Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, Brazil

In the map area the rocks are divided into two large subdivisions: the Archaean Nova Lima greenstone and the Bonfim granitoid gneisses, and the overlying Proterozoic Minas metasedimentary and metavolcanic rocks, including abundant iron formation. These groups are separated by a major unconformity. T...

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Detalles Bibliográficos
Autor: Pires, Fernando Roberto Mendes
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:1979
País:Brasil
Institución:Universidade Federal do Rio de Janeiro (UFRJ)
Repositorio:Repositório Institucional da UFRJ
Idioma:inglés
OAI Identifier:oai:pantheon.ufrj.br:11422/1688
Acceso en línea:http://hdl.handle.net/11422/1688
Access Level:acceso abierto
Palabra clave:Geologia estrutural
Evolução
Minas Gerais
CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::GEOLOGIA REGIONAL
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spelling Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, BrazilGeologia estruturalEvoluçãoMinas GeraisCNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::GEOLOGIA REGIONALIn the map area the rocks are divided into two large subdivisions: the Archaean Nova Lima greenstone and the Bonfim granitoid gneisses, and the overlying Proterozoic Minas metasedimentary and metavolcanic rocks, including abundant iron formation. These groups are separated by a major unconformity. These new studies in the Minas Series culminated with the following results: reassignement of the conglomerate -quartzite sequence of the Mutuca area to the Moeda Formation rather than to the Nova Lima Group; identification of a suite of greenstones and peraluminous potassic schists in the Batatal and Gandarela Formations and Piracicaba Group ; recognition of the riebeckite in one of the itabirite sequences; and redefinition of the Gandarela Formation through the identification of stromatolites and greenstones. The structure of the junction of the Curral and Moeda structures consists of two elements: on the north is the recumbent northeast -trending Curral anticline with its lower limb faulted against Archaean Nova Lima rocks, and the upper limb deformed into the Moeda syncline to the south. In the south, the westward overturned Moeda syncline trends north -south, with both of the limbs strongly deformed. The western limb is folded into recumbent folds indicating a northerly transport direction. The eastern limb has become rotated westward during thrusting until now it is overturned by Nova Lima greenstones. This overturned limb of the Moeda syncline is separated from the Curral anticline by the Barreiro-Agua Quente zone of tear faults. The features demonstrate two major phases of deformation, the earlier D1 with a north-westward vergence and the later D2 -episode, with a westward vergence. Extensive development of quartz and muscovite in the sediments and of chlorite and talc in the mafic and ultramafic greenstones, and the quartz grain-size in itabirite, in general, smaller than 0.1 mm are indicative of low -grade metamorphism in the area. The Quadrilátero Ferrifero and the Michigan iron ore district show similarities in the occurrence of peraluminous potassic schists indicated by the log (SiO2/A1203)-(Na20 + Ca0/K20)- diagrams, the presence of greenstones, the strain-induced quartz grain-size variation in itabirites, and the basement controlling tectonics.CAPESIndisponível.Michigan Technological UniversityEstados UnidosGeology and Geological EngineeringMTUKalliokoski, Jormahttp://lattes.cnpq.br/37984802206661532017-03-29T19:54:20Z2023-12-21T03:02:15Z1979info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisPIERS, Fernando Roberto Mendes. Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, Brazil. 1979. 220 f. Dissertation (Doctor of Philosophy Geology) - Michigan Technological University, Houghton, 1979.http://hdl.handle.net/11422/1688enginfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRJinstname:Universidade Federal do Rio de Janeiro (UFRJ)instacron:UFRJPires, Fernando Roberto Mendes2023-12-21T03:02:15Zoai:pantheon.ufrj.br:11422/1688Repositório InstitucionalPUBhttp://www.pantheon.ufrj.br/oai/requestpantheon@sibi.ufrj.bropendoar:2023-12-21T03:02:15Repositório Institucional da UFRJ - Universidade Federal do Rio de Janeiro (UFRJ)false
dc.title.none.fl_str_mv Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, Brazil
title Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, Brazil
spellingShingle Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, Brazil
Pires, Fernando Roberto Mendes
Geologia estrutural
Evolução
Minas Gerais
CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::GEOLOGIA REGIONAL
title_short Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, Brazil
