The change occurs within 30 km, suggesting that the anomaly largely reflects an increase in radioactive. Eclogite xenoliths, together with garnet pyroxenites and some mafic garnet granulites, found in kimberlites located along the southern margin of the kaapvaal craton in southern. Nov 01, 2011 sedimentary provenance of the neoarchean ventersdorp supergroup, southern africa. It forms parts of the countries of gabon, cameroon, and the central. Two episodes of fluid migration in the kaapvaal craton lithospheric mantle associated with cretaceous kimberlite activity. Kaapvaal craton ancient foundation the foundations of kwazulunatal comprise two distinct geological units, the kaapvaal craton and the natal metamorphic province. Kaapvaal project the data for this study were collected as part of the southern africa seismic experiment.
Program to study crust and mantle of the archean craton in. The meaning of ages other than the kimberlite eruption age is unclear. Mantle seismic structure beneath the kaapvaal and zimbabwe. Mantleeclogitesandgarnetpyroxenitesthemeaningoftwo.
Eclogite and garnet pyroxenite xenoliths from kimberlites. In 2006, the fortescue, hamersley, and the pilbara region of western australia is one of only two areas on earth the other being the kaapvaal craton. All structured data from the file and property namespaces is available under the. Paleoproterozoic rocks in west africa host a considerable number of orogenic gold deposits and these have. Archean accretion and crustal evolution of the kalahari. Vearncombe, a possible archaean island arc in the murchison belt, kaapvaal craton, south africa, journal of african earth sciences and the middle east, 1991, 34, 299crossref. Vaalbara palaeomagnetism canadian journal of earth sciences. If you would like to participate, you can choose to edit this article, or visit the project page.
The foundations of kwazulunatal comprise two distinct geological units, the kaapvaal craton and the natal metamorphic province. Overnight at river view lodge in prieska bb 20 aug 16 satur day windpomp and nouga farms drive to nouga farm, c. Successful models of subarray structure displayed significant radial anisotropy in the uppermost mantle but no shear. Overall, there is a slight decrease of endt values with decreasing age, but no clear distinction is apparent at the ap boundary at 2. The joint inversion of rayleigh wave group velocities and body wave receiver functions is used to constrain the shear wave velocity structure across the kaapvaal craton and surrounding mobile belts. Highlights for the volcanosedimentary succession of the. A census of atmospheric variability from seconds to decades. Pdf archaean crystalline rocks of the eastern kaapvaal craton. Structure of the kaapvaal craton from surface waves.
Pdf two episodes of fluid migration in the kaapvaal. Thhe data were obtained for four minerals baddeleyite. Evolution of the kaapvaal craton as viewed from geochemical. Nature of the archean midcrust in the core of the vredefort. Kaapvaal continental lithosphere must have experienced shear deformation associated with continental drift, the above geological observation can be turned into an important constraint on the rheology of lithospheric mantle. The congo craton occupies a large part of central southern africa, extending from the kasai region of the drc into sudan and angola. The kaapvaal craton is marked by dramatic events such as the intrusion of the bushveld complex 2. Papers should have broad and immediate implications meriting rapid decisions and high visibility.
The bushveld complex, the outcrop limbs of which are shown in fig. This file is licensed under the creative commons attributionshare alike 3. To the south and west, the kaapvaal craton is flanked by proterozoic orogens, and to the east by the lebombo monocline that contains jurassic igneous rocks associated with the breakup of. Almost all of kaapvaal pelites have tom ages greater than their depositional ages but younger than 3. This page was last edited on 25 september 2019, at 00. Evidence from a harzburgite containing a unique assemblage of metasomatic. The kaapvaal craton centred on limpopo province in south africa, along with the pilbara craton of western australia, are the only remaining areas of pristine 3. Formation of the craton assuming some form of plate tectonics to have been operative, formation of the nucleus of the kaapvaal craton figure 1 by approximately 3. Formation of the archean kaapvaal province revisited. The 500kmlong great dyke is likely the eroded remnant of a large igneous province.
