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Kontroles van goudmineralisasie by die Sheba-goudmyn, Barberton-distrikSchouwstra, Robert Pieter 11 February 2014 (has links)
M.Sc. (Geology) / The Main Reef Complex (MRC) section is developed in the Zwartkoppie and Sheba Formations of the Onverwacht and Fig Tree Group respectively. The section is represented by three shear zones, associated with a prominent anticlinal structure, locally known as the Birthday No.2 anticline. This tight isoclinal structure is marked by a chert unit, with a core of green quartz-carbonate schist, and is overlain and surrounded by greywackes and shales of the Sheba Formation. At depth the main mineralized fracture occurs to the south of, and parallel to the Birthday No.2 chert bar. Above the crest of the anticlinal structure gold mineralization is associated with three shear zones (which transgress the bedding of the greywackes and shales) known as the No .. I, No. 2 and No. 3 Fractures. Pyrite and arsenopyrite are the main ore minerals, with minor amounts of chalcopyrite, sphalerite, tetrahedrite and pyrrhotite. Pyrite mineralization is ubiquitously developed along the shear zones, while arsenopyrite mineralization is restricted to certain areas. Assay data of the greywackes and shales show that there is a correlation between gold contents and the abundance of arsenopyrite. Gold has been observed in association with all the sulphide minerals present, and as inclusions within pyrite and arsenopyrite. Electron microprobe analyses have revealed significant levels of gold in arsenopyrite, probably as submicroscopic inclusions.
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Excellence and client focus through personnel restructuring of a South African gold plantVoordewind, H. 13 September 2012 (has links)
M.Comm. / The South African gold mining industry has in the last decade increasingly come under pressure. The radical drop in the dollar price of gold, the lowest it has been in 16 years, has depressed revenues to the point where drastic action is needed. Furthermore, costs have been escalating. Where the South African Industry was the international leader in low cost production ten years ago, it has now become the most expensive. The following statement by the Chamber of Mines President, Bobby Godsell (1998: Godsell) , underlines the problem: "The gold mining industry world-wide is in a state of crisis, with the price of its product at a 16-year low. Few industries would not be in crisis if they were receiving 1982 prices for their product. In South Africa, two other features contribute to an even more acute crisis. Over the last decade South Africa has moved from being the lowest cost major gold producer to being the highest. Secondly, many South African gold companies are facing physical depletion of their ore reserves. Many companies have now been in operation for more than half a century. Eventually every mine must come to the end of its mineable reserves. Members of the Chamber are deeply committed to meeting the challenges of low prices, high costs and one depletion constructively and effectively. To this end the Chamber proposed a productivity-linked wage agreement last year. Since that agreement we have seen a further $30-drop in the gold price, with a third of Chamber member gold mines making losses, aggregating about R12-million a week. The Chamber shares the National Union of Mineworkers' concerns about job losses. Retrenchments are the consequences of the industry's problems - not their causes. Without addressing the causes, a moratorium on retrenchments will, in our view,achieve nothing, and possibly create expectations which would not be fulfilled. There is only one way to reduce job losses and this is to find ways to return companies to profitability and to make them cost-competitive with producers of gold elsewhere in the world. Much as it understands the National Union of Mineworkers' anger, the industry will not find a way forward through marches, protests or strikes. The combined wisdom, and then the combined effort of management, labour and government will be required to find a way forward for the South African gold industry."
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Fracturing and deformation at the edges of tabular gold mining excavations and the development of a numerical model describing such phenomenaBrummer, Richard Kenneth 10 September 2014 (has links)
D.Ing. (Civil Engineering) / This thesis describes an Investigation Into the nature of the fracture and deformation mechanism which occur at the edges of tabular gold mining excavation. Published Information on these phenomena Is reviewed, and the necessary underground Investigation required to consolidate the previous work Is described. It Is concluded that the rock near the reef plane at the edges of these mining excavations Is subject to stresses sufficiently high to cause It to fracture through the formation of regular patterns of shear planes. These fractures can form In the solid rock some distance ahead of the mining excavation. Nearer the mining face, extension fractures form which result In slabbing or splitting of the exposed rock. An Idealization of the observed rock behavior Is proposed, which Is then incorporated with conventional boundary element techniques Into a numerical model (SEAMS) which Is capable of analyzing two Dimensional tabular mining excavations where the rock near the reef plane at the edge of the mining excavation fractures, deforms and sheds load. A Sensitivity analysis of the numerical model Is described which Identifies those mining parameters capable of being used to advantage In controlling the size of the fracture zone.
