Eclogites and garnet pyroxenites from kimberley, kaapvaal. Late neoarchaeanpalaeoproterozoic supracrustal basinfills. The kaapvaal craton along with the pilbara craton of western australia, are the only. Port nolloth zone and the oceanic western marmora terrane, which together document. The reso lution tests indicate that both laterally and vertically the cratonic. Pdf formation of the archean kaapvaal province revisited. Jelsma encyclopedia of life support systems eolss the worldwide 1. Compositional trends among kaapvaal craton garnet peridotite xenoliths and their effects on seismic velocity and density derek l. Crustal structure and tectonic evolution of the kaapvaal craton. Mukasa et al 2000 or the socalled munyati subduction zone. Received 16 october 2011 received in revised form 28 february 2012. Structure of the kaapvaal craton from surface waves. They have placed pilbara to the northwest of kaapvaal in the kaapvaal reference frame. Precambrian research 169 2009 1527 isotopic data, previous work suggested that the archean carbon cycle operated in a manner different from younger times in earth history, with little or no burial of organic carbon.
Sulfuroxidizing bacteria prior to the great oxidation. Paleomagnetism of neoproterozoic intraplate igneous rocks in. On the nature and origin of garnet in highlyrefractory. Sporadic epigenetic antimonygold mineralisation along the enetrending antimony line of the murchison schist belt is structurally controlled and spatially related to carbonated rock types with quartzcarbonate veins in. Geochemistry volume 4, number 2 geophysics geosystems. Authors personal copy olivine rheology, shear stress, and grain growth in the lithospheric mantle. Late neoarchaeanpalaeoproterozoic supracrustal basinfills of the kaapvaal craton. Structural history of the southwestern corner of the kaapvaal craton. Pdf late neoarchaeanpalaeoproterozoic supracrustal. In this study, the lithospheric strength of the kaapvaal craton is determined using deformation laws describing the failure of. Further to the west of the kaapvaal craton, we found a crustal thickness of 42 km and a. The kaapvaal craton in south africa hosts one of the beststudied kimberlite populations on earth. Using mineral chemistry to constrain the pt conditions of. Evolution of the namaquanatal belt, southern africa a.
Relevance of the supercontinent cycle, the great oxidation event and snowball earth. Implications for the birth and growth of its diamondiferous root h. In this study, the lithospheric strength of the kaapvaal craton is determined using deformation laws describing the failure of rocks at lithospheric depths. Mesoarchean assembly and stabilization of the eastern. Here we expand our previous work with an additional suite of 19 samples from 15 kimberlite pipes in an eastwest transect across the kaapvaal craton to constrain the erosion histories and patterns across the southern african plateau interior.
A case study of the kaapvaal craton and limpopo belt, southern africa. Recent detailed mapping of the isua supracrustal belt, west greenland has been interpreted as evidence for modernlike plate tectonics, including subduction. It has been argued that africa has been relatively stationary with respect to the underlying mantle and the earths spin axis since 30 ma burke and wilson, 1972. 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. We provide new constraints for the amalgamation and stabilization of the eastern kaapvaal craton in the vicinity of the barberton greenstone belt circa 3. Deformation and hydration of the lithospheric mantle beneath the. Map of kaapvaal craton in southern africapng wikimedia. These images suggest that seismic velocities are about 0. Visualizing the volcanic history of the kaapvaal craton.
The kaapvaal craton is one of the best preserved of all archean cratons. Cartoon figure showing the cso geochemical model used in this study. The geological evolution of africa encyclopedia of life. 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. Spectacular examples of these are preserved in both mantle xenoliths and large, isolated crystals megacrysts from the kaapvaal craton of southern africa, and provide direct evidence that some garnet in the subcontinental lithospheric mantle initially formed by isochemical rather than metasomatic processes. Kaapvaal craton, when the thermal boundary layer was thinner and hotter than today, these kaapvaal peridotites would have been positively buoyant with respect to the convecting mantle at shallower pressures. Eriksson b adepartment of geology, rhodes university, grahamstown 6140, south africa bdepartment of geology, university of pretoria, pretoria 0002, south africa. In this thesis, a total of 24 thin sections of peridotite xenoliths from group i letlhakane, letseng, premier and frank smith kimberlites were investigated to constrain the pressure, temperature and depth of these mantle xenoliths. Unconformity above ventersdorp rocks, basal conglomerates, transition to quartzites, beach and aeolian deposits, transition to carbonates. Pdf formation of the archean kaapvaal craton revisited. A primary remanence direction from the lower part of the swaershoek formation provides. This allows the spatial extension of the different volcanic stratigraphic units to be interpreted. Comparison with published paleomagnetic poles from rock units of similar age from the congo craton to the north supports a model in which the two cratons were originally separated by a wide ocean basin prior to the formation of the gondwana supercontinent.
