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21-873: The Mwembeshi Shear Zone lies between the Congo craton to the NW and the Kalahari craton to the SE, to the west (in today's orientation) of the Mozambique Belt , which is on the north and east side of the Kalahari Craton. It was formed during the Pan-African orogeny when "North" and "South" Gondwana were amalgamated along the Kuunga orogeny zone between 580 Ma and 480 Ma. The date of around 550 Ma for

42-719: A large part of central southern Africa, extending from the Kasai region of the DRC into Sudan and Angola . It forms parts of the countries of Gabon , Cameroon , and the Central African Republic . A small portion extends into Zambia as well, where it is called the Bangweulu Block . The Congo Craton and the São Francisco Craton are stable Archaean blocks that formed a coherent landmass until

63-520: A short emplacement interval and resulted in a 3,000–4,000 m (9,800–13,100 ft) thick sequence. Mafic-felsic magma sequences (6,000 m (20,000 ft) thick) on the western edge of the Congo Craton are similar to those of the Paraná and Deccan LIPs, but in the Congo Craton the magma source became shallower with time. There was no geodynamic activity along the western Congo margin during

84-699: Is a stub . You can help Misplaced Pages by expanding it . Congo craton The Congo Craton , covered by the Palaeozoic -to-recent Congo Basin , is an ancient Precambrian craton that with four others (the Kaapvaal , Zimbabwe , Tanzania , and West African cratons) makes up the modern continent of Africa . These cratons were formed between about 3.6 and 2.0 billion years ago and have been tectonically stable since that time. All of these cratons are bounded by younger fold belts formed between 2.0 billion and 300 million years ago. The Congo Craton occupies

105-737: Is an ancient craton in the heart of Siberia . Today forming the Central Siberian Plateau , it formed an independent landmass prior to its fusion into Pangea during the Late Carboniferous - Permian . The Verkhoyansk Sea , a passive continental margin, was fringing the Siberian Craton to the east in what is now the East Siberian Lowland . Angaraland was named in the 1880s by Austrian geologist Eduard Suess who erroneously believed that in

126-946: The Cretaceous with Siberia remaining part of present-day northeastern Eurasia . Today, Siberia forms part of the landmass of Afro-Eurasia . To the east it is joined to the North American Plate at the Chersky Range . In around 250 million years from now Siberia may be in the subtropical region and part of the new supercontinent of Pangaea Proxima . [REDACTED] Africa [REDACTED] Antarctica [REDACTED] Asia [REDACTED] Australia [REDACTED] Europe [REDACTED] North America [REDACTED] South America [REDACTED] Afro-Eurasia [REDACTED] Americas [REDACTED] Eurasia [REDACTED] Oceania This palaeogeography article

147-786: The Keweenawan Rift in Laurentia (although the latter was located far from the other continental blocks). A series of 1500 Ma dyke swarms also support the close relation between Congo–São Francisco and Siberia: Kuonamka in Siberia and Curaçá and Chapada Diamantina in São Francisco and Angola. These dyke swarms radiate from a mantle plume centre located in what is now north-eastern Siberia. Magmatic events in Congo (Kunene) and Siberia (Chieress) at 1384 Ma also corroborate

168-771: The Paleozoic Era there were two large continents in the Northern Hemisphere: "Atlantis", which was North America connected to Europe via a peninsula (Greenland and Iceland), and "Angara-land", which would have been eastern Asia, named after the Angara River in Siberia. About 2.5 billion years ago (in the Siderian Period), Siberia was part of a continent called Arctica , along with the Canadian Shield . Around 1.1 billion years ago (in

189-634: The Stenian Period), Siberia became part of the supercontinent of Rodinia , a state of affairs which lasted until the Tonian about 750 million years ago when it broke up, and Siberia became part of the landmass of Protolaurasia . During the Ediacaran Period around 600 million years ago, Protolaurasia became part of the southern supercontinent of Pannotia but around 550 million years ago, both Pannotia and Protolaurasia split up to become

210-502: The Congo-Sao Francisco Craton approached the remainder of southwestern Gondwana from the north, although at the time southwestern Gondwana was oriented about 90 degrees clockwise of today's orientation, and the Congo Craton approached from the east. There was little vertical displacement, but Mwembeshi is a major sinistral transcurrent shear zone. The shear zone accommodates a change in the structural vergence between

