Dacitic Volcanism in the Course of the Rio das Velhas (2800-2690 Ma) Orogeny: A Brazilian Archean Analogue (TTD) to the Modern Adakites

dc.creatorSILVA, Luiz Carlos da
dc.creatorNOCE, Carlos Maurício
dc.creatorLOBATO, Lydia Maria
dc.date2013-12-19T16:32:32Z
dc.date2013-12-19T16:32:32Z
dc.date2000
dc.date.accessioned2023-10-03T22:23:55Z
dc.date.available2023-10-03T22:23:55Z
dc.identifierSILVA, Luiz Carlos da; NOCE, Carlos Maurício; LOBATO, Lydia Maria. Dacitic Volcanism in the Course of the Rio das Velhas (2800-2690 Ma) Orogeny: A Brazilian Archean Analogue (TTD) to the Modern Adakites. Revista Brasileira de Geociências, São Paulo, v.30, n.3, p.384-387, São Paulo.
dc.identifier0375-7536
dc.identifierhttps://rigeo.cprm.gov.br/handle/doc/505
dc.identifier.urihttps://repositorioslatinoamericanos.uchile.cl/handle/2250/9183335
dc.descriptionThe evolution of the Rio das Velhas Greenstone Belt followed two main episodes of crustal addition. An initial phase of ocean- floor spreading is associated with tholeiitic to komatiitic magmatism. This early accreted, short-lived oceanic crust underwent rapid subduction, giving rise to widespread arc-related, felsic calc-alkaline volcanism, triggered by the direct melting of the oceanic slab. The felsic rocks comprise lavas and pyroclastic facies, extruded at ca. 2775 Ma and rapidly dispersed through syn- and post-eruptive submarine resedimentation processes. The sequence is coeval with a series of granitoids intrusive into the belt margins, characterizing a tonalite-trondhjemite-dacite (TTD) magmatism. The LILE depleted, Na-rich, chemical signature shown by the volcanic rocks fits well with a genetic model which incorporates aspects of the evolution of adakites in the modern Circum-Pacific arcs, and also the ancient FI dacites from the Barberton Greenstone Belt.
dc.formatapplication/pdf
dc.languageen
dc.subjectPETROGRAFIA
dc.subjectTECTÔNICA
dc.subjectVULCANISMO
dc.subjectOROGÊNESE
dc.subjectFÉLSICAS
dc.subjectTTD
dc.subjectBRASIL
dc.subjectMINAS GERAIS
dc.titleDacitic Volcanism in the Course of the Rio das Velhas (2800-2690 Ma) Orogeny: A Brazilian Archean Analogue (TTD) to the Modern Adakites
dc.typeArticle


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