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Management perceptions regarding skills shortages in gold minesXingwana, Lumkwana January 2012 (has links)
The skills shortages in mining and mineral sector had existed for a decade and had a widespread effect on South Africa economy. It affects the level of economic productivity and reduces the country’s capacity to develop a knowledge society. This, in turn, affects the country’s functioning in the global economy. Despite the sector’s best efforts, the shortages continue to grow and threaten the delivery of projects and growth plans. Some researchers contend with the view that the persistence of skills shortages in mining and mineral sector is largely due to entrenched attitudes among both the industry and the community. They claim that employers have the means to change the educational profile of the subsectors by appointing recruits with higher levels of schooling. However, owing to the limited number of higher educated people living in the communities surrounding the mining operations and lack of interest in mining of people with higher levels of education, to name but few, employers are perceived to have a habit of employing people with little skills. The current study was aimed at investigating the impact of skills shortage on organisational performance, propensity to leave, competitive advantage and sustainability, from the management perceptive. The main objective of this study was to incorporate and embed previous research findings and theories into a comprehensive hypothetical model. A hypothetical model showed various factors that may influence skills shortage. Four independent variables (working environment, employment conditions, resources and education and training) were identified as variables that may influence skills shortage; and mediating variable (skills shortage) was also identified as a variable that have potential to affect dependent variables (organisational performance, propensity to leave, competitive advantage and sustainability) of gold mining sector. Furthermore, eight hypotheses were developed to test the relationship between independent, mediating and dependent variables. All these variables were clearly defined and operationalized with various items obtained from measuring instruments used in other similar studies. A purposive sample of 343 respondents was drawn from the population. A seven-point Likert scale and structured questionnaire were administered in person to the respondents and of which 300 were usable and subjected further to several statistical analyses. The validity and reliability of the measuring instrument was evaluated using significant effect p< = 0.001 and Pearson’s correlation test (α = 0.05). Data gathered were fed to and analysed by STATISTICA (version 10) and factor analysis and regression analyses were the statistical procedures used to test the significance of the relationships between the various independent and dependent variables. Consequently, working environment, resources and education and training were three independent variables that were identified as having ability to predict propensity to leave, competitive advantage and sustainability. An attempt was made to establish whether various demographic variables have an influence on mediating and dependent variables through the introduction of gender and position in the organisation while conducting an Analysis of Variance and Multiple linear regressions, but they obtained negative values. The conclusion is that demographic variables do not have over mediating and depended variables. The findings of this study states that with conducive working environment, availability of resources, the high levels of education and training, the country could produce skills that would reduce propensity to leave, drive competitive advantage and sustainability, innovation and entrepreneurship, create competitive advantages and boost employment sustainability.
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Gold-sulphide mineralisation in the Giyani Grrenstone Belt case studies at Black Mountain and West-59 targets, Limpopo Province, South AfricaMuzerengi, Confidence 30 January 2015 (has links)
Department of Mining and Environmental Geology / MESMEG
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Distribution and mode of occurrence of gold in the Chibougamau District, Quebec.Prochnau, John Franklin. January 1971 (has links)
No description available.
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Towards sustainable economic development in the gold mining areas of South Africa and GhanaBoaduo, Adwoa Pokuaa January 2017 (has links)
A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering, 2017 / In many mineral resource rich African countries, mining activity makes a significant contribution towards the Gross Domestic Product (GDP) and economic growth. This stimulus gives the mining industry the potential to fuel growth and development. Although some mining areas have been able to experience positive economic growth, many have struggled to achieve and sustain economic development due to the inability to manage mineral wealth challenges. African mining regulatory bodies generally lack proper local planning, resulting in inadequate policy instruments to enable the sector to make a sustainable contribution towards economic welfare.
