Origin Of Ohe Pond In Nsukka, Evidence From Geophysical Investigation

ABSTRACT

The study area is located in Nsukka Local Government Area of Enugu State Nigeria. It lies between latitudes 6° 49' N, and 6° 50' N, and longitudes 7° 15' E, and 7° 21' E respectively. The area is underlain by Nsukka Formation, which is capped by the laterites, and underlain by heterolithic Sandstone / Siltstone layers with some clays or shale at some deeper horizons.  Geophysical investigation using Electrical Resistivity and IP methods with ABEM Terameter, SAS 1000, reveal the presence of fault in one section of the area, (Profiles 1 and 2, see Fig. 13, 14a and 14b of pages, 47 and 48 respectively) which potentially serves as the conduit through which water percolates to aquifer which eventually feeds the pond throughout the seasons.  This is indicated by the interpretation of anomalous low resistivity values within this zone, which shows a downward continuity within the geo-electric section in these profiles. A shallow possible source of the water in a perched aquifer following precipitation during the wet season, serves as recharge to the deep seated aquifer.  The result of the Profile 3 shows no continuity of the fault across that point, hence no anomalous drop in the resistivity in this area.