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The development and some practical applications of a statistical value distribution theory for the Witwatersrand auriferous depositsRoss, F. W. J. January 2015 (has links)
No description available.
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The emergence of major retail centres in the townships : case studies of Daveytown and Dobsonville.Kgara, Sidney Rammoa. January 1998 (has links)
No abstract available. / Thesis (M.T.R.P.)-University of Natal, Durban, 1998.
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The significance of unconformities in the development of Witwatersrand gold and uranium placersBeater, Christian Douglas 03 April 2013 (has links)
Most of the economic gold and uranium placers are developed on low angle disconformities in the Central Rand Group and concentrations of gold and uranium are usually at their optimum on unconformity surfaces. Examples include the Kimberley Reef and South Reef of the East Rand, the Main Reef Leader of the Central Rand, the Carbon Leader of the Carletonville goldfield, the Vaal Reef of the Klerksdorp goldfield and the Basal/Steyn placers of the Welkom goldfield. The individual goldfields represent fluvial fans which are composed of a large number of tectonogenetic sedimentary packages separated by unconformities. The tectonic responses between cycles of sedimentation produced unconformities and tectonically controlled cyclic sedimentation is one of the key factors culminating in the preparation and deposition of auriferous placers within the Witwatersrand succession. Unconformities, which represent breaks in sedimentation, result in the preconditioning of palaeosurfaces and redistribution of sediments and heavy minerals on them. Winnowing of sands produced heavy mineral residual accumulations on erosion surfaces which were generally preserved by small-pebble lags or algal mats. Reworking of units truncated by the unconformities provided additional gold, uranium and heavy minerals to unconformity surfaces.
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The occurrence and bioaccumulation of selected metals and radionuclides in aquatic and terrestrial ecosystems on the Witwatersrand.De Wet, Louis Petrus Daniël 17 August 2012 (has links)
Ph.D. / The investigations reported here conducted during 1990-1994 had the following objectives: Selection of representative localities in impoundments and rivers in wetlands affected by radionuclide- and metal-containing effluents and seepage water from mines and metal-processing industries. To determine the occurrence and concentration of radionuclides and selected metals in mine- and industry-polluted waters and sediments in catchments of the Blesbokspruit, the Klip River and the Crocodile River systems. To establish radionuclide and metal concentrations in some semi-aquatic and aquatic weeds in these mine- and industry-polluted waters with observations on the ability of some plants to accumulate certain metals in their roots and/or shoots. To evaluate some benthic macro-invertebrate organisms as possible indicators of radionuclide and metal pollution in the affected streams. To determine the radionuclide and metal concentrations in selected vegetable crops irrigated with mine- and industry-polluted water. The localities where the investigation took place were mainly in wetland regions on the East and West Rand. Water of polluted streams traverse expansive wetlands containing floating, emergent and submerged aquatic vegetation. These plants play an important role in the recovery from pollution of the affected waters. Pollutants are also available to and accumulated by other aquatic organisms such as crabs, fish and birds. In addition, the same water is often used for the irrigation of vegetable crops, thereby creating potential pathways through which these pollutants may be consumed by humans. All the above objectives have largely been met in as such that potential sources of pollution were identified and pollutants detected in the abiotic (water and sediments) environment. These pollutants were also found in wetland biota as well as agricultural crops irrigated with contaminated water. Potential pathways for the transfer of these pollutants were identified and dose assessment modelling was conducted.
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The nature of the western margin of the Witwatersrand BasinVan der Merwe, Roelof 07 October 2014 (has links)
D.Phil. (Geology) / The tectonic evolution of the "western margin" of the Witwatersrand Basin is examined and indications are that it has undergone a long and complex history. In order to examine the nature of Witwatersrand-age structures, structures in both pre- and post-Witwatersrand sequences are also examined. Rocks of the ±3074 Ma Dominion Group were subjected to a tectono-metamorphic event prior to the deposition of Witwatersrand strata on an angular unconformity. An oligomictic conglomerate is sporadically developed at the base of the Witwatersrand Supergroup. PreVentersdorp structures in Witwatersrand strata are developed in two distinct trends, north-south and northeast-southwest. The relationship between the two directions of folds and thrust faults are best explained within a regional, sinistral transpressive shear couple; the north-south faults are sinistral strike-slip faults and the northeast-southwest trending folds and thrust faults are secondary structures associated with the strikeslip faults. The implications of this model are that Witwatersrand sedimentation was probably controlled by lateral movements on north-south trending faults and not by thrust faults in a foreland system as suggested by the most recent models of Witwatersrand basin development. Post-Witwatersrand deformation is complex. Southeastward verging, pre-Ventersdorp, thrust faults were reactivated as normal faults during Platberg times and the resultant half-grabens were infilled by conglomerates of the Kameeldoorns Formation. Later deformational events include eastward verging post-Ventersdorp thrust faults and post-Transvaal normal and strike-slip faults. It can be demonstrated that the majority of this later fault movements took place along pre-existing fault planes and therefore tectonic inversion is a fundamental process in the evolution of the Witwatersrand Basin. Clearly therefore, the present distribution of Witwatersrand strata does not reflect the original basin geometry, it is the result of several periods of basin inversion and no basin margins can be defined.