A pdf file listing the public data used in this compilation and the references from which they were drawn may be downloaded from the ftp site ftp. The kaapvaal craton and adjacent orogens, southern. Paleomagnetism of selected neoarcheanpaleoproterozoic. Lesherb,1 a department of geosciences, colorado state university, 322 natural resources building, campus delivery 1482, fort collins, co, usa 805251482. Eighteen jurassic to cretaceous south african kimberlites representative of group 1, group 11 and transitional varieties that have been emplaced through both the archean kaapvall craton on craton and proterozoic namaquanatal belt off craton, have been selected for a comparative study aimed at characterising their geochemistry and source region compositions, as well as understanding the. The significance of ferruginous argillite, jaspilite and bif which overlie 3. The kalahari craton during the assembly and dispersal of.
Geochemistry of selected south african group i, group ii and. Authors personal copy accompanied by multiple olistostromes overlain by siltstone andferruginous sedimentsfig. The tectonometamorphic event at 2 ga in the limpopo belt. Kaapvaal cratons, which amalgamated along the limpopo province e. Crustal structure of the kaapvaal craton and its significance.
Isotope dilution thermal ionization mass spectrometry u. Formation of the kaapvaal mantle root as early as 3. Paleomagnetism of neoproterozoic intraplate igneous rocks. Mesoproterozoic crust and became a larger entity, the kalahari craton. Description at regional level of the anatomy and of the continental kaapvaal structure intra crustal redistribution of generating heat. Asimilar breakoccursin the western pilbara craton at 3. Witwatersrand supergroup which mining companies have exploited at certain stratigraphic positions. All structured data from the file and property namespaces is available under the creative commons cc0 license. Representative transmitted light photomicrographs showing pyrite opaque particles distribution patterns in the samples analyzed in this study. Files are available under licenses specified on their description page. The kaapvaal craton south africa is an assemblage of archean terranes that extends. The kaap vaal craton itself is comprised of an eastern domain with.
Evolution of the atmosphere, hydrosphere, and biosphere. It is partially covered by the supracrustal sequences of the witwatersrand, ventersdorp and transvaal basin and correlated griqualand west basin, which span almost a billion years 3. Deposition of basal conglomerates on undulating basement with topographic relief formation of placers in fluvial to fluvio deltaic environment sediment re working to enrich placers but in wits also constant new supply overall upward coarsening sequence. Anhaeusser, john dixon, alfred kroner, lopamudra saha, allan wilson et al. The sequence stratigraphic concept and the precambrian rock record. The bushveld complex, the outcrop limbs of which are shown in fig. Paleomagnetism of the lower two unconformitybounded. Our study broadly confirms the established apwp, but reveals some previously unidentified complexities in the time interval 2. Samples were collected from three different terranes in southern. The archaean geology of the kaapvaal craton, southern africa. Structures related to the antimony line, murchison schist. Prof wlady altermann and ms vusani v mathada bsc hons archean proterozoic sedimentary transition, volcanism, structural geology, early life, stromatolites, and glacial deposits between 2750 and 2220 ma. Crustal structure and tectonic evolution of the kaapvaal. The kaapvaal craton hosts a number of large gold deposits e.
We describe the petrography and mineral chemistry of sixteen eclogite and garnet pyroxenite xenoliths from the reworked boshof road dump kimberley and define three groups that stem from different depths. The chert was sampled from five sites at two localities in the northern cape province. Late neoarchaeanpalaeoproterozoic supracrustal basin. Furthermore, the kaapvaal cratonlimpopo beltzimbabwe craton boundaries are ill defined in botswana and the relationship between the. However, in someregions, the ages of thesclmand crustare decoupled. Erosion patterns and mantle sources of topographic change. This page was last edited on 25 september 2019, at 00. Based on c and n stable isotope ratios, n concentration and n aggregation state data obtained by fouriertransform infrared.
