En Afrique du Sud, le supergroupe Pongola s’est déposé sur le craton du Kaapvaal à environ 3 milliards d’années. Le groupe Mozaan repose sur le groupe basal Nsuze et contient des pélites, des arénites quartziques, des grès et des conglomérats. Dans ce type de conglomérat, des gisements d’uranium et des minéralisations d’or ont été reconnus dans le monde, au Canada, au Brésil, en Australie et en Afrique du Sud. Des petites minéralisations ont été avérées dans le groupe Mozaan, très différentes de celles qui ont été exploitées dans le bassin voisin du Witwatersrand. Ce travail pétrographique, minéralogique et géochimique concerne les formations conglomératiques et gréseuses basales du Mozaan Group dans le Denny Dalton. Il est fondé sur l’étude de deux carottes dans lesquelles des minéralisations en uranium ont été reconnues. Une attention particulière a été portée sur le matériel détritique car, dans ces conglomérats, les gisements sont de type placer avec des remobilisations plus ou moins marquées. Les grains détritiques identifiés associés à la pyrite détritique, sont la monazite fréquente, les oxydes de titane, les minéraux d’uranium thorium (coffinite, thorite, thorianite), le zircon, l’apatite, la chromite ainsi que d’autres sulfures (chalcopyrite, arsénopyrite). La roche source est vraisemblablement de matériel acide avec un faible apport basique ainsi que métamorphique. La morphologie des minéraux suggère un transport court de la source vers le bassin de Pongola. Les analyses pétrographiques et chimiques mettent en évidence les différentes minéralisations qui caractérisent les processus diagénétiques et hydrothermaux qui ont affecté le groupe Mozaan. Des observations nouvelles ont été réalisées sur les minéraux d’uranium avec la mise en évidence de phospho-coffinite, de phosphates alumineux hydratés de terres rares et des altérations très développées qui affectent les grains de monazite. Ces assemblages minéralogiques révèlent une diagenèse avec la circulation de fluides acides comme l’atteste la présence de pyrite et des APS dans la porosité secondaire des roches. Aucun grain d’uraninite détritique ni d’uraninite authigène n’a été observé dans cette étude. L’hypothèse la plus vraisemblable est que l’uranium des zones minéralisées provient de l’altération des grains de monazite à 2.54 Ga par des fluides acides. La remobilisation se fait en milieu ouvert et l’uranium cristallise essentiellement en bordures des grains de pyrite sous forme de phospho-coffinite. / In South Africa, the Pongola Supergroup was deposited on the craton Kaapvaal about 3 Ga years. The Mozaan group based on the basal Nsuze group and contains mudstones, arenites, sandstones and conglomerates. In this type of conglomerate, uranium and gold mineralization deposits have been recognized in the world, Canada, Brazil, Australia and South Africa. Small mineralization have been proved to in the Mozaan group, very different from those that have been exploited in the the neighbor of the Witwatersrand Basin. The petrographic, mineralogical and geochemical work concerns basal conglomerate and sandstone formations of Mozaan Group in Denny Dalton. It is based on the study of two cores where uranium mineralizations have been recognized. Particular attention was focused on the detrital material, because in these conglomerates, the deposits are placer type with the remobilizations more or less marked. The detrital grains identified associated with the detrital pyrite are frequent monazite, titanium oxides, thorium uranium minerals (coffinite, thorite, and thorianite), zircon, apatite, chromite and other sulphides (chalcopyrite, arsenopyrite). The source rock is likely acidic material with low basic contribution and metamorphic.The mineral morphology suggests a short transport the source to the Pongola basin. Petrographic and chemical analyzes show that characterize the different diagenetic mineralization and hydrothermal processes that have affected the Mozaan group. New observations were made on uranium minerals with the detection of phospho-coffinite, aluminous hydrated rare earth phosphates and highly developed alterations affecting monazite grains. These mineral assemblages reveal a diagenesis with the flow of acidic fluids as evidenced by the presence of pyrite and APS in the secondary porosity of the rocks. Detrital and authigène uraninite grains were not observed in this study. The most likely hypothesis is that the uranium mineralized zones comes from the weathering of monazite grains to 2.54 Ga by acidic fluids. Remobilization is done in open and uranium mainly crystallizes edges of pyrite grains in the form of phospho-coffinite.

