Dissertations / Theses on the topic 'African Shelf'

South Africa has an extensive coastline offshore of which lies the prominent South African continental shelf, a relatively flat extension of the onshore coastal plain. The continental shelf is host to major mineral and petroleum deposits, home to South Africa’s major sea fisheries and full of navigation hazards. Therefore, knowledge of the seafloor features, or bathymetry, of the continental shelf is essential to understanding both its long-term geological evolution and present-day use for resources and navigation. Unfortunately there has been little advancement in our knowledge of the South African continental shelf since the marine studies of the 1970’s and 1980’s which culminated in the “Bathymetry around Southern Africa” map of Dingle et al. (1987). Although bathymetric mapping equipment and techniques have greatly improved during the last few decades, very little high resolution bathymetric data of the South African continental margin are currently available for scientific use, with the majority of the high resolution multi-beam echo-sounding bathymetric surveys being undertaken by privately owned mineral exploration and mining companies (such as De Beers, Alexkor, Petro SA, Petroleum Agency of South Africa, etc.), the Council for Geoscience and the South African Navy and Hydrographic Office. More recent advances in satellite altimetry have had a major impact on ocean floor bathymetric mapping especially in deep ocean areas where the sea surface generally reflects the underlying bathymetry. The Department of Agriculture, Forestry and Fisheries (DAFF) annually collect single-beam echo-sounding data in order to monitor the abundance of fish species along the South African continental shelf and along with that collect seafloor bathymetry as an additional benefit. The aim of this project is to create a detailed bathymetric map of the continental shelf of South Africa by using digital single-beam echo-sounding data collected by the Fisheries Division of the DAFF over the last two decades. The bathymetric dataset of ±7 million single-beam echo-sounding data points was manually processed, gridded and exported to produce a detailed bathymetric map of the entire South African continental shelf between the Orange River mouth and Kosi Bay complemented by Satellite Altimetry data from the ETOPO 1 – 1 Arc-Minute Global Relief Model (Amante and Eakins 2009) for the deep ocean area adjacent to the continental shelf. The single- beam bathymetric data were collected by the F.R.S. Africana II and F.R.S. Algoa vessels using SIMRAD EKS-38, EK 400, EK 500 and more recently the EK 60 single-beam echo-sounders along with a the SIMRAD ES38B split beam transducer. The West Coast and South Coast margins have the greatest bathymetric detail due to DAFF’s Cape Town base of operations, whilst the East Coast margin is less detailed due to fewer research campaigns in this area. The Bathymetric Map of the South African Continental Margin produced in this thesis reveals several new and more detailed bathymetric features. New bathymetric features include the northern extension of the Olifants Valley submarine canyon, details of the rocky inner shelf related to glacial period sea level lowstands, as well as the coast parallel wave cut terraces and palaeo dune ridges on the middle shelf between Cape Seal and Cape Recife. Other prominent bathymetric features such as Childs Bank, Cape Canyon, Cape Point Valley, the offshore submerged river valleys of the Breede and Gouritz Rivers and the east-west trending, basement anticlinal ridges situated at the southernmost extent of the Agulhas Arch were revealed in greater detail by this study. The underlying geology, physical Oceanography, drainage patterns as well as eustatic sea-level fluctuations can all be linked to the bathymetry of the continental shelf, which is why this thesis examines the influences of each of these factors on the seafloor morphology around the South African coastline.

Bibliography: pages 147-155.
92 cytheracean species, representing 44 genera are recorded from the Palaeogene Agulhas Bank and west coast margin of South Africa. 11 genera and 3 species are common with the Upper Cretaceous faunas. 12 genera (18 species) are left in open nomenclature. The following genera are represented:- Bythoceratina, Incongruellina, Ruggieria, Eucythere, Krithe, Parakrithe, Eucytherura, Cytheropteron, Ambostracon, Urocythereis, Muellerina, Leguminocythereis, Loxoconcha, Schlerochilus, Poseidonamicus, Bradleya, Agrenocythere, Australileberis, Chrysocythere, Costa, Echinocythereis, Haughtonileberis, Henryhowella, Parvacythereis, Phacorhabdotus, Soudanella, Stigmatocythere, Togoina, Trachyleberis, Veenia, Atlanticythere, Xestoleberis. Data on South African Cretaceous and Palaeogene ostracod faunas are discussed in terms of: faunal associations for the South African Palaeogene JC-1, Agulhas Bank and west coast provinces; characteristic species of Upper Eocene and Upper Eocene to Oligocene strata; generic variations across the Cretaceous/Tertiary boundary. Palaeo-environmental trends from a Cytheracea, Cypridacea + Bairdiacea, Cytherellidae (CCBC) plot indicate a sea level change from <100m (Palaeocene- Eocene), to shallower water with restricted circulation (Upper Eocene) to moderate depth, 100 - 200m (Lower Oligocene). South African faunas are compared with those from adjacent Palaeogene ostracod faunal provinces. Strong generic links occur with West Africa (8 genera in common) and Pakistan (9 genera in common) with only 3 genera in common with Australia and 3 with Argentina.

Situated between the southeast coast of South Africa and the western edge of the Agulhas Current, is the southeast African shelf. The Agulhas Current, like other western boundary currents of the world, strongly influences the oceanographic conditions of its adjacent shelf system. Limited societal drivers have resulted in the southeast African shelf being one of the least studied and under-sampled shelf systems in southern Africa. The in situ sample deficit has led to the majority of studies conducted in this region to be carried out using satellite data and modelling. In order to identify the physical oceanographic processes occurring on the southeast African shelf and slope, as well as the influence that the Agulhas Current has on them, this study analysed satellite data combined with high resolution in situ data, acquired during two hydrographic surveys of the southeast African shelf and slope, during January/February (austral summer) and July/August (austral winter) 2017. The Agulhas Current as well as a number of physical processes were observed to influence the shelf region. The snapshot of the two seasons given by the January/February and July/August in situ data presented indications of seasonality of temperature and salinity within the upper water masses but not within the deeper water masses. The same five water masses, Tropical Surface Water (TSW), Subtropical Surface Water (STSW), South Indian Central Water (SICW), Red Sea Water (RSW) as well as Antarctic Intermediate Water (AAIW), were observed during each cruise. As a result of the westward widening shelf from just east of East London, divergence-induced upwelling was observed between the coast and the inshore edge of the Agulhas Current, during both January/February and July/August. Ekman veering in the bottom boundary layer was observed between Port Alfred and East London during January/February as a result of the close proximity of the Agulhas Current to the slope. Altimetry data indicated the presence of a cyclonic eddy during both the January/February and July/August 2017 surveys. The presence of cold nutrient-rich SICW in the bottom layers on the shelf during January/February and July/August was as a result of the uplift caused by Ekman pumping associated with the cyclonic eddies. AAIW, usually observed along the offshore edge of the Agulhas Current, was found on the slope along the inshore edge of the Agulhas Current, as a result of the presence of cyclonic eddies. Wind-driven upwelling, induced by offshore Ekman transport and vertical mixing, resulted in the surfacing of cooler waters from below at several locations. Chlorophyll-a concentrations were found to be higher during January/February than during July/August 2017. The dissolved oxygen levels observed on the shelf during both surveys were found to be in the range where the biological responses would be insignificant, suggesting that oxygen availability, on the southeast African shelf, adequately facilitates the survival of the existing shelf biology and that low oxygen conditions do not seem to impact the shelf. This study provides the description of the first high resolution shelf wide hydrographic surveys of the region, during the austral summer and winter (even though they are considered as snapshots) which sets a baseline of oceanographic conditions on the shelf as well as the processes affecting it. The results of this study can be used by the scientific community and governmental departments to better implement conservation regulations regarding marine protected areas in the region.

This study investigates the hydrographic and dynamic properties of the continental shelf region between Cape Juby (28.5 °N) and Agadir (30.4 °N) within the Moroccan Sub-region of the North West African Upwelling System. Data came from two cruises conducted in June (beginning of summer) and November (end of autumn) 2013. Coastal upwelling was obvious in both cruises in the in-situ temperature and salinity data as well as in remotely sensed sea surface temperature maps. ADCP data showed the presence of a strong jet like current associated with enhanced upwelling off Cape Juby. This strong quasi-permanent upwelling center was observed during both cruises. It results from the orientation of this portion of coast which is aligned with the dominant wind direction, as well as a wind intensification near the cape. The presence of a secondary upwelling front was also observed near the shelf break. It was accompanied by an intense baroclinic jet. The EK60 data showed evidence of internal waves as well as small and mesoscale turbulence that were probably strongly interacting with the mean upwelling circulation and made a straightforward interpretation of the data quite challenging. However, this study revealed the main physical processes of this poorly studied region, as well as their seasonal variability.

