1. Geology Department, Ekiti State University, Ado Ekiti, Nigeria
2. Geology Department, University of Leicester, University Road, Leicester, LE1 7RH, UK
3. Environmental Remediation and Water Pollution Chemistry Group. Department of Ecology and Resource Management, University of Venda. Private Bag X5050, Thohoyandou, 0950, South Africa
4. Department of Mining Geology, School of Environmental Studies, University of Venda, Private Bag, X5050, Thohoyandou, 0950, South Africa