This research investigates how mineral wealth can be used as a catalyst for sustainable economic development. The research presents the case studies of three mining areas with the aim of determining why the economic development of Johannesburg differs substantially from that of Tarkwa and Obuasi. The research gives a comparative analysis of the political economy and socio-economic trends that have transpired in the three areas over the years. It ends by making recommendations on how Tarkwa and Obuasi can better manage the challenges of mineral wealth, and work towards achieving sustainable economic development that is like or even better than that of Johannesburg / CK2018
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A case study from a gold mining company : a call for leadership towards more sustainable futuresMakuluma, Hlombe Azukile 12 1900 (has links)
Thesis (MPhil)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Gold mining in South Africa is an industry that is more than a century old. The impact of gold
mines on communities and the environment are enormous. This thesis is a case study based
in one of the major gold producers in South Africa that has been in operation for more than
50 years and has more than 30 years of life still left. Exploring the impact mining has had on
communities and the environment, this thesis is a call for leadership action towards
sustainable futures. This call is made through a suggested sustainable development
leadership framework. Georgius Agricola gave a warning regarding the devastating environmental impacts of
mining as early as 1556, however mining still has the same negative impacts to the
environment and people. The argument in this thesis is that, it is only through genuine
leadership that the impacts of mining can be mitigated. However leadership is looked at not
from the position of the leader or the leadership style but from the belief system of the
leader when it comes to environmental management and community development.
The motivation for the study was based in observing how leadership at our Gold mine rallied
behind prevention of mine closure when the mine was faced with electricity crisis in 2008.
The electricity crisis demonstrated that it is through genuine and committed leadership that
all challenges can be overcome including sustainable development crisis. The call for
leadership at our mine is to demonstrate the same leadership commitment in addressing
environmental and community development challenges.
The literature review begins by highlighting sustainable development global challenges and
initiatives to address them. This is followed by impacts of gold mining on society and the environment around the various regions of the world. Leadership belief systems are then
discussed, highlighting, how belief systems influence the way a leader responds to
environmental issues.
In developing the sustainable development leadership framework findings from
observations, conversations, interviews and focus group discussion that were conducted
throughout the mine are presented. The aim of the research was to determine the
understanding of employees on the impact of our company on communities, environment
and themselves and also the employees’ opinions of leadership.
The findings were that the majority of employees believe that leadership is not genuine in
addressing community, employee safety and health, and environmental issues at our
company and through interviews with leadership, the findings are that, environment and
community issues are done for compliance and reputation purposes with no genuine belief
that they should be done.
To address this understanding a call to leadership is made through a suggested sustainable
development leadership framework that takes into consideration the findings from the case
study. The thesis ends by proposing that this suggested framework should be tested further
within our company. / AFRIKAANSE OPSOMMING: Goud mynbou in Suid-Afrika is 'n bedryf wat meer as 'n eeu oud is. Die impak van goudmyne
op gemeenskappe en die omgewing is enorm. Hierdie proefskrif is 'n gevallestudie wat
gebaseer is op een van die groot goudprodusente in Suid-Afrika wat al vir meer as 50 jaar
reeds in werking is en wat 'n veredere lewensverwagting van meer as 30 jaar het. Hierdie
tesis is 'n ondersoek na die impak wat mynbou op die omliggende gemeenskappe en
omgewing het asook 'n beroep om leieskap optrede vir volhoubare ontwikkeling. Hierdie
beroep vir volhoubare ontwikkeling word gemaak deur middel van 'n volhoubare
ontwikkeling leierskap raamwerk.
Georgius Agricola het alreeds in 1556 gewaarsku teen die impak wat mynbou op die
omgewing en mense sou hê. Vandag het mynbou het egter nog steeds dieselfde negatiewe
impak op die omgewing en die mense. Die argument in hierdie tesis is dat dit slegs deur
ware leierskap is dat die impak van mynbou versag kan word. Leierskap word egter nie
bekyk uit die posisie van die leier of die leierskap-styl nie, maar eerder uit die gewetens
oortuiging oogpunt van die leier wanneer dit kom by omgewingsbestuur en ontwikkeling
van die gemeenskap.
Die motivering vir hierdie studie is gebaseer op die waarneming van hoe leierskap by ons
goudmyn mynsluiting voorkom het gedurende die 2008 elektrisiteitskrisis. Die
elektrisiteitskrisis het getoon dat uitdagings sowel as volhoubare ontwikkelings krisisse wel
deur ware en toegewyde leierskap oorkom kan word. Die versoek is nou vir ons myn om
dieselfde leierskap toewyding toe te pas waar omgewing en gemeenskap ontwikkelings
uitdagings aangepak word.