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A seismically oriented study of mining induced fracturing around deep level gold mine stopeRorke, Anthony John 10 June 2014 (has links)
M.Sc. (Geology) / Please refer to full text to view abstract
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Negatiewe faalangs en prestasiemotiveringMeyer, Elsje Catharina 05 November 2014 (has links)
M.Ed. (Orthopedagogics) / The purpose of this study is to determine whether milieu-deprived school beginners reveal fear of failure and achievement motivation tendencies. Fear of failure is a phenomenon which normally occurs among all people, although it can vary in degrees of intensity. It would appear, from the literature, that fear of failure can be viewed as a specific form of anxiety which has a detrimental effect on achievement. Owing to the human functioning as a totality, the concepts of fear of failure and achievement motivation can not be examined in isolation, therefore the relationship between these concepts and those of anxiety and achievement has been investigated. Several researchers agree that pre-school children are quite capable of forming a clear notion concerning their personal capabilities and that motives are established in their pre-school years. Views expressed by researchers suggest that at school entry, motive preferences are already perceptible in school beginners; these children may be achievement motivated or reveal a fear of failure. The low achievement motivation and negative self-concept of milieu deprived school beginners are conspicuous at school entry. These children are neither able to measure up to the school's expectations nor actualize their potential properly because of limited experiences, deficient cognitive and language development, as well as inadequate concentration. This is a result of unfavourable educational circumstances and insufficient developmental opportunities during the pre-school period. The above-mentioned short-comings which milieu-deprived school beginners experience, cause anxiety. They perceive school as a threat and anticipate and fear failure...
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Risk assessment of inhaled and ingested airborne particles in the vicinity of gold mine tailings : case study of the Witwatersrand BasinMaseki, Joel 25 November 2013 (has links)
M.Sc. (Geography) / Severe Aeolian deposition of windblown dust from mine tailings storage facilities (TSFs) is a common phenomenon on the Witwatersrand, especially during the spring windy season. For communities around tailings storage facilities, this poses health and environmental challenges. This dissertation estimates the risk of adverse health effects resulting from human exposure to hazardous elements in particulate matter (sub 20 μm diameter) for selected tailings storage facilities: East Rand Gold and Uranium Company (ERGO); East Rand Proprietary Mine (ERPM); Crown Gold Recoveries (CGR) and Durban Roodepoort Deep (DRD). Samples of surface material from these TSFs were analysed for heavy metal content using the ICP-MS method. Other than the expected gold, five heavy metals (arsenic, cadmium, chromium, lead and uranium) exhibited enrichments in the tailings material significantly above average (greater than a factor of 2) crustal composition. These elements were selected for comprehensive risk assessment through airborne exposure routes. The mean ambient particulate concentration in air of 540 μg m-3 (used in the risk calculations) was based on a conservative worst-case exposure scenario. U.S. Environmental Protection Agency (US EPA) risk assessment methods were used to determine the inhalation and ingestion hazard quotient and hazard indices for adults and children. The sum of the hazard indices was below the non-cancer benchmark (hazard indices 1.0) considered to be acceptable for a lifetime exposure. The risk cancer included the excess life cancer risk for the inhalation and the ingestion risk. The total risk for both exposures was within the range of 1 in 1 000 000 to 100 in 1 000 000 - taken as “acceptable risk” by the U.S. Environmental Protection Agency for adults and children.