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The mechanics of bedding-parallel faulting associated with the Ventersdorp contact reef on the Kloof Gold MineBerlenbach, Joachim Wilhelm 02 June 2014 (has links)
D.Phil. (Geology) / The structural history and mechanisms of bedding-parallel faulting associated with the Ventersdorp Contact Reef (VCR) on the Kloof Gold Mine are discussed. Pre-VCR deformation is determined by folding of the Booysens Shale Formation and the Turffontein Subgroup. Extension of Ventersdorp age (± 2700 Ma) probably took place by the simultaneous operation of normal, strike-slip and oblique slip faults (mixed-mode extension). Because the strikeslip and oblique-slip faults were extensional, they could be utilised as conduits for dykes, forming "Fault and Dyke Zones". Northwestward directed thrusting, which postdates the normal faulting, resulted in positive inversion. The thrust faults have a ramp-flat symmetry with ramps forming in the VCR horizon and the overlying Alberton Formation and flats forming in the underlying Booysens Shale Formation and along the contact between the VCR and the Alberton Formation. The thrust faults follow complex deformation paths, indicated by out-of-sequence thrusting, simultaneous folding and thrusting, underthrusting and compressed boudins. Hanging-wall ripouts, which can be related to this thrust event, are introduced as a shear sense indicator. No northwestward verging thrust faults of post-Transvaal age (post 2430 Ma) could be identified, indicating that this compressional event occurred prior to the deposition of the Black Reef Quartzite Formation. The minimum amount of shortening due to northwestward directed thrusting was estimated as 37 % with the help of restored sections. However, due to the out-of-sequence propagation of thrust faults, a control of the strain estimation was possible and true shortening probably exceeded the calculated amount of shortening considerably. The restoration of sections with out-of sequence thrusts is discussed in detail. Sheath fold-like structures in pseudotachylyte can be related to northwestward directed thrusting and are introduced as a new shear sense indicator.
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The impact of the gold mining industry on the water quality of the Kromdraai catchmentMalan, Joël D. 11 June 2014 (has links)
M.Sc. (Geography) / One of the main objectives of the National Water Act (Act 36 of 1998) is the protection of natural resources (water resources) against pollution and misuse. These resources must be protected for the sustainable use by future and present generations. The study area consisted of the Kromdraai Catchment which included the Upper Wonderfonteinspruit, Lower Wonderfonteinspruit, Loopspruit and the Mooi River. This area is known for the amount of gold mining activities which may have a negative influence on the environment and especially on water. The aim of this study is to determine the impact of the gold mining industry may have on the water quality of the Kromdraai Catchment. Huge volumes of water quality data were collected from certain major monitoring stations throughout the Kromdraai catchment. A good indicator of pollution in a water sample is the electrical conductivity (Ee) of the sample. EC values were used to determine the pollution in each of the water samples because it saves time and costs. Pollution trends were established and conclusions were drawn to determine the impact of the gold mines on the water quality. A clear impact of a tailings dam on the water quality of the Turffontein Oog was established by the sharp increase in the EC values since the Doornfontein Gold Mine started depositing huge volumes of slime on the no. 3 tailing dam. The EC values of the Turffontein Oog have started to decline when the depositing of the slime was ceased. The conclusion of the study is that the gold mining industry has a definite negative impact on the water quality of the water resources in the Kromdraai catchment. The only effective way to mitigate and, manage these negative impacts, is through integrated environmental management. The sharing of data by all interested and affected parties is of critical importance, since most neighbouring goldmines are directly impacting on each other through the pumping and discharging of huge volumes of mine water. Catchment forums were established for the integrated environmental management of the Kromdraai catchment by all interested and affected parties. These forums have become important bodies representing stakeholders in the establishment of catchment management authority (CMA) that Will be established in the Upper Vaal Water Management Area.
