Here, we estimate the diameter of the transient cavity at the present level of erosion as. As corollary, the published data for the structural character of the free state welkom, klerksdorp, west wits line, west rand, central rand, east rand and south rand goldfields are summarised and evaluated to search for basin wide similarities andor correlations that would support tectonic models for the witwatersrand basin, and explain its. The basin hosts the worlds biggest gold resource in thin pebble. Witwatersrand wikimili, the free encyclopedia wikimili, the free encyclopedia. These include the dominion group and the witwatersrand, ventersdorp and basal transvaal supergroups. The gold mines in this area are situated around an ancient sea over 2700 million years old where rivers deposited their sediments in the form of sand and gravel which became the conglomerate containing the gold. Viljoen department of geology, university of the witwatersrand figure 1. The witwatersrand basin remains the worlds largest gold resource. Hein1, and nick king3 abstract inrushes of ground water and the ignition of flammable gases pose risks to workers in deep south african gold mines. Neoarchaean tectonic history of the witwatersrand basin. During 1999 and 2005, south africa produced 4 650 t of uranium oxide. Western basin, the klerksdorp, orkney, stillfontein and hartbeesfontein kosh basins and the free state gold mines. Although the witwatersrand has been subject for decades of research, the genesis of gold and uranium ore is still unclear.
Pdf gold mineralization within the witwatersrand basin, south. The evolution of oxygen levels in the archean atmosphere is one of the most important questions in the study of early earth environments. The origin of au u deposits in the archaean witwatersrand basin of south africa is the subject of longstanding discussion. Pdf the current concepts concerning the genesis of the unique orebearing reefs of the. They therefore believed the gold could not continue for more than about 30 to 50 meters underground. Selected extracts from south africas environmental. The gold bearing reefs in the witwatersrand basin are tabular and most are mined at widths of about 1 m. The witwatersrand is a large basin of metamorphosed conglomerates that forms the greatest goldfield in the world. The witwatersrand basin of south africa is an elongate structure of archean. Witwatersrand basin hartbeespoort, south africa atlas obscura. Neoarchaean tectonic history of the witwatersrand basin and ventersdorp supergroup. A gold rush is a new discovery of goldsometimes accompanied by other precious metals and rareearth mineralsthat brings an onrush of miners seeking their fortune.
Land use after mine closure risk assessment of gold and. Largest gold deposits in the world witwatersrand gold fields. Flexural partitioning of the late archaean witwatersrand. The impact of gold mining on the witwatersrand on the rivers. Michael meyer i department of geology, university of the witwatersrand, private bag 3, wits 2050, south africa received 19 december 1994. It shows the closest traceelement affinity to pyrites from the barberton mountain land, the source area model for the witwatersrand sediments.
Hollister on the carlin trend in nevada and burnstone in the witwatersrand basin. Although the free state mines are within the witwatersrand basin, the close proximity of overlying coal seams differentiates them from most of the other high occurrence reporting gold mines. Request pdf flexural partitioning of the late archaean witwatersrand foreland system, south africa the witwatersrand basin is part of a retroarc foreland system formed during the late archaean. Due to continued population growth, the expansion of industries on the witwatersrand and the development of the free state gold fields after wwii, the vaal dam wall was raised to increase the capacity to 2330 gl. Quantitative major and trace elemental mapping by pixe of. The witwatersrand basin project wbp comprises two historic mining centres known as the durban roodepoort deep and the rand leases on the northern edge of the witwatersrand basin in the central rand goldfield immediately southwest of the city of johannesburg figure 1. Free state goldfield, and v to discuss the application of sedimentology and geostatistics in the evaluation of these reef horizons.
The witwatersrand basin is the largest goldfield in the world having yielded over. The evaluation of proposed mining layouts for remnant or. Gold mining in the witwatersrand basin has been responsible for the creation. The effects of uranium mining on health case studies. The mesoarchaean witwatersrand basin represents the largest known gold anomaly and has produced more gold. Beatrix is a large, shallow to intermediate level gold mining and processing operation located in the free state goldfields of the witwatersrand basin, near the town of welkom in the free state province of south africa, 240 km southwest of johannesburg. Although gold overgrowths on pyrite are rarely well crystallized, sufficient particles have been observed to indicate that the cube faces of the gold crystals grow on the cube faces of the pyrite rotated by 45 genesis of the witwatersrand gold deposits although at one time the subject of controversy, the fossil placer nature of the. Aachen, germany mine water managing the challenges imwa 2011. In the largest basin, the central basin, the water level has been rising at an average rate of 0. Durrheim a,c a school of geosciences, university of the witwatersrand johannesburg, pbag 3, wits, 2050, republic of south africa.
