Journal articles: 'Kaapvaal'

1

de Wit, M. J. "Kaapvaal Craton special volume- An introduction." South African Journal of Geology 107, no. 1-2 (June 1, 2004): 1–6. http://dx.doi.org/10.2113/107.1-2.1.

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2

Herzberg, Claude T. "Lithosphere peridotites of the Kaapvaal craton." Earth and Planetary Science Letters 120, no. 1-2 (November 1993): 13–29. http://dx.doi.org/10.1016/0012-821x(93)90020-a.

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3

Baptiste, V., and A. Tommasi. "Petrophysical constraints on the seismic properties of the Kaapvaal craton mantle root." Solid Earth Discussions 5, no. 2 (July 16, 2013): 963–1005. http://dx.doi.org/10.5194/sed-5-963-2013.

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Abstract. We calculated the seismic properties of 47 mantle xenoliths from 9 kimberlitic pipes in the Kaapvaal craton based on their modal composition, the crystal preferred 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. These data allow constraining the variation of seismic anisotropy and velocities with depth. The fastest P wave and fast split shear wave (S1) polarization direction is always close to olivine [100] maximum. Changes in olivine CPO symmetry result in minor variations in the seismic anisotropy patterns. Seismic anisotropy is higher for high olivine contents and stronger CPO. Maximum P waves azimuthal anisotropy (AVp) ranges between 2.5 and 10.2% and S waves polarization anisotropy (AVs) between 2.7 and 8%. Seismic properties averaged in 20 km thick intervals depth are, however, very homogeneous. Based on these data, we predict the anisotropy that would be measured by SKS, Rayleigh (SV) and Love (SH) waves for 5 end-member orientations of the foliation and lineation. Comparison to seismic anisotropy data in the Kaapvaal shows that the coherent fast directions, but low delay times imaged by SKS studies and the low azimuthal anisotropy and SH faster than SV measured using surface waves may only be consistently explained by dipping foliations and lineations. The strong compositional heterogeneity of the Kaapvaal peridotite xenoliths results in up to 3% variation in density and in up to 2.3% of variation Vp, Vs and the Vp/Vs ratio. Fe depletion by melt extraction increases Vp and Vs, but decreases the Vp/Vs ratio and density. Orthopyroxene enrichment decreases the density and Vp, but increases Vs, strongly reducing the Vp/Vs ratio. Garnet enrichment increases the density, and in a lesser manner Vp and the Vp/Vs ratio, but it has little to no effect on Vs. These compositionally-induced variations are slightly higher than the velocity perturbations imaged by body-wave tomography, but cannot explain the strong velocity anomalies reported by surface wave studies. Comparison of density and seismic velocity profiles calculated using the xenoliths' compositions and equilibrium conditions to seismological data in the Kaapvaal highlights that: (i) the thickness of the craton is underestimated in some seismic studies and reaches at least 180 km, (ii) the deep sheared peridotites represent very local modifications caused and oversampled by kimberlites, and (iii) seismological models probably underestimate the compositional heterogeneity in the Kaapvaal mantle root, which occurs at a scale much smaller than the one that may be sampled seismologically.

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4

Rasmussen, Birger, Jian-Wei Zi, and Janet R. Muhling. "U-Pb evidence for a 2.15 Ga orogenic event in the Archean Kaapvaal (South Africa) and Pilbara (Western Australia) cratons." Geology 47, no. 12 (October 2, 2019): 1131–35. http://dx.doi.org/10.1130/g46366.1.

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Abstract There is geological evidence for widespread deformation in the Kaapvaal craton, South Africa, between 2.2 and 2.0 Ga. In Griqualand West, post-Ongeluk Formation (ca. 2.42 Ga) and pre-Mapedi Formation (>1.91 Ga) folding, faulting, and uplift have been linked to the development of a regional-scale unconformity, weathering horizons, and extensive Fe-oxide mineralization. However, the lack of deformational fabrics and the low metamorphic temperatures (<300 °C) have hampered efforts to date this event. Here we show that metamorphic monazite in Neoarchean shales from four stratigraphic intervals from the Griqualand West region grew at ca. 2.15 Ga, >400 m.y. after deposition. Combined with previous studies, our results show that sedimentary successions across the Kaapvaal craton deposited before ca. 2.26 Ga record evidence for crustal fluid flow at ca. 2.15 Ga, which is locally associated with thrust faulting, folding, and cleavage development. The style of the deformation is similar to that of the Ophthalmian orogeny in the Pilbara craton, Australia, which is interpreted to reflect the northeast-directed movement of a fold-thrust belt between 2.22 and 2.15 Ga. Our results suggest that the Kaapvaal and Pilbara cratons, which some paleogeographic reconstructions place together as the continent Vaalbara, experienced an episode of synchronous folding and thrusting at ca. 2.15 Ga. Deformation was followed by uplift and the development of unconformities that are associated with some of Earth’s oldest oxidative weathering and with the onset of Fe-oxide mineralization.