Die literatuur oorsig begin deur die globale uitdagings op volhoubare ontwikkeling onder die
vergrootglas te plaas en wys hoe om die uitdagings te addresseer. Dan volg die impak wat
die goudmynbedryf het op die omgewing en samelewing van verskeie streke in die wêreld.
Leierskap geloof oortuiging word dan bespreek met die klem op hoe geloofsoortuiging 'n
invloed het op die manier wat 'n leier reageer op omgewings kwessies. Die ontwikkeling van die volhoubare ontwikkelings raamwerk is gebasser op obserwasies,
gesprekke, onderhoude en fokusgroepsbesprekings van regoor die myn. Die doel van die
navorsing was om die begrip van die werknemers te bepaal aangaande die impak wat ons
maatskappy het op die gemeenskap, omgewing en hulself en ook om die werknemers se
opinies van leierskap te bepaal.
Die bevindinge was dat die meerderheid van die werknemers van mening is dat leierskap by
ons maatskappy nie opreg is wanneer dit kom by aanspreek van gemeenskap kwessies,
werknemer veiligheid en gesondheid, en omgewingskwessies nie. Deur middel van
onderhoude met die leiers van ons maatskappy is ook bevind dat die omgewing en die
gemeenskaps kwessies slegs aandag geniet aangesien dit vir die nakoming van vereistes en
reputasiedoeleindes verys word en nie as gevolg van 'n werklike oortuiging dat dit gedoen
moet word nie.
Om hierdie begrip aan te spreek word 'n beroep gemaak tot leierskap deur middel van
hierdie voorgestelde volhoubare ontwikkeling leierskap raamwerk wat die bevindings van
die gevallestudie in ag neem. Die tesis eindig deur voor te stel dat hierdie voorgestelde
raamwerk verder getoets moet word in ons maatskappy.
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Structural geology and controls of gold mineralization in the Siguiri Mine, Guinea, West AfricaSteyn , Juan Greisch 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: This study presents results of a detailed geological mapping and structural analysis of auriferous quartz-vein sets of the nine current open-pit operations, of the Siguiri Mining Complex in the northeastern parts of Guinea. The Siguiri Mining Complex is hosted by a low-grade metamorphic, turbiditic succession within the larger Siguiri Basin, which forms part of the Palaeoproterozoic Birimian Supergroup of the Boualé-Mossi domain on the West African Craton.
The Siguiri Mining Complex is located in a deeply weathered saprolite profile developed over the monotonous succession of interlayered metapelites and -psammites. In fresh bedrock and core samples, the host succession is mainly made up of quartz-muscovite schists, muscovite-chlorite schists and metagreywackes, with isolated occurrences of intraformational breccias.
The main deformation to have affected the metasedimentary succession of the Siguiri Mining Complex can be assigned to a D2 deformational event. D2 structures comprise of north-south trending strike-slip and reverse faults anastomosing around and enveloping open- to tightly folded domains exposed over an area of 12 by 3 km. The geometry, orientation and kinematics of faults and folds suggest that D2 structures formed during progressive deformation in an overall dextral transpressive brittle-ductile shear zone. Structures within the D2 corridor record east-northeast subhorizontal shortening and north-northwest subhorizontal extension.
An omnipresent carbonate alteration in form of carbonate-alteration spots testifies to the pervasive, syn-D2 hydrothermal fluid-flow within the sediments. A structurally- and fracture-controlled fluid-flow is evidenced by the abundance of auriferous quartz veins throughout the Siguiri Mining Complex. These quartz veins host the bulk of the gold mineralization. One main and, at least, three minor sets of auriferous quartz veins can be distinguished. The main quartz-vein set shows very consistent easterly to northeasterly trends and steep southerly dips throughout the Siguiri Mining Complex. This orientation is consistent with the dextral transpressive kinematics and strain within the D2 host structure and illustrates the significance of D2 strains for the mineralization. The volumetrically minor vein sets can be shown to be related to different stages of F2 folding and fold amplification. Zones of economic-grade mineralization occur in areas where competent, psammitic units are developed in structural sites of increased dilatancy. Areas of dilatancy are represented by either dilational jog geometries within the overall transpressive structure or zones of pronounced shear-zone subparallel stretch. Jog geometries could be identified in the larger Bidini-Toubani-Sanu Tinti Complex having formed as a result of the anastomosing geometry of the bounding D2 shear zones. In the large Kami Complex, F2 axial culminations and depressions correspond to zones of increased stretch within the D2 transpression zone, delineated by closer vein spacing and the formation of D2 normal faults parallel to the main vein set and normal to F2 fold hinges.
