Geophysical exploration for groundwater in the sedimentary environment: a case study

The interpretation of live resistivity curves over Nanka town within geologic terrain often referred to as Nanka Formation in Anambra Basin, south-eastern Nigeria indicates that the area has a great groundwater potential. A correlation of the curves with the lithologic log from a nearby borehole suggests that the major lithologic units penetrated by the sounding curves are Laterite, Clay Sandstone and clay. The sandstone unit which is the aquiferous zone has a resistivity range of between 500 ohm.m and 960 ohm.m and thickness in excess of 200 m. The depth to the water table is at least 100 m. Global Journal of Pure and Applied Sciences Volume , No 1 January (2001) pp. 97-102 KEY WORDS: Vertical electrical, Sounding, groundwater potential, aquifer thickness, Nanka Formation, Anambra Basin