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Vinnik, L. P., R. W. E. Green, L. O. Nicolaysen, G. L. Kosarev, and N. V. Petersen. "Deep seismic structure of the Kaapvaal craton." Tectonophysics 262, no. 1-4 (September 1996): 67–75. http://dx.doi.org/10.1016/0040-1951(96)00012-1.

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6

Rollinson, H. R. "A terrane interpretation of the Archaean Limpopo Belt." Geological Magazine 130, no. 6 (November 1993): 755–65. http://dx.doi.org/10.1017/s001675680002313x.

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AbstractThe Limpopo Belt is a zone of thickened Archaean crust whose origin is currently explained by a late Archaean continent-continent collision between the Kaapvaal and Zimbabwe cratons. This review shows that the two cratons have fundamentally different geological histories and that the Zimbabwe Craton was unlikely to have behaved as a stable ‘cratonic’ block at the time of the Limpopo Belt collision. The geological histories of the Zimbabwe Craton, the North Marginal, Central and South Marginal zones of the Limpopo Belt and the Kaapvaal Craton are shown to be sufficiently different from one another to warrant their consideration as discrete terranes. The boundaries between the five units outlined above are all major shear zones, further supporting a terrane model for the Limpopo Belt. The five units were all intruded by late- to syn-tectonic granites c.2.6 Ga, constraining the accretion event to c. 2.6 Ga.

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7

Baptiste, V., and A. Tommasi. "Petrophysical constraints on the seismic properties of the Kaapvaal craton mantle root." Solid Earth 5, no. 1 (January 29, 2014): 45–63. http://dx.doi.org/10.5194/se-5-45-2014.

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Abstract. We calculated the seismic properties of 47 mantle xenoliths from 9 kimberlitic pipes in the Kaapvaal craton based on their modal composition, the crystal-preferred 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. These data allow constraining the variation of seismic anisotropy and velocities within the cratonic mantle. The fastest P and S2 wave propagation directions and the polarization of fast split shear waves (S1) are always subparallel to olivine [100] axes of maximum concentration, which marks the lineation (fossil flow direction). Seismic anisotropy is higher for high olivine contents and stronger CPO. Maximum P wave azimuthal anisotropy (AVp) ranges between 2.5 and 10.2% and the maximum S wave polarization anisotropy (AVs), between 2.7 and 8%. Changes in olivine CPO symmetry result in minor variations in the seismic anisotropy patterns, mainly in the apparent isotropy directions for shear wave splitting. Seismic properties averaged over 20 km-thick depth sections are, therefore, very homogeneous. Based on these data, we predict the anisotropy that would be measured by SKS, Rayleigh (SV) and Love (SH) waves for five endmember orientations of the foliation and lineation. Comparison to seismic anisotropy data from the Kaapvaal shows that the coherent fast directions, but low delay times imaged by SKS studies, and the low azimuthal anisotropy with with the horizontally polarized S waves (SH) faster than the vertically polarized S wave (SV) measured using surface waves are best explained by homogeneously dipping (45°) foliations and lineations in the cratonic mantle lithosphere. Laterally or vertically varying foliation and lineation orientations with a dominantly NW–SE trend might also explain the low measured anisotropies, but this model should also result in backazimuthal variability of the SKS splitting data, not reported in the seismological data. The strong compositional heterogeneity of the Kaapvaal peridotite xenoliths results in up to 3% variation in density and in up to 2.3% variation of Vp, Vs, and Vp / Vs ratio. Fe depletion by melt extraction increases Vp and Vs, but decreases the Vp / Vs ratio and density. Orthopyroxene enrichment due to metasomatism decreases the density and Vp, strongly reducing the Vp / Vs ratio. Garnet enrichment, which was also attributed to metasomatism, increases the density, and in a lesser extent Vp and the Vp / Vs ratio. Comparison of density and seismic velocity profiles calculated using the xenoliths' compositions and equilibration conditions to seismological data in the Kaapvaal highlights that (i) the thickness of the craton is underestimated in some seismic studies and reaches at least 180 km, (ii) the deep sheared peridotites represent very local modifications caused and oversampled by kimberlites, and (iii) seismological models probably underestimate the compositional heterogeneity in the Kaapvaal mantle root, which occurs at a scale much smaller than the one that may be sampled seismologically.

