Geochemical characteristics of Cretaceous carbonatites from Angola

Alberti, Antonio; Castorina, Francesca; Censi, P.; Comin-Chiaramontí, P.; Gomes, Celso B.

doi:10.1016/s0899-5362(99)00127-x

Cited by 55 publications

(23 citation statements)

References 30 publications

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“…Comin-Chiaramonti et al (2007) suggested that the Early Cretaceous occurrences from the Brazilian Platform are usually associated with potassic magmatism that shows, following Foley's (1992) scheme, a "plagioleucititic" composition Alberti et al, 1999). This magmatism is characterized mainly by syenitic rocks and volcanic equivalents (trachyphonolite-phonolite), while the Late Cretaceous occurrences (e.g.…”

Section: Geochemistrymentioning

confidence: 99%

Alkaline magmatism in the Ponta Grossa Arch, SE Brazil: A review

Gomes

Ruberti

Comin-Chiaramontí

et al. 2011

Journal of South American Earth Sciences

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Section: Geochemistrymentioning

confidence: 99%

Alkaline magmatism in the Ponta Grossa Arch, SE Brazil: A review

Gomes

Ruberti

Comin-Chiaramontí

et al. 2011

Journal of South American Earth Sciences

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“…Tristan da Cunha and Trindade mantle plumes) with melts derived of a previously metasomatized lithosperic mantle source. On the other hand, , 1999, 2005c, 2007a, Castorina et al (1997), Alberti et al (1999), Ernesto et al (2002) and Riccomini et al (2005) proposed for the alkaline-carbonatite events in the Paraná-Angola-Namíbia system an origin from metasomatized lithospheric mantle sources without the contribution of plume-derived components.…”

Section: Petrological Considerationsmentioning

confidence: 99%

Cretaceous carbonatites of the southeastern Brazilian Platform: a review

et al. 2018

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“…In Angola, carbonatites and kimberlites are concentrated along the Lucapa structure, a riftrelated Lower Cretaceous fault system; they are mostly Early Cretaceous in age (Coltorti et al, 1993;Alberti et al, 1999). Carbonatites are concentrated in the southwest of the structure and kimberlites in the northeast (Lapido-Loureiro, 1973).…”

Section: Geological Settingmentioning

confidence: 99%

Niobium and rare earth minerals from the Virulundo carbonatite, Namibe, Angola

et al. 2012

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The Virulundo carbonatite in Angola is one of the largest in the world and contains pyrochlore as an accessory mineral in all of the carbonatite units (calciocarbonatites, ferrocarbonatites, carbonatite breccias and trachytoids). The primary magmatic pyrochlore is fluorine dominant and typically contains about equal molar quantities of Ca and Na at the A site. High-temperature hydrothermal processes have resulted in the pseudomorphic replacement of the primary pyrochlore by a second generation of pyrochlore with less F and Na. Low-temperature hydrothermal replacement of the first and second generation pyrochlore, associated with quartz-carbonate-fluorite vein formation in the carbonatite, has produced a third generation of pyrochlore, with a high Sr content. The Sr appears to have been released by low-temperature hydrothermal replacement of the primary magmatic carbonates. Finally, supergene alteration processes have produced late-stage carbonates, goethite, hollandite and rare earth element (REE) minerals (mainly synchysite-(Ce), britholite-(Ce), britholite-(La), cerite-(Ce)). Cerium separated from the other REEs in oxidizing conditions and Ce 4+ was incorporated into a late generation of supergene pyrochlore, which is strongly enriched in Ba and strongly depleted in Ca and Na.

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Geochemical characteristics of Cretaceous carbonatites from Angola

Cited by 55 publications

References 30 publications

Alkaline magmatism in the Ponta Grossa Arch, SE Brazil: A review

Alkaline magmatism in the Ponta Grossa Arch, SE Brazil: A review

Cretaceous carbonatites of the southeastern Brazilian Platform: a review

Niobium and rare earth minerals from the Virulundo carbonatite, Namibe, Angola

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