The Kalahari craton occupies a large portion of South Africa and consists of the Kaapvaal, the Zimbabwe craton, the Limpopo belt, and the Namaqua Belt. It has formed a stable unit for the past 2.3 billion years (2.3 Ga). As such, it contains some of the oldest known rocks and microfossils in the world. The oldest rocks are in the Transvaal province that consists of granites, gneisses, and migmatites that are ~3.4 Ga. Within this granitic basement are a number of greenstone belts where the rocks have been less highly metamorphosed and contain many primary features. These rocks comprise the Swaziland system. They form a thick pile of volcanics and cherts, which pass up into turbidites and sandstones. The ancient basement became stabilised around 3.0 Ga, and was then covered by a thick sequence of shallow-water sediments, lavas, and igneous intrusions. The Kaapvaal craton (Limpopo province of South Africa), along with the Pilbara craton of Western Australia, are the only remaining areas of pristine 3. ... The Zimbabwe craton is an example of Early Archaean lithology dating back to 3. ... The Limpopo Belt is located in South Africa, runs E-NE, and separates the Rhodesian and Transvaal massifs. ... Flag of Transvaal The Transvaal was one of the provinces of South Africa from 1910 until 1994. ... Close-up of granite from Yosemite National Park, valley of the Merced River Quarrying granite for the Mormon Temple, Utah Territory. ... Gneiss Gneiss (IPA: ) is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from preexisting formations that were originally either igneous or sedimentary rocks. ... Ptygmatic folding in migmatite Migmatite on the coast of Saaremaa. ... In geology, the terms basement and crystalline basement are used to define the rocks below a sedimentary basin, or more generally any rock below sedimentary rocks or sedimentary basins that are metamorphic or igneous in origin. ... This article is about zones of mixed sedimentary and volcanic rock sequences that often contain minable concentrations of gold, silver, copper, zinc and lead. ... The term Metamorphic can be associated with a number of meanings:- Metamorphic rock The term for rocks that have been transformed by extreme heat and pressure. ... This article is about volcanoes in geology. ... Chert Chert (IPA: ) is a fine-grained silica-rich cryptocrystalline sedimentary rock that may contain small fossils. ... USGS image Turbidite geological formations have their origins in turbidity current deposits, deposits from a form of underwater avalanche that are responsible for distributing vast amounts of clastic sediment into the deep ocean. ... Red sandstone interior of Lower Antelope Canyon, Arizona, worn smooth due to erosion by flash flooding over millions of years Sandstone is a sedimentary rock composed mainly of sand-size mineral or rock grains. ... This article or section cites very few or no references or sources. ... Look up lava, Aa, pahoehoe in Wiktionary, the free dictionary. ... Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ... Devils Tower, an igneous intrusion exposed when the surrounding softer rock eroded away. ...