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8

Hofmann, A., H. Xie, L. Saha, and C. Reinke. "Granitoids and greenstones of the White Mfolozi Inlier, south-east Kaapvaal Craton." South African Journal of Geology 123, no. 3 (September 1, 2020): 263–76. http://dx.doi.org/10.25131/sajg.123.0019.

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Abstract A Palaeoarchaean greenstone fragment and associated granitoid gneisses from an area south of Ulundi in KwaZulu-Natal is described. The fragment consists of an association of garnetiferous amphibolite and calc-silicate that was intruded at 3388 ± 4 Ma by tonalite and at 3275 ± 4 Ma by trondhjemite. Strong ductile deformation of the greenstones and granitoids under amphibolite facies conditions (7 kbar and 600 to 650°C) took place prior to uplift and emplacement of a granite batholith at ~3.25 Ga ago in which the granitoid gneiss-greenstone domain is now found. Magmatism 3.27 to 3.25 Ga ago was a direct response to regional metamorphism and anataxis, and gave rise to stabilization of the southeastern Kaapvaal Craton at that time, earlier than other parts of the craton. Deposition of quartz-arenites on stable granitic basement took place <3.1 Ga ago. Contrasting ages in magmatic pulses and regional metamorphism reflect a different crustal growth history of the eastern and southeastern part of the Kaapvaal Craton.

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9

Jones, M. Q. W. "Heat flow in the Bushveld Complex, South Africa: implications for upper mantle structure." South African Journal of Geology 120, no. 3 (September 1, 2017): 351–70. http://dx.doi.org/10.25131/gssajg.120.3.351.

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Abstract Geothermal measurements in South Africa since 1939 have resulted in a good coverage of heat flow observations. The Archaean Kaapvaal Craton, in the central part of South Africa, is the best-studied tectonic domain, with nearly 150 heat flow measurements. The greatest density of heat flow sites is in the Witwatersrand Basin goldfields, where geothermal data are essential for determining refrigeration requirements of deep (up to 4 km) gold mines; the average heat flow is 51 ± 6mWm-2. The Bushveld Complex north of the Witwatersrand Basin is an extensive 2.06 Ga ultramafic-felsic intrusive complex that hosts the world’s largest reserves of platinum. The deepest platinum mines reach ~2 km and the need for thermal information for mine refrigeration engineering has led to the generation of a substantial geothermal database. Nearly 1000 thermal conductivity measurements have been made on rocks constituting the Bushveld Complex, and borehole temperature measurements have been made throughout the Complex. The temperature at maximum rock-breaking depth (~2.5 km) is 70°C, approximately 30°C higher than the temperature at equivalent depth in the Witwatersrand Basin; the thermal gradient in the Bushveld Complex is approximately double that in the Witwatersrand Basin. The main reason for this is the low thermal conductivity of rocks overlying platinum mines. The Bushveld data also resulted in 31 new estimates for the heat flux through the Earth’s crust. The overall average value for the Bushveld, 47 ± 7 mW m-2, is the same, to within statistical error, as the Witwatersrand Basin average. The heat flow for platinum mining areas (45 mW m-2) and the heat flux into the floor of the Witwatersrand Basin (43 mW m-2) are typical of Archaean cratons world-wide. The temperature structure of the Kaapvaal lithosphere calculated from the Witwatersrand geothermal data is essentially the same as that derived from thermobarometric studies of Cretaceous kimberlite xenoliths. Both lines of evidence lead to an estimated heat flux of ~17 mW m-2 for the mantle below the Kaapvaal Craton. The estimated thermal thickness of the Kaapvaal lithosphere (235 km) is similar to that defined on the basis of seismic tomography and magnetotelluric studies. The lithosphere below the Bushveld Complex is not significantly hotter than that below the Witwatersrand Basin. This favours a chemical origin rather than a thermal origin for the upper mantle anomaly below the Bushveld Complex that has been identified by seismic tomography studies and magnetotelluric soundings.

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10

Heaman, Larry M., and D. Graham Pearson. "Nature and evolution of the Slave Province subcontinental lithospheric mantleThis article is one of a series of papers published in this Special Issue on the theme Lithoprobe — parameters, processes, and the evolution of a continent." Canadian Journal of Earth Sciences 47, no. 4 (April 2010): 369–88. http://dx.doi.org/10.1139/e09-046.