All consumers engage in some form of grocery shopping in order to satisfy their most basic needs. During grocery shopping consumers tend to make their final decision about grocery purchases within the store. This increases the importance of the availability of in-store information. Shelf-edge labels can be viewed as informative point-of-purchase promotional material providing information, such as price. Since the implementation of bar-coded shelf-edge labels, the practice of individually pricing items declined, leaving the shelf-edge label often to be the only source indicating price and similar in-store information. The provision of in-store promotional and informational material can be associated with high costs and therefore needs to be optimised to its fullest potential. However, the use of shelf-edge labels by South African consumers is a question on the minds of retailers as well as consumer scientists, since an empirical research regarding this topic has been neglected in the past. Therefore, neither retailers, nor scientists know the extent to which consumers use shelf-edge labels during grocery shopping. Consumers' reasons for certain responses to or expectations of shelf-edge labels have not yet been properly investigated. This research aimed to answer these questions. The results of the study answered the study's objectives in a descriptive and exploratory manner, which led to the development of a conceptual frame. This conceptual frame provides a content specific decision-making model which indicates the use of shelf-edge labelling during grocery shopping. Retailers can use this model, as well as other results drawn from the study, to implement shelf-edge labels as informational material to its fullest potential. The study is furthermore beneficial to science in its ability to assist in the understanding of consumer behaviour.
Thesis (M. Consumer Science)--North-West University, Potchefstroom Campus, 2006.

Includes bibliographical references.
The degree of sustaining business performance, while maintaining competitive costs, satisfied consumers and customers has become more difficult and harder to achieve. To date, both retailers and manufacturers are economically challenged as they enter into a new age and era that is characterised by a restructuring of the supply and demand known today, the one in which the consumer demand chain will both lead and direct all organisational processes. The greatest challenge in manufacturing and retail supply chains today continue to be the inconsistency of product availability. Both retailers and their manufacturers frequently find themselves in positions where they either have too much stock of specific stock-keeping units (SKUs) or insufficient stock levels of a particular SKU, Steve (2010). Retailers and their suppliers both seek to avoid the costly out-of-stock (OOS) situations, which result in lost revenue opportunity for both parties. OOS can also damage shopper loyalty as frustrated consumers might seek out alternative retailers for the same merchandise, while on the other hand suppliers' brand loyalty can be impacted if a competitor's product is substituted instead. It remains true that the two pillars of business, namely demand and supply, still rule. Traditionally, putting supply before demand, with its implied precedence, was the correct approach to apply, but in today's business environment, there is a major shift taking place, predominantly driven by the cycles in globalisation that would be faster than in the traditional way, oversupply in the fast -moving consumer goods industry, a parallel loss of pricing power, consumers with a twenty-four hours access to precise pricing information, which terminates the power of information scarcity, and shorter product life cycles. The global economic crash that represented a global economic storm led many organisations to rethink the manner in which organisations are led. A consensus exists among many authors and commentators that the emerging economic order has imposed changes to the very way companies are doing business.

Para estimar a distribuição das diferentes classes de tamanho do fitoplâncton através de imagens de sensoriamento remoto e as propriedades bio-ópticas esse trabalho foi realizado em duas regiões. Durante o inverno de 2007 foi feito o cruzeiro com 58 estações hidrográficas sobre Banco de Abrolhos e adjacências e em 2009 o cruzeiro hidrográfico a longo do Atlântico Sul entre as plataformas continentais do Brasil e da África, limitado pelas latitudes 20ºS e 30ºS. Os valores de clorofila_a total mostraram que a região do Banco de Abrolhos é oligotrófica, com baixa produtividade primária e sustenta pelas células do picoplâncton que são influenciadas diretamente pela disponibilidade de fosfato. A matéria orgânica dissolvida (cdom) foi o constituinte bio-óptico com os maiores valores. Sobre a plataforma Africana, a presença da Corrente de Bengala influenciou diretamente nas altas concentrações da clorofila_a e nos tamanhos das células do fitoplâncton. A biomassa dessa região de ressurgência é sustentada por células principalmente do nanoplâncton. As propriedades bio-ópticas da plataforma continental da África são diferentes tanto em valores como nas contribuições relativas das observadas na costa do Brasil. Sobre a plataforma Africana a absorção do fitoplâncton foi o constituinte que prevaleceu sobre os demais (adetritos e cdom).
The distribution of different classes of size phytoplankton are estimated using remote sensing and the bio-optical properties this work was carried out in two regions. During the winter of 2007 the cruisers was done with 58 hydrographic stations on Abrolhos Bank and adjacencies and in 2009 the hydrographic cruise of South Atlantic between the continental shelf of Brazil and Africa, limited by the latitudes 20ºS and 30ºS. The values of chlorophyll a showed that the region of the Bank is oligotrophic area, with low primary productivity and supports for cells of picoplankton that are influenced straightly by the availability phosphate. The organic dissolved matter (cdom) was the constituent bio-optical with the highest values. On the African continental shelf, the presence of Benguela Current influenced straightly the high concentrations of chlorophyll a and the sizes of phytoplankton cells. The upwelling biomass of this region is supported by nanoplankton. The bio-optical properties of continental shelf of Africa are different from Brazilian shelf, the values and in the relative contributions the phytoplankton absorption was prevailed over the others constitute (adetritos and cdom).

The interaction of numerous sedimentary processes at key transition points along the depositional profile results in a complex heterogeneity in ancient basin margin successions. This complexity is generally well studied along depositional dip sections, but lateral (strike) variability and consequent implications for sediment distribution and stratigraphic architecture is commonly less well constrained. In the Karoo Basin, continuous NW-SE-oriented exposure over 80 km has been characterized by 53 logs with 9910 m of cumulative thickness, >2500 palaeocurrent measurements, and ground-, drone- and helicopter-based photo panels. Palaeoflow indicators suggest dominant sediment transport was to the N-NE, with E-W and NE-SW bidirectional components. These are consistent with a strike orientation of the outcrop belt relative to the NE-N margin progradation direction and a NE-SW reworking by waves orientation. In the south of the study area, upper slope and shelf edge parasequences (50-75 m-thick), show current ripples and inverse-to-normal grading in micaceous and organic-rich siltstones and sandstones. They are interpreted as river-dominated prodelta and mouth bar deposits, locally incised by distributary channels (100 m-thick, 1.5 km-wide). Overlying shelf parasequences are thinner (15-50 m) with symmetrical ripple tops, HCS and low angle cross bedding, interpreted as wave-influenced deltaic or shoreface deposits. They transition upward into erosive-based, fining-up sandstones and isolated sharp-based tabular climbing-rippled sandstones, interpreted as channels and crevasse splays within delta plain mudstones. Along strike to the north, upper slope parasequences show more wave reworking indicators and no evidence of gullying or incision. Overlying shelf parasequences are sandier, more amalgamated and strongly influenced by wave action. They are interpreted as offshore, shoreface, foreshore and strandplain deposits. Southern nearshore environments were therefore more river-dominated with bypass and sediment delivery to deeper parts of the basin across a steep, more erosive margin. Wave and storm current redistribution along strike to the northern, lower gradient margin resulted in higher net-to-gross and sand connectivity on a wider shelf, without major incision, bypass and sand supply to the upper slope. No evidence of major avulsions in the upstream tributary and distributary systems are interpreted because the bypass and fluvial-dominated characteristics are persistent in the southern areas through time, whereas the northern margin maintained a sand-starved upper slope and a wave dominated shelf succession. The overall thicker and delta- dominated succession in the south, and the thinner, more condensed and wave dominated stratigraphy in the north are interpreted to be controlled by a combination of basement and basin configuration and differential basin margin physiography. However, relative sea level fluctuations controlled the stacking patterns, with an overall shallowing-upward profile that can be subdivided into two prograding phases, separated by a transgressive phase. At parasequence scale, climate, autocyclicity and coastal processes influenced the equilibrium between sediment input, redistribution and compensational stacking. This study demonstrates that although basin margin successions may be consistently progradational, the interaction of mixed coastal processes and differential spatial configuration can result in a complex along-strike sedimentary architecture, with major implications for sediment distribution through time and space.