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Exploring ethical leadership and its association with sustainable economic performance within the gold mining industryNkosi, Nhlanhla Terance Mashobane January 2014 (has links)
The concept of ethical leadership has been intrinsically evident for over a century, but studies have only recently been documented that have attempted to observe and analyse the phenomenon. The concept has become more popular in the information age as companies start to employ additional knowledge workers who search for enhanced meaning in their respective occupations.
The gold mining industry in Africa has improved substantially as conflicts have subsided slightly. As such, industry leaders need demonstrate better skills of engagement when managing legacy issues. While the shareholders’ interest remain high on leaders’ radar, leaders need effectively manage operations to address issues that might not be immediately evident in balance sheet, but that nonetheless have an effect on economic sustainability of the gold mining entities. Given that the concept of ethical leadership is known, there are still scandals that have recently been documented that involve leaders who have made decisions that led to demise of entities for which they were responsible.
The purpose of this research was to explore ethical leadership and its association with sustainable economic performance within gold mining industries. The study aimed to analyse companies that have an African footprint, while originating from South Africa. A qualitative research method was employed following a phenomological approach to obtain insights of how African leaders have operated gold mines in Africa and have managed operations that performed very well. The aim was to crystallise and distil the findings for the use by future leaders so that they could avoid future scandals and not destroy shareholder value and disappoint stakeholders. The personal and leadership traits of ethical leaders were reviewed with the aim of determining the mental development that would be required, as well as which aspects would require consideration when determining the effects on economic sustainability.
The African leaders interviewed were familiar with the concept of ethical leadership, economic sustainability and implicitly understood the association of ethical leadership with economic sustainability. The concept of ethical leadership generated two new terms, as described by the interviewees that could be infused to the definition to cater for an African context. The concept of “Ubuntu” and “displaying appropriate conduct” were the two terms that were derived from the leaders. The concept of greed was identified as a strong impediment towards economic sustainability. The gap of
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displaying that ethical leadership has a favourable outcome towards economic sustainability was demonstrated. By attempting to close this gap, it could help curb unemployment rates, as decisions would be made differently. From the propositions made, which were all proven successfully, there remains opportunities for future quantitative studies to be undertaken to add insight to the existing body of knowledge. / Dissertation (MBA)--University of Pretoria, 2014. / zkgibs2015 / Gordon Institute of Business Science (GIBS) / Unrestricted
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Economic evaluation of Gold-Sulphides Mineralization within the North Leader Congleomate at N0:5 Shaft of Blyvoorvitzicht Gold Mine South AfricaMahlaule, Ntiyiso Ally 12 February 2016 (has links)
Department of Mining and Environmental Geology / MESMEG
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The history of Tuolumne County during the gold rushTremain, Harry C. 01 January 1947 (has links)
Back in the foothills of the Sierra Nevada, in the heart of the Mother Lode, lies Tuolumne County, whose history is rich with memories of the days of forty-nine. It was in this country of yesterdays, during those frenzied days of gold, that men fought and toiled and died for that precious metal. Miners in search of this precious substance penetrated into its forests, prospected up and down its canyons, and climbed its steep and rugged mountains. Towns sprang up overnight and disappeared almost as quickly. The miners were forever moving on to richer diggings in search of the “El Dorado.”
The gold rush days found Tuolumne a wild and rough country, with the most varied population of any country in the whole region. Yankees, Mexicans, Englishmen, “Sidney Ducks”, Frenchmen, Germans, Spaniards, Chinese, Negroes, Irishmen, and Chileans rubbed elbows and occasionally fists with each other. The region was full of gamblers, drunkards, fast women and lumps of gold.