Crustal structure and tectonic evolution of the kaapvaal craton. Recent fluid processes in the kaapvaal craton, south africa. Download this book provides a comprehensive overview of the evolution of one of the oldest and bestexposed archaean cratons on this planet. Sulfur isotopes in diamonds reveal differences in continent. The archean orogenic gold deposits of the kilo moto area of the congo craton democratic republic of the congo were described by woodtli 1961a, b and those of the tanzania craton of east africa were mentioned briefly by mackay 1944. The archaean geology of the kaapvaal craton, southern. The seismic experiment was a major component of the kaapvaal project, a multidisciplinary program to study cratonic formation. P and s tomography models for the kaapvaal craton james et al. Received 16 october 2011 received in revised form 28 february 2012. Nov, 2018 the timing of these changes are not synchronous but vary from craton to craton. Note the relatively small fluctuations in both p and s, and the lack of correlation of the anomalies with the transition zone discontinuities. About cookies, including instructions on how to turn off cookies if you wish to do so. The kaapvaal craton in south africa is, along with the pilbara craton of western australia, the only areas where midarchean 3.
Snyder and the editor inchief lutz nasdala is highly appreciated. The highgrade limpopo terrane was amalgamated with the kaapvaal craton between 2. Imaging teleseismic p to s scattered waves using the. We calculated the seismic properties of 47 mantle xenoliths from 9 kimberlitic pipes in the kaapvaal craton based on their modal composition, the crystalpreferred orientations cpo of olivine, ortho and clinopyroxene, and garnet, the fe content of olivine, and the pressures and temperatures at which the rocks were equilibrated. Kaapvaal craton is part of wikiproject geology, an attempt at creating a standardized, informative, comprehensive and easytouse geology resource.
Pdf crustal evolution of southern africa download ebook. Sep 09, 2019 vaalbara is the name given to a proposed configuration of continental blocksthe kaapvaal craton southern africa and the pilbara craton northwestern australiathought to be the earths oldest. Visualizing the volcanic history of the kaapvaal craton. The geological evolution of africa encyclopedia of life. Vaalbara is the name given to a proposed configuration of continental blocksthe kaapvaal craton southern africa and the pilbara craton northwestern australiathought to be the. The kaapvaal craton in south africa hosts one of the beststudied kimberlite populations on earth. There is currently a renewed interest in the early earth, and the kaapvaal craton. Available literature data from the slave and kaapvaal craton for the smnd and luhf isotope systems and our own new data from bellsbank kaapvaal provide a whole range of twopoint isochron ages from younger than the kimberlite eruption age to early proterozoic. Structural geology and tectonic setting of the sutherland greenstone. Early to middle archaean evolution of the kaapvaal craton encompassed amalgamation of a.
It consists of two cratons separated by the limpopo belt. The kalahari craton is a craton, an old and stable part of the continental lithosphere, that occupies large portions of south africa, botswana, namibia and zimbabwe. Geophysical research letters publishes highimpact, innovative, and timely communicationslength articles on major advances spanning all of the major geoscience disciplines. Pdf neoarchean large igneous provinces on the kaapvaal. Similarities of rock records from both these cratons, especially of the overlying late archean sequences, suggest that they were once part of the vaalbara supercontinent. The archaean geology of the kaapvaal craton, southern africa. Geological constraints from the kaapvaal craton xu chun, jun korenaga department of geology and geophysics, yale university, new haven, ct 06520, usa article info article history. All structured data from the file and property namespaces is available under the creative commons cc0 license.
By continuing to browse this site you agree to us using cookies as described in about cookies remove maintenance. Crustal structure of the kaapvaal craton and its significance. The kaapvaal craton is broadly divisible into an older and generally poorly exposed granitegreenstone basement, formed between 3. Archaean crystalline rocks of the eastern kaapvaal craton. Crustal structures across the central kaapvaal craton from. Feb 01, 2004 read nature of the archean midcrust in the core of the vredefort dome, central kaapvaal craton, south africa 1 1 associate editor.
Kaapvaal craton geological region, africa britannica. He has published more than 400 scientific papers and was editor or was on the editorial board of several international earth science journals. Younger diamonds from the kaapvaal, zimbabwe, and west african cratons do contain mif sulfur, which suggests craton construction by advective thickening of mantle lithosphere through conventional subductionstyle horizontal tectonics. The kaapvaal craton south africa was the host of several major magmatic events during the palaeoproterozoic, including the volcanic hekpoort and ongeluk formations. The bushveld,the worlds largestlayered igneous intrusion, has been referred to as the intrusive equivalent of a flood basalt, given its extensive volume and short duration 8,12. Crustal structure and dynamics of botswana agu publications. Mar 17, 2020 eclogite xenoliths, together with garnet pyroxenites and some mafic garnet granulites, found in kimberlites located along the southern margin of the kaapvaal craton in southern africa have been analysed by electron microprobe and mass spectrometry techniques to determine their geochemical characteristics. Mantleeclogitesandgarnetpyroxenitesthemeaningoftwopoint. Petrophysical constraints on the seismic properties of the. Available literature data from the slave and kaapvaal craton for the smnd and luhf isotope systems and our own new data from bellsbank kaapvaal provide a whole range of twopoint isochron ages. The kaapvaal province of the archean kalahari craton differs from other african archean terrains by its early cratonization, representing a nearly 1 mill.