The Atlantic Seaboard is an 18 km stretch of coastline located on the Cape Peninsula, South Africa, roughly between the Cape Town suburbs of Mouille Point in the north and Hout Bay in the south. It borders heavy shipping traffic and contains a mix of urban and natural environments including up-market seaside neighbourhoods and is part of the Table Mountain National Park. The predominantly rocky coastline has a northeast–southwest orientation with interspersed sandy pocket beaches. A narrow, low-lying coastal plain (marine terrace) in the north merges with coastal cliffs further south. The geomorphology and sedimentology of the coast are closely linked to the underlying geology, influencing the shape of coastal embayments and promontories, as well as the composition and distribution of sediment. Hydrographic, geophysical and sedimentological techniques were used to collect high-resolution bathymetry, seafloor geology and sediment distribution data to better understand modern coastal processes. The results indicate a low-relief seafloor consisting of Malmesbury Group rocks in the north. To the south the seafloor consists of high-relief Cape Granite reefs interspersed with fine to medium grain sand and bioclastic (shelly) gravel. Sediment transport is generally northward by longshore drift. In the south, the high-relief granite reef and headlands form sediment traps resulting in several large pocket beaches and offshore sediment deposits. In the north, the low-relief Malmesbury bedrock is largely free of sediment, except within narrow erosional gullies. Most sediment rapidly passes through to the north resulting in a sediment-starved rocky seafloor. The three principal sources of beach sand are aeolian fine sand transported by the Karbonkelberg headlands bypass dune entering the sea at Sandy Bay, biogenic carbonate production along the coast, and weathering of Table Mountain Group sandstone and granite bedrock. A fourth source is sediment entering the system via longshore drift from the south of Duiker Point. The water depth around the Duiker Point headland is presently too deep for sediment to be transported easily through longshore drift, other than during large storm events, but during past sea-level low stands this would have played an important part in supplying sediment to the coast. Changes in sea level play an important part in shaping the geomorphology of the coastline. Beach deposits, both sandy and boulder beaches have been left at various elevations along the coast, both offshore and onshore. Although today the Sea Point area is protected by sea walls and man-made structures, a higher sea level was responsible for shaping the narrow coastal plain. Increasing rates of global sea-level change are becoming an important issue all over the world and the Atlantic Seaboard coast is not immune to the effects of sea-level rise. The frequency and magnitude of storm events that breach the sea defences erode beaches and sea cliffs and cause damage to private and public property are likely to increase in the future

Lake Tanganyika (LT), in the East African Rift, contains extensive shell beds that are noteworthy because the gastropods composing most of the LT shell beds are absent from the living in-situ assemblages of organisms hosted by the shell bed substrate. Understanding the geologic and biologic processes that formed these beds has the potential to improve our understanding of fossil shell beds in East Africa. The shell beds may also record recent lake-wide environmental change from climate or watershed impacts, which may be evident through community and taphonomic changes in the populations of shelly invertebrates and so the research seeks to examine whether shell bed substrates have experienced significant anthropogenic impacts that have altered the living assemblages. We investigated total abundance and taphonomic properties of ostracode fossils from shell beds at two sites in LT, one near the Luiche River Delta (a highly deforested site along the northern Tanzanian coast) and another near the Mahale Mountains National Park, an area of substantially lower human population density, 157 km to the south of the Luiche site. In laymen terms, ostracods are microscopic crustaceans that thrive in lacustrine environments and serve as very good indicators for past paleo-environmental and paleochemical reconstructions (Cohen, Nielsen 1986). We studied ostracode assemblage because of its sensitivity to chemical and physical changes in the environment. Ostracods indicate changes in shell beds. The analysis was done by sampling each site along 8 depth transects at the Luiche site and 7 transects at the Mahale site at water depths of 3, 6, 9, 12, 15, 20, 30, 40, 50, and 60 meters. We analyzed total abundance, %valves vs. carapace, % adult vs. juvenile, % carbonate coated, reduction stained, oxidation stained, and %broken vs intact valves for ostracode shells. Results of LT show that there is a decrease in proportion of broken valves, slight decrease in carbonate staining, and an increase in reduction staining and proportion of whole carapaces with increasing water depth. Results of MT show that there is a decrease in broken valves and whole carapaces and an increase in adults, carbonate coated and reduction stained ostracodes with depth. The implications of this study towards paleo-limnology is that the pattern and post-mortem alterations record environmental conditions in shell bed area which can be used to further research in the study of ostracods and environmental changes.

The priority of understanding marine systems increases as expanding pressures are exerted on them. In South Africa, efforts are underway to utilise the ocean to stimulate economic growth which will result in further pressures on marine systems. The aim is to mitigate pressures, largely through proposed offshore marine protected areas (MPAs). One of these proposed MPAs is situated off the Kei river mouth in the Eastern Cape of South Africa. The area offshore of the Kei river mouth is an endemism hotspot, and a transitional zone between the Subtropical East Coast and the Warm Temperate South Coast. The region waslargely unexplored because of itstreacherous sea conditions and because it was no longer an area of commercial fishing importance. A remotely operated vehicle (ROV) explored the regions’ fish and benthic habitats and investigated their associations. This study’s results provide quantitative information on fish and habitat diversity in the intermediate depths off the Kei river mouth. Observations of rare, commercially important, yet critically endangered charismatic reef fish species were made. These included red steenbras (Petrus Rupestris), seventy-four (Polysteganus undulosus), red stumpnose (Chrysoblephus gibbiceps) and dageraad (Chrysoblephus cristiceps). Habitat types, including rhodolith beds, sponges, and deep-water corals were documented. Maximum predicted fish diversity corresponded with mid-continental shelf, which is incorporated into the regions proposed MPA. The highest fish diversity was 10km within the shelf edge (which had a depth of approximately 100m) and was associated with the most structurally complex habitat biota: Fan Coral. Depth was a fundamental predictor associated with the presence and abundance of species distributions. The results support the location of the proposed MPA and are a step forward in identifying critical habitat to protect diversity and endangered species, and thus contribute to the regions spatial management and governance.

Upliftment of rural areas and poverty alleviation are priorities for development in South Africa. Information and knowledge are key strategic resources for social and economic development and ICTs act as tools to support them, enabling innovative and more cost effective approaches. In order for ICT interventions to be possible, infrastructure has to be deployed. For the deployment to be effective and sustainable, the local community needs to be involved in shaping and supporting it. This study describes the technical work done in the Siyakhula Living Lab (SLL), a long-term ICT4D experiment in the Mbashe Municipality, with a focus on the deployment of ICT infrastructure in schools, for teaching and learning but also for use by the communities surrounding the schools. As a result of this work, computing infrastructure was deployed, in various phases, in 17 schools in the area and a “broadband island” connecting them was created. The dissertation reports on the initial deployment phases, discussing theoretical underpinnings and policies for using technology in education as well various computing and networking technologies and associated policies available and appropriate for use in rural South African schools. This information forms the backdrop of a survey conducted with teachers from six schools in the SLL, together with experimental work towards the provision of an evolved, efficient and effective off-the-shelf computing infrastructure in selected schools, in order to attempt to address the shortcomings of the computing infrastructure deployed initially in the SLL. The result of the study is the proposal of an evolved computing infrastructure model for use in rural South African schools.

Observations of habitats are reported. A series of underwater experiments were conducted in natural habitats to answer questions concerning a) why Lamprologus ocellatus and Lamprologus ornatipinnis bury gastropod shells refuges into the substrate, and b) to examine interspecies differences in shell-using behaviours. Some behaviour patterns were analysed using phylogenetic methods. Lamprologus ocellatus and L. ornatipinnis responded to new shells in a variety of ways, shells were moved, buried (and used) or hidden (buried and not used). How shells are utilised seems to be dependant on a complex of factors such as the size and quality of new the shell and the number already in the territory. Shell use may also be affected by neighbour species, sex, size and predation levels. There are interspecific differences in the size of shells used and the methods of shell use. The latter results in species-characteristic shell orientations, vertical burial in L. ocellatus and horizontal burial in L. ornatipinnis. Shell orientation does affect other species/use of shells. Shell movement and vertical orientation appear to be apomorphic while shell hiding and burial are pleisiomorphic within the genus Lamprologus. Numerous cues are involved in stimulating shell burial. Most of these cues are actively sought by the fish by external and internal inspections. Shell burial therefore appears to be a method of reducing the information gathering ability of potential shell-dwelling competitors. Shell burial can therefore be regarded as an investment process which enhances the residents ability to defend its territory. Males can also control the distribution of open shells within teritories and thus control mate access to shells. This behaviour could be a significant factor in the evolution of marked sexual dichromatism exhibited within the genus.