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A review of the ages determined for mantle material (xenoliths and xenocrysts entrained in kimberlite) derived from the Slave Province continental lithospheric mantle (CLM) indicates that a portion of the central Slave lithosphere may be ancient (3.5–3.3 Ga) harzburgite, but the majority of this lithosphere is much younger (2.9–2.0 Ga). Relying on the most robust chronometers, the majority of Slave lithosphere peridotite formed in the Neoarchean (peak at 2.75 Ga), whereas the majority of eclogite formed in the Paleoproterozoic (2.2–2.0 Ga). The northern Slave lithosphere contains evidence of peridotite xenolith ages that young with depth. The Paleoproterozoic eclogites may have multiple origins including remnants of subducted oceanic crust and mafic–ultramafic magmas that crystallized at great depth (100–200 km). Re–Os studies of sulfide inclusions in diamond indicate that some diamonds currently mined are ancient (∼3.5 Ga), but many Slave diamonds could be considerably younger. Most eclogitic diamonds recovered from the Slave craton are interpreted to be related to the formation of Paleoproterozoic eclogite. There is abundant evidence for Mesoproterozoic modification of the Slave lithosphere (e.g., heating by magma emplacement at great depth and metasomatism) and possible new addition to the lithosphere at that time. The Canadian Slave and African Kaapvaal lithospheres have similar peaks in cratonic peridotite formation ages at about 2.8 Ga, indicating that a large portion of the CLM in these two cratons formed and stabilized in the Neoarchean. One difference is that the Slave peridotites are much less enriched in SiO2, possibly reflecting the more metasomatized nature of the Kaapvaal CLM. The dominance of Paleoproterozoic formation ages for Slave mantle eclogites contrasts with the dominance of Neoarchean formation ages for Kaapvaal mantle eclogites.

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11

Eriksson, P. G., K. C. Condie, W. van der Westhuizen, R. van der Merwe, H. de Bruiyn, D. R. Nelson, W. Altermann, et al. "Late Archaean superplume events: a Kaapvaal–Pilbara perspective." Journal of Geodynamics 34, no. 2 (September 2002): 207–47. http://dx.doi.org/10.1016/s0264-3707(02)00022-4.

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12

Nelson, D. R., A. F. Trendall, and W. Altermann. "Chronological correlations between the Pilbara and Kaapvaal cratons." Precambrian Research 97, no. 3-4 (September 1999): 165–89. http://dx.doi.org/10.1016/s0301-9268(99)00031-5.

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13

Freybourger, Marion, James B. Gaherty, and Thomas H. Jordan. "Structure of the Kaapvaal Craton from surface waves." Geophysical Research Letters 28, no. 13 (July 1, 2001): 2489–92. http://dx.doi.org/10.1029/2000gl012436.

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14

Sunder Raju, P. V., P. G. Eriksson, O. Catuneanu, S. Sarkar, and S. Banerjee. "A review of the inferred geodynamic evolution of the Dharwar craton over the ca. 3.5–2.5 Ga period, and possible implications for global tectonics." Canadian Journal of Earth Sciences 51, no. 3 (March 2014): 312–25. http://dx.doi.org/10.1139/cjes-2013-0145.

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The geological history and evolution of the Dharwar craton from ca. 3.5–2.5 Ga is reviewed and briefly compared with a second craton, Kaapvaal, to allow some speculation on the nature of global tectonic regimes in this period. The Dharwar craton is divided into western (WDC) and eastern (EDC) parts (separated possibly by the Closepet Granite Batholith), based on lithological differences and inferred metamorphic and magmatic genetic events. A tentative evolution of the WDC encompasses an early, ca. 3.5 Ga protocrust possibly forming the basement to the ca. 3.35–3.2 Ga Sargur Group greenstone belts. The latter are interpreted as having formed through accretion of plume-related ocean plateaux. The approximately coeval Peninsular Gneiss Complex (PGC) was possibly sourced from beneath plateau remnants, and resulted in high-grade metamorphism of Sargur Group belts at ca. 3.13–2.96 Ga. At about 2.9–2.6 Ga, the Dharwar Supergroup formed, comprising lower Bababudan (largely braided fluvial and subaerial volcanic deposits) and upper Chitradurga (marine mixed clastic and chemical sedimentary rocks and subaqueous volcanics) groups. This supergroup is preserved in younger greenstone belts with two distinct magmatic events, at 2.7–2.6 and 2.58–2.54 Ga, the latter approximately coincident with ca. 2.6–2.5 Ga granitic magmatism which essentially completed cratonization in the WDC. The EDC comprises 2.7–2.55 Ga tonalite–trondhjemite–granodiorite (TTG) gneisses and migmatites, approximately coeval greenstone belts (dominated by volcanic lithologies), with minor inferred remnants of ca. 3.38–3.0 Ga crust, and voluminous 2.56–2.5 Ga granitoid intrusions (including the Closepet Batholith). An east-to-west accretion of EDC island arcs (or of an assembled arc – granitic terrane) onto the WDC is debated, with a postulate that the Closepet Granite accreted earlier onto the WDC as part of a “central Dharwar” terrane. A final voluminous granitic cratonization event is envisaged to have affected the entire, assembled Dharwar craton at ca. 2.5 Ga. When Dharwar evolution is compared with that of Kaapvaal, while possibly global magmatic events and freeboard–eustatic changes at ca. 2.7–2.5 Ga may be identified on both, the much earlier cratonization (by ca. 3.1 Ga) of Kaapvaal contrasts strongly with the ca. 2.5 Ga stabilization of Dharwar. From comparing only two cratons, it appears that genetic and chronologic relationships between mantle thermal and plate tectonic processes were complex on the Archaean Earth. The sizes of the Kaapvaal and Dharwar cratons might have been too limited yet to support effective thermal blanketing and thus accommodate Wilson Cycle onset. However, tectonically driven accretion and amalgamation appear to have predominated on both evolving cratons.