Four grids, each 3,42 ha (4 morgen) in size, were live trapped from April 1967 through May 1969 in two soil and vegetation types (black turf~ Acacia nigrescens community, and brown reddish soil: Acacia tortilis community) at Pongola, northern Zululand, to determine the effect of dieldrin coverspraying, at a dosage of 87,4 g/hectare (2,64 oz/morgen), on rodents. Low population numbers before and especially at the time of spraying made clear-cut conclusions impossible to reach. Rodent populations (mainly Praomys (Mastomys) natalensis, Saccostomus campestris, and Lemniscomys griselda) were apparently not adversely effected, although L. griselda numbers showed a decline which was not in correspondence with that on the control area. This might be ascribed to dieldrin spraying. Relatively higher numbers of s. campestris and L. griselda were observed during periods of lower P.( M.) ~talensis numbers. Decreases in P.( Me) natalensis populations coincided with times of food scarcity. Praomys (Mastomys) natalensis are thus found in association with other rodents when abundant food is available, but seems to give way when competition due to food scarcity occurs. Reproductive data obtained from the study were too meagre to allow any conclusions concerning the effect of spraying thereon. The method involving the calculation of maximum distance between captures was used to express movement patterns of the species studied. Populat~on structure is express~d in terms of sex ratios, and frequency per mass class for each season. The size of animals was investigated by measuring total length, tail length, and head and body length. Behavioural features of the species captured were also noted. / Dissertation (MSc)--University of Pretoria, 1972. / gm2014 / Zoology and Entomology / Unrestricted

The study is concerned with economic restructuring and its effects on small towns. A small town, Pongola, has been chosen to illustrate how economic change affects small agriculturally based settlements. Local economic development (LED) is then suggested as one approach to address some of the problems that exist in places like Pongola. What motivated me to undertake this study is that many of the problems that exist in South Africa's big cities and large towns emanated from the fact that small towns and rural areas are generally neglected by national government. One problem that needs to be mentioned here is that of hyperurbanisation. This problem has been caused by the neglect of rural areas leading to overly rapid rural-urban migration. Whilst urbanisation per se is not a problem, urbanisation in excess of the absorption capacity of cities. Rural areas account for 40% of the total population of South Africa yet the pattern of rural settlement, for a variety of historical reasons, has been distorted. There is massive rural overcrowding in some areas, to the point where ecological collapse is imminent (Dewar 1994). In other areas, the essential social and service infrastructure necessary to support a vibrant local agrarian economy is declining steadily. The result is an ongoing contribution to hyperurbanisation: people who are involuntarily displaced from the countryside move to towns and cities that are growing at rates that outstrip the ability of the urban systems to deliver jobs and services. A main challenge in the new political and social dispensation is to target these areas that have been disadvantaged in the past and which are now the source of major problems for the country as a whole. As many urban areas are experiencing major plant closings and more retrenchments in the context of global economic competition, it becomes imperative to consider developing small towns and their rural hinterlands. Planning analysts like Dewar, McCarthy, Rogerson and Nel, have all commented that rural areas have a potential, that of available land, which could be used to address some of the problems. They also call for the social, economic and urban reconstruction of small towns. This study does not intend seeking a solution to all agricultural and rural problems. However, after looking at the strengths, weaknesses, opportunities and threats of this particular case study, I will suggest that local economic development (LED) is an alternative planning strategy that could be used to address some of the problems of small town development. Although LED has its own short-comings, it has the advantage of using local comparative advantage of a particular locality to create jobs and achieve economic growth. It therefore avoids trying to resolve problems of small towns by diverting growth from other areas as it happened for example, with the old Regional Industrial Development Programme. This dissertation will look first at global economic restructuring and its effects on localities. Secondly this study will discuss the restructuring of commercial agricultural production, looking specifically at the implications of this restructuring process for workers in agriculture, and will also look at some processes that have brought about this transformation and the phenomenon of declining small towns. Thirdly, this study seeks to explore in the literature that is available what other South African small towns, have done to address problems that exist in their localities. Stutterheim will be used as an example of a local development initiative with apparent considerate success, although a recent study disputes this. Finally, this study seeks to use alternative interpretations of local economic development (both locally and internationally) as a bases for draWing policy recommendations for Pongola. Another general concern is to explore how Pongola is responding to problems of decline. / Thesis (M.T.R.P.)-University of Natal, 1998.