Includes bibliographical references.
This report is on the Environmental Impact Assessment Rectification Process conducted by Environmental Resource Management (ERM) on behalf of Shell Marketing (Pty.) Ltd. for Shell's fuel storage installations within the province of Gauteng, South Africa. This is a feedback report on a selection of sites in Gauteng assessed by four University of Cape Town students who assisted ERM in the project. South African legislation (Environmental Conservation Act 73 of 1989) requires Environmental Impact Assessments (EIAs) to be carried out before the installation of fuel storage tanks. A number of Shell's fuel storage tanks within South Africa were installed without conducting EIAs in violation of this legislation. The Gauteng Government gave Shell and other such companies a six month amnesty period to conduct EIAs retrospectively for fuel tank installations, terming this activity an EIA Rectification Process. Shell thus was expected to conduct Rectification EIAs within the province. Shell commissioned ERM, an independent consultancy, to conduct the EIA Rectification Process. The EIA Rectification process was conducted under the specification of the Gauteng Department of Agriculture, Conservation and Environment (GDACE). ERM divided the applicable tank locations amongst five teams, with a total of 176 sites in Gauteng. Two teams consisted of four University of Cape Town (UCT) Master of Philosophy students in Environmental Management, who assessed 39 sites, on which this report is mostly based. A list of the 39 sites is provided in appendix H, with examples of actual compiled reports shown in appendices G-J. The site inspections conducted by the UCT Masters students were in strict accordance with the environmental assessment requirements stipulated by GDACE for the EIA Rectification Process. The major findings, based on site environmental assessments of tank installations, are that: * the location of the majority of tanks are not accurately listed in Shell's database; * 44% of tank installations are in a dilapidated condition; * 28% of sites show evidence of product leakage; * 92% of sites do not have any pollution prevention measures; and * 87% of sites were assessed to be in the 'moderate vulnerability' category in terms of groundwater pollution analysis. Based on the findings of the study, a number of recommendations have been made to Shell, these include: *

Thesis (MPhil)--University of Stellenbosch, 2007.
ENGLISH ABSTRACT: United National Breweries (SA) (PTY) Limited (UNB) has been manufacturing, marketing and distributing sorghum beer for the last twenty years. Sorghum beer has a short shelf life of five days and hence requires an integrated and efficient distribution system to back its production and marketing. Though the company has changed owners twice during this period, it has retained its knowledge base. The company has outgrown most of its competitors over the last four years, however in order to maintain its leadership, it has identified better market penetration through improved distribution as a major area of opportunity. Almost seventy percent of UNB products are sold and consumed in the townships. These products are almost exclusively consumed by black South Africans. The analysis done by the company on the basis of population and market segmentation indicates that the maximum opportunity of product growth lies in townships most of which are affected by high level of crime. KwaMashu is one such township in Durban. B B Bakeries (BBB) has been manufacturing, marketing and distributing bread in most provinces of South Africa. They are part of Premier Foods. Though their business has been growing in KwaZulu Natal for the last three years, they have been focussing on improving distribution in these markets. Bread, like sorghum has a short shelf life and hence depends heavily on an effective and efficient distribution system. New product variations are also being explored to gain more market share. The aim of this study project was the development of an effective physical distribution system for short shelf life products in crime affected KwaMashu township. “An analysis of the external environment is undertaken to discover the opportunities and threats that are evolving and that need to be addressed by the organization” (Drummond & Ensor; 2005: 33). The external environment for analysis was broken down into three key steps, each becoming more specific to the organization. The first step was an analysis of the macro- environmental influences that the organization faces. This was followed by an examination of the competitive environment the organization operates within and for this Porter’ five forces model was chosen. Finally the integration of such inputs which emerged out of the social environment, business understanding and empirical data was done to come up with a comprehensive strategy. The departure point was the analysis of the characteristics of the environment prevailing in the township. These included study of crime, inputs from police and community policing forum, needs of informal businesses, role of locals to the trade, their possible impact on thefts and hijackings and changes if any envisaged in the near future. The outcome of the study addresses the penetration of the retail segment despite the crime environment. It had to take risk to vehicles, staff and cash while planning distribution while ensuring that the company maintains a hold on the retail market to a reasonable degree. Company’ future growth plans which included new product introductions also had to be taken into account. Out of the possible alternatives, the outsourcing of distribution to local vendor drivers was recommended. Practical guidelines regarding the implementation of such a system keeping in view the unique environment, in which business is conducted, were discussed. Recommendations were made keeping such challenges in view while also supporting the company’ current and future plans.
AFRIKAANSE OPSOMMING: United National Breweries (SA) (PTY) Beperk (UNB) vervaardig, bemark en versprei sorghum bier vir die afgelope twintig jaar. Sorghum bier het ‘n kort rakleeftyd van vyf dae and vereis dus ‘n geïntegreerde en effektiewe verspreidingstelsel om die produksie en bemarking te rugsteun. Alhoewel die maatskappy twee keer van eienaars verwissel het oor die afgelope vier jaar, het die kennisbasis behoue gebly. Die maatskappy het die meeste van sy kompetisie ontgroei oor die afgelope vier jaar maar om voor te bly is markpenetrasie deur verbeterde verspreiding as ‘n belangrike geleentheid gedefiniëer. Byna sewentig persent van UNB se produkte word verkoop en verbruik in swart woongebiede. Hierdie produkte word byna uitsluitlik verbruik deur swart Suid- Afrikaners. Die analise wat die maatskappy on die basis van die bevolking en marksegmentasie gedoen het dui aan dat die maksimum groeipotensiaal in juis in dié swart woonbuurte lê wat deur hoë vlakke van kriminaliteit geaffekteer word. KwaMashu is een so ‘n woonbuurt in Durban. BB Bakeries (BBB) produseer, bemark en versprei brood in die meeste provinsies van Suid-Afrika. Die maatskappy is deel van Premier Foods. Alhoewel die besigheid in KwaZulu Natal gegroei het oor die afgelope drie jaar, het hulle ook gefokus op die verbetering van verspreiding in hierdie markte. Brood is ‘n kommoditeit wat net soos sorghum bier, ‘n kort rakleeftyd het en dus afhanklik is van effektiewe en suksesvolle verspeidingsisteme. Nuwe produktvariasie word ook ondersoek ten einde groter markaandeel te verkry. Die doel van die studie is om die ontwikkeling van fisiese verspreidingsisteme vir kort rakleeftydprodukte in die kriminaliteit geaffekteerde KwaMashu woongebied. “An analysis of the external environment is undertaken in order to discover the opportunities and threats that are evolving and that need to be addressed by the organization” (Drummond & Ensor 2005:33). ‘n Analise van die eksterne omgewing moet afgebreek word in drie sleutel stappe waarvan elkeen telkens meer spesifiek op die organisasie toegespits word. Die eerste stap is die analise van die makroekonomiese faktore wat die organisasie beïnvloed. Dit word opgevolg deur ‘n ondersoek van die kompetisie (mikro) omgewing waarbinne die organisasie sake doen. Hirvoor is Porter se bekende ‘five forces’ model gekies. Laastens word ‘n spesifieke kompeterende analise gedoen waarin die kragte wat voorspruit uit die sosiale omgewing, besigheidsbenadering en empiriese date geintegreer word vir ‘n omvattende strategie. Die vertrekpunt is die analise van die eienskappe van die omstandighede in ter sake swart woongebiede. Hierdie sluit die studie van kriminaliteit met polisie, gemeenskap en polisiëringsforums-perspektiewe, die behoeftes van informele besighede met die rol van plaaslike handelaars en hul impak op diefstal en skakings asook veranderings wat in die nabye toekoms geantisipeer word. Die resultaat van die studie het implikasies vir die deurdringingskrag van die kleinhandel ten spyte van die kriminaliteit in die omgewing. Risiko ten opsigte van voertuie, personeel en kontant moet in ag geneem word tydens verspreidingsbeplanning. Daar moet verseker word dat die maatskappy sy houvas op die kleinhandel mark tot ‘n redelike mate behou. Daarmee word die maatskappy se toekomstige groeiplanne met die invoer van nuwe produkte ondersteun. Van die moontlike alternatiewe word die uitkontraktering van plaaslike afleweraars aanbeveel. Praktiese riglyne vir die implimentering van sodanige sisteme word bespreek en aanbeveel in terme van die maatskappy se huidige en toekomstige beplanning.