Additional crust was formed and reworked along all of the craton’s margins at 1.4–1.0 Ga. To the north, the Damara-Lufilian-Zambezi Fold Belt separates the Congo craton to the north with the Kalahari. Central Zambia exhibits the largest number of Precambrian eclogite occurrences in Africa. These eclogites and the associated gabbros are interpreted as relics of a fossil subducted slab that marks a suture zone between the Congo craton to the north and the Kalahari. The Zambezi Belt and the Lufilian Arc are part of the Pan-African orogenic system that crosscuts southern Africa, separating the Congo and Kalahar cratons and their respective Paleo- and Mesoproterozoic units. These Pan-African belts were formed during the assembly of the Gondwana supercontinent. Eclogite facies metamorphism occurred at ca. 600 Ma, whereas peak metamorphism during the subsequent continental collision occurred around 530 Ma ago, with metamorphic P–T conditions reaching the high pressure amphibolite facies. The Zambezi Belt crosscuts and thus divides the Meso-proterozoic parts of Zambia into the Irumide Belt and the Choma-Kalomo Block. The junction of the Neoproterozoic belts and the Mesoproterozoic parts is marked by a 200 km long and up to 40 km wide zone containing lenses of eclogite, metagabbro, gabbro and rare ultramafic rocks. The eclogite-bearing zone is located in the interior of the Zambezi Belt, and runs parallel to strike. The eclogites and associated mafic rocks form isolated hills of 10 to 100 metres in diameter (Timm and Schenk, 2003). Look up Crust in Wiktionary, the free dictionary. ... The Congo craton, covered by the Palaeozoic-to-recent Congo basin, is an ancient Precambrian craton that with four others (the Kaapvaal, Zimbabwe, Tazania, and West African cratons) makes up the modern continent of Africa. ... The Precambrian (Pre-Cambrian) is an informal name for the eons of the geologic timescale that came before the current Phanerozoic eon. ... Eclogite is a coarse-grained, mafic-to-ultramafic grouping of metamorphic rocks of special interest on account of the variety of minerals they contain and their microscopic structures and geological relationships. ... Gabbro specimen. ... Orogeny (Greek for mountain generating) is the process of mountain building, and may be studied as a tectonic structural event, as a geographical event and a chronological event, in that orogenic events cause distinctive structural phenomena and related tectonic activity, affect certain regions of rocks and crust and happen within... Gondwanaland redirects here. ... In geology, a supercontinent is a land mass comprising more than one continental core, or craton. ... The term facies was introduced by the Swiss geologist Amanz Gressly in 1838 and was part of his significant contribution to the foundations of modern stratigraphy (see Cross and Homewood 1997), which replaced the earlier notions of Neptunism. ... Metamorphism can be defined as the solid state recrystallisation of pre-existing rocks due to changes in heat and/or pressure and/or introduction of fluids i. ... Amphibolite Amphibolite (IPA: , ) is the name given to a rock consisting mainly of hornblende amphibole, the use of the term being restricted, however, to metamorphic rocks. ... Ultramafic (or ultrabasic) rocks are igneous rocks with very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium and are composed of usually greater than 90% mafic minerals (dark colored, high magnesium and iron content). ...

Pan-African belts along the northern and eastern craton margins are associated in one area with a 1.4 Ga ophiolite/arc terrane. The orthogneisses form part of an extensive region north of the Kalahari craton and east of the Congo craton that includes large amounts of 1.15–1.0 Ga arc-type rocks containing juvenile crustal components. This region may represent one of the main convergent zones active during Rodinia assembly, although its original relations are obscured by intense Pan-African overprinting. Along the southern margin, the Namaqua–Natal–Maud belt underwent arc magmatism, terrane accretion, polyphase amphibolite- to granulite-grade contractional/transpressional deformation, and late-syntectonic granite intrusion at 1.38–1.0 Ga. A largely buried orogen along the western margin records amphibolite-grade deformation and granitoid plutonism at 1.35–1.2 Ga and is inferred to connect with the Namaqua belt to the south. 1.1–1.0 Ga granitoid orthogneisses within Widespread intraplate magmatism affected much of the Kalahari craton at 1.1 Ga and is inferred to record impact of a mantle plume inboard of the Namaqua–Natal–Maud belt. Depiction of Rodinia at time of initial breakup. ... Magma is molten rock located beneath the surface of the Earth (or any other terrestrial planet), and which often collects in a magma chamber. ... A terrane in paleogeography is an accretion that has collided with a continental nucleus, or craton but can be recognized by the foreign origin of its rock strata. ... Accretion, means any growth or increase in size by a gradual external addition or inclusion. ... Polyphase can refer to: a polyphase system in electrical engineering a polyphase filter in signal processing Category: ... Modern petrology defnes a granulite sensuo stricto as a coarse grained, high-grade metamorphic rock composed primarily of pyroxene, plagioclase feldspar and accessory garnet, oxide and amphibole. ... Look up Contraction in Wiktionary, the free dictionary. ... Figure 1. ... In engineering mechanics, deformation is a change in shape due to an applied force. ... In geology, orogeny is the process of mountain building. ... Pluton redirects here. ...

