Heavy metal characteristics of groundwater in Ibadan South Western, Nigeria

Water, an essential commodity is consequently being affected by natural and human activities. Investigations were made on groundwater of the study area to evaluate the impact of heavy metals. Groundwater samples were collected and analyzed using Inductively coupled plasma- emission spectrometry method, at Acme laboratories Canada. Geochemical analysis revealed a significant concentration of increasing order K > Ca > Mg > Fe > Zn > Cu > Pb > As > Cd. Ca, Fe and K were above the WHO standard. Index of geo-accumulation (Igeo), revealed no contamination of the trace metals. Inter-elemental analysis showed a strong correlation between Cd to Zn (‘r’- 0.983) and Fe to Pb (‘r’- 0.900), indicating that the metals are governed by the same geochemical factors and are from the same anthropogenic source. Piezometric map revealed southwest direction of groundwater flow that shows direction of contamination influx. The study can then be concluded to be contaminated with Ca, Fe and K due to the impact of man’s activities in the environment. Public health effect of these metals could be anemia, kidney damage, brain damage, cancer and ultimately death.Key words: Water, contamination degree, geochemical factors, public health, heavy metal

Evaluation of Electrical Resistivity Anisotropy in Geological Mapping - A Case Study of Odo Ara, West Central Nigeria.

The study of electrical resistivity anisotropy in rocks has become important in increasing the accuracy of geological mapping using electrical resistivity survey. The study area, Odo Ara near Egbe, west central Nigeria, has been surveyed using electrical resistivity soundings. Sixty Radial Vertical Electrical sounding (RVES) measurements were carried out in the study area which comprises of the banded gneiss, amphibolites, schist and intrusive pegmatites. The aim of the study is to use the electrical resistivity anisotropy properties of the area to resolve its geological setup. The VES data showed a significant presence of electrical resistivity anisotropy. The VES curves obtained were predominantly of 3 geoelectric layer of H-type (ρ1>ρ2<ρ3) curves; the topsoil, sandy clay/ clay layer and fractured basement. The pseudo-sections show a good correlation with the geoelectric section. Moreover, the iso-resistivity and isopach maps also show a significant correlation with the lithological and strike of the rocks in the area but due to the non uniqueness of electrical resistivity, the lithologic difference between the banded gneiss and the amphibolite at the south western part of the area could not be totally resolved. However, the combination of the anisotropy polygons and the iso-resistivity map has reduced the ambiguity inherent in using a single geophysical parameter.Key words: Electrical resistivity anisotropy, radial vertical electrical sounding, anisotropy polygons

Depth estimates from a ground magnetic survey across a North- South trending geologic structure in a part of the basement complex terrain of Ilorin, west of central Nigeria

No Abstract.Global Journal of Pure and Applied Sciences Vol. 13 (2) 2007: pp. 209-21