Exposures of the lower Waterford Formation, Karoo Basin, South Africa provide rare three-dimensional control to an exhumed low-gradient basin margin, which permits increased understanding of sub-seismic scale process-regime and lateral variability. The study section overlies a 500-m-thick channelized submarine slope succession and is subdivided into eight mappable parasequences clinothems. The central 40 km 2D reference profile parallel to depositional dip (i.e. west-to-east) enables characterization of the shelf-to-slope transition for two successive clinothems and the establishment of robust criteria for identifying the shelf edge at outcrop. The two clinothems exhibit differing process responses to the gradient increase at the shelf edge rollover. The fluvial-dominated, mouth-bar clinothem of WfC 3 exhibits a 5 km dip-parallel zone of extensional growth faulting at the shelf edge with limited delivery of sediment beyond the shelf edge rollover. In contrast, WfC 4 is a wave and storm dominated shoreface-clinothem that supplied a thick upper slope turbidite succession via closely spaced gullies at the shelf edge and a large upper slope channel. This suggests that the delivery of sediment to deep-water settings is governed by parameters other than the presence and proximity of a fluvial point source, which is heavily advocated in current models for shelf construction. It would be common practice to attribute variability between successive clinothems on a single 2D dip profile to lateral variability across the basin margin. However, two additional, sub-parallel dip profiles across depositional strike to the north and south of the reference profile indicate significant 3D variability in the nature of the clinothems. A greater supply of sediment to the upper slope in the north of the region, in the absence of a clear fluvial driver, suggests that the deltaic/shoreface system was able to transit quickly to the shelf edge and establish itself in that position for an extended period. Increasing parasequence thickness toward the north indicates greater accommodation in this area throughout the lower Waterford succession. It is therefore likely that differential subsidence across the margin controlled the position of the shelf edge and maintained a narrower shelf in the north, which would have had significant influence on sediment routing paths, diverting them to the north. Abundant shelf-confined soft sediment deformation in successive clinothems along all three dip margin profiles is attributed to instability on the frontal slopes of inner shelf deltas, due to high rates of sediment supply. The basinward splitting and abrupt thinning of deformed packages beyond the inferred shelf edge rollover shows that the presence of soft-sediment deformation alone is not an adequate criterion with which to define the shelf edge rollover. The significant thickness of shelf deposits without subaerial exposure indicates that the margin was subject to a relatively high subsidence rate but that the rate of sediment supply was sufficient to drive the system to the shelf edge and deliver sand to the slope without the development of incised valleys. Therefore, the lower Waterford Formation is considered a high accommodation / high supply system. This study provides a high-resolution outcrop-based dataset with three-dimensional constraints. It enables greater understanding of the controls on basin margin construction, and the sub-seismic scale processes that control the spatial and temporal variability of sediment delivery to the slope and basin floor.

This project aims to provide a better understanding of the deposition of Quaternary and Holocene sediments along the west coast of Southern Africa between Wreck Point at approximately 28º50.00′S and the Kamma River at approximately 29º20.00′S, based primarily on seismic stratigraphy. The high resolution airgun seismic survey performed by De Beers Marine during 1998 was interpreted based on seismic stratigraphic principles and the chronology of the seismic profiles was based on correlation to radiocarbon-dated gravity cores from offshore the Holgat River determined by Herbert (2009). Seismic profiles were interpreted to the north and south of the central Holgat River sequence with the identified Type 1 Sequence divided into systems tracts. The Type 1 Sequence Boundary represents a major erosional unconformity formed as a result of tectonic uplift and a relative drop in sea level. A wave-cut knick point provides accommodation space for the deposition of Pleistocene and Holocene sediment above the erosional unconformity. The Lowstand Systems Tract (LST) consists of a condensed gravel lag. The LST is divided into subunits where possible which reflect the complex depositional history as the gravel lag was variably reworked as the strandline migrated across the shelf in response to late Pleistocene sea-level fluctuations. This study attempts to delineate some of the more distinctly different units within the economically important gravel body of the LST. The extent and seismic character of five subunits were identified within the complex LST. The Transgressive Systems Tract (TST) formed after a rapid rise in sea level between 19 and 7 thousand years ago (ka). Two transgressive packages were formed as sea level migrated landward. An older deeper water package was identified and labelled Unit 4 while a younger shallower water package was identified upslope, Unit 5, as the mudbelt depocentre migrated landward. The Highstand Systems Tract (HST) is characterized by a set of prograding sigmoidal clinoforms having formed in response to increasingly limited accommodation space after 5.5 ka. Clinoforms, seismic reflectors with slightly higher amplitude than the underlying units, represent depositional hiatuses during periods of lower sedimentation rates. The HST units show southward progradation as accommodation space around the Orange River Mouth became limited. The resulting sequence startigraphy and stratal geometries of the studied sequence are controlled by sea level fluctuation, accommodation space and sediment supply.