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15

Winter, H. De la R. "Episode - en chronometriese tydperk-tabelle: implikasies vir provinsies soos die Kaapvaal." Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 16, no. 3 (July 11, 1997): 108–21. http://dx.doi.org/10.4102/satnt.v16i3.673.

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An accurate basin analysis and knowledge of its evolutionary development being a prerequisite framework for metallogenic modelling, a procedure was developed for the Kaapvaal Province to maximise quantitative observational data and constrain assumptions and interpretations. Employing an episodes chart to display various events interactively and its conversion to a geochronometric chart as the geological model, the method was applied to existing stratigraphic studies.

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16

Gibson, Sally A. "On the nature and origin of garnet in highly-refractory Archean lithospheric mantle: constraints from garnet exsolved in Kaapvaal craton orthopyroxenes." Mineralogical Magazine 81, no. 4 (August 2017): 781–809. http://dx.doi.org/10.1180/minmag.2016.080.158.

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AbstractThe widespread occurrence of pyrope garnet in Archean lithospheric mantle remains one of the 'holy grails' of mantle petrology. Most garnets found in peridotitic mantle equilibrated with incompatible-trace-element enriched melts or fluids and are the products of metasomatism. Less common are macroscopic intergrowths of pyrope garnet formed by exsolution from orthopyroxene. 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 inthe sub-continental lithospheric mantle formed initially by isochemical rather than metasomatic processes. The orthopyroxene hosts are enstatites and fully equilibrated with their exsolved phases (low-Cr pyrope garnet ± Cr-diopside). Significantly, P-T estimates of the postexsolution orthopyroxenes plot along an unperturbed conductive Kaapvaal craton geotherm and reveal that they were entrained from a large continuous depth interval (85 to 175 km). They therefore represent snapshots of processes operating throughout almost the entire thickness of the sub-cratonic lithosphericmantle.New rare-earth element (REE) analyses show that the exsolved garnets occupy the full spectrum recorded by garnets in mantle peridotites and also diamond inclusions. A key finding is that a few low-temperature exsolved garnets, derived from depths of ∼90 km, are more depleted in light rare-earth elements (LREEs) than previously observed in any other mantle sample. Importantly, the REE patterns of these strongly LREE-depleted garnets resemble the hypothetical composition proposed for pre-metasomatic garnets that are thought to pre-date major enrichment events in the sub-continental lithospheric mantle, including those associated with diamond formation. The recalculated compositions of pre-exsolution orthopyroxenes have higher Al2O3 and CaO contents than their post-exsolution counterparts and most probably formed as shallow residues of large amounts of adiabatic decompression melting in the spinel-stability field. It is inferred that exsolution of garnet from Kaapvaal orthopyroxenes may have been widespread, and perhaps accompanied cratonization at ∼2.9 to 2.75 Ga. Such a process would considerably increase the density and stability of the continental lithosphere.

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17

Fouch, M. J. "Mantle seismic structure beneath the Kaapvaal and Zimbabwe Cratons." South African Journal of Geology 107, no. 1-2 (June 1, 2004): 33–44. http://dx.doi.org/10.2113/107.1-2.33.

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18

Moser, D. E. "Birth of the Kaapvaal Tectosphere 3.08 Billion Years Ago." Science 291, no. 5503 (January 19, 2001): 465–68. http://dx.doi.org/10.1126/science.291.5503.465.

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Jones, A. "The Slave–Kaapvaal workshop: a tale of two cratons." Lithos 71, no. 2-4 (December 2003): ix—xi. http://dx.doi.org/10.1016/s0024-4937(03)00108-7.

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20

Creighton, Steven, Thomas Stachel, Sergei Matveev, Heidi Höfer, Catherine McCammon, and Robert W. Luth. "Oxidation of the Kaapvaal lithospheric mantle driven by metasomatism." Contributions to Mineralogy and Petrology 157, no. 4 (October 19, 2008): 491–504. http://dx.doi.org/10.1007/s00410-008-0348-3.

