Global Journal of Science Frontier Research, H: Environment & Earth Science, Volume 23 Issue 1

III. G eological S etting According to Kogbe (1976) and Avbovbo (1986) the geological history of the area started in the Upper Albian with the deposition of mainly marine sometimes deltaic and fluviatile interbedded clays, silts and sands (Fig: 5). It is possible that after Maastrichtian, this sedimentation continued up to Paleocene leaving the continental series of sandstones interbedded with claystones and siltstones called Kerri-Kerri Formation. There was no evidence of deposition after that until almost late Pliocene when sedimentation resumed and lasted without interruption to date. The product of this deposition is what is referred to as Chad Formation which consists of interbedded clays, silts and subordinate sands of continental origin measuring up to 1000 m in thickness (Carter et al, 1963, Kogbe, 1992 and MacDonald et al, 2005). Figure 5: Generalized Geological Map of Nigeria (After MacDonald et al. , 2005) IV. M aterial and M ethods Twenty five (25) water samples were collected which comprises of nine (9) hand dug wells, ten (10) surface water and six (6) from boreholes. These constitute the major source of water supply in the research area. The top film of the surface water and groundwater were removed, twolitres of water samples was then collected in clean dry plastic bottles filled completely and cap tight to avoid excessive agitation or exposure to sunlight. Each sample was then labelled and preserved in the refrigerator until when they are ready for chemical analysis. The position of each sample location was taken using Global Positioning System (GPS) Garmin type. Physical parameters of the samples suchus electrical conductivity, temperature, total dissolve solid and hydrogen exponent were measured directly on the field at spot. The analytical method employed includes Atomic Absorption and Spectrometer which was adopted for the analysis of Mg 2+ and K 2+ . While digital titration method were used in the determination of SO 4 - , HCO 3 - and Cl - . The flame photometer was used in determining Ca 2+ and Na + respectively (Figure 6). Hydrochemical Assessment of Surface and Groundwater in Some Selected Communities of Borno and Yobe State 1 Year 2023 59 © 2023 Global Journals Global Journal of Science Frontier Research Volume XXIII Issue ersion I VI ( H )