In the area sampled, the rocks of the Oban Massif consist of phylitic schist, gneiss, meladiorite, granodiorite, and dolerite.
The basement rocks are basically of the age of the Precambrian.
This is a typically multi-layered artesian aquifer which consists of sandstone and conglomerate with high heterogeneous permeability.
The groundwater mostly belongs to HCO3-Mg-Ca hydrochemical type.
These rocks are interjected by fractures, faults, joints and unconformities at some of the sections. The Tertiary Imo Shale Formation, a lithofacies equivalent of marine Akata Formation (prolific source rock) in subsurface Niger Delta, requires proper evaluation of its hydrocarbon generative potentials to complement organic geochemical...
more The Tertiary Imo Shale Formation, a lithofacies equivalent of marine Akata Formation (prolific source rock) in subsurface Niger Delta, requires proper evaluation of its hydrocarbon generative potentials to complement organic geochemical data in Anambra Basin. %) in Nzam-I well indicating that the sediments contain appreciable quantity of organic matter that can generate hydrocarbon.The shales are fine grained, fissile and light to dark grey in colour, the sandy shale is medium grained and grey in colour while the mudstones are fine grained and brownish grey in colour. Rock-eval data suggest that the sediments are poor to fair source rock for gaseous hydrocarbon and the organic matter is predominantly type IV kerogen sourced from terrestrial materials which does not yield significant amounts of hydrocarbon.The Total Organic Carbon (TOC) values of the samples range from 0.39 to 0.94 wt. Thermal maturity derived from Rock-eval data revealed that the Imo Formation samples are immature with respect to hydrocarbon generation.This study attempts to evaluate aspects of the source rock potential for hydrocarbon generation of the Imo Shale Formation penetrated by the Akukwa-II and Nzam-I wells in Anambra basin. Hydrogen Index, Oxygen Index and Tmax of the samples range from 11.0 to 28.0 mg HC/g TOC, 53.0 mg/g to128 mg/g and 409 to 430 o C respectively in Akukwa-II well and 14.0 to 48.0 mg HC/g TOC, 45.0 to 294.0 mg HC/g TOC and 421 to 497 o C respectively in Nzam-I well.The sediments encountered at depth range of 120 to 240 m and 550 to 650 m in Akukwa-II and Nzam-1 wells respectively, are made up of shales, sandy shale and mudstones. Genetic Potential (GP), Production Index (PI) and Calculated vitrinite reflectance (% Ro) in Akukwa-II and Nzam-I wells are 0.10 to 0.34 mg/g, 0.22 to 0.50, 0.202 to 0.580 and 0.08 to 0.73 mg/g, 0.04 to 0.32, 0.418 to 1.786 respectively.In the north part of the studied area post volcanic emissions of H2S, CO2 and H2O vapor continue to the present day.All the samples were analysed for heavy metals by the ICP method.more Given the water stresses in South Africa and the Western Cape specifically, the heavy reliance on surface water resources for most of the potable and non-potable water supply, the natural aridity of the region and the decreasing water quality which will be exacerbated by climate change, it is evident that South Africa cannot afford to ignore the deteriorating state of aquatic ecosystems, making their rehabilitation an urgent necessity.This study measured nutrient dynamics of uptake rates and cycling to geochemically assess river health and ecological integrity of the riparian ecosystem of the Eerste River in the Western Cape of South Africa.The content of iron is higher than that WHO and EU recommended, which were 21% and 25% respectively, while the content of manganese were 17% and 23%, respectively.Abstraction of groundwater with high quantities by deeper wells would be accompanied by increase of dissolved iron and manganese content in groundwater which should be treated (with aeration) in order to decrease the content of these two elements in the water before using it.