Academic Wits Research Outputs (All submissions)
Permanent URI for this collectionhttps://hdl.handle.net/10539/36827
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Item Mining landscapes of the Gauteng City-Region(Gauteng City-Region Observatory, 2018-01) Bobbins, Kerry; Trangos, GuyThe extraction of gold along the Witwatersrand mining belt has fundamentally shaped the Gauteng City-Region (GCR) over more than a century. Mining in the region occurred across a vast area. The Witwatersrand basin is made up of three sub-basins – the West’, ‘Central’ and ‘East’ Rand – and stretches across a further seven distinct gold mining areas. These goldfields attracted prospectors, industrialists and work-seekers from across South Africa and around the world. They were responsible for the formation of Johannesburg and, over time, the development of large parts of the extended metropolis around it. For many years, gold mining produced immense wealth for mining companies, banks and residents – indeed the wealth extracted fired the entire South African economy. But there have been negatives. Gold mining also spawned a war, entrenched deep social divides, instilled exploitative labour practices, and devastated the natural environment. Though the industry is now in decline, the landscapes affected by mining are still identifiable by toxic scars that traverse the city-region. This Research Report, GCRO’s seventh, considers how the legacies of mining have been imprinted on the towns and cities of the Gauteng City-Region. The report uses ‘mining landscapes’ as a conceptual device to structure an analysis of the diverse impacts of mining, and to highlight the need for a comprehensive and collaborative approach to manage its after-effects. The report makes a unique contribution to existing literature on mining and mining waste in the city-region by presenting an integrated perspective on their urban, environmental, social and economic processes, characteristics and consequences, both historical and contemporary. While accounts are often told from the viewpoint of specific disciplines (such as history, geography or sociology), the analyses presented in this report – comprising of written pieces, archival excerpts and photo essays – are unbounded by distinctive disciplinary conforms. This allows for the diversity of the landscape to be explored in new ways. The report makes a call for the GCR’s mining landscapes to be understood as a connected landscape of systems rather than a set of isolated and forgotten features of a bygone mining era. From the abandoned mine areas that scatter the surface of the GCR, to earth tremors caused by hollowed out cavities below the earth, silicosis, acid mine drainage, distressed mining towns and more recent histories of artisanal mining – the legacy of gold mining in Gauteng has a variety of expressions, all emerging from the same interconnected history. The concluding chapter looks to the future and considers the possibilities for innovative and collaborative approaches to unshackle the towns and cities of the Witwatersrand from their gold-mining inheritance. This includes the prospects for spatial transformation, repairing social divisions, cultivating natural assets, and remedying the destructive health and environmental effects of a century of mining activity.Item Attenuation of pollution arising from acid mine drainage by a natural wetland on the Witwatersrand(Academy of Science of South Africa (ASSAf), 2017-01) Humphries, M.S.; McCarthy, T.S.; Pillay, L.Wetlands are well known to be efficient at sequestering pollutants from contaminated water. We investigated metal accumulation in the peats of the Klip River, a natural wetland that has received contaminated water from gold mining operations in Johannesburg for over 130 years. Previous work conducted in the downstream portion identified the wetland as an important system for sequestering metals. We focused on the upstream section of the wetland, more proximal to the source of acid mine drainage, to provide a better understanding of the pollutant sources and the role of the wetland in pollutant attenuation. Geochemical and mineralogical analyses of peat cores revealed considerable metal enrichments in the peat ash, particularly in Co, Ni, Zn, Pb, Cu and U. Metal concentrations are typically between 4 to 8 times higher than those previously reported for the downstream, more distal portion of the wetland. The distribution of metal accumulation within the peat profiles suggests that contamination arises from a combination of sources and processes. Elevated concentrations in the shallow peat are attributed to the input of contaminated surface water via tributaries that drain the Central Rand Goldfield, whereas enrichments in the deeper peat suggest significant sub-surface inflow of contaminated water through the underlying dolomitic rocks. Metal immobilisation occurs through a combination of mechanisms, which include the precipitation of gypsum, metal sulfides, Fe-Mn oxyhydroxides and phosphates. Our study highlights the environmental and economic importance of natural wetland systems which have the ability to accumulate large quantities of metals and thus remediate polluted waters.