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BIBTEX RIS

PETROGRAFIA E MICROESTRUTURAS DE TECTONITOS DA ZONA DE CISALHAMENTO RIBEIRA, VALE DO RIBEIRA, SP E PR: IMPLICAÇÕES NO ZONEAMENTO METAMÓRFICO E ESTRUTURAL DO SUPERGRUPO AÇUNGUI E UNIDADES CORRELATAS

2004; Sociedade Brasileira de Geologia; Volume: 34; Issue: 3 Linguagem: Inglês

10.25249/0375-7536.2004343419430

ISSN

2177-4382

Autores

Frederico Meira Faleiros, Ginaldo Ademar da Cruz Campanha,

Tópico(s)

Geological and Geochemical Analysis

Resumo

The Ribeira Shear Zone, in the homonymous valley, Southeastern Brazil, is a dextral transcurrent, east-northeast trending structure that cuts metasedimentary and metabasics rocks of the Açungui Supergroup and granitic plutons. Petrographic and microstructural data indicate a long deformational history of the shear zone that is characterized by mylonites formed under amphibolite (500°-600°C) to greenschist (300°-400°C) facies conditions, followed by formation of breccias. A clearly spatial distribution of the mylonites of different metamorphic degrees indicate that the Ribeira Shear Zone had a fundamental role in the metamorphic and structural zoning of part of the Açungui Supergroup and correlated units. A vertical displacement about 3,5-4,4 km is inferred between the neighboring tectonic blocks.

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