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21

Kampmann, Tobias C., Ashley P. Gumsley, Michiel O. de Kock, and Ulf Söderlund. "U–Pb geochronology and paleomagnetism of the Westerberg Sill Suite, Kaapvaal Craton – Support for a coherent Kaapvaal–Pilbara Block (Vaalbara) into the Paleoproterozoic?" Precambrian Research 269 (October 2015): 58–72. http://dx.doi.org/10.1016/j.precamres.2015.08.011.

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22

Simon, Nina S. C., Richard W. Carlson, D. Graham Pearson, and Gareth R. Davies. "The Origin and Evolution of the Kaapvaal Cratonic Lithospheric Mantle." Journal of Petrology 48, no. 3 (January 9, 2007): 589–625. http://dx.doi.org/10.1093/petrology/egl074.

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23

Chevrot, S., and L. Zhao. "Multiscale finite-frequency Rayleigh wave tomography of the Kaapvaal craton." Geophysical Journal International 169, no. 1 (April 2007): 201–15. http://dx.doi.org/10.1111/j.1365-246x.2006.03289.x.

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24

Byerly, G. R. "An Archean Impact Layer from the Pilbara and Kaapvaal Cratons." Science 297, no. 5585 (August 23, 2002): 1325–27. http://dx.doi.org/10.1126/science.1073934.

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25

Lubnina, Natalia, Richard Ernst, Martin Klausen, and Ulf Söderlund. "Paleomagnetic study of NeoArchean–Paleoproterozoic dykes in the Kaapvaal Craton." Precambrian Research 183, no. 3 (December 2010): 523–52. http://dx.doi.org/10.1016/j.precamres.2010.05.005.

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26

Simon, N. "The origin of garnet and clinopyroxene in “depleted” Kaapvaal peridotites." Lithos 71, no. 2-4 (December 2003): 289–322. http://dx.doi.org/10.1016/s0024-4937(03)00118-x.

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27

Nelson, David R., Alec F. Trendall, and Wladyslaw Altermann. "Erratum to “Chronological correlations between the Pilbara and Kaapvaal cratons”." Precambrian Research 112, no. 3-4 (December 2001): 331–32. http://dx.doi.org/10.1016/s0301-9268(01)00224-8.

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28

Hunter, D. R. "Crustal processes during Archaean evolution of the southeastern Kaapvaal province." Journal of African Earth Sciences (and the Middle East) 13, no. 1 (January 1991): 13–25. http://dx.doi.org/10.1016/0899-5362(91)90041-v.

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29

Dietvorst, E. J. L. "Instability and basin formation on the Kaapvaal Craton, southern Africa." Journal of African Earth Sciences (and the Middle East) 13, no. 3-4 (January 1991): 359–65. http://dx.doi.org/10.1016/0899-5362(91)90099-k.

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30

Letts, Shawn, Trond H. Torsvik, Susan J. Webb, and Lewis D. Ashwal. "New Palaeoproterozoic palaeomagnetic data from the Kaapvaal Craton, South Africa." Geological Society, London, Special Publications 357, no. 1 (2011): 9–26. http://dx.doi.org/10.1144/sp357.2.

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31

Arndt, N. T., A. J. Naldrett, and D. R. Hunter. "Ore deposits associated with mafic magmas in the Kaapvaal craton." Mineralium Deposita 32, no. 4 (July 9, 1997): 323–34. http://dx.doi.org/10.1007/s001260050099.

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32

Brey, Gerhard P., and Qiao Shu. "The birth, growth and ageing of the Kaapvaal subcratonic mantle." Mineralogy and Petrology 112, S1 (June 1, 2018): 23–41. http://dx.doi.org/10.1007/s00710-018-0577-8.

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33

Peslier, A. H., A. B. Woodland, D. R. Bell, M. Lazarov, and T. J. Lapen. "Metasomatic control of water contents in the Kaapvaal cratonic mantle." Geochimica et Cosmochimica Acta 97 (November 2012): 213–46. http://dx.doi.org/10.1016/j.gca.2012.08.028.

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34

Evans, Michael E., and Adrian R. Muxworthy. "Vaalbara Palaeomagnetism." Canadian Journal of Earth Sciences 56, no. 9 (September 2019): 912–16. http://dx.doi.org/10.1139/cjes-2018-0081.

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Vaalbara is the name given to a proposed configuration of continental blocks—the Kaapvaal craton (southern Africa) and the Pilbara craton (north-western Australia)—thought to be the Earth’s oldest supercraton assemblage. Its temporal history is poorly defined, but it has been suggested that it was stable for at least 400 million years, between 3.1 and 2.7 Ga. Here, we present an updated analysis that shows that the existence of a single supercraton between ∼2.9 and ∼2.7 Ga is inconsistent with the available palaeomagnetic data.

