ABSTRACT Volcanic and sedimentary rocks of the Sinclair Supergroup occur in the Konkiep Terrane of Southern Namibia. Three volcanic and sedimentary cycles are recognised. The Barby Formation belongs to the second cycle which consists of the Kunjas Formation, Barby Formation and the Guperas Formation. In this work, the volcanic rocks of the Barby Formation, a key unit in the Sinclair area are described and dated. The coeval Spes Bona Syenite and the Tiras Granite are also described and dated. ...
Abstract Knowledge of groundwater age / residence time in Okongo perched aquifer is important in understanding key issues in the evolution of groundwater, recharge rates, recharge mechanisms, resource renewability, flow rate and distribution of recharge areas. The build-up in the atmosphere of trace gases such as sulfur hexafluoride (SF6) and tritium (3H) from over a centenary ago offers a convenient way of dating groundwater up to the age of 60 years. These gases are well mixed in the atmosp...
Geogenic groundwater pollution in volcanic rock aquifer systems on the eastern, western and northern flanks of mount Meru, Tanzania – special reference to fluoride
ABSTRACT Namibia has been known as water-scarce, attributing mostly to its geographic location and primarily because of the limited surface water as well as the high potential evaporation rates beyond 2000 mm/year. Groundwater therefore quickly becomes crucial, most of which is located in aquifers in the savannah biome which covers a large part of the country. This is also where most industrialization, as well as most farming, is practised. It is however unknown how these savannah aquifers ...
Abstract The United Nation predicted that by 2025, 1.8 billion people will be living in countries with absolute water scarcity and two-thirds of the world population could be under stress condition. In semi-arid regions, most communities depend on groundwater as the source of drinking water and thus with changes in global climatic conditions and increase in population, groundwater resources are facing challenges of both over-exploitation and contamination. Therefore, there is an urgent ne...
Abstract This study highlights the distribution of hydraulic conductivity (K) in the regional aquiferous Ajali Formation of SE-Nigeria on one hand and assesses the possible influences of textural and geochemical characteristics on the hydraulic conductivity on the other hand. The investigation approach involved field sampling and collection of 12 sandstone samples from different outcrop locations, followed by laboratory studies such as grain-size analysis (GSA), constant head permeameter test...
Abstract Subsurface samples from the Akinside 1582 well, located within the eastern Dahomey Basin were evaluated to determine the lithofacies, depositional environment, and hydrocarbon potential of the basin. The sediments within the interval 138-197m consist of limestones, shales, mudstone and glauconite; thus representing sediments belonging to the Ewekoro and Akinbo Formations. The limestones are greyish, highly indurated, partly recrystallised and reveal six microfacies notably biosparite...
ABSTRACT A sequence of conglomerates, sandstones, slltstones, claystones carbonaceous shales and mudstones which rims the Oban Massif in the Calabar Flank, constitutes the Early Cretaceous (probably Aptian) Awi Formation In the southeastern Nigeria. Field studies and laboratory analyses were conducted on these sediments to determine their provenance and depositlonal environment. Field observations show that the sediments are grently dipping (.< 16°) in a southwesterly direction. They vary in...
ABSTRACT Most studies on groundwater in Nigeria have always been limited to either their occurrence or chemistry, with insufficient attention on potential, chemical character and evolution. This study therefore was designed to evaluate groundwater in Abeokuta (Basement Complex) and Ikorodu (Sedimentary) areas with the aim of highlighting groundwater potential, chemical characteristics and provenance in the two geologically contrasting terrains. A total of 125 Vertical Electrical Soundings (VE...
Abstract The Ohangwena Multi-Layered Aquifer (KOH) is one of the six Aquifer Systems found in the Cuvelai-Etosha Basin, Namibia. The aquifer system is multi layered, consisting of a shallow perched Ohangwena 0 aquifer (KOH-0), semi-confined Ohangwena I aquifer (KOH-1), and confined Ohangwena II aquifer (KOH-2). Currently, a large portion of the population in the study area rely on water from KOH-0 by means of hand-dug wells. The occurrence and potential of this perched aquifer is not fully u...
Abstract An understanding of the water used by vegetation in water limited environment is critical to fully understand water relations of natural areas with vegetation. Such information can be integrated in water management plans to estimate the influence of groundwater abstraction on the vegetation. Trees and shrubs are able to access water from: the upper unsaturated soil profile, the capillary zone of a groundwater store, from nearby streams and rivers. Previous studies have proven that u...
Abstract The Langer Heinrich and Klein Trekkopje U deposits are located within the Namib Desert in Central Namibia. Both deposits are hosted by calcretes developed within palaeo-channel systems of Tertiary age. The sources of both U and V in the two deposits and the reasons why the two deposits differ in terms grade and tonnage have remained unclear to many researchers. The study aimed to resolve these uncertainties. During the study, the geology of the area was reviewed and a number of rese...
ABSTRACT A number of environmental studies previously conducted in the Tsumeb Mining district analysed total metal concentrations in soils and vegetation; with results showing high concentrations of heavy metals such as arsenic, cadmium, copper, lead and zinc which exceed international guidelines for different land uses. However, the actual concentrations of only potentially harmful species for each element were not ascertained. This study aimed at determining the concentrations of potential...
ABSTRACT of the electrical resistivity technique, which red to the seismic technique in fault seal . .. ., ....... . . . , The Agu Abor fault is a prominent growth fault that provides insights on the processes of clay smearing at the fault zone. The properties of the sheared zone in the Cretaceous Enugu Shale were investigated to evaluate the dimensions of the fault, by the use is a cheaper method when compa study. The methodology used for evaruaang tnese possltmtles Involves tne resistivity...
Grateloupia filicina is a carrageenophytic red alga which is in demand as a carrageenan raw material and for use in food. There is therefore interest in developing a technique for mariculturing this species. Since vegetative propagation from thallus fragments has not been successful, the present study was initiated to determine suitable conditions for spore liberation and growth of G. filicina from spores. It was also attempted to propagate G. filicina sporelings from crust and thallus fragme...