Orthogneiss
Mostrando 1-7 de 7 artigos, teses e dissertações.
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1. U-Pb SHRIMP dating of basement rocks of the Iriri-Xingu domain, Central Amazonian province, Amazonian craton, Brazil
Abstract The Iriri-Xingu domain, located in the central part of the Amazonian craton, consists of extensive occurrences of Paleoproterozoic volcanic rocks and granites with published ages of ca. 1990 to 1840 Ma, which show a strong crustal contribution for their magmas. Exposures of basement rocks are small and rare. Samples from two areas were dated in this
Braz. J. Geol.. Publicado em: 21/10/2019
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2. Stratigraphy, petrography and tectonics of the manganese-bearing Buritirama Formation, Northern Carajás Domain, Amazon Craton
Abstract The Buritirama Formation (BF) occurs at the extreme north of the Carajás Province, close to the contact with the Bacajá domain, in the southeastern portion of the Amazon Craton (Brazil). The BF consists of a 40 km long, ca. 3 km wide NW-SE trending structure arranged in four imbricated thrusts that individualize three main stratigraphic units. The
Braz. J. Geol.. Publicado em: 15/04/2019
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3. Nepheline syenites to syenites and granitic rocks of the Itatiaia Alkaline Massif, Southeastern Brazil: new geological insights into a migratory ring Complex
ABSTRACT: The Itatiaia Alkaline Massif comprises some of the largest meso-cenozoic alkaline igneous occurrences in Brazil, covering over 215 km2 between the states of Minas Gerais and Rio de Janeiro. It appears as an elongated, 30-km long and 4.5-11.5-km wide SE-NW-trending body emplaced along accommodation zones of the Continental Rift of Southern Brazil, i
Braz. J. Geol.. Publicado em: 21/05/2018
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4. Geologia, petrografia e litogeoquímica dos Gnaisses Porto Alegre, RS, Brasil: implicações geotectônicas
The Porto Alegre gneiss is a unit composed of granodioritic to monzogranitic gneisses, with subordinate tonalitic and dioritic rocks. The unit represents the basement intruded by several granitic plutons of Neoproterozoic age. The gneisses show an elongate form of NE-SW direction, and constitute a roof pendant. They have composite banding, which results of i
Publicado em: 2010
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5. Geoquímica de rocha total, geocronologia de u-pb e geologia isotópica de sm-nd das rochas ortognáissicas e unidades litológicas associadas da região ipameri - Catalão (Goiás)
The part of the southern Brasília Belt, Tocantins Province, exposed in central Brazil, comprises metasedimentary rocks, metavolcano-sedimentary sequences, amphibolites and intrusive granites, and a large orthogneiss belt. These units are tectonically imbricated, and vary in metamorphic grade from lower greenschist to amphibolite facies, characterized by a 7
Publicado em: 2008
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6. CaracterizaÃÃo geolÃgica da regiÃo situada entre as localidades de Paranatama e Currais Novos (PE), porÃÃo Centro-Norte do DomÃnio TectÃnico Pernambuco-Alagoas, ProvÃncia Borborema
This thesis presents the geological characteristics of an important region inserted in the Pernambuco-Alagoas Tectonic Domain (PEALTD), considered as an integrated part of a Neoproterozoic orogenic belt that borders the northern portion of the SÃo Francisco Craton. In this context, the main geological units that outcrop in the PEALTD are: 1) Paleoproterozoi
Publicado em: 2005
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7. Litogeoquimica e controles geocronologicos da suite metamorfica algodões-choro
This thesis proposes an interpretation of the tectonic evolution of the Algodoes-Choro Metamorphic Suite (ACMS) - a paragneiss-amphibolite association intruded by granite-tonalite orthogneisses that crops out in the central region of the Ceara State, NE Brazil. The geological data support the division of this suite in the following units: 1) Algodões amphib
Publicado em: 2000