Geophysical Analysis of Basement Terrain Groundwater Using Vertical Electrical Sounding: A Case Study of Parts of Abuja North Central Nigeria

The successful exploitation of groundwater requires a proper understanding of the hydrogeological characteristics of the sub-surface aquifers found within the basement complex. This can be carried out using various geophysical survey methods. Groundwater occurs in the joints, fissures, fractures, shear zones and weathered overburden of un-weathered rocks. Therefore effective groundwater development requires careful geophysical analysis and interpretation of data. The use of vertical electrical sounding (VES) for groundwater (hydrogeological) exploration is popular in the basement complex rocks and sedimentary basins. This study was aimed at analysing the hydro geological characteristics such as bedrock depth, lithological units and degree of fracturing and drilling location of groundwater in the basement complex / terrain of Garki, Kurudu, Dei-Dei and Kubwa areas of Abuja, North central Nigeria using Resistivity Method. Finally, the results indicate that the choice of geophysical survey method determined by physical properties of the area; influence groundwater availability, susceptibility and supply

Geophysical Analysis of Basement Terrain Groundwater Using Vertical Electrical Sounding: A Case Study of Parts of Abuja North Central Nigeria

The successful exploitation of groundwater requires a proper understanding of the hydrogeological characteristics of the sub-surface aquifers found within the basement complex. This can be carried out using various geophysical survey methods. Groundwater occurs in the joints, fissures, fractures, shear zones and weathered overburden of un-weathered rocks. Therefore effective groundwater development requires careful geophysical analysis and interpretation of data. The use of vertical electrical sounding (VES) for groundwater (hydrogeological) exploration is popular in the basement complex rocks and sedimentary basins. This study was aimed at analysing the hydro geological characteristics such as bedrock depth, lithological units and degree of fracturing and drilling location of groundwater in the basement complex / terrain of Garki, Kurudu, Dei-Dei and Kubwa areas of Abuja, North central Nigeria using Resistivity Method. Finally, the results indicate that the choice of geophysical survey method determined by physical properties of the area; influence groundwater availability, susceptibility and supply

2-1/2 Dimensional Modeling of the Major Structures Underlying Dong and Shelleng of the Upper Benue Valley, Using GM-SYS Computer Modeling

Airborne magnetic data over part of Dong and Shelleng area of the upper Benue Valley, N-E basement complex of Nigeria's was carried out to investigate the deep and thick structures of the underlying geology and their relationship with granitic intrusion. These features are interpreted in terms of deep geologic structures, and/or susceptibility variations within basement rocks. The residual separation exercise revealed the area is underlain by a NE-SW regional trends, which shows it is in agreement with Benue trough, presumed they have the same structure control. Furthermore, the 3-D residual magnetic anomaly map suggests Dong is likely to be the sedimentary basin. It shows that the magnetic field there is smoother, which is masked off by the effects of the stronger magnetic basement. High amplitude of the anomalies which outcrop at eastern part of Dong where the profile cut across 6 could be the presence of Ngurore basalts. The thickness revealed by the model (DD 1), Northwestern part Numan has a maximum thickness of 1.4km and minimum of 0.2km. In D-D1 modeling, it revealed a porphyritic granite with non- uniform thickness of about 1.1Km and minimum of 0.17Km with a width approximately 2.9Km. The first sedimentary layer reveals has a thickness of about 1.0Km and the second varies from 1.0 to 1.6km thick. The width is about 4km.The Alluvium thickness increases progressively between 0.2Km to 0.7Km and the width of about 18km, reveals by the model. The thickness of the basin varies between 0.9km to 2.9Km. The model reveals the width of the basin to about 136Km

Natural Radioactivity and Geological Influence on Subsurface Layers at Kubwa and Gosa Area of Abuja, Northcentral Nigeria

The concentration of 238U, 232Th and 40K in rock samples were analysed using gamma ray spectrometry. In Kubwa, the concentration ranges from 15 to 52 Bq kg-1 for 238U, 32 to 84 Bq kg-1 for 232Th and 119 to 705 for 40K Bq kg-1. In Gosa area, the concentration of 238U ranges from 23 to 30 Bq kg-1, 232Th varied from 48 to 76 Bq kg-1, and 40K varied from 438 to 820 Bq kg-1. The dose rate, radium equivalent activity and annual effective dose rate at Kubwa and Gosa were calculated and compared with international standard values

Geoelectrical Investigation Of Aquifer Problems In Gosa Area Of Abuja, North Central, Nigeria

The study of aquifer problems in Gosa area of Abuja, North-central Nigeria, has been undertaken. Abuja, the capital city of Nigeria, is underlain by Precambrian basement rocks. Vertical electrical sounding (VES) was carried out at twelve locations within and around the Gosa area. The interpretation of the data obtained from the sounding revealed that six non-aquiferous geoelectrical layers overlie the unfractured basement. The first layer with average thickness of about 0.5 m and resistivity of 83 Ohmm. The thickness of the second layer is about 0.7 m and resistivity of 438 Ohm-m. The third layer is about 3.4 m thick and resistivity of about 63 Ohm-m. The fourth layer with average thickness of about 16.0 m and resistivity, 236 Ohm-m. The fifth layer with average thickness of 42.7 m and resistivity of about 68 Ohm-m. The thickness of sixth layer varies from 42.7 m to infinity and resistivity of about 2067 Ohm-m. Eight boreholes of varying depths, 45 to 70 m were drilled. Other areas were drilled with good yield of static water level of about 3.7 m, whereas Gosa aquifers were found dried. It could be attributed to basaltic intrusion that shattered the aquifer bearing rocks thereby devoid water in the zone after pronouncing from geophysical investigation