Weathering Structure of Southwestern Niger Delta, Nigeria.

Seismic refraction survey was conducted in southwestern Niger delta to determine the weathering structure. The velocity and depth of the weathered layer and the velocity of the refractor in the area were calculated from critically refracted arrivals using flat layer models. Using the time-intercept method for interpretation, the thickness of the low velocity weathered layer in the area varies from 3.6 m to 46.2 m with a regional average of about 24.0 m. The weathered layer and the refractor beneath it have an average P wave velocity of about 600.0 m/s and 1842.0 m/s; respectively. The knowledge of the weathering structure is extremely valuable for oil and groundwater exploration in the area of study. The structure is also interest to those engaged in civil engineering practice. (Keywords: seismic refraction, weathering structure,