The size and extent of the Siguiri Mining Complex suggests that the host D2 transpressive corridor must be assumed to have a significantly larger along-strike continuation, being part of a larger shear zone system related to the accretionary history of Palaeoproterozoic basins and arcs onto the Archaean Man Shield in West Africa. / AFRIKAANSE OPSOMMING: Hierdie studie lewer die resultate voor van 'n gedetailleerde geologiese kartering en strukturele analise van die gouddraende kwarts-aar stelle in die huidige nege oop-groef operasies van die Siguiri Myn Kompleks, in die noordoostelike deel van Guinea. Die Siguiri Myn Kompleks is geherberg deur 'n lae metamorfiese graad turbidiet suksessie in die groter Siguiri Kom, wat deel form van die Paleo-Proterosoïkum Birimian Supergroep van die Boualé-Mossi streek op die Wes Afrika Kraton.
Die Siguiri Myn Kompleks is geleë in die diep veweerde saproliet profiel, wat onwikkel het oor die eentonige suksessie van metapeliete en -psammiete. In vars bodemrots en kern monsters is die herberg-gesteente opgemaak uit kwarts-muskoviet skiste, muskoviet-chloriet skiste en metagrouwakte, as ook afgesonderde voorvalle van intraformasie breksies.
Die hoof deformasie fase wat die metasedimentêre suksessie van die Siguiri Myn Kompleks geaffekteer het, kan toegeken word aan 'n D2 deformasie gebeurtenis. D2 strukture bestaan uit noord-suid neigende strekkingwaartse verskuiwings en opskuiwings, wat anastomoserend oop- en steil geplooide gebiede omsluit en is oor 'n area van 12 by 3 km ontbloot. Die geometrie, oriëntasie en kinematika van verskuiwings en plooie stel voor dat D2 strukture gevorm het tydens progressiewe deformasie in 'n algemene regse transpressie skuifskeursone, onder brosheid-duktiliteit toestande. Strukture in die D2 gang wys 'n oos-noordoos subhorisontale verkorting en 'n noord-noordwes subhorisontale verlenging. Die alomteenwoordigheid van karbonaat alterasie, in die vorm van karbonaat-alterasie spikkels, getuig van die deurdringende, sin-D2 hidrotermiese vloeistof vloei in die sedimente. Die strukturele- en breuk-beheerde vloeistof vloei is ook duidelik, as gevolg van die oorvloed van gouddraende kwarts-are reg deur die Siguiri Myn Kompleks. Die kwarts-are bevat die grootmaat van die goud mineralisasie. Een hoof, en te minste drie minder belangrike stele van gouddraende kwarts-aar stelle kan uitgeken word. Die hoof kwarts-aar stel wys konstante oostelike to noordoostelike neigings en steil suidelike hellings, reg deur die Siguiri Myn Kompleks. Die oriëntasie is konstant met regse transpressie kinematika en vervorming in die D2 strukture en illustreer die belangrikheid van D2 vervorming vir mineralisasie. Die minder-belangrike aar stelle is verwant aan die verskillende staduims van F2 plooiing en plooi amplifikasie.
