Kaapvaal craton, South Africa

Kaapvaal Craton, South Africa Newlands Kimberlite, K PG U-Pb 114Ma... 

Kaapvaal Craton, South Africa Eesotho, South Africa K MGG, MG, ME, TE, 90-140 Ma... 

Durrheim R. J. and Green R. W. E. (1992) A seismic refraction investigation of the Archaean Kaapvaal craton. South Africa, using mine tremors as the energy source. Geophys. J. Int. 108, 812-832. 

Wilson, A. H. Carlson, R. W. 1989. A Sm-Nd and Pb isotope study of Archaean greenstone belts in the southern Kaapvaal craton. South Africa. Earth and Planetary Science Letters, 96, 89-105. 

Watanabe, Y., Naraoka, H., Wronkiewicz, D. J., CoNDlE, K. C. Ohmoto, H. 1997. Carbon, nitrogen and sulfur geochemistry of Archean and Proterozoic shales from the Kaapvaal craton. South Africa. Geochimica et Cosmochimica Acta, 61, 3441-3460. 

FIGURE 3.12 The composition of the subcontinental lithosphere, (a) Differences in composition between Archaean, Proterozoic, and Phanerozoic subcontinental lithosphere (after Griffin et al., 2003), compared to estimates of the BSE (from Table 3.1). The diamonds represent the average compositions given in Table 3.4. (b) Differences in composition between oceanic and continental lithosphere, as expressed in % modal olivine and olivine mg oceanic peridotites define the trend shown as the dashed line whereas garnet peri-dotites from the Kaapvaal Craton, South Africa - illustrative of Archaean subcontinental lithosphere - plot in the shaded field. The diamonds are the averages of the two fields (after Boyd, 1989). Also shown is the field for Proterozoic subcontinental lithosphere (ellipse) after Griffin et al. (2003). 

Wilson, A.H., 2003. A new class of silica enriched, highly depleted komatiites in the southern Kaapvaal Craton, South Africa. Precambrian Res., 127, 125-41. 

More recently there have been several indications that the oxygen isotope geochemistry of mantle xenoliths from certain exotic settings can be more variable than indicated by Mattey et al. s (1994) survey and subsequent work of Chazot et al. (1997). Zhang et al. (2000) present oxygen isotope measurements on variably metasomatized and re-crystallized ultramafic xenoliths from the Kaapvaal craton. South Africa, which document inter-mineralic disequilibrium and intra-crystalline zonation that presumably... 

The Kaapvaal Craton, South Africa has preserved a remarkably complete sediment package that records coastal environments seaward to deeper water facies (e.g Klein and Beukes 1989). For example, the Kaapvaal includes the earliest known example of an extensive carbonate platform that resembles modern platforms in remarkable detail (Grotzinger and Kasting 1993). The extent and diversity of associated stromatolitic carbonate reefs are fully consistent with the existence at that time of highly productive, cyanobacterial (oxygenic photosynthetic) communities (Grotzinger 1989 Des Marais 2000). 

Wilson A.H. Versfeld J.A. 1994 - The Elary Archaean Nondweni greenstone belt, southern Kaapvaal Craton, South Africa Part 1, Stratigraphy, sedimentology, mineralization and depositional environment Precambrian Research, 67 243-276. http //minerals.usgs.gov/ minerals/ pubs/ commodity/... 

Dawson J. B. and Smith J. V. (1987) Reduced sapphirine granuhte xenohths from the Lace Kimberhte, South Africa impheations for the deep structure of the Kaapvaal Craton. Contrib. Mineral. Petrol. 95, 376—383. 

Fig. 1. Map showing station locations, topography and principal geological provinces in the region of study within southern Africa, Fifty-five broadband (REFTEK/STS-2) stations were installed in April 1997 in South Africa, Botswana and Zimbabwe. Stations in light blue were redeployed in April 1998 to sites indicated in yellow. A total of 82 sites were occupied over the two year deployment. In addition, three global seismic network broadband stations (white triangles) are located in the region and their data incorporated in the analysis. The array extends from the Cape Fold Belt in the south, through the Proterozoic Namaqua-Natal Mobile Belt, across the Kaapvaal Craton and Bushveld Province, through the Archaean Limpopo Mobile Belt and into the Zimbabwe Craton. On the west, the array covers part of the Kheis and Okwa Proterozoic Fold and Thrust Belts of Botswana and western South Africa. To the east, the array extends into the Early Archaean Barberton terrane, near the NW border with Swaziland. Published in James et al., GRL28, 2001, fig. 1.

Zhang, H., Menzies, M., Gurney, J. J. Zhou, X. 2001. Cratonic peridotites and Si-rich melts diopside-enstatite relationships in polymict xeno-liths, Kaapvaal, South Africa. Geochimica et Cos-mochimica Acta, 65, 3365-3377. 

The relatively small number of late Archaean basins may reflect a low preservation potential, but may also indicate that relatively few cratonic nuclei had stabilized before the end of the Archaean. Examples of late Archaean basins include the (3.1-2.7 Ga) Witwatersrand basin in South Africa (Robb Meyer, 1995), and its correlative the 3.0-2.67 Ga Pongola Supergroup in Swaziland (Walraven. Pape, 1994 Gold von Veh, 1995), both unconformable upon the Kaapvaal Craton. In western Australia the 2.77-2.71 Ga Fortescue Group is unconformable upon older Archaean rocks of the Pilbara Craton (Blake et al., 2004). 

Limpopo Belt Zimbabwe, Botswana, South Africa 2.7-2.9 The north and south marginal zones are the lower crustal sections of the Zimbabwe and Kaapvaal Cratons respectively, thrust onto their respective cratons... 

Richardson and colleagues working at MIT in the 1980s showed that diamond inclusions in mantle xenoliths from beneath the >3.0 Ga Kaapvaal Craton in South Africa were extremely ancient. This discovery demonstrated for the first time a link between the age of the continental crust and its underlying lithospheric mantle (Richardson et al., 1984, 1985). 

Relatively little well preserved sedimentary rock and associated C can be found in lithosphere older than 3.0 Ga. The tectonically active Archean marine basins favored rapid destruction of crust by continental collisions, partial melting and mantle/crust exchange (Windley 1984). Most of Archean continental crust had not yet become stabilized by cratonization (Rogers 1996), therefore a greater fraction of continental sediments experienced greater instability and thermal alteration. The freshest sediments occur in the 3.5 to 3.2 billion-year-old Kaapvaal Craton of South Africa and the Pilbara Block of Western Australia (Lowe 1992). These deposits are associated with episodes of greenstone activity and intrusive events that created stable microcontinents or cratons. These cratons became the nuclei of full-sized modern continents. 

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