title_full Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, Brazil
title_fullStr Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, Brazil
title_full_unstemmed Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, Brazil
title_sort Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, Brazil
dc.creator.none.fl_str_mv Pires, Fernando Roberto Mendes
author Pires, Fernando Roberto Mendes
author_facet Pires, Fernando Roberto Mendes
author_role author
dc.contributor.none.fl_str_mv Kalliokoski, Jorma
http://lattes.cnpq.br/3798480220666153
dc.subject.por.fl_str_mv Geologia estrutural
Evolução
Minas Gerais
CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::GEOLOGIA REGIONAL
topic Geologia estrutural
Evolução
Minas Gerais
CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::GEOLOGIA REGIONAL
description In the map area the rocks are divided into two large subdivisions: the Archaean Nova Lima greenstone and the Bonfim granitoid gneisses, and the overlying Proterozoic Minas metasedimentary and metavolcanic rocks, including abundant iron formation. These groups are separated by a major unconformity. These new studies in the Minas Series culminated with the following results: reassignement of the conglomerate -quartzite sequence of the Mutuca area to the Moeda Formation rather than to the Nova Lima Group; identification of a suite of greenstones and peraluminous potassic schists in the Batatal and Gandarela Formations and Piracicaba Group ; recognition of the riebeckite in one of the itabirite sequences; and redefinition of the Gandarela Formation through the identification of stromatolites and greenstones. The structure of the junction of the Curral and Moeda structures consists of two elements: on the north is the recumbent northeast -trending Curral anticline with its lower limb faulted against Archaean Nova Lima rocks, and the upper limb deformed into the Moeda syncline to the south. In the south, the westward overturned Moeda syncline trends north -south, with both of the limbs strongly deformed. The western limb is folded into recumbent folds indicating a northerly transport direction. The eastern limb has become rotated westward during thrusting until now it is overturned by Nova Lima greenstones. This overturned limb of the Moeda syncline is separated from the Curral anticline by the Barreiro-Agua Quente zone of tear faults. The features demonstrate two major phases of deformation, the earlier D1 with a north-westward vergence and the later D2 -episode, with a westward vergence. Extensive development of quartz and muscovite in the sediments and of chlorite and talc in the mafic and ultramafic greenstones, and the quartz grain-size in itabirite, in general, smaller than 0.1 mm are indicative of low -grade metamorphism in the area. The Quadrilátero Ferrifero and the Michigan iron ore district show similarities in the occurrence of peraluminous potassic schists indicated by the log (SiO2/A1203)-(Na20 + Ca0/K20)- diagrams, the presence of greenstones, the strain-induced quartz grain-size variation in itabirites, and the basement controlling tectonics.
publishDate 1979
dc.date.none.fl_str_mv 1979
2017-03-29T19:54:20Z
2023-12-21T03:02:15Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/doctoralThesis
format doctoralThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv PIERS, Fernando Roberto Mendes. Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, Brazil. 1979. 220 f. Dissertation (Doctor of Philosophy Geology) - Michigan Technological University, Houghton, 1979.
http://hdl.handle.net/11422/1688
identifier_str_mv PIERS, Fernando Roberto Mendes. Structural geology and stratigraphy at the junction of the curral anticline and the moeda syncline, Quadrilatero Ferrifero, Minas Gerais, Brazil. 1979. 220 f. Dissertation (Doctor of Philosophy Geology) - Michigan Technological University, Houghton, 1979.
url http://hdl.handle.net/11422/1688
dc.language.iso.fl_str_mv eng
language eng
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Michigan Technological University
Estados Unidos
Geology and Geological Engineering
MTU
publisher.none.fl_str_mv Michigan Technological University
Estados Unidos
Geology and Geological Engineering
MTU
dc.source.none.fl_str_mv reponame:Repositório Institucional da UFRJ
instname:Universidade Federal do Rio de Janeiro (UFRJ)
instacron:UFRJ
instname_str Universidade Federal do Rio de Janeiro (UFRJ)
instacron_str UFRJ
institution UFRJ
reponame_str Repositório Institucional da UFRJ
collection Repositório Institucional da UFRJ
repository.name.fl_str_mv Repositório Institucional da UFRJ - Universidade Federal do Rio de Janeiro (UFRJ)
repository.mail.fl_str_mv pantheon@sibi.ufrj.br
_version_ 1853662089115074560
score 15,301629

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