The field data obtained have been analyzed using computer software (Zondip) which gives an automatic interpretation of the apparent resistivity. Four locations were dealt with Saint Ambrose School and Lebanese School for the Freetown Complex and Makalie town and Makeni Government Hospital for the Granite Greenstone Terrain. and the geological and hydrogeological parameters were analysed. Vertical electrical sounding (VES) were carried out in the locations mentioned above to understand the geology and also to verify the extent of weathering, fractures and other features like joints, dykes etc. Though several parameters are used to identify the groundwater prospects of an area, this research was narrowed to evaluate the groundwater potential through Geophysical survey (Electrical resistivity). The Freetown Complex on the other hand is younger (Jurassic to Triassic) and therefore has limited fractures and thin weathered layers (Overburden) with varying thicknesses. Grey and pink granites are exposed in most parts of the area. The geology of the Granite Greenstone Terrain constitutes medium- to coarse-grained granite which is typical of the older Achaean formation. The purpose of this study was to determine the groundwater potential of the Freetown Complex and the Granite Greenstone Terrain in Sierra Leone. Based on the drilling report the VES was productive. VES 2 is observed to have much groundwater and geologically, the thickness of weathered rock unit and fractured bedrock formation, which are the major aquiferous unit, in VES 2 is thicker than VES 1, VES 2 is expected to store and transmit more groundwater, therefore this VES is recommended for drilling. The fifth layer is the fractured basement and this layer has resistivity values from 2000Ω□ to 2400Ω□. It is very favorable and productive in borehole construction. This layer thickness and aquifer properties enhance the accumulation for efficient groundwater potential. The fourth layer is the fractured bedrock layer and the resistivity value ranges from 1480Ω□ to 1600Ω□ and the thickness ranging from 19.9□ and15.5□. The third layer is partially weathered rock unit and has apparent resistivity of 640Ω□ and 350Ω□ and a thickness of 11.4□ and 7.8□.This layer is partially convenient for ground water accumulation and hence the aquifer cannot yield water in sufficient quantity. The second layer is the lateritic sand, the apparent resistivity ranges from 96.2 Ω□ to 38.25 Ω□ and the thickness ranges from 1.8□ and 3.74m, having poor hydrogeological characteristics. This layer is generally unreliable for groundwater accumulation. Based on the geophysical survey (horizontal and two vertical electrical sounding points), the first layer is the clayey topsoil formation with apparent resistivity values which ranges between 148 Ω□ to 255 Ω□ and a thickness between 0.48□ and 0.74□. Ajibade’s residence, Akuru Area, Off Elebu Oluyole Extension, Ibadan, Oyo State, Nigeria. The case study of this report is based on the geophysical survey and drilling carried out at Mr. Geophysical survey (electrical resistivity method) is used to delineate suitable points for hydrogeological borehole sitting, the major systematic processes involved in borehole construction are borehole drilling, borehole completion and borehole development. The water moves down into the ground because of the gravity, passing between particles of soil, sand, gravel, or rock until it reaches a depth where the ground is filled, or saturated, with water. Groundwater comes from rain, snow, and hail, etc. The student industrial work experience scheme (SIWES) is a programme designed to expose student to working experience in the industry, this report covers my experience under the geophysical and drilling departments of Waterworld Solutions.
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