Ages of altered granites adjoining the witwatersrand basin. They are particularly abundant in a zone tangential to the vredefort dome, a structure which is now widely accepted to be the eroded remnant of the central uplift of the. Mine water management in the witwatersrand gold fields. The life, death and revival of the central rand goldfied m. East rand goldfield, and also in the free state area welkom. Impact cratering research group, school of geosciences, university of the witwatersrand, private bag 3, p. As of 31 december 2018, beatrix has total surface and underground gold mineral reserves. Abstract historically, there have been a range of diameter estimates for the large, deeply eroded vredefort impact structure within the witwatersrand basin, south africa. Witwatersrand basin, which contains nearly half the worlds gold, covers an area the size of west virginia in the northeastern part of south africa. The witwatersrand basin and its gold deposits springerlink. The gold and uraniumbearing deposits of the witwatersrand basin took some 360 ma to form during the archaean period, between 3074 and 2714 ma ago robb and robb, 1998. The witwatersrand basin is a largely underground geological formation which surfaces in the witwatersrand, south africa. Currently, uranium production from the witwatersrand basin amounts to less than 1 000 t of uranium oxide yearly.
In addition to aeons of natural weathering, a hundred and twenty years of mining and mine residue deposition has resulted in the transport. Helena gold mine in the orange free state have lead. Witwatersrand basin, johannesburg, south africa outcome worlds largest gold rush ever led to the eventual boer defeat in the second boer war 18991902, the loss of boer autonomy and selfgovernment, and total british rule in south africa. Witwatersrand, johannesburg, in partial fulfilment of the requirements for the degree of master of science in engineering. The witwatersrand basin in south africa has been the focus of gold exploitation for more than 100 years, and the subject of hundreds of research. The witwatersrand basin is the largest goldfield in the world having yielded over 52,000 tonnes of gold 1,672 moz.
The life, death and revival of the central rand goldfied. Diamictite, banded iron formation bif and mafi c lava are minor. Witwatersrand basin operations projects sibanye witwatersrand basin operations projects eastern cape lesotho free state north west randfontein carletonville westonaria potchefstroom vredefort welkom virginia theunissen bloemfontein limpopo western cape northern cape cape town johannesburg balfour 0 100 200km eastern cape kwazulunatal lesotho. The basin straddles the old provinces of transvaal and the orange free state, and consists of a. Apr 20, 2017 the witwatersrand basin in south africa hosts the largest known gold repository on earth but how was it formed. The application of geophysics to gold exploration in south. The formation of gold deposits in south africa geology page. Evaluating the structural character and tectonic history of. Read the growth and concentration of uranium and titanium minerals in hydrocarbons of the carbon leader reef, witwatersrand supergroup, south africa, chemical geology on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Select any poster below to play the movie, totally free. Four depositional sequences, separated by major erosional surfaces, build the vaal reef package.
The companys prospecting rights contain inferred resources of 159. Pdf health risk assessment of heavy metals in soils from. It is delimited by the witwatersrand basin and the bushveld igneous complex. Pseudotachylitic breccias, associated with either beddingparallel or normal faults, are abundant in the northern and northwestern parts of the gold and uraniumrich witwatersrand basin in south africa.
Gold accumulation in the archaean witwatersrand basin, south. Some materi als associated with the witwatersrand gold give ages older than the host conglomerates whereas others give younger ages. Witwatersrand gold rush wikimili, the free encyclopedia. Major gold rushes took place in the 19th century in australia, new zealand, brazil, canada, south africa and the united states, while smaller gold rushes took place elsew. It holds the worlds largest known gold reserves and has produced over 1. The basin is located in the northeastern part of the republic of south africa, within the provinces of the transvaal and the orange free state. Deposition of the predominantly siliciclastic basin. Its estimated that half of the worlds gold was mined from south africas golden arc.
When george harrison discovered the main reef of gold at langlaagte farm in 1886, it was believed by many to be an old river that had been turned on its side. The mesoarchaean witwatersrand basin represents the largest known gold anomaly and has produced more gold than any other ore province in the world. The witwatersrand mining basin is composed of the far east basin, central rand basin, western basin, far western basin, kosh and the free state gold mines a remotesensing and gisbased integrated approach for risk based prioritization of gold tailings facilities witwatersrand, south africa. The witwatersrand basin is approximatly 350 km long and 200 km wide. Hallbauer 0 0 mining technology laboratory, chamber of mines of south africa studies of the morphology and other properties of the gold particles in the fossil placer gold deposits of the witwatersrand provide fascinating glimpses of the conditions under which they were formed. The upper witwatersrand beds underlie an area of some 15,000 square miles in what is generally called the main witwatersrand basin. On imdb tv, you can catch hollywood hits and popular tv series at no cost. A paper on the origins of the original witwatersrand gold. More than 120 mines extracted 43,500 t of gold in one century and 73,000 t of uranium between 1953 and. It has produced some 2 billion ounces over a century of mining and at an average grade of 15 gt au with a current head grade of 610 gt au and they still have estimated reserves of some 1,161 billion ounces. The chemical characteristics of acid mine drainage with particular reference to sources, distribution and remediation. Worlds largest gold rush ever led to the eventual boer defeat in the second boer war 18991902, the loss of boer autonomy and selfgovernment, and total british rule in south africa.