Sones van ekonomiese graad mineralisasie kom voor in areas waar bevoegde eenhede van psammiete ontwikkel het in strukturele terreine van verhoogde dilatasie. Areas van dilatasie word verteenwoordig deur dilatasie uitwykings in die transpressie strukture of sones van skuifskeur subparalelle verlenging. Uitwykings geometrië kan geidentifiseer word in die groter Bidini-Toubani-Sanu Tinti Kompleks, waar dit gevorm het asgevolg van die anastomoserende geometrie van die D2 skuifskeur sones. In die groter Kami Kompleks kom F2 aksiale kulminerings en depressies voor in sones van verhoogde strekking binne-in die D2 transpressie sone en word uitgebeeld deur nader aar-spasiëring en die formasie van D2 afskuiwings, parallel aan die hoof kwarts-aar stel en normaal met betrekking tot die F2 plooi-skarniere.
Die groote en omvang van die Siguiri Myn Kompleks stel voor dat die D2 transpressiewe gang nog n groter voorsetting het, en vorm deel van 'n groter skuifskeur sisteem en is verwant aan die anngroeings geskiedenis van die Paleo-Proterosoïese komme en boë aan die Argeïese Man Skild in Wes Afrika.
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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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The sedimentology and depositional environment of the Beatrix Reef: Witwatersrand supergroup.Genis, Jac H January 1990 (has links)
A Dissertation Submitted to the Faculty of Science
University of the Witwatersrand, Johannesburg
for the Degree of Master of Science. / Beatrix Mine is located 35 km south of the city of Welkom in
the Welkom Goldfield and as such forms the most southerly of
the Witwatersrand-type gold mines.
The Beatrix Reef overlies an angular unconformity at the
base of the Turffontein Subgroup, Central Rand Group
Significant, southerly truncation of over 600m of the
Johannesburg Subgroup, and the lower formations of the
Turffontein Subgroup, occur at this unconformity in the
Beatrix area..
characteristics of the Beatrix Reef conglomerates such as
the morphology, sorting and packing of clasts, and the
arrangement. of the sediments in various sedimentary
structures and facies/ sequences, suggest deposition within a
braided fluvial environment on a coarse-grained braid-delta.
Sedimentation occurred after the fluvial degradation of
previously deposited units, and culminated in a marine/
lacustrine transgression. Low aggradation rates led to
significant reworking and concentration of placer materials
in a depositional model probably typical of ventral Rand
Group placer formation. Heavy minerals (and gold) are
concentrated in response to hydraulic conditions and show a
close association with large and small scale sedimentary
features. Transport directions deduced from the sedimentary
structures suggest a north to south dispersal of sediment
down the braid plain.
Sedimentary structures in the finer rained units at the
base of the Eldorado Formation are indicative of tidal
influences and document the marine transgression as the
culmination of the degradational events.
The lithologys sedimentary structures and facies sequences
of the coarser grained units of the Eldorado Formation
well as the overall coarsening upward of these lithologies
indicate sedimentation in a braided , fluvial system, on an
alluvial fan prograding across the preyiously deposited
units" Sedimentary ~tructures and lithologic variations
confirm a continued north to south dispersal pattern.
In the area south of the Sand over the period of fluvial
degradation and transgression after the formation of the
Beatrix: Reef was followed by more rapidly aggreding fluvial
progradation due to a major change in base level in response
to compressional tectonics and uplift along the Western
Margin Structure. Only in post-Central Rand Group times did
relaxation and extensional tectonics result in the
outpourings of the Ventersdorp .supergroup lavas and the
cessation of active Witwatersrand Supergroup sedimentation. / Andrew Chakane 2018
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Use of remote sensing and GIS in a risk assessment of gold and uranium mine residue deposits and identification of vulnerable land useSutton, Malcolm William 29 April 2013 (has links)
A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Environmental Science Johannesburg, November 2012. / Acid rock drainage (ARD) and dust are potential consequences of gold and uranium mine residue deposits (MRDs) on the Witwatersrand basin. Urbanisation has taken place around mines and, with the curtailing of mining activities and clearing of land previously covered by MRDs, there is pressure to use this land for residential, industrial and agricultural purposes. However, mining companies historically were not required to provide pollution control measures and there is evidence for contamination of land and water. Thus, there is a need to prioritise contamination sources for mitigation and to understand the extent of contamination and potential risks associated with different categories of land-use on mining land.