Sloss editor, sedimentary covernorth american craton. The profiles cover a total length of 500km and are projected into a common section that strikes northwest to southeast across the central part of the kaapvaal craton. Jelsma encyclopedia of life support systems eolss the worldwide 1. Files are available under licenses specified on their description page. Crustal structure and tectonic evolution of the kaapvaal. The composition of dissolved organic matter dom in extremely deep groundwaters has rarely been investigated. The origin and evolution of the kaapvaal cratonic lithospheric mantle. Measurements at nine localities in a 90kmlong northsouth traverse show an increase of heat flow from typically cratonic values of about 45 mw m. Jay barton co editor, south african journal of geology. Focusing on deep fracture waters in billion year old rocks in south africa, we hypothesized the dom would be predominantly derived from in situ microbial sources, consistent with h 2driven lithoautotrophic ecosystems previously documented in these fluids. Unconformity above ventersdorp rocks, basal conglomerates, transition to quartzites, beach and aeolian deposits, transition to carbonates.
Formation of the craton assuming some form of plate tectonics to have been operative, formation of the nucleus of the kaapvaal craton figure 1 by. Isotopic composition of mg and fe in garnet peridotites from the kaapvaal and siberian cratons article pdf available in geochimica et cosmochimica acta 200 december 2016 with 315 reads. Eight deepseismic reflection profiles 16 seconds twt. Late neoarchaeanpalaeoproterozoic supracrustal basinfills of the kaapvaal craton. This research was supported by funding from the canada excellence research chairs program and by the deutsche forschungsgemeinschaft br1012331.
Wilson on an earlier version of the manuscript helped. The kaapvaal craton covers an area of approximately 1,200,000 km 2 460,000 sq mi and is joined to the zimbabwe craton to the north by the limpopo belt. The ages that have been determined across the kaapvaal craton. Eclogites and garnet pyroxenites from kimberley, kaapvaal. That is, the lithospheric mantle beneath the kaapvaal craton has to be strong enough to preserve. Further to the west of the kaapvaal craton, we found a crustal thickness of 42 km. Using mineral chemistry to constrain pt conditions for. Structure and metamorphism of the archean murchison belt. The 2000 legislative council elections in the hong kong special administrative region guest editor. He has published more than 400 scientific papers and was editor. Outside of the witwatersrand basin significant quantities of gold have been recovered from archaean greenstone belts of the 3500 to 2700 ma kaapvaal craton as well as from various occurrences in the. Pdf recent fluid processes in the kaapvaal craton, south. Summary of sedimentary sequences in the kaapvaal craton the general stratigraphic sequence of the kaapvaal craton is shown in fig. He is a field geologist with interest in tectonics and geochronology and has mainly worked on aspects of crustal evolution in africa, specifically the kaapvaal craton of southern africa.
No evidence for a supercontinental affinity prior to 2. Feb 10, 2020 craton plural cratons a part of the earths crust that has survived the splitting and merging of continents. An investigation of the carbonatites of the kaapvaal. The atmosphere varies naturally on all length scales from millimeters to thousands of kilometers, and on all time scales from seconds to decades and longer. The kaapvaal craton and adjacent orogens, southern. Thebasinis320 kmalonganortheasterlyaxisby160 kmalong a northwesterly strike. Shedding light on the evolution of the kaapvaal craton during the neoarchean e. Neon identifies two billion year old fluid component in. Frost, geochimica et cosmochimica acta on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. A pdf file listing the public data used in this compilation. The archean kaapvaal craton of south africa kc and pilbara craton of australia pc are the only two sizable areas in the world 1. In this thesis, a total of 24 thin sections of peridotite xenoliths from group i letlhakane, letseng, premier and. Authors personal copy olivine rheology, shear stress, and grain growth in the lithospheric mantle. Mar 03, 2014 the geological history and evolution of the dharwar craton from ca.