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Bostock, M. G., and J. F. Cassidy. "Upper mantle stratigraphy beneath the southern Slave craton." Canadian Journal of Earth Sciences 34, no. 5 (May 1, 1997): 577–86. http://dx.doi.org/10.1139/e17-046.

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A large teleseismic data set comprising 724 broadband, three-component P-wave seismograms has been compiled for the southern Slave craton with the objective of characterizing underlying mantle stratigraphy. Coherent P to S wave conversions are identified by simultaneously deconvolving seismograms as functions of epicentral distance and along theoretical moveout curves corresponding to possible mantle phases. Clear PDs conversions are observed from the 410 and 660 km discontinuities at times that are only slightly faster than those predicted from the IASP91 model, and over 1.0 s slower than corresponding times observed at other stations on the Canadian Shield and the south African Kaapvaal craton. The PDs times show very little azimuthal variation, implying an absence of major lateral velocity variations in the lithospheric mantle underlying the Slave craton, and adjacent Wopmay orogen and Taltson magmatic zone. Considered in light of other geophysical and geological evidence, these results suggest that the root underlying the Slave province has been modified along its margins and may remain intact only toward a central core. Another important result involves the observation of a PDs conversion from a negative velocity contrast interface at approximately 360 km depth. It and a similar phase, observed on the Kaapvaal craton, would appear not to be directly related to tectospheric structure, but may originate at the top of a layer containing a dense silicate partial melt just above the mantle transition zone.

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Gumsley, Ashley P., Kevin R. Chamberlain, Wouter Bleeker, Ulf Söderlund, Michiel O. de Kock, Emilie R. Larsson, and Andrey Bekker. "Timing and tempo of the Great Oxidation Event." Proceedings of the National Academy of Sciences 114, no. 8 (February 6, 2017): 1811–16. http://dx.doi.org/10.1073/pnas.1608824114.

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The first significant buildup in atmospheric oxygen, the Great Oxidation Event (GOE), began in the early Paleoproterozoic in association with global glaciations and continued until the end of the Lomagundi carbon isotope excursion ca. 2,060 Ma. The exact timing of and relationships among these events are debated because of poor age constraints and contradictory stratigraphic correlations. Here, we show that the first Paleoproterozoic global glaciation and the onset of the GOE occurred between ca. 2,460 and 2,426 Ma, ∼100 My earlier than previously estimated, based on an age of 2,426 ± 3 Ma for Ongeluk Formation magmatism from the Kaapvaal Craton of southern Africa. This age helps define a key paleomagnetic pole that positions the Kaapvaal Craton at equatorial latitudes of 11° ± 6° at this time. Furthermore, the rise of atmospheric oxygen was not monotonic, but was instead characterized by oscillations, which together with climatic instabilities may have continued over the next ∼200 My until ≤2,250–2,240 Ma. Ongeluk Formation volcanism at ca. 2,426 Ma was part of a large igneous province (LIP) and represents a waning stage in the emplacement of several temporally discrete LIPs across a large low-latitude continental landmass. These LIPs played critical, albeit complex, roles in the rise of oxygen and in both initiating and terminating global glaciations. This series of events invites comparison with the Neoproterozoic oxygen increase and Sturtian Snowball Earth glaciation, which accompanied emplacement of LIPs across supercontinent Rodinia, also positioned at low latitude.

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Office, Editorial. "Nuwe insigte oor Kaapvaalse geologic en mineraalbronne spruit uit ’n rigoristiese komontledingsmetode." Suid-Afrikaanse Tydskrif vir Natuurwetenskap en Tegnologie 15, no. 3 (July 11, 1996): 131–33. http://dx.doi.org/10.4102/satnt.v15i3.645.

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Attempts to derive the geohistory of the Kaapvaal Province without a scientifically disciplined methodology incorporating all the relevant events in their correct interactive temporal relationships have led to costly errors. Episodic charts record all other events against a chronostratigraphic column converted from a lithostratigraphic equivalent employing sequence stratigraphic techniques. Geochronometric charts transform the relative sequence so derived into an approximation of real time, by means of isotopic age dating of marker beds. The predictive power of these charts enables both research and mineral exploration to be goal-orientated.

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Pearton, T., and M. Viljoen. "Gold on the Kaapvaal Craton, outside the Witwatersrand Basin, South Africa." South African Journal of Geology 120, no. 1 (March 1, 2017): 101–32. http://dx.doi.org/10.25131/gssajg.120.1.101.

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Shirey, S. B. "Diamond Genesis, Seismic Structure, and Evolution of the Kaapvaal-Zimbabwe Craton." Science 297, no. 5587 (September 6, 2002): 1683–86. http://dx.doi.org/10.1126/science.1072384.

