Topic
Gondwana
About: Gondwana is a research topic. Over the lifetime, 6078 publications have been published within this topic receiving 263050 citations. The topic is also known as: Gondwanaland.
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TL;DR: Using the satellite derived gravity map to approximate the ocean-continent boundary has been used to generate a much tighter fit for the reconstructed supercontinent then previously attempted as mentioned in this paper, which produces overlap between cratonic East Antarctica and the Limpopo Plain of Mozambique.
Abstract: Gondwana, with East Antarctica as its center, began to break up during Late Triassic to Early Jurassic time. Use of the satellite derived gravity map to approximate the ocean-continent boundary allows us to generate a much tighter fit for the reconstructed supercontinent then previously attempted. Major mantle plumes such as the Karoo-Ferrar Plume that first split Gondwana at about 182 Ma, the Parana-Etendeka plume at 132 Ma that split South America and Africa, the Marion plume at 88 Ma that split Madagascar and India and finally the Reunion hotspot that split the Mascarene Plateau from India at 64 Ma, were all critical events in the break-up of Gondwana. Our tight-fit produces overlap between cratonic East Antarctica and the Limpopo Plain of Mozambique but there is no evidence that the crustal material underlying the Limpopo Plain pre-dates the break-up of Gondwana. Likewise Madagascar has been recon structed so that it substantially overlies coastal East Africa in the vicinity of the Anza Trough, an early Jurassic rift in Kenya. The western margin of the island of Madagascar may in fact be crustal material that is younger than the break-up. It may have been produced as a result of the Karoo mantle plume or some may have been the result of the Marion hotspot. Between South America and Africa there are three significant overlaps. Two of them are deltaic, and the third is the Abrolhos and Royal Charlotte banks which post-date Gondwanide breakup by 80 to 100 million years. key words: Gondwana break-up, Mesozoic Paleoreconstructions, ocean-continent boundaries, Karoo-Ferrar Mantle Plume, overlap
154 citations
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TL;DR: The collisional orogeny in Permo-Triassic times in the Northern Andes related to the construction of the Pangea supercontinent is recorded by metamorphic U-Pb SHRIMP ages in inherited zircons around 280 ǫ and magmatic U-pb SHrIMP and Ar-Ar Triassic ages around 228 Ám in granitic stocks indicate the presence of late tectonic magmatism as mentioned in this paper.
154 citations
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TL;DR: In this paper, the authors quantified the timing and extent of exhumation across the southern Cape escarpment and coastal plane, using apatite fission track analysis (AFTA) of 25 outcrop samples and 31 samples from three deep boreholes (KW1/67, SA1/66, CR1/68).
154 citations
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TL;DR: In this paper, a reconstruction map from Early Ordovician to Mid-Devonian times is presented, highlighting the North Atlantic Caledonian evolution and the destruction of the Iapetus Ocean and the Tornquist Sea.
Abstract: Palaeozoic palaeogeography, highlighting the North Atlantic Caledonian evolution and the destruction of the Iapetus Ocean and the Tornquist Sea, is recapitulated with reconstruction maps from Early Ordovician to Mid-Devonian times. In the Early Ordovician (Trem-adoc-Arenig), Laurentia, Siberia, and the North China Block were positioned in equatorial latitudes, Baltica was located at intermediate southerly latitudes, whilst Avalonia and the European Massifs were located together with the North African part of Gondwana in high southerly latitudes. During the Ordovician, Baltica drifted northwards and approached Siberia while undergoing counter-clockwise rotations. Aval-onia rifted away from Gondwana during Arenig-Llanvirn time, and the Tornquist Sea, separating Avalonia and Baltica, narrowed gradually during the Ordovician followed by Late Ordovician ‘soft docking’ of Eastern Avalonia and Baltica prior to their joint collision with Lau-rentia. The main collisional event between Baltica and Laurenti...
153 citations
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TL;DR: Paleomagnetic analysis on 15 early Cambrian mafic dikes from Itabaiana (Paraiba State) yielded a southern (northwestern) direction with steep upward (downward) inclination.
153 citations