Davis discovered the first gold in the witwatersrand, leading to the south african gold rush and the discovery of much more gold deposits within the basin. This type was eroded from primary deposits in the hinterland of the witwatersrand basin and deposited with the witwatersrand sediments. Post witwatersrand supergroup lithologies are not shown for simplicity. Pdf the witwatersrand basin in south africa has been the focus of. Major geological features of the witwatersrand basin stripped of younger cover and showing major goldfields and main remaining deep and shallow gold resource paper 77. Most of the basin is deeply buried under younger rocks, but outcrops occur in gauteng, the free state, as well as in some of the surrounding provinces. The basin straddles the old provinces of transvaal and the orange free state. Discover witwatersrand basin in hartbeespoort, south africa. Health risk assessment of heavy metals in soils from witwatersrand gold mining basin, south africa article pdf available in international journal of environmental research and public health 7. Witwatersrand gold deposits formed by volcanic rain. Scientists were able to figure out how parts of the earths largest gold deposits. A remotesensing and gisbased integrated approach for risk based prioritization of gold tailings facilities.
At a first glance, the witwatersrand basin, the largest known gold resource on our planet, is not automatically related to ocean research. It stretches for 350 km long by 200 km wide with a thickness that can exceed 10,000m. The discovery and development of the free state gold. The witwatersrand gold rush was a gold rush in 1886 that led to the establishment of johannesburg, south africa.
One of the main problems in understanding the origin of the witwatersrand basin mineralization concerns the source of the prodigious concentrations of gold and uranium in the basin. Neoarchaean tectonic history of the witwatersrand basin and. Pdf the origin of gold in south africa ancient rivers. Pdf evaluating the structural character and tectonic history of the. The basin succession is composed of weakly metamorphosed siliciclastic sedimentary rocks, comprising conglomerate, quartzite, and shale. Nov 14, 2016 the gold fields of the witwatersrand basin in south africa are, by a landslide, the largest single gold producing district in the world. It stretches for 350 km long by 200 km wide with a thickness that can exceed. Witwatersrand gold rush wikipedia republished wiki 2. As of 31 december 2018, beatrix has total surface and underground gold mineral reserves continued. Witwatersrand system, major division of precambrian rocks in south africa the precambrian began about 3. The witwatersrand basin in south africa is one of the bestpreserved records of fluvial sedimentation on an archaean continent 1.
Gold deposits were discovered in 1886, and have been mined 79 continuously since then, yielding approximately 50 000 tonnes of gold, equivalent to about 31% 80 of all gold ever mined anywhere throughout history mccarthy. Apr 21, 2019 great basin gold limited is an international mining company with two emerging mines in the worlds richest gold regions. Facies analysis and sequence stratigraphic methods resolve the correlation and relative chronology of vaal reef facies associations at the great noligwa and kopanang mines in the klerksdorp goldfield, witwatersrand basin. The witwatersrand mining basin is composed of the far east basin, central rand basin, western basin, far western basin, kosh and the free state gold mines. Witwatersrand gold deposits formed by volcanic rain, anoxic. Geological framework and mineralization processes laurence j. Apr 20, 2017 however, in its 3 billion years old geological history, the witwatersrand basin in south africa has been covered by seawater, but experienced also episodes of drying out, flooding and erosion by. Because of the close spatial association of pyrite with au and u in the mineralised conglomerates, the origin of pyrite is a central aspect in all genetic hypotheses of witwatersrand mineralisation, in both primary placer models robb and meyer. The vaal dam with an original storage capacity of 994 gl was built upstream at the confluence of the vaal and wilge rivers in 1938.
An outlier, separated by structural deformation occurs 40 miles east of the main basin outcrop, whereas the outlier is entirely covered by younger rocks. The presence of redoxsensitive uraninite in the archean witwatersrand basin, south africa, has been cited as evidence for a reducing archean atmosphere. The witwatersrand mining basin is composed of the far east basin, central rand basin, western basin, far western basin, kosh and the free state gold mines a remotesensing and gisbased integrated approach for risk based prioritization of gold. For report purposes the witwatersrand gold mines are. The witwatersrand rocks overlie rocks of the dominion reef system, underlie those of the ventersdorp system, and occur in an eastwest band. The term witwatersrand basin is used here in a broad sense to encompass all archaean volcanosedimentary units that accumulated in the central part of the kaapvaal craton between 3. Beatrix is the southernmost mine in the witwatersrand basin and has shown that low grade ore deposits can be pro. Impact cratering research group, school of geosciences, university of witwatersrand, private bag 3, p. Introduction 77 the witwatersrand basin goldfields wbg comprise an area of approximately 25 000 km2 in north78 central south africa. Sketch map of the main stratigraphic subdivisions in the witwatersrand basin. The application of geophysics to gold exploration in south africa. It is estimated that an inferred resource of about 30,000 tonnes. Sap flow in searsia pendulina and searsia lancea trees. Wits gold has been granted new order prospecting rights over 910 km2 in key areas of the witwatersrand basin, adjacent to active mining operations.
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