The Limpopo Belt separates the Rhodesian province to the north from the Transvaal province to the south. The Limppoo Belt also joins the Zimbabwe craton to the north with the Kaapvaal craton to the south. The belt is composed of a granitic basement with narrow greenstone belts. Within the greenstone belts, the sequence consists of basic volcanics, covered by greywackes, shales, and conglomerates. The Limpopo Belt is located in South Africa, runs E-NE, and separates the Rhodesian and Transvaal massifs. ... The Zimbabwe craton is an example of Early Archaean lithology dating back to 3. ... The Kaapvaal craton (Kaapvaal province of South Africa), along with the Pilbara craton of Western Australia, are the only remaining areas of pristine 3. ... Greywacke (German grauwacke, signifying a grey, earthy rock) is a variety of sandstone generally characterized by its hardness, dark color, and poorly-sorted, angular grains of quartz, feldspar, and small rock fragments set in a compact, clay-fine matrix. ... Shale Shale is a fine-grained sedimentary rock whose original constituents were clays or muds. ... A conglomerate with iron oxide cementing material Conglomerate, Submarine Landslide located at Point Reyes, Marin County California. ...

Kalahari craton with Laurentia, Rodinia and Gondwana

Early paleomagnetic studies showed that the Umkondo sills in eastern Zimbabwe correlated with similar mafic intrusions in Botswana and South Africa. It was therefore suggested that the Umkondo igneous province is present over a large part of the Kalahari craton, and also a detached fragment now located in East Antarctica. New paleomagnetic data are in excellent agreement with this. The great majority of the sites have the same polarity suggesting that the dolerites were emplaced during a limited time span, consistent with the geochronology. The pole position places the Kalahari craton off southeast Laurentia within the Rodinia supercontinent. In Laurentia, there is widespread within-plate magmatism coeval with the Umkondo event, raising the possibility that the two igneous provinces were linked within Rodinia (Blenkinsop et al, 2003).

The Kalahari craton probably converged with southwestern Laurentia between 1060 and 1030 Ma to become part of the Rodinia supercontinent by 1000 Ma. In Rodinia, the Kalahari craton lay near East Antarctica with the Namaqua–Natal orogenic belt facing outboard and away from the Laurentian craton (Jones et al). The Kalahari and Congo cratons probably collided during the assembly of Rodinia, however they could have also been just juxtaposed during the assembly of Gondwana (550-500 Ma) at the end of the Neoproterozoic. In the former case, the transcontinental, ~550 Ma Damaran-Lufilian-Zambezi orogen separating the two cratons would represent a Himalayan-style collisional belt formed by the consumption of a wide ocean. In the later case it may have been a closure of narrow Neoproterozoic basins that developed across previously assembled parts of Rodinia (Hanson, 2004). A third view is that there was a convergence between the Kalahari craton and a composite Congo-Laurentia craton during the assembly of Rodinia, generating the Kibaran-Grenvillian-Llano belts. This orogenic belt system extends for over 3000 km and is over 400 km wide in Africa and is the result of the convergence of Paleoproterozoic/Archaean cratonic blocks forming the Congo craton to the north and a mosaic including the Kalahari, Bangweulu, Tanzania and West-Nilian cratons (hereafter called the Kalahari craton) to the south (Deschamps, 2003). This article or section does not adequately cite its references or sources. ... In geology, a supercontinent is a land mass comprising more than one continental core, or craton. ... The Neoproterozoic Era is the unit of geologic time from 1,000 to 542 +/- 0. ... The Paleoproterozoic is the first of the three sub-divisions of the Proterozoic occurring between 2500 to 1600 million years ago. ... The Archean is a geologic eon; it is a somewhat antiquated term for the time span between 2500 million years before the present and 3800 million years before the present. ... The Congo craton, covered by the Palaeozoic-to-recent Congo basin, is an ancient Precambrian craton that with four others (the Kaapvaal, Zimbabwe, Tazania, and West African cratons) makes up the modern continent of Africa. ...

The arc on the flank of Madagascar collided with the African margin at ~640 Ma, and remained attached to the African margin when Madagascar rifted during Gondwana breakup. This ~640 event has been considered to date the collision of India, Madagascar, parts of eastern Antarctica and Kalahari cratons (IMSLEK terranes) with the Congo-Tanzania Craton and Arabian Nubian Shield (Cutten, 2006).