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Klausen, M. B., U. Söderlund, J. R. Olsson, R. E. Ernst, M. Armoogam, S. W. Mkhize, and G. Petzer. "Petrological discrimination among Precambrian dyke swarms: Eastern Kaapvaal craton (South Africa)." Precambrian Research 183, no. 3 (December 2010): 501–22. http://dx.doi.org/10.1016/j.precamres.2010.01.013.

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Kobussen, Alan F., William L. Griffin, and Suzanne Y. O'Reilly. "Cretaceous thermo-chemical modification of the Kaapvaal cratonic lithosphere, South Africa." Lithos 112 (November 2009): 886–95. http://dx.doi.org/10.1016/j.lithos.2009.06.031.

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Vinnik, L. P., R. W. E. Green, and L. O. Nicolaysen. "Seismic constraints on dynamics of the mantle of the Kaapvaal craton." Physics of the Earth and Planetary Interiors 95, no. 3-4 (June 1996): 139–51. http://dx.doi.org/10.1016/0031-9201(95)03123-5.

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Cheney, Eric S., C. Roering, and H. de la R. Winter. "The Archean-Proterozoic boundary in the Kaapvaal Province of Southern Africa." Precambrian Research 46, no. 4 (March 1990): 329–40. http://dx.doi.org/10.1016/0301-9268(90)90019-m.

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Clendenin, C. W., E. G. Charlesworth, and S. Maske. "An early Proterozoic three-stage rift system, Kaapvaal Craton, South Africa." Tectonophysics 145, no. 1-2 (January 1988): 73–86. http://dx.doi.org/10.1016/0040-1951(88)90317-4.

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Lippmann-Pipke, Johanna, Barbara Sherwood Lollar, Samuel Niedermann, Nicole A. Stroncik, Rudolf Naumann, Esta van Heerden, and Tullis C. Onstott. "Neon identifies two billion year old fluid component in Kaapvaal Craton." Chemical Geology 283, no. 3-4 (April 2011): 287–96. http://dx.doi.org/10.1016/j.chemgeo.2011.01.028.

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Katz, Amitai, Abraham Starinsky, and Giles M. Marion. "Saline waters in basement rocks of the Kaapvaal Craton, South Africa." Chemical Geology 289, no. 1-2 (October 2011): 163–70. http://dx.doi.org/10.1016/j.chemgeo.2011.08.002.

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Oberholzer, Jacobus D., and Patrick G. Eriksson. "Subaerial volcanism in the Palaeoproterozoic Hekpoort Formation (Transvaal Supergroup), Kaapvaal craton." Precambrian Research 101, no. 2-4 (June 2000): 193–210. http://dx.doi.org/10.1016/s0301-9268(99)00088-1.

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Gress, Michael U., Daniel Howell, Ingrid L. Chinn, Laura Speich, Simon C. Kohn, Quint van den Heuvel, Ellen Schulten, Anna S. M. Pals, and Gareth R. Davies. "Episodic diamond growth beneath the Kaapvaal Craton at Jwaneng Mine, Botswana." Mineralogy and Petrology 112, S1 (May 24, 2018): 219–29. http://dx.doi.org/10.1007/s00710-018-0582-y.

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Lubnina, N. V., and A. I. Slabunov. "Karelian сrаtоn in the struсturе of the Nео-Аrсhаеаn supercontinent Kеnоrlаnd: nеw paleomagnetic and isotopic-geochronological data on granulites of the Onega complex." Moscow University Bulletin. Series 4. Geology, no. 5 (October 28, 2017): 3–15. http://dx.doi.org/10.33623/0579-9406-2017-5-3-15.

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New paleomagnetic and isotopic-geochronological data obtained for Neoarchean Onega granulite complex, were used to reconstruct the position of the Karelian craton in the Neoarchean supercontinent Kenorland. Geological correlations were made for the Karelian, Kaapvaal, Pilbara, Superior, and Slave cratons. Comparison of independent geological and paleomagnetic data allowed us to propose a new configuration of the Neoarchean supercontinent Kenorland. The position of the ancient core of the Karelian craton (the Vodlozero terrane), located in the North-Western margin of the supercontinent structure, reconstructed based on the previously paleomagnetic data for the Neoarchean Panozero sanukitoid massif and new one for granulite of Onega complex.

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de Wit, M. "Crustal structures across the central Kaapvaal craton from deep-seismic reflection data." South African Journal of Geology 107, no. 1-2 (June 1, 2004): 185–206. http://dx.doi.org/10.2113/107.1-2.185.

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Journal articles on the topic 'Kaapvaal'

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