Research
Geochemical Investigation of Groundwater in Some Parts of Birnin Kebbi, Northwestern Nigeria
Geochemical study on groundwater quality was undertaken from Bayankara, Badariya and Old Town areas in Birnin Kebbi, situated in sedimentary basin, northwestern Nigeria. The hydrogeochemical study was carried out on 30 water samples, 10 from each of the 3 locations with the intent to determining the quality of the water sources such as tap water, borehole, and hand-dug well used for drinking and domestic purposes; to determine the causes, sources of the pollutants and suggest solutions towards solving the problem. The 30 water samples were analyzed for major elements and important anions. Atomic Absorption Spectrometer (AAS) was used to analyze the cations while NO3 -, PO4 3- and SO4 2- were determined using Spectrophotometer. Both Fand Clwere determined by titration method. The results show that all the cations Na, K, Ca, Mg, Fe, Cu, and Zn ions have values far less than maximum limit recommended by WHO except Mn ion that exhibits average concentration values in Bayankara 0.39mg/l, Badariya 0.16mg/l greater than 0.05mg/l tolerable limit by WHO standard. However, Old Town area has Mn ion values within the recommended limit. PI index on manganese ion further show that Bayankara is more polluted than Badariya having PI index > 1 probably due to unhygienic conditions of the areas and possibly due to dissolution of manganese mineral present in the sandstone aquifer. The anions analyzed Cl, F, NO3 and SO4 have ion concentrations within the limits of WHO recommended for drinking water with the exception of NH4 and PO4 ion concentration values that are anomalously high in the 3 locations; showing values greater than 0.5mg/l for NH4 and 0.3mg/l for PO4. In Bayankara, average NH4 and PO4 ion concentration values are 3.7mg/l and 0.81mg/l respectively; Badariya, 4.0mg/l and 0.75mg/l respectively, while Old Town is 3.8mg/l and 0.87mg/l respectively. The contaminants resulted from anthropogenic means such as poor hygienic condition from sewage leaching and excessive application of leached fertilizer and manure rich in PO4 and NH4 in farming, aided by tectonic and sedimentary structures that characterize the study areas.
Palynology and Stratigraphy Relationship of the Facies Intertongueing between the Afikpo Sandstone and Nkporo Shale in the Cretaceous Anambara Basin, Southeastern Nigeria
Palynological research on ditch cutting samples from the upper part of the Ubiaja- 1 well (40-1425ft) located in the western flank of the Anambra Basin Nigeria shows that sandstone of the Campanian to Early Maastrichtian age in Afikpo Basin has lateral extension into the Anambra Basin. Lithological description of the stratigraphic sequence indicates that the interval is characterized by nine different lithofacies units. These include granulestone, conglomeratic sandstone which are poorly sorted, thickly bedded and deposited in continental setting; pebble sandstone, coarse sandstone are also poorly sorted, with more pebble grains, deposited under high energy current in continental environment. Other lithofacies include claystone, mudstone, deposited in fluviatile environment; heterolith facies of various proportions of sand and shale comprising of shaly sand and sandy shale deposited in deltaic setting; followed by dark grey shale, deposited in the marginal marine environment. The sandstone facies is dated Campanian to Early Maastrichtian; equivalent to Afikpo Sandstone in the adjacent Afikpo Basin. Two palynological zones: Milfordia spp acme zone I characterized by relative high abundance of Milfordia spp. such as Milfordia sp. and Milfordia jardinei, dated Campanian and the overlying Foveotriletes margaritae zone II characterized by paucity of Milfordia spp. and co-occurrence of Monocolpopollenites sphaeroidites, Syncolporites sp., Ephedripites sp., and Monosulcites sp.; dated Early Maastrichtian age. The age dating and the stratigraphic lithofacies is equivalent to Nkporo Shale/Afikpo Sandstone known for Afikpo Basin stratigraphy but here reported newly in the Anambra Basin. This suggests lateral facies intertongueing of Afikpo Sandstone characterized by erosional surfaces, unconformable with Nkporo Shale, extended into Anambra Basin. The result reveals a new sandstone member in the Nkporo Formation or in another way makes Nkporo Formation to become Nkporo Group comprising of Nkporo Shale and Afikpo Sandstone.