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A history of silicosis on the Witwatersrand Gold Mines, 1910-1946Donsky, Isidore Jack 10 June 2014 (has links)
D.Phil. (History) / Silicosis as an occupational disease, has plagued the gold mining industry since its inception in 1886. This thesis attempts to describe the impact that silicosis had on the labour force of that industry from 1910 to 1946 and how all three participants, i.e. the state, industry and mine- workers became involved in attempting to combat this vital and dangerous problem, which was draining the health of a large and important sector of white and black workers within the South African community. This study focuses on two main themes, namely the cause and prevention of silicosis, which involves the development and use of advanced technology applied to mining operations and the compensation awarded to silicotic beneficiaries and their dependents. The disease not only became a health problem, but rapidly erupted into a sensitively politicised and emotional issue, which forms an important part of this thesis, involving all three parties. Another complex issue revolves around the question of contributions towards compensation to silicotic miners and who was liable for payment. This central problem only emerged after 1910, but continued throughout the period under discussion until 1946. In the process it became a highly controversial matter on which the state, industry and labour held widely divergent viewpoints. Also analysed are the attitudes and policies of the state and the mines towards white and black silicotics, the social responsibilities extended to each labour group and the effect racial relationships then current in South Africa had on the health problem as a whole.
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The white death: silicosis (miner's phthisis) on the Witwatersrand gold mines 1886-1910Katz, Elaine N January 1990 (has links)
A THESIS SUBMITTED TO THE FACULTY OF ARTS, UNIVERSITY OF THE WITWATERSRAND, JOHANNESBURG, IN FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY. / In its chronic form silicosis had always been been taken for granted as one of the occupational hazards of mining. But both during and shortly after the Anglo-Boer War it manifested itself in a new accelerated form amongst former Witwatersrand rock drillers. Despite the appointment in the Transvaal of a commission of enquiry in 1902 and the promulgation of dust precaution measures, by 1912 the prevalence of and mortality from the disease amongst the Witwatersrand miners had not diminished. This finding suggests two of the purposes of the study: first, the reasons for the continued prevalence of the disease; and second, the extent of the mortality from silicosis amongst the miners. Because of the apparently low prevalence of and mortality from the disease amongst African mineworkers, the disease was ironically nick-named the "white death". Therefore another aim of the study is to examine the validity of the medical claim that the short contracts of African migrant workers safeguarded them from contracting accelerated si licosis. As the subject is complex, the study uses a thematic approach. Chapters two to nine deal with significant themes: first, the growing medical knowledge concerning silicosis, the mining and medical precautions against the disease and the age-old disregard for the occupational illness in its chronic form; second, the industrialists* need to reduce working costs, the development of mass-production technologies and the resort by management to "speeding up"; and third, the miners' needs for job and wage security, the encroachment of African competitors in semi-skilled and skilled spheres of mining and the introduction and the extension of the colour bar. Chapter nine deals with underground health conditions. Chapter ten explores the awareness of the new form of the disease, accelerated silicosis, and the establishment in 1902 of the first Transvaal commission on silicosis. Chapter eleven discusses the failure to implement remedies. Finally, chapter twelve explores the prevalence of and mortality from silicosis and the impact of the disease on the workforce of the mines. In chapters ten, eleven and twelve a synthesis is offered of the themes and findings of the previous chapters. The project is based almost entirely on contemporary primary and published sources. Apart from silicosis, a unifying theme throughout the discrete sections is the perceptions of miners of their vocation in general, and of this occupational disease in particular. The study requires periodization. As silicosis is a slow-developing disease the starting point of the investigation is 1886, when gold was discovered on the Rand. The study ends in 1910 because the establishment of Union in 1910 and the legal award of compensation in 1911 heralded a new era in the history of silicosis on the South African gold mines. The following are the conclusions. First, almost an entire generation of overseas miners, most of whom remained migrants and whose skills pioneered the South African gold mining industry, died from silicosis. Second, for reasons of self-interest, some of which they shared with one another, both the Transvaal state and the Randlords did virtually nothing to remedy the occurrence of the disease. Both parties were culpable for the neglect of the health of the industry's workforce: using only perfunctory dust safeguards, management intensified production through the deployment of both modern technology and labour intensive practices, peculiar to the Witwatersrand; and most of the state's interventionist initiatives were the result of pressure from the British House of Commons. Third, the fear and anger of miners at being the victims of a preventable occupational disease, provided the catalyst for their militancy during the period. Fourth, the industry's power was partly responsible for causing both the press and medical profession to be silent about the problem until 1910. Finally, the mineowners both seized and promoted the unsubstantiated medical orthodoxy, namely that the short contracts of African mineworkers protected them from accelerated silicosis, as an important rationale for perpetuating the migrant labour system / Andrew Chakane 2018
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