Economic Geology

The Witwatersrand system is the world's most productive source of gold. Gold ores occur in fracture systems in the greenstone belts. The Transvaal system contains important iron ores, and the Bushveld igneous complex contains platinum, chromium, titanium-iron, and tin ores.

Diamond mining: Based on current annual output the Southern African Kalahari craton (approximately 48 million carats (9,600 kg)) leads the combined Central African cratons (37 million carats (7400 kg)) and the West African craton (2.1 million carats (420 kg)). The difference is even more pronounced in value terms where the Kalahari craton (approximately US$5.1 billion) is clearly ahead of the Central African (US$2.2 billion) and West African cratons (US$0.34 billion). The dominance of the Southern African Craton is largely due to the excellent infrastructure, favourable climate and stable political and socio-economic regime, which have ensured continuous exploration and mining activities for the past century (MSA Geoservices, 2006). The Kasai craton extends over the border into Angola where 77 diamond kimberlites have been discovered. Eleven others have been found in the less explored DRC section of the craton (Gravity, 2006).

Manganese of high-grade is mined in the large Kalahari manganese field from hydro-thermal enrichments in stratabound deposits that formed approximately 2.1 Ga (Armbruster et al., 2003; Beukes et al, 2001).

See also

• Kaapval craton
• Zimbabwe craton
• Copperbelt Province
• Limpopo Belt
• South Africa

The Kaapvaal craton (Limpopo province of South Africa), along with the Pilbara craton of Western Australia, are the only remaining areas of pristine 3. ... The Zimbabwe craton is an example of Early Archaean lithology dating back to 3. ... The Copperbelt is a province of Zambia which is very rich in mineral deposits. ... The Limpopo Belt is located in South Africa, runs E-NE, and separates the Rhodesian and Transvaal massifs. ...

References

• Armbruster, Thomas, Edwin Gnos and Igor M. Villa. (2003) “Norrishite, K(Mn₂³⁺Li)Si₄O₁₀(O)₂,an oxymica associated with sugilite from the Wessels Mine, South Africa: Crystal chemistry and ⁴⁰Ar-³⁹Ar dating.” American Mineralogist, Volume 88, pages 189-194[1]
• Beukes, N.J., D.A.D. Evans, J. Gutzmer, and J.L. Kirschvink. (2001) “Paleomagnetic Constraints on Ages of Mineralization in the Kalahari Manganese Field, South Africa.” Economic Geology, Vol. 96, 2001, pp. 621-631[2]
• Blenkinsop, T., S. Bowring, J. Crowley, I. Dalziell, W. Gose, R. Hanson, J. Mukwakwami, J. Pancake, and J. Ramezani. (2003) “New Paleomagnetic and geochronical Data from the Meso-Proterozoic Data Umkondo Dolerites, South Africa.” Geophysical Research Abstracts, Vol. 5, 07201[3]
• Cutten, Huntley M.C. (2006) “Ph.D. Mozambique Belt[4]
• Deschamps, Y., A.B. Kampunzu, and J.P. Milesi. (2003) “Africa within Rodinia Supercontinent: Evidence from the Kibaran Orogenic System.” Geological Society of America, 2003 Seattle Annual Meeting, Paper No. 110-3[5]
• Gravity Diamond Limited. (2006) "Discovery and Development from Ground-Breaking Exploration Technology"[6]
• Hanson, R.E. (2004) “Mesoproterozoic Tectonic Evolution of the Kalahari Craton: Implications for Rodinia Reconstructions.” Geological Society of America , 2003 Seattle Annual Meeting, Paper No. 110-4[7]
• Jone, D.L., S. Pisarevsky, C. McA. Powell, and M.T.D. Wingate. “Paleomagnetic Constraints on the Position of the Kalahari Craton in Rodinia.”[8]
• MSA Geoservices (2006) “Africa’s Diamond Exploration”[9]
• Timm, John and Volkar Schenk. (2003) “Partial eclogitisation of gabbroic rocks in a late Precambrian subduction zone (Zambia): prograde metamorphism triggered by fluid infiltration.” Contrib Mineral Petrol (2003) 146: 174–191[10]