Overnight at river view lodge in prieska bb 20 aug 16 satur day windpomp and nouga farms drive to nouga farm, c. Geochemistry of selected south african group i, group ii. Eighteen jurassic to cretaceous south african kimberlites representative of group 1, group 11 and transitional varieties that have been emplaced through both the archean kaapvall craton oncraton and proterozoic namaquanatal belt offcraton, have been selected for a comparative study aimed at characterising their geochemistry and source region compositions, as well as. When and how has the wyoming craton been modifiedreactivated chemically and physically. It also hosts the largest platinum group element pge deposits e. Episodic diamond growth beneath the kaapvaal craton at. The archean kaapvaal and zimbabwe cratons form the continental nucleus of southern africa. If our model for the eastern kaapvaal craton is correct, it also implies decoupling between the crust and mantle in the eastern kaapvaal craton during circa 3. Pdf document this is the final published version of the article version of record.
Exploration and sampling techniques for conglomerate gold. The nitrogen record of crustmantle interaction and mantle. 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. The origin and stabilisation of the kaapvaal craton lithosphere ird. Bozhko, 1997 what is the significance of the similarity in the petrogenic and geochemical pathways between the great dyke and other archaean to early proterozoic complexes. Pb geochronology and thermochronology are combined with mapping and structural analysis around the margins of this belt in.
No evidence for a supercontinental affinity prior to 2. Original paper episodic diamond growth beneath the kaapvaal craton at jwaneng mine, botswana michael u. Therefore we propose that peridotite at the base of the kaapvaal plate, in the mantle thermal. What links here related changes upload file special pages permanent link page.
Insitu trace element and sr isotopic compositions of. However, additional work from the congo craton is needed to test this hypothesis. Simplified geological map of the transvaal supergroup in the transvaal and griqualand west basins, kaapvaal craton, south africa. Sulfuroxidizing bacteria prior to the great oxidation event. While the palaeoproterozoic geological record of kaapvaal does broadly support the goe, this postulate itself is being questioned on the basis of isotopic data used as oxygenproxies, and sedimentological data from extant river systems on the craton argue for a prolongation of the greenhouse palaeoatmosphere possibly in parallel with a. The sequence stratigraphic concept and the precambrian. In addition, the geology of the two cratons, including magmatic events, passive margin sedimentation, and orogenies, match well with. The kaapvaal craton in south africa is, along with the pilbara craton of western australia, the only areas where midarchean 3. Stratigraphic and structural interpretation of seismic. Severalyounger clea vages destroy older structures in. Wyoming doesis there any effect on subsequent history. While seismology remains the primary tool of geophysicists to study the.
The great dyke of great treasures and great mysteries. With this placement the apw paths of the two cratons match reasonably well during 2. Geochemistry of palaeoarchaean to palaeoproterozoic. Eglington department of geological sciences, saskatchewan isotope laboratory, university of saskatchewan, 114 science place. Toshiaki tsunogae abstract major and minor elements chemistry of archean pelitic rocks was analyzed by xray fluorescence spectrometer. The sequence stratigraphic concept and the precambrian rock. Formation and evolution of archaean cratons geological society. To test these hypotheses, we employed a combination of theory, new geologic. The paleopoles established here, together with existing paleopoles from the kaapvaal craton, are used to evaluate the apparent polar wander path of the craton during the neoarcheanpaleoproterozoic and are compared with poles of similar age from the pilbara craton as a test of the vaalbara hypothesis.
Insitu trace element and sr isotopic compositions of mantle. The tectonometamorphic event at 2 ga in the limpopo belt and. Bushveld igneous complex which mining companies have exploited in different mineralised layered magmatic zones. The origin and stabilisation of the kaapvaal craton lithosphere. Although outlines of the apparent polar wander path apwp for the paleoproterozoic kaapvaal craton have been proposed for decades e.
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