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	Provedor de dados Anais da ABC (AABC) (2) Autor Lima,Evandro F. (2) Bastos Neto,Artur C. (1) Campos,Cristina P. de (1) Ferron,José M.T.M. (1) Liz,Joaquim D. (1) Nardi,Lauro V. S. (1) Nardi,Lauro V.S. (1) Pierosan,Ronaldo (1) Prado,Maurício (1) Sommer,Carlos A. (1) Waichel,Breno L. (1) Mais... Palavra-chave Amazonian Craton (1) Caldera complex (1) Ignimbrite (1) Iricoumé volcanism (1) Na-alkaline (1) Neoproterozoic (1) Post-collisional (1) Shoshonite (1) Surge deposits (1) Uatumã magmatism (1) Volcanism (1) Mais... Tipo do documento Info:eu-repo/semantics/article (2) Ano 2011 (1) 2006 (1) País Brazil (2) Idioma Inglês (2)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 2 Primeira ... 1 ... Última The evolution of Neoproterozoic magmatism in Southernmost Brazil: shoshonitic, high-K tholeiitic and silica-saturated, sodic alkaline volcanism in post-collisional basins Anais da ABC (AABC) Sommer,Carlos A.; Lima,Evandro F.; Nardi,Lauro V. S.; Liz,Joaquim D.; Waichel,Breno L.. The Neoproterozoic shoshonitic and mildly alkaline bimodal volcanism of Southernmost Brazil is represented by rock assemblages associated to sedimentary successions, deposited in strike-slip basins formed at the post-collisional stages of the Brasilian/Pan-African orogenic cycle. The best-preserved volcano sedimentary associations occur in the Camaquã and Campo Alegre Basins, respectively in the Sul-riograndense and Catarinense Shields and are outside the main shear belts or overlying the unaffected basement areas. These basins are characterized by alternation of volcanic cycles and siliciclastic sedimentation developed dominantly on a continental setting under subaerial conditions. This volcanism and the coeval plutonism evolved from high-K tholeiitic and... Tipo: Info:eu-repo/semantics/article Palavras-chave: Post-collisional; Neoproterozoic; Volcanism; Shoshonite; Na-alkaline. Ano: 2006 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652006000300015 Paleoproterozoic (~1.88Ga) felsic volcanism of the Iricoumé Group in the Pitinga Mining District area, Amazonian Craton, Brazil: insights in ancient volcanic processes from field and petrologic data Anais da ABC (AABC) Pierosan,Ronaldo; Lima,Evandro F.; Nardi,Lauro V.S.; Campos,Cristina P. de; Bastos Neto,Artur C.; Ferron,José M.T.M.; Prado,Maurício. The Iricoumé Group correspond to the most expressive Paleoproterozoic volcanism in the Guyana Shield, Amazonian craton. The volcanics are coeval with Mapuera granitoids, and belong to the Uatumã magmatism. They have U-Pb ages around 1880 Ma, and geochemical signatures of α-type magmas. Iricoumé volcanics consist of porphyritic trachyte to rhyolite, associated to crystal-rich ignimbrites and co-ignimbritic fall tuffs and surges. The amount and morphology of phenocrysts can be useful to distinguish lava (flow and dome) from hypabyssal units. The morphology of ignimbrite crystals allows the distinction between effusive units and ignimbrite, when pyroclasts are obliterated. Co-ignimbritic tuffs are massive, and some show stratifications that suggest deposition... Tipo: Info:eu-repo/semantics/article Palavras-chave: Amazonian Craton; Caldera complex; Ignimbrite; Iricoumé volcanism; Surge deposits; Uatumã magmatism. Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000300012 Registros recuperados: 2 Primeira ... 1 ... Última

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