol.1(1) 2003: 43-50