The aim of my study was to conduct a first-order risk assessment to aid in identifying vulnerable land use in the vicinity of gold and uranium mining, and prioritising MRDs, including footprints, for mitigation. To achieve this I constructed a Geographical Information System (GIS) using publicly available spatial data, and then tested the usefulness of historical aerial photographs and remote sensing imagery for mapping MRDs and impacts of MRD origin under Highveld conditions (i.e. a seasonal climate with summer rainfall and annual evapotranspiration of >2.5 times mean annual precipitation). The Ekurhuleni Metropolitan Municipality (EMM; 1923 km2) is an area of extensive historical mining with major urbanisation, while retaining areas for agricultural land use; thus it was selected as a representative study site.
I used a numerical rating scheme, which combined a number of parameters in two separate stages to calculate a risk index. The first stage involved the classification of hazards associated with MRDs while the second involved an assessment of land use vulnerability based on exposure pathways and proximity. Historical aerial photographs (1938, 1964 and 2003) and the Chamber of Mines (CoM) Dump Indexes were used to identify and classify MRDs in terms of basic geotechnical properties, current status and historical failure. Multi-spectral data, acquired over two years (2002 and 2003) in two seasons (spring and summer) by the TERRA satellite’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor, were used to compile thematic images, indicating potential contamination of surrounding land. It was intended that a zone of influence could be distinguished for each MRD enabling me to rate the hazard severity. The thematic images I selected included primary minerals (pyrophyllite and chlorite), secondary minerals (copiapite and jarosite), an indicator of uranium-bearing ore (referred to as mincrust) and the normalised difference vegetation index (NDVI). These minerals were chosen as potential indicators of different transport routes of contaminants and I tested their associations with different features and land use. I also tested for seasonal differences in the detection of these minerals, and used NDVI to examine the masking effect of active vegetation.
I found GIS to be well suited for combining the various forms of spatial data and providing information about MRDs, aqueous pathways, proximity to vulnerable land uses and impacted areas. However, I found that the potential severity of the hazards posed by each MRD, as indicated by a zone of influence, could not be determined from aerial photographs and ASTER alone. I therefore utilised the findings expressed in the literature survey to assign ratings for the different classes of MRDs. The vulnerability assessment was also supplemented by literature review to rate land uses based on human exposure pathways.
I determined that MRDs (including footprints) cover 4.1% of EMM, with slimes dams, totalling 3.5%, occupying the majority of this area. I found that 64% of slimes dams had failed prior to 2003 and I plotted a further 0.6% of EMM covered by visible mine residue spillage. Fifty three percent of MRDs were situated within 100 m of drainage lines or old wetlands, while 52% of these (i.e. 27% of the total) had been constructed in the watercourse. I also found that 15% were constructed on dolomites. Informal settlements were located on or bordering 6% of MRDs, with 41% of MRDs within 1 000 m. Eighty eight percent of MRDs were found within 1 000 m of formal residential areas, 71% within 500 m, and formal settlements were located on or bordering 5% of MRDs. Twenty three percent of MRDs were located within 500 m of agricultural land, while 35% were within 1 000 m; and industrial land use was on 9% of MRDs (footprints), with 40% of MRDs being within 500 m of industrial areas and 61% within 1 000 m
I found that chlorite did not provide a ‘signature’ of gold and uranium mine residue, whereas the other four minerals did. I also found that, of the two seasons examined (spring and summer), the best time to take an ASTER image to detect mineral signatures of gold and uranium mine contamination is after a few dry days following the first spring rains. For this reason, I used the ASTER taken in late October (spring) 2003 to examine associations with pathways and land use.
I found more pyrophyllite and copiapite on industrial and business land use than background, which I suggest is associated with the settling of windborne dust on large and flat roofs; although, in the case of copiapite this could be related to the oxidation of settled wind blown pyrite material. I found jarosite to be a reliable indicator of mine residue, which, together with mincrust, helped me identify contamination in former agricultural holdings, which are now a township. Although, chemically undefined, mincrust was a useful indicator of contamination, as I found it to be reliably detected on MRDs (including footprints), mine residue spillage, wetlands and other contaminated sites, and absent from known uncontaminated sites. Furthermore, it was not necessarily masked by active vegetation, whereas copiapite, jarosite and pyrophyllite were. Mincrust was also detected on irrigated agricultural land with an odds ratio of between 10 to 36 times greater than for rain-fed. Consequently, the most likely
pathway for mincrust is the aqueous. The mincrust signature, together with historical aerial photographs, also assisted me to identify historical mining along Black Reef outcrops, through detection in a wetland upstream of known mining activities.
