...Musa S. D. Manzi; Mark A. S. Gibson; Kim A. A. Hein; Nick King; Raymond J. Durrheim ABSTRACT As expensive as 3D seismic reflection surveys are, their high cost is justified by improved imaging of certain ore horizons in some of the Witwatersrand basin gold mines. The merged historical 3D seismic...

...) and the Witwatersrand Supergroup (~2.85 Ga) from the Kaapvaal Craton, South Africa, along with subeconomic methane accumulations. In all cases, the petroleum was apparently sourced from Archean shales, generated during the Archean, and migrated before the late Archean or early Early Proterozoic metamorphism occluded...

... the northern margin of the Witwatersrand basin and the Johannesburg dome ( cf. Figure 3 ). Based on this geometry, they concluded that these structures resulted from the formation of the Vredefort dome. Working on the northern side of the Johannesburg dome (Locality 1, Figures 2 , 3 ), Gibson et al. (1999...

...G. L. ENGLAND; B. RASMUSSEN; B. KRAPEZ; D. I. GROVES Abstract Abstract: The Late Archaean Witwatersrand Supergroup of South Africa hosts the largest known gold-uranium-pyrite ore deposits. Oil preserved in fluid inclusions in quartz grains in siliciclastic sedimentary rocks of that supergroup...

... that they represent the former trace of heavy mineral strands (see also Robb et al., 1997c ). Seams of detrital monazite are not recorded from the Dongara Sandstone, but modern placers from Western Australia (cf. Fig. 10A and B ) provide a clearer analogy for Witwatersrand uraninite strands. Although...

... Mineralogical Society of America The readers has free access to the “free” material but MSA holds the rights hydrometallurgy pyrometallurgy sustainability Witwatersrand gold fields Kalahari manganese deposit L eft to right : Tapping molten alloy from a furnace; false colour image...

...Dimitri L. Meier; Christoph A. Heinrich; Mark A. Watts Abstract The process responsible for the gold mineralization in the Witwatersrand Basin, South Africa, remains controversial; the debate is between a detrital placer enrichment in laterally extensive conglomerate layers, and hydrothermal...

... facies metamorphism (~2 to 3 kbar; 350°C) and the formation of peak-metamorphic mineral assemblages in West and Central Rand Group lithologies in the northern and central Witwatersrand Basin at ~2.06 to ~2.05 Ga, but appears not to have thermo-metamorphically effected the southern portion of the basin...

..., argillaceous material within such river systems likely resulted from warm and humid palaeoclimatic conditions, thus enabling localized debris-flow and hyperconcentrated flow processes. We postulate that temporary “floodbasin playas” (cf. Rainbird, 1992 ) formed localised elevated base levels and provided muddy...

...-igneous Complex being the lower sequence in a ~2980 to 2960 Ma island arc. Despite being implicated as a source of gold for the world’s largest natural accumulation of gold in the Witwatersrand Basin, the absolute age of Sb-Au mineralisation in the Murchison Belt is poorly constrained. We have utilised...

.... Compston W. Retief E.A. Williams I.S. Welke H.J. Zircon ion microprobe studies bearing on the age and evolution of the Witwatersrand triad Precambrian Research 1991 53 243 266 Arndt N.T. Nelson D.R. Compston W. Trendall A.F. Thorne A.M. The age...

... in the Witwatersrand basin, some redbeds older than 2 Ga, and several Archean sulfate-bearing assemblages. Carbon and sulfur isotopes might favor an oxidizing atmosphere, as might the positive correlation between carbon and clay in clastic sediments, but much other evidence is either poorly supported, or nondiagnostic...

...Kenneth A. Eriksson; Wilson S. McClung Abstract To date, all source-to-sink research has focused on the Phanerozoic and Proterozoic stratigraphic record. This study attempts to apply source-to-sink principles to the 2.8–3.0 Ga placer gold–hosting Witwatersrand Supergroup in South Africa, for which...

...Andrea Agangi; Axel Hofmann; Cora C. Wohlgemuth-Ueberwasser Abstract The Archean metasedimentary succession of the Witwatersrand basin, South Africa, hosts the largest Au deposit in the world. Gold mineralization is mostly concentrated in conglomerate horizons, or “reefs,” and is tightly associated...

... mercury contents (cf. Poujol et al., 1996 ). As stated above, the precise source or sources of the gold are currently unclear, but mass-balance arguments ( Frimmel et al., 2005 ) clearly show that there was sufficient gold in the hinterland of the Witwatersrand basin to produce the recorded gold...

... stratigraphy of the Neoarchean Fortescue Group in Western Australia has renewed comparisons with the Witwatersrand conglomerate Au deposits in South Africa. As such, this has reignited the question of the Pilbara and Kaapvaal cratons being linked as part of the postulated Vaalbara continent during the Archean...

... = Witwatersrand Block; TML = Thabazimbi-Murchison Lineament; BWL = Barberton-Wits Lineament; NL = Natal Lineament (modified from de Wit et al. , 1992a ; Brandl and de Wit, 1997 ; Good and de Wit, 1997 ). Inset (b) simplified basement age (in Ga) map of southern Africa. The Kaapvaal Craton is surrounded...

... analysed to establish their composition and for comparison with rocks of the Kraaipan granite-greenstone basement terrane. Major and trace element compositions of the megabreccia were determined by XRF analysis at the School of Geosciences, University of the Witwatersrand. The predominantly granitic rocks...

... and uranium deposits of Witwatersrand, South Africa. These formations have long been recognized as indicating that near-surface atmospheric, continental, and marine conditions were very different from those of the present day. In recent years, detailed isotope studies have focused on the period of time...

... nodules are absent in the uppermost part of the subzone. Vertebrates        Pisces Atherstonia scutata   cf. Atherstonia minor   Bethesdaichthys kitchingi   Blourugia seeleyi   Westlepis kempeni   Namaichthys digitata      Amphibia Rhinesuchus whaitsi...