Thesis (MSc)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: This study presents an outcrop characterisation and modelling of the excellently exposed Permian Kookfontein Formation of the Ecca Group in the Tanqua-Karoo sub-Basin. The sedimentary modelling (i.e. facies architecture and geometry) and petrophysical characterisation followed a hierarchical and deterministic approach. Quantitative outcrop data were based on the thirteen sedimentary cycles that characterise this stratigraphic succession at the Pienaarsfontein se Berg locality; and these data were analysed using a combination of detailed sedimentary log, gamma ray log and photopanel analysis, as well as petrographic thin-section and grain size-based petrophysical analysis. Based on texture and sedimentary structures, twelve depofacies are recognised which are broadly grouped into four lithofacies associations i.e. sandstone facies, heterolithic facies, mudstone facies and soft-sediment deformation facies; these depofacies and lithofacies form the basic building blocks for the flooding surface-bounded facies succession (i.e. cycle). Also, based on sediment stacking and cycle thickness patterns as well as relative position to the shelf break, the succession is sub-divided into: (1) the lower Kookfontein member (i.e. cycles 1 to 5) exhibiting overall upward thickening and coarsening succession with progradational stacking pattern; representing deposition of mid-slope to top-slope/shelf-margin succession, and (2) the upper Kookfontein member (i.e. cycles 6 to 13) exhibiting overall upward thickening and coarsening succession with aggradational stacking pattern; representing deposition of top-slope/shelf-margin to outer shelf succession. Lateral juxtaposition of observed vertical facies variations across each cycle in an inferably basinwards direction exhibits upward change in features, i.e. decrease in gravity effects, increase in waves and decrease in slope gradient of subsequent cycles. This systematic upward transition in features, grading vertically from distal to proximal, with an overall upward thickening and coarsening progradational to aggradational stacking pattern indicates a normal regressive prograding delta. However, in detail, cycles 1-3 show some anomalies from a purely thickening and coarsening upward succession. Deposition of each cycle is believed to result from: (1) primary deposition by periodic and probably sporadic mouthbar events governed by stream flow dynamics, and (2) secondary remobilisation of sediments under gravity. The facies distribution, architecture and geometry which governs the sedimentary heterogeneity within the deltaic succession is therefore mainly a consequence of the series of mouthbar flooding events governed by sediment supply and base-level changes. These series of flooding events resulted in the delineation of the studied stratigraphic interval into two main parasequence sets, i.e. transgressive sequence set and the overlying regressive sequence set. This delineation was aided through the identification of a maximum flooding surface (i.e. maximum landwards shift in facies) above Cycle 3 in the field. The architecture and geometry of the ensuing deposystem is interpreted to have been a river-dominated, gravitationally reworked and waveinfluenced shelf edge Gilbert-type delta. Widespread distribution of soft-sediment deformation structures, their growth-style and morphology within the studied succession are empirically related to progradation of Gilbert-type mouthbars over the shelf break as well as the slope gradients of the Kookfontein deltaic clinoformal geometry. Analysis of hypothetical facies stacking and geometrical models suggests that the Kookfontein sedimentary cyclicity might not be accommodation-driven but rather sediment supply-driven. The workflow employed for petrophysical evaluation reveals that the distribution of reservoir properties within the Kookfontein deltaic sandbody geometries is strongly influenced both by depositional processes and by diagenetic factors, the latter being more important with increased burial depth. The reservoir quality of the studied sandstones decreases from proximal mouthbar sands, intermediate delta front to distal delta front facies. The major diagenetic factors influencing the reservoir quality of the studied sandstones are mechanical compaction, chemical compaction (pressure solution) and authigenic pore-filling cements (quartz cement, feldspar alteration and replacement, calcite cement, chlorite and illite). Mechanical compaction was a significant porosity reducing agent while cementation by authigenic quartz and clay minerals (i.e. illite and chlorite) might play a major role in permeability distribution. The porosity-permeability relationship trends obtained for the studied sandstones show that there is a linear relationship between porosity and permeability. The relative timing of diagenetic events as well as the percentages of porosity reduction by compaction and cementation indicates that compaction is much more responsible for porosity reduction than cementation. The described internal heterogeneity in this work is below the resolution (i.e. mm-scale) of most conventional well-logs, and therefore could supplement well-log data especially where there is no borehole image and core data. The combination of ‗descriptive‘ facies model and schematic geological model for this specific delta, and petrophysical characterisation make the results of this study applicable to any other similar ancient deposystem and particularly subsurface reservoir analogue.
AFRIKAANSE OPSOMMING: Hierdie studie bied ‘n dagsoomkarakterisering en -modellering van die duidelik blootgelegde Permiese Kookfontein-formasie van die Ecca-groep in die Tankwa-Karoo-subkom. Wat die sedimentêre modellering (d.w.s. fasiesargitektuur en -geometrie) en petrofisiese karakterisering betref is ‘n hiërargiese en deterministiese benadering gevolg. Kwantitatiewe dagsoomdata is gebaseer op dertien sedimentêre siklusse wat hierdie stratigrafiese opeenvolging in die Pienaarsfontein se Berg-lokaliteit kenmerk; en die data is geanaliseer met behulp van ‘n kombinasie van gedetailleerde sedimentêre seksie, gammastraal-profiel en fotopaneelanalises, asook petrografiese slypplaatjie- en korrelgrootte-gebaseerde petrofisiese analises. Op grond van tekstuur en sedimentêre strukture is twaalf afsettingsfasies onderskei wat rofweg in vier assosiasies van litofasies gegroepeer kan word: sandsteenfasies, heterolitiese fasies, moddersteenfasies en sagtesediment-deformasiefasies. Hierdie afsettingsfasies en litofasies vorm die basiese boustene vir die fasiesopeenvolging (d.w.s. siklus) wat oorstromingsoppervlakgebonde is. Verder word die opeenvolging aan die hand van sedimentstapeling en skilusdiktepatrone, asook relatiewe posisie tot die rakbreuk, in die volgende onderverdeel: (1) die benede-Kookfontein-deel (d.w.s. siklus 1 tot 5), wat in die geheel ‘n opwaartse verdikkings- en vergrowwingsopeenvolging met ‘n progradasiestapelpatroon vertoon en die afsetting van middelhelling-tot-boonstehelling- of rakrand-opeenvolging verteenwoordig, en (2) die benede-Kookfontein-deel (d.w.s. siklus 6 tot 13) wat in die geheel ‘n opwaartse verdikkings- en vergrowwingsopeenvolging met ‘n aggradasiestapelpatroon vertoon en die afsetting van boonste helling- of rakrand-tot-buiterakopeenvolging verteenwoordig. Die laterale jukstaposisie van waargenome vertikale fasiesvariasies oor elke siklus heen, in ‘n afleibare komwaartse rigting, vertoon opwaartse verandering wat kenmerke betref, naamlik afname in gravitasiegevolge, toename in golwe en afname in die hellinggradiënt van daaropvolgende siklusse. Hierdie stelselmatige opwaartse oorgang van kenmerke, wat vertikaal van distaal tot proksimaal gradiënteer en in die geheel opwaartse verdikking en vergrowwing in ‘n progradasie-tot-aggradasie-stapelpatroon vertoon, dui op ‘n normale regressiewe progradasiedelta. Van naby beskou, vertoon siklus 1-3 egter bepaalde afwykings van ‘n suiwer opwaartse verdikkings- en vergrowwingsopeenvolging. Die afsettings van elke siklus is vermoedelik die gevolg van: (1) primêre afsetting deur periodieke en waarskynlik sporadiese mondversperringsgebeure wat deur stroomvloeidinamika beheer word, en (2) sekondêre hermobilisering van sedimente deur gravitasie. Die fasiesverspreiding, -argitektuur en -geometrie wat die sedimentêre heterogeniteit in die deltaïese opeenvolging beheer, is dus hoofsaaklik ‘n gevolg van die reeks oorstromingsgebeure by die mondversperring, wat deur sedimentvoorsiening en basisvlakveranderings beheer word. Hierdie reeks oorstromingsgebeure het gelei tot die delineasie van die bestudeerde stratigrafiese interval volgens twee hoofparasekwensie stelle, naamlik die transgressiewe opeenvolgings- en die oordekkende, regressiewe opeenvolgingsgroep. Dié delineasie word ondersteun deur die feit dat ‘n maksimum oorstromingsoppervlak (d.w.s. maksimum landwaartse verskuiwing in fasies) bo siklus 3 in die veld uitgeken is. Die argitektuur en geometrie van die daaropvolgende afsettingstelsel word geïnterpreteer as behorende tot ‘n Gilbert-rakranddelta wat deur ‘n rivier gedomineer, deur gravitasie herbewerk en deur golfwerking beïnvloed is. Die wye verspreiding van sagtesediment-deformasiestrukture, en die groeiwyse en morfologie daarvan binne die bestudeerde opeenvolging, is empiries verwant aan die progradasie van Gilbertmondversperrings oor die rakbreuk heen, asook aan die hellinggradiënte van die Kookfontein-deltaïese, klinoformele geometrie. Die analise van hipotetiese fasiesstapeling en geometriese modelle dui daarop dat die Kookfontein-sedimentêre siklisiteit dalk nie deur akkommodasieruimte gedryf word nie, maar deur sedimentvoorsiening. Die werkvloei wat vir petrofisiese evaluering gebruik is dui daarop dat die verspreiding van reservoir-eienskappe in die Kookfontein- deltaïese sandliggaam geometries sterk beïnvloed word deur afsettingsprosesse en diagenetiese faktore. Die diagenetiese faktore word belangriker op groter begrawing diepte. Die reservoir-aard van die bestudeerde sandgesteentes neem algaande af van proksimale mondversperring-sandsoorte tot intermediêre deltafront tot distale deltafrontfasies. Die hoof-diagenetiese faktore wat die reservoir-kenmerke van die bestudeerde sandsteensoorte beïnvloed is meganiese verdigting, chemiese verdigting (oplossingsdruk) en outigeniese porievullingsement (kwartssement, veldspaatomsetting en -vervanging, kalsietsement, chloriet en illiet). Meganiese verdigting is ‘n beduidende poreusheidreduseermiddel, terwyl sementering deur outigeniese kwarts- en kleiminerale (d.w.s. illiet en chloriet) moontlik ‘n belangrike rol by permeabiliteitsverspreiding kan speel. Die poreusheid-permeabiliteit-verhoudingstendense wat bekom is vir die bestudeerde sandsteensoorte dui daarop dat daar ‘n lineêre verhouding tussen poreusheid en permeabiliteit bestaan. Die relatiewe tydberekening van diagenetiese gebeure, asook die persentasie poreusheidvermindering deur verdigting en sementering, dui daarop dat verdigting baie meer as sementering tot poreusheidvermindering bydra. Die interne heterogeniteit wat in hierdie werk beskryf word, is onder die resolusie (d.w.s. mm-skaal) van die meeste konvensionele boorgatopnames, en kan dus boorgatopnamedata aanvul, veral waar daar geen boorgatafbeelding en kerndata bestaan nie. Die kombinasie van die 'deskriptiewe‘ fasiesmodel en skematiese geologiese model vir hierdie spesifieke delta, asook petrofisiese karakterisering, beteken dat die resultate van hierdie studie op enige ander soortgelyke antieke afsettingstelsels toegepas kan word, maar veral op suboppervlakreservoir-analoogstelsels.

Les variations multidécennales et saisonnières de la Mousson Ouest-Africaine (MOA) au cours des deux derniers millénaires dans la région sahélienne sont peu documentées en raison du manque d'archives paléoclimatiques. Pour cela, on se propose dans ce travail de thèse d'explorer une nouvelle archive paléoclimatique basée sur l'étude sclérochronologique des coquilles du mollusque bivalve Anadara senilis dans des amas coquilliers fossiles afin de reconstituer les variations hydrologiques multidécennales et saisonnières dans le Delta du Saloum au Sénégal de 460 à 1090 A.D. L'hydrologie de cet estuaire hypersalin est très sensible aux variations de la MOA. Les variations hydrologiques passées sont reconstituées à travers des analyses isotopiques (δ18O, δ13C) des coquilles modernes et des coquilles fossiles dans le delta. Le signal isotopique saisonnier de ces coquilles retrace fidèlement les variations hydrologiques liées au régime de la mousson. Nos résultats montrent que ces variations isotopiques, associées aux stries de croissance dont la périodicité est connue, permettent de reconstituer les durées des saisons avec une précision de 25 jours, une précision jamais atteinte dans les études paléoclimatiques antérieures dans la région sahélienne. Les variations hydrologiques multidécennales sont reconstituées à travers la composition isotopique des coquilles fossiles prélevées dans un amas coquillier massif (Dioron Boumak) dont le taux d'accumulation est très important. Les coquilles fossiles prélevées dans cet amas présentent des valeurs isotopiques moyennes en δ18O plus négatives de 1.4 ‰ par rapport à leurs analogues modernes. Ceci est une indication que les conditions hydrologiques étaient plus douces qu'aujourd'hui dans le Saloum qui n'était pas hypersalin à cette époque. Le bilan Précipitation-Evaporation était par conséquent plus positif en réponse à des pluies plus intenses et/ou plus étalées dans le temps de 460 à 1090 A.D. Il semblerait que les pluies hivernales et printanières, caractéristiques de la frange littorale sénégalo-mauritanienne, plutôt rares et insignifiantes de nos jours se produisaient plus fréquemment pendant cette période. La jonction entre ces pluies et les pluies de mousson aurait favorisé l'établissement de saisons des pluies beaucoup plus longues (~5 mois environ au lieu de 3 aujourd'hui) et une augmentation du bilan Précipitation-Evaporation. Cette étude met en lumière le potentiel considérable d'A. senilis comme archive paléoclimatique à haute résolution de la variabilité des précipitation dans la région sénégalaise. Elle montre également l'importance de la saisonnalité des précipitations dans les cycles hydrologiques passés dans cette région qui doit être prise en compte dans les études paléoclimatiques futures
The multidecadal and seasonal variations of the West African Monsoon (WAM) in the last two millennia remain poorly documented in the Sahel region because paleoclimate archives are lacking. For this, we propose in this PhD thesis a sclerochronological study of the mollusk bivalve Anadara senilis from massive shell middens to reconstruct multidecadal and seasonal variations of hydrological conditions in the Saloum Delta (Senegal) between AD 460 and 1090. Hydrological conditions in this hypersaline estuary are highly sensitive to the WAM variations.Past hydrological variations are reconstructed by using isotopic composition (δ18O, δ13C) of modern and fossil shells in this Delta. The shells' seasonal isotopic signals reflect faithfully hydrological variations, linked to monsoonal regime. Our results show that the variations of these seasonal isotopic signals, associated to shell growth patterns with known periodicities allow the reconstruction of season durations with a precision of 25 days, a precision that has never been achieved in paleoclimate studies in the Sahel region.Multidecadal variations of hydrological conditions are reconstructed by using isotopic composition of fossil shells collected in the massive shell middens (Dioron Boumak), characterized by high accumulation rate. The averaged δ18O value of fossil shells was more negative by 1.4‰ compared to modern shells' isotopic signature. This result indicates fresher mean conditions in the Saloum Delta that was likely not hypersaline as it is today. The precipitation-evaporation budget was thus more positive in response to a more intense and/or longer rainfall season during from AD 460 to 1090. We propose that winter and early spring rainfall events, which are observed very occasionally today, were occurring frequently during this period. These rains restricted to the western Sahelian coast and followed by the monsoon would have increased the total duration of the rainy season (~ 5 months instead of 3 months today) and substantially increased the annual precipitation-evaporation budget.This study shed light on the high potential of A. senilis as a high resolution paleoclimate archive of rainfall variability in the Sahel region. It shows also the importance of rainfall seasonality in past hydrological cycles that should be taken into account in the future paleoclimate studies

Bibliography: leaves 105-111.
HIV/AIDS poses a global medical epidemic threatening social and economic development in most developing countries. Sub-Saharan Africa currently bears the brunt of the epidemic with close to 30 million people infected with the disease. South Africa has the second fastest growing infection rates in the world as at December 2002. Currently no known cure for the disease exists. Interventions involve education and awareness programs and multiple therapy medical treatment. The aim of this thesis is to evaluate the perceptions and knowledge of participants at the Shell AIDS Champions workshop. The research used a triangulatory approach utilizing pre-test and post-test survey questionnaires group discussions, participant observation and semi-structured interviews. 22 participants from Shell Southern Africa and Easigas attended the workshop. Statistical techniques were applied to the questionnaire findings. Content analysis was used to analyse the qualitative data. Findings from the evaluation indicate that participant perceptions show agreement with current Shell policy on HIV/AIDS. The findings show that the major impact of the workshop was observed on the knowledge-based section of the evaluation. The results of the evaluation confirm that participant knowledge was increased through participation in the AIDS Champions workshop.

L'etude des formations sableuses aux embouchures des oueds tensift, ksob et souss de l'atlas-atlantique (maroc) permet de mettre en evidence les processus de leur mise en place, ainsi que l'origine de leur materiel. Les oueds apportent jusqu'a l'ocean des elements terrigenes (quartz, feldspaths et mineraux lourds). Ces elements sont remanies et melanges aux depots marins. Le stock sedimentaire est redistribue par les actions marines, et principalement une forte derive littorale nord-sud. Ainsi, dans le systeme du tensift, le materiel dunaire evolue sous l'influence des alizes et des vents d'ouest, mais l'activite de ces derniers se revele plus efficace. Dans le systeme de ksob, le materiel dunaire evolue sous l'action principale des alizes. Dans le systeme du souss, la dynamique eolienne se fait sous l'action conjuguee des alizes et des vents d'ouest. Ces evolutions sedimentaires se traduisent par une amelioration du tri, une diminution progressive du grain moyen et des teneurs en carbonates et mineraux lourds, ainsi que par une eolisation croissante des grains quartz.

Service quality has always been a tacit assumption within the delivery of academic library services, but since the 1990s demands for accountability from different stakeholders, including the clients, made service quality a highly debated and researched focus in academic libraries all over the world. The scope of the study covers a wide-ranging analysis of discourses underpinning service quality and its accompanying performance indicators in academic libraries. Using the academic library of the University of South Africa as an illustrative case study, this study examines the possible impact of inventory control on the service quality of the academic library in three areas, namely access to information resources, retrieval of information resources and positive implications for sound financial management. The study's findings all point to a positive enhancement of service quality in regard to the three areas mentioned.
Information Science
M. Inf.

This study proposes that the submarine canyons of the northern Kwazulu-Natal continental margin formed contemporaneously with hinterland uplift, rapid sediment supply and shelf margin progradation during the forced regression of upper Miocene times. These forced regressive systems tract deposits volumetrically dominate the shelf sediments, and comprise part of an incompletely preserved sequence, amongst which six other partially preserved sequences occur. The oldest unit of the shelf corresponds to forced regression systems tract deposits of Late Cretaceous age (seismic unit A), into which a prominent erosive surface, recognized as a sequence boundary, has incised. Fossil submarine canyons are formed within this surface, and underlie at least one large shelf-indenting canyon in the upper continental slope. Smaller shelf indenting canyons exhibit similar morphological arrangements. Late Pliocene deposits are separated from Late Cretaceous lowstand deposits (seismic unit B) by thin veneers of Late Palaeocene (seismic unit C) and mid to early Miocene (seismic unit D) transgressive systems tract deposits. These are often removed by erosive hiatuses of early Oligocene and early to mid Pliocene age. These typically form a combined hiatus surface, except in isolated pockets ofthe upper slope where late Miocene forced regressive systems tract units are preserved (anomalous progradational seismic unit). These sediments correspond to the regional outbuilding of the bordering Tukhela and Limpopo cones during relative sea level fall. Either dominant late Pliocene sediments (seismic unit E), or transgressive systems tract sediments which formed prior to the mid Pliocene hiatus, overlie these sediments. Widespread growth faulting, slump structures and prograding clinoforms towards canyon axes indicate that these sediments initiated upper slope failure which served to create proto-canyon rills from which these canyons could evolve. The association of buried fossil canyons with modern day canyons suggests that the rilling and canyon inception process were influenced by palaeotopographic inheritance, where partially infilled fossil canyons captured downslope eroding flow from an unstable upper slope. Where no underlying canyons occur, modern canyons evolved from a downslope to upslope eroding system as they widened and steepened relative to the surrounding slope. Statistical quantification of canyon forms shows a dominance of upslope erosion. Landslide geomorphology and morphometric analysis indicate that this occurred after downslope erosion, where the canyon axis was catastrophically cleared and incised, leading to headward retreat and lateral excavation of the canyon form. Trigger mechanisms for canyon growth and inception point to an overburdening ofthe upper slope causing failure, though processes such as freshwater sapping may emulate this pattern of erosion. It appears that in one instance, Leven Canyon, freshwater exchange with the neighbouring coastal waterbodies has caused canyon growth. The canyons evolved rapidly to their present day forms, and have been subject to increasingly sediment starved conditions, thus limiting their evolution to true shelf breaching canyon systems. Sedimentological and geomorphological studies show that the shelf has had minor fluvial influences, with only limited shelf-drainage interaction having occurred. This is shown by isolated incised valleys of both Late Cretaceous and Late PleistocenelHolocene age. These show classic transgressive valley fills of wave dominated estuaries, indicating that the wave climate was similar to that of today. The narrowness of the shelf and the inheritance of antecedent topography may have been a factor in increasing the preservation potential of these fills. Canyons thus appear to have been "headless" since their inception, apart from Leven Canyon, which had a connection to the Last Glacial Maximum (LGM) St Lucia estuary, and Wright Canyon, which had an ephemeral, shallow LGM channel linking it to the Lake Sibaya estuarine complex. Coastline morphology has been dominated by zeta bays since at least 84 000 BP, thus littoral drift has been limited in the study area since these times. The formation of beachrock and aeolianite sinks during regression from the last interstadial has further reduced sediment supply to the shelf. The prevalence of sea-level notching in canyon heads, associated with sea levels of the LGM indicates that canyon growth via slumping has been limited since that time. Where these are obscured by slumping in the canyon heads (Diepgat Canyon), these slumps have been caused by recent seismic activity. The quiescence of these canyons has resulted in the preservation of the steep upper continental slope as canyon erosion has been insufficient to plane the upper slope to a uniform linear gradient such as that of the heavily incised New Jersey continental margin. Progressive sediment starvation of the area during the Flandrian transgression has resulted in a small shore attached wedge of unconsolidated sediment (seismic unit H) being preserved. This is underlain by a mid-Holocene ravinement surface. This crops out on the outer shelf as a semi-indurated, bioclastic pavement. Thinly mantling this surface are Holocene sediments which have been reworked by the Agulhas Current into bedforms corresponding to the flow regime and sediment availability to the area. Bedforms are in a state of dis-equilibrium with the contemporary hydrodynamic conditions, and are presently being re-ordered. It appears that sediment is not being entrained into the canyons to the extent that active thalweg downcutting is occurring. Off-slope sediment loss occurs only in localized areas, supported by the dominance of finer grained Early Pleistocene sediments of the outer slope. A sand ridge from the mid shelf between Wright and White Sands Canyons appears to have been a palaeo-sediment source to White Sands Canyon, but is currently being reworked southwards towards Wright Canyon. The prevalence of bedform fields south of regularly spaced canyon heads is considered a function of hydrodynamic forcing of the Agulhas Current by canyon topography. These bedforms are orientated in a northerly direction into the canyon heads, a result ofnortherly return eddying at the heads of these canyons.
Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2009.

