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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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Journal ArticleDOI
TL;DR: In this article, the Nama Basin and the Camaqua Basin are shown to have formed on both sides of the Pan-African- Brasiliano orogen when the Congo and Kalahari Cratons collided with the Rio de la Plata Craton during the formation of western Gondwana.
Abstract: Late- to post-orogenic basins formed on both sides of the Pan-African – Brasiliano orogen when the Congo and Kalahari Cratons collided with the Rio de la Plata Craton during the formation of western Gondwana. Trace fossil evidence and radiometric age dating indicate that deposits on both sides are coeval and span the Cambrian–Precambrian boundary. A peripheral foreland basin, the Nama Basin, developed on the subducting southern African plate. Lower, craton-derived fluviomarine clastics are overlain by marine platform carbonates and deltaic flysch derived in part from the rising subduction complex along the northern (Damara Belt) and western (Gariep Belt) orogenic margins. Rare, thin volcanic ash layers (tuffs and cherts) are present. Upper sediments consist of unconformable red molasse related to collisional orogenesis. Orogenic loading from the north and west led to crustal flexure and the formation of a remnant ocean that drained to the south and closed progressively from north to south. During final collision SE-, E- and NE-verging nappes overrode the active basin margins. Although younger than most of the post-orogenic magmatism, its setting on the cratonic edge of the subducting plate precluded marked volcanism or granitic intrusion, the only exception being the youngest intrusions of the Kuboos-Bremen Suite dated at 521±6Ma to 491±8 Ma. Two foreland-type basins, perhaps faulted remnants of a much larger NE–SW elongated retroarc foreland basin, are found west of the Dom Feliciano Belt on the edge of the Rio de la Plata Craton in southern Brazil. In the southern Camaqua Basin, basal fluvial deposits are followed by cyclical marine and coarsening-up deltaic deposits with a notable volcanic and volcaniclastic component. This lower deformed succession, comprising mainly red beds, contain stratabound Cu and Pb–Zn deposits and is overlain unconformably by a fluviodeltaic to aeolian succession of sandstones and conglomerates (with minor andesitic volcanics), derived primarily from an eastern orogenic source and showing southerly longitudinal transport. In the northern Itajai Basin, sediments range from basal fluvial and platform sediments to fining-up submarine fan and turbidite deposits with intercalated acid tuffs. The Brazilian basins had faulted margins off which alluvial fans were shed. They also overlie parts of the Ribeira Belt. Thrust deformation along the orogenic margin bordering the Dom Feliciano Belt was directed westward in the Camaqua and Itajai basins, but reactivated strike-slip and normal faults are also present. Late- to post-orogenic granitoids and volcanics of the Dom Feliciano Belt, ranging in age from 568±6 Ma to 529±4 Ma, occur in the foreland basins and are geochemically related to some of the synsedimentary volcanics.

89 citations

Journal ArticleDOI
12 Mar 1987-Nature
TL;DR: The Permo-Carboniferous glacigenic sediment at the base of the Gondwanan basins reflects the culmination of the glacial episode that started in Australia and southern South America in the Namurian, after two local episodes in northern South America and adjacent Africa in the Visean and latest Devonian.
Abstract: The Permo-Carboniferous glacigenic sediment at the base of the Gondwanan basins reflects the culmination1,2 of the glacial episode that started in Australia and southern South America in the Namurian, after two local episodes in northern South America and adjacent Africa in the Visean and latest Devonian3 (Fig. 1). Here we show that the start of each episode was associated with orogenic uplift of the bordering regions: northern South America and adjacent Africa in the latest Devonian and Visean, and southern South America and eastern and central Australia in the Namurian. All areas, except southern South America in the Namurian, were at mid- (and not high) latitudes. Thus, we show that whereas the first order control of glaciation was the configuration of the continents and oceans during the closing of Palaeo-Tethys, orogenesis provided a second order control by the accumulation of ice about bordering uplifts during the three glacial episodes.

89 citations

Journal ArticleDOI
TL;DR: A review of the Cretaceous and early Tertiary angiosperm floras of the North American area (which includes Meso-America, and the Greater Antilles) has been the subject of considerable interest.
Abstract: The biogeographic affinities of the Cretaceous and early Tertiary angiosperm floras of the North American area (which includes Meso-America, and the Greater Antilles) have been the subject of considerable interest. Although recent treatments of isolated taxa have shown affinities between North American, European, east Asian and Neotropic floras, the relationships have not been quantified. This study compiles the records of fossils whose familial relationships seem secure. This provides a carefully culled, and uniformly presented review of the Cretaceous and Paleogene record from 1950 to 1989 and supplements LaMotte (1950). A subset of these records, which showed compelling evidence of subfamilial relationships, was analyzed to quantify the relationships of the Cretaceous, Paleocene, Eocene and Oligocene floras to other regions. The analysis suggests that for the entire period 24% of the fossil species had affinities with extant taxa from the Northern Hemisphere; 10% with taxa from the Northern Hemisphere that have a few species in South America; 17% with taxa from Eurasia; 3% with taxa with a disjunct Eurasian-South American pattern; 19% with taxa from South America and/or Africa; 8% with taxa from South America and/or Africa that have an important sister group in southeast Asia; 5% with taxa from the Old World; and 13% with taxa having other distribution patterns. Those fossils with affinities to Laurasian taxa are mostly found in the northern and western portions of the North American area. The fossils with affinities to South American and/or African taxa are found in the southern portions of North America, Meso-America, and the Greater Antilles. The taxa with disjunct distributions show both patterns. These patterns suggest that during this time there were wide-spread temperate elements, found throughout Laurasia; Boreotropical flora elements, distributed in North America, Europe and along the Tethys seaway to southeast Asia; and West Gondwana elements which show dispersion from South America across the proto-Caribbean. The paleobotanical data are compatible with current geological, paleontological and biogeographical studies.

89 citations

Book ChapterDOI
01 Jan 1995
TL;DR: In this paper, the development of the Late Carboniferous-Liassic, Late Jurassic-Early Cretaceous, and Late Eocene-Early Miocene western Gondwanian rift systems and related magmatic provinces is related to the reactivation of preexisting Pan-African zones of lithospheric weakness.
Abstract: The development of the Late Carboniferous-Liassic, Late Jurassic—Early Cretaceous, and Late Eocene—Early Miocene western Gondwanian rift systems and related magmatic provinces is related to the reactivation of preexisting Pan—African zones of lithospheric weakness. It resulted in the breakup of Pangea and Gondwana, and the opening of the Indian Ocean, western Tethys, and the South Atlantic Ocean. Changes in the intraplate stress regimes of Africa—Arabia and South America are indicated by alternating phases of crustal extension, sag-basin development and lithospheric compression. The compressive events can be correlated with changes in the rate and direction of the opening of the Central, South, and North Atlantic oceans. However, the repetition of rifting episodes, particularly within wide areas of Niger and Sudan, the persistence of some rift-independent magmatic provinces (e.g., Nigeria and Nubia) and geophysical data suggest the presence of large-scale, mantle upwelling below equatorial Africa, which could explain the specific geodynamic history of the African Plate.

89 citations

Journal ArticleDOI
TL;DR: In this article, the authors report the first study integrating in situ U-Pb and Hf isotope data from magmatic zircon and whole-rock Sm-Nd data for granitic rocks of the Sierras Pampeanas, Argentina, in order to evaluate the Palaeozoic growth of the proto-Andean margin of Gondwana.

89 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023269
2022497
2021307
2020281
2019293
2018230