Geo-Electric and Hydrogeologic Investigations of the Upper River Shemankar Basin within the Gu Volcanic Province, Jos Plateau, Nigeria
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Geo-electric and hydrogeologicinvestigations of some selected areas within the upper reaches of River Shemankar basin around the Gu Volcanic Line, Jos Plateau was carried out to determine the factors influencing the peculiar difficult hydrogeological disposition of the area resultingin the high borehole failure rate. The area is underlain by Basement Complex rocks (migmatites, granite gneiss and pegmatites) and Newer Basalt. The general physiographic setting of the area is characterised by basement highlands and interconnected with constricted and wide valleys breached with basalts flows from the Gu Line volcanoes. A total of 84 geo-electric soundings (VES) were carried out in three selected locations (AbworDyis, Kapil-Dyerok and Jibam). The geo-electric resistivity sounding data interpretation using WinResist software revealed 4-5 geo-electric layers/lithologic units from the geo-electric parameters. The geo-electric layers are- (1) Topsoil from 0.4 to 0.6m, (2) weathered basalts from 0.6 to 21m, (3) fresh/fractured basalt from 0.1 to 55m, (4) sub-basalt alluvium with variable thickness from 20 to ≥ 80m and (5) fresh/fractured basement and are characterised by resistivity value range of 93 to 634 ohm-m, 23 to 152 ohm-m, 178 to 693 ohm-m, 28 to 106 ohm-m and 272 to 853 ohm-m respectively. The interpreted geo-electric parameters from the VES model curves were used to produce geo-electric sections which are correlated with exploratory borehole lithologic logs and aided the groundwater evaluation of the area. The study revealed that the successes of the boreholes are highly dependent on the depth, presence of sub-basalt alluvium and/or fractured basement.
Publication Info:
Author: Longpia, C.B. , Dakwo, P.D. , Kutse, N. and Ramadan, J.
Volume: 53
Issue: September
Published By: Journal of Mining and Geology, 2024-09-01