[From introduction] Subtidal research presents numerous challenges that restrict the ability to answer fundamental ecological questions related to reef systems. These challenges are closely associated with traditional monitoring methods and include depth restrictions (e.g. safe diving depths for underwater visual census), habitat destruction (e.g. trawling), mortality of target species (e.g. controlled angling and fish traps), and high operating costs (e.g. remotely operated vehicles and large research vessels. Whereas many of these challenges do not apply or are avoidable in the shallow subtidal environment, the difficulties grow as one attempts to sample deeper benthic habitats. This situation has resulted in a paucity of knowledge on the structure and ecology of deep water reef habitats around the coast of South Africa and in most marine areas around the world. Furthermore, the inability to effectively survey deep water benthic environments has limited the capacity of researchers to investigate connectivity between shallow and deep water habitats in a standardised and comparable fashion.

Blendcor (Pty) Limited is a joint venture lubricants blending and grease manufacturing plant and equally owned by its shareholders, British Petroleum Southern Africa and Shell South Africa. BP purchased Castrol worldwide in March 2000. The merger of BP and Castrol has created opportunities for consolidation of production at Blendcor. The inclusion of the Castrol lubes portfolio would increase current production at Blendcor to approximately 150 million liters per annum. The purpose of this research is to establish if the merger between BP and Castrol would have a positive or negative effect on Blendcor. We begin this research by seeking an understanding of the strategy framework and its role in assisting a company to achieve its objectives. The framework starts by explaining how strategy is formulated, the development of a vision, mission statement, the examination of the company's external environment, the company's internal environment, the impact of globalisation, the company's long-term goals, and finally organizational structure and leadership. Emphasis is placed on companies that employ Joint Ventures, Mergers and Alliances as grand strategies. The history of the Oil industry in South Africa, the history of Blendcor's partners, a brief history and background of Blendcor, followed by a discussion on the merger of BP and Castrol, and its impact on Blendcor, is examined. Blendcor is then evaluated by conducting a SWOT analysis. It's strengths; weaknesses, opportunities and threats are discussed briefly. The current strategy employed by Blendcor is subsequently evaluated against the suitability criteria. The plant is benchmarked against other plants worldwide in terms of cost and production. The strategy development process at Blendcor is then evaluated to determine the synergies of the leadership team. The merger is then profiled using the PIMS model to determine whether the merger was a good or bad decision. Finally, various recommendations are made to improve the plant and its processes. The replacement of Blendcor's Information system is discussed in length and the lack of a suitable measurement system is highlighted.
Thesis (MBA) - University of Natal, 2003.

This research investigates the character and significance of shelf-edge deltas within the sedimentary source-to-sink system, and how variability at the shelf edge leads to different styles of deep-water deposition. Because the shelf-edge represents one of the key entry points for terrigenous sediment to be delivered into the deep water, understanding of the sedimentary processes in operation at these locations, and the character of sediment transported through these deltas is critical to understanding of deep-water sedimentary systems. The research was carried out using three datasets: an outcrop dataset of 6000 m of measured sections from the Permian-Triassic Karoo Basin, South Africa, a 3D seismic data volume from the Eocene Northern Santos Basin, offshore Brazil and a dataset of 29 previously published descriptions of shelf-edge deltas from a variety of locations and data types. The data presented highlight the importance of sediment instability in the progradation of basin margins, and deep-water transport of sediment. The strata of the Karoo Basin shelf margin represent river-dominated delta deposits that become more deformed as the shelf-edge position is approached. At the shelf edge, basinward dipping, offlapping packages of soft-sediment-deformed and undeformed strata record repetitive collapse and re-establishment of shelf-edge mouth bar packages. The offlapping strata of the Karoo outcrops record progradation of the shelf margin through accretion of the shelf-edge delta, for over 1 km before subsequent transgression. The Eocene Northern Santos Basin shelf margin, in contrast, exhibits instability features which remove kilometers-wide wedges of the outer shelf that are transported to the basin floor to be deposited as mass-transport packages. In this example, shelf-edge progradation is achieved through „stable. accretion of mixed turbidites and contourites. The data also emphasize the importance of the role of shelf-edge delta processes in the delivery of sediment to the basin floor. A global dataset of 29 examples of shelf-edge systems strongly indicates that river domination of the shelf-edge system (as read from cores, well logs or isopach maps) serves as a more reliable predictor of deep-water sediment delivery and deposition than relative sea level fall as traditionally read in shelf-edge trajectories or sequence boundaries.
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Cowpea (Vigna unguiculata) and moringa (Moringa oleifera) are nutritious and medicinal vegetables, but could also harbor harmful microbial contaminants. The main aim of the project was to determine the effect of each processing techniques on the microbiology, proximate nutrients and shelf life of these vegetables to produce nutritious, tasty, safe and long lasting vegetable products. The processing techniques used were: washing, blanching, and drying. Leaf samples were collected at each stage of processing and were analysed for total viable count, coliform count, yeast and mould count and nutritional content. Microbial plate analysis showed the presence, particularly on cowpea leaves, of yeasts and bacteria such as Pseudomonas, Klebsiella, Staphylococci, Streptococci, and enterobacter including enteropathogens such as Salmonella spp., Shigella dysenteriae and E coli. The presence of E.coli on the leaves was also confirmed using polymerase chain reaction-amplified ribosomal DNA analysis. The most effective processing technique which reduced microbial load to below SABS standards while retaining nutritional quality was the washing of the leaves twice with tap water followed by steam tunnel blanching at 94oC for 12 minutes. Oven drying the leaves at 60oC gave satisfactory and extended shelf life results. Proximate analysis comparison of the two leaf types showed that on average moringa leaves contained more ash (2.37 vs 1.1 g), protein (6,9 vs 3,6 g), fat (0,41 vs 0.2 g) and energy (305,1 vs 70KJ) but less dietary fibre (0,9 vs 7,5 g) than cowpea leaves. No significant differences were noted in these values following washing and steam blanching. These results indicate that washing of these leaves is effective as to reducing microbial load and maintaining proximate values in the short term (up to 4 days) but that oven drying is effective for longer-term storage.
Life and Consumer Sciences
M. Sc. (Life Sciences)