231-570: The Mesoproterozoic. [REDACTED] Africa [REDACTED] Antarctica [REDACTED] Asia [REDACTED] Australia [REDACTED] Europe [REDACTED] North America [REDACTED] South America [REDACTED] Afro-Eurasia [REDACTED] Americas [REDACTED] Eurasia [REDACTED] Oceania Siberia (continent) Siberia , also known as Siberian Craton , Angaraland (or simply Angara ) and Angarida ,

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252-668: The Mwembeshi shear zone is based on U-Pb zircon ages of syntectonic granites from the Hook massif and of associated hypabyssal rhyolite. During the amalgamation there was sinistral transpression along the boundary between the Kalahari craton and the Congo and Tanzanian cratons (which had already amalgamated), which is now expressed as the Mwembeshi Shear Zone. The sinistral sense shows that, in modern coordinates,

273-619: The São Francisco–Congo continent. The West Congo Pan-African Belt includes major magmatic events at c. 1000 and 910 Ma. In the Early Neoproterozoic, the western edge of Congo Craton was the location for the initial rifting of Rodinia before its break-up. During the Neoproterozoic, Central Congo or Bas-Congo became a passive margin on which was deposited 4,000 m (13,000 ft) sediments. At

294-640: The Zambezi Belt and the Lufilian Arc. Further to the southwest, the shear zone extends along part at least of the Damaran belt . There are known to be basic connections between geological terranes and mineralization models, so understanding the Mwembeshi Shear Zone is important to understanding where mineral resources may be found in the region. Despite this, as of 1990 there had been relatively little exploration. This palaeogeography article

315-631: The closeness of these two continents during at least 120 million years. It is possible that the 1110 Ma LIP in Congo–São Francisco, Amazonia, and India was part of a much larger event that also involved West Africa and Kalahari (with a possible but unlikely link to the 1075 Ma Warakurna LIP in Australia). However, while the palaeo-latitudes of India and Kalahari are well constrained, those of Amazonia and Congo–São Francisco are not, making any plate tectonic reconstruction speculative. At

336-571: The continents of Laurentia , Baltica and Siberia. Siberia was an independent continent through the early Paleozoic until, during the Carboniferous Period, it collided with the minor continent of Kazakhstania . A subsequent collision with Euramerica/Laurussia during the Late Carboniferous - Permian formed Pangea . Pangaea split up during the Jurassic though Siberia stayed with Laurasia . Laurasia gradually split up during

357-487: The end of the Neoproterozoic, Bas-Congo was only affected by the Pan-African orogeny at 566 Ma to a limited extent protected by this passive margin and by the thickness of the craton. At 1000 Ma peralkaline magmatism initiated an early transtensional setting along the western edge of the Congo Craton. An LIP at c. 930–920 Ma was followed by felsic magmatism between c. 920–910 Ma which had

378-614: The opening of the South Atlantic Ocean during the break-up of Gondwana ( c. 2000–130 Ma). They stabilised during the Transamazonian orogeny and Eburnean Orogeny and have been affected by a long series of orogens since resulting in similar sequences on both blocks. Congo–São Francisco experienced three large igneous province (LIP) events at 1380–1370 Ma, c. 1505 Ma, and c. 1110 Ma. The relative position of Congo–São Francisco within

399-698: The opening of the South Atlantic the São Francisco and Congo cratons were connected by a "cratonic" bridge, the Bahia–Gabon Bridge. The most recent orogenic event on this bridge occurred at 2 Ga, so the connection between São Francisco and Congo must have formed during the Palaeoproterozoic. South of this cratonic bridge the Araçuaí–West Congo orogen evolved in the Neoproterozoic in a sea basin made of oceanic crust, an embayment in

420-919: The supercontinent Nuna/Columbia can be reconstructed because these LIP events also affected other Precambrian continental blocks. Within Nuna the northern part of Siberia was located adjacent to western São Francisco. 1110 Ma dyke swarms in Angola are absent in Siberia but coincide with the Umkondo LIP on the Kalahari Craton and magmatic event in the Bundelkhand Craton in India, the Amazonian Craton in South America, and

441-568: The time for the formation of the supercontinent Gondwana at c. 550  Ma the Congo Craton formed the already amalgamated central African landmass. The southern and eastern margins (modern coordinates) of this landmass was made of the Archaean Angola-Kasai block and Tanzanian Craton. These proto-Congo blocks were deformed in the Palaeoproterozoic Eburnean orogeny but later stabilised. Before

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