The culmination of my study was a risk class and index for MRDs from which ‘risk maps’ were produced. These maps provide a guide to the level of risk posed by each MRD to the surrounding land use. Of the total 287 MRDs (including footprints) identified in the EMM, 50% were classified lower-risk; 40% medium-risk; 10% higher-risk and 0% as much higher risk. The lower-risk MRDs were predominantly rock dumps, whereas the higher-risk MRDs were slimes dams. The findings from my study will contribute to meaningful recommendations for future land use and enable mining companies, landowners, developers and government to allocate their resources judiciously (i.e. appropriate to the level of risk).
The results of this study have been published as:
Sutton, M.W., Weiersbye, I.M., Galpin, J.S and Heller, D., 2006. A GIS-based history of gold mine residue deposits and risk assessment of post-mining land uses on the Witwatersrand Basin, South Africa. In: A. B. Fourie and M. Tibbett (eds.), Mine Closure 2006: Proceedings of the 1st International Seminar on Mine Closure, Perth, ISBN: 0-9756756-6-4, pp. 667–678 (Appendix I).
Sutton, M.W. and Weiersbye, I.M., 2007. South African legislation pertinent to gold mine closure and residual risk. In: A.B. Fourie, M. Tibbett and J. Wiertz (eds.), Mine Closure 2007: Proceedings of the 2nd International Seminar on Mine Closure, Santiago, ISBN: 978-0-9804185-0-7, pp. 89–102 (Appendix II).
Sutton, M.W. and Weiersbye, I.M., 2008. Land use after mine closure – Risk assessment of gold and uranium mine residue deposits on the eastern Witwatersrand, South Africa. In: A.B. Fourie, M. Tibbett, I.M. Weiersbye and P.J. Dye (eds.), Mine Closure 2008: Proceedings of the 3rd International Seminar on Mine Closure, Johannesburg, ISBN: 978-0-9804185-6-9, pp. 363–374 (Appendix III).
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Arsenic in plants important to two Yukon First Nations : impacts of gold mining and reclamation practicesNicholson, Heather Christine 05 1900 (has links)
This project examines arsenic in plants growing near closed or reclaimed gold
mines located in the traditional territories of two Yukon First Nations. A total of 238 soil
and plant samples (comprising 9 different species) were collected from Mt. Nansen,
Arctic Gold and Silver, and Venus Mine tailing properties. At each property, samples
were collected near the suspected point source of contamination, approximately 1 -3 km
away, and from background sites. Species were chosen for their ethnobotanical
significance to the Little Salmon/Carmacks and the Carcross/Tagish First Nations,
based on interviews with Elders and other knowledgeable people. Total and inorganic
arsenic concentrations were determined using ICP-MS and AAS instrumentation, and
organic arsenic concentrations were calculated from the difference.
Uptake of arsenic by plants was low compared to soil arsenic concentrations. In
both plants and soil, the arsenic form was predominantly inorganic. Concentrations in
berries at all three sites were low or undetectable, and are therefore considered safe to
eat under Health Canada tolerable daily intake guidelines for inorganic arsenic.
At Mt. Nansen, the lichen "caribou moss" (Cetraria/Cladina spp.), Bolete
mushrooms (Leccinum spp.), and the medicinal shrubs willow (Salix spp.) and Labrador
tea (Ledum groenlandicum/L. decumbens spp.) had high mean arsenic concentrations
around point sources or at sites up to 1.5 km away. These localized high
concentrations will not likely affect foraging animals, given their constant movement.
However, Carmacks residents could avoid gathering all species with elevated arsenic
around the Mt. Nansen mining property until reclamation is complete.
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