Before the great rush for gold, California was a quiet, peaceful, sparsely settled land. In 1842, the population was about 5,000, not including the Indians. There were about 4,000 native Californians, 90 Mexicans, 80 Spaniards, 80 Frenchmen, 360 Scotchment, Irishmen and Englishmen, 90 Germans, Italians, and Portuguese. There was little immigration, and by 1847 the population had increased to only 7,000 or 8,000. The pueblos of Monterey, San Jose and Yorba Buena were the principal centers of trade. San Diego, Los Angeles, Sonoma and New Helvetia (now Sacramento) also contained a small population. Then came the discovery of gold. It took a little while for the news to travel, and at first people thought the reports were exaggerated, but as more and more reports were carried back to the pueblos, the excitement increased. On the first of April, 1848, the California Star printed “We are happy to be able to say that California continues to be perfectly quiet…. For more than a year no disorders have occurred, -the native Californians are beginning to mingle with our people, and are gradually turning their attention to agriculture. No further difficulties are apprehended.” Little did the writer of this article dream what was to take place before very long.
BY the end of May only about 300 men were in the gold fields. So rapidly did the gold-fever take hold, however, that by the tenth of June, the same newspaper was fearing that every town would be depopulated. It reported that “every seaport south to San Diego and every interior town is drained of human beings.” As yet, of course, the news had not had time to reach the Atlantic states, so the gold rush was purely local, and there were relatively few digging for gold. The Star estimated that there were “1,000 souls washing gold”, and that about $100,000 had been taken from the mines since the first of May from an area about 100 miles in length and 200 miles wide.
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Witwatersrand genesis: a comparative study of some early gold mining companies, 1886-1894Webb, Arthur (Arthur C M) January 1982 (has links)
Preface: For anyone standing on the ridge of the Witwatersrand on a spring day in September 1886 the sight immediately to the south represented a hive of activity and hope. Nearly a hundred years later ample evidence stretches away on both sides of the watershed to confirm the fulfilment of those early sentiments. It is, nevertheless, all too easy to ignore the struggles and failures which marked the beginnings of the world's greatest gold field in the light of its subsequent abundant success. Only when attention is turned to the individual companies formed to exploit the discovery does the true picture emerge of the lack of adequate technological and managerial knowledge amongst the early pioneers and of the financial frailty of their companies. The object of this thesis is to shed light on these beginnings by reviewing the histories of four of the earliest companies established to work the main reef. The approach adopted is to scrutinize the material available with a view to determining the motivations and actions of the managements of the various companies with regard to their economic environment, whether within or without the individual company. Clearly, the availability of information is a major determinant of the success of any such venture and this was particularly so in the case of the companies considered. With the exception of the Barlow Rand Limited holding of the H. Eckstein and Company Archives, which offers an integral coverage of that firm's dealings with the emerging industry, and which is certainly the most comprehensive source of information available to the researcher, little material relating to specific gold mining companies has survived. Under these circumstances it was necessary to rely heavily for information on the local press. These newspapers proved an invaluable source in this regard. As a mining camp with a limited capacity for generating newsworthy incidents, the newspapers of early Johannesburg found an eager readership for information about the industry which lay at the heart of the community. For their part, the managements of the various mining companies found in the pages of the local press an outlet for intelligence both true and false; the press was a useful vehicle for the publication of directors' and annual reports to meet a wider audience, but similarly it could be and was used to disseminate 'spectacular' reports calculated to influence the status of a company's stock on the local share market. As a research source the press has thus to be approached with caution but its value, if the warning is heeded, is in no way diminished. Beyond these two sources the next most valuable accumulation of data on the early industry is "The Gold Fields Collection" housed in the Cory Library for Historical Research at Rhodes University. As a collection it is far from complete and it is to be hoped that the donors will in future see fit to augment it with further material as this becomes available. It neverthess proved an invaluable source for the investigation of at least one of the companies of the study and for a general background to the industry.
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Alteration and gold mineralisation in the Roodepoort Goldfield, Pietersburg Granite-Greenstone Terrane20 November 2014 (has links)
M.Sc. (Geology) / Please refer to full text to view abstract
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