Dewatering of the Far West Rand dolomitic area by gold mining activities and subsequent ground instability

Autor: H. J. van Niekerk, I. J. van der Walt
Rok vydání: 2006
Předmět:
Zdroj: Land Degradation & Development. 17:441-452
ISSN: 1099-145X
1085-3278
Popis: In the 1960s, the Malmani dolomite landscape of the Transvaal Sequence on the Far West Rand experienced ground subsidence in the form of sudden catastrophic sinkhole formations and extensive development of dolines by gradual subsidence. The management of the gold mines had decided to dewater some of the dolomitic compartments to allow their workers to extract the gold-bearing ore of the underlying Witwatersrand Supergroup economically and safely. Several of the gold mines on the Far West Rand have now reached the end of their life span and are due to be decommissioned. Dewatering will be discontinued. Some of the dykes that form the boundaries of the individual dolomitic compartments have been breached by mining activities so that flooding of one compartment will eventually impact on the other compartments. The eventual static level of the water-table in this new ‘super-compartment’, as well as the points of decant of the dolomitic water, are uncertain. Flooding of the ‘super-compartment’ will cause the original dolomitic eyes feeding the Wonderfontein Spruit to start flowing again, which will impact on groundwater quality and ground instability. Of particular concern is the occurrence of millions of tonnes of mine tailings within the catchment area. The most important problem in the catchment area is that the sedimentary phase of the Wonderfontein Spruit and its impoundments is continually being enriched with heavy metals and radio nuclides originating at the mining works. These could be remobilized and released into the downstream water, causing deterioration of water quality for downstream users. Copyright © 2006 John Wiley & Sons, Ltd.
Databáze: OpenAIRE
Externí odkaz: