Basamento paleoproterozoico del área de San Miguel, Sierras Septentrionales de la provincia de Buenos Aires: registro de una cuenca de retroarco en el margen sur del cratón del Río...

Autores
Lajoinie, María Florencia; Lanfranchini, Mabel Elena; Etcheverry, Ricardo O.
Año de publicación
2017
Idioma
español castellano
Tipo de recurso
documento de conferencia
Estado
versión publicada
Descripción
New information obtained from the characterization of biotite gneises and migmatites from the San Miguel area allowed the interpretation of metamorphic processes that formed a portion of the Paleoproterozoic basement of the Tandilia Belt. Biotite gneiss shows a compositional Sj banding (N35°E/60°NW) and a mineral composition: microcline, (oligoclase-andesine), quartz and biotite. Migmatites oc- cur as differentiated bodies with stromatic structure with Sj orientation and quartz, oligoclase, microcline leucoso- mes. Also almandine gamet appears in voluminous leucosomes. Chemical analyses indícate that the gneiss derived from a sedimentary protolith (wacke) while the migmatites would have formed from partial melting of the gneiss through decomposition of biotite in presence of quartz and plagioclase. This fact must have generated the gametife- rous phase with potassic feldspar and a peraluminous granitic melt in imbalance: low ratio (La/Yb)N <55.85 and low Th and Zr contents. Migmatization must have started during the Transamazonian Cycle (~2200Ma) considering that most of the leucosomes are concordant with the banding gneiss orientation, formed during the mentioned Cycle. Thus, the pressure gradient favoured the migration and the intrusión of the melt (before to rebalance) into the gneiss and also in marbles generating metasomatism and skamification. This metamorphic evolution scheme matches with a tectonic context of back-arc basin associated with an oceanic-continental crust subduction that occu- rred during the Archaean-Paleoproterozoic period, and finished with the amalgamation of Tandilia Terrane to the Rio de la Plata Craton.
Materia
Geología
ciclo transamazónico
procesos metamórficos
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-nd/4.0/
Repositorio
CIC Digital (CICBA)
Institución
Comisión de Investigaciones Científicas de la Provincia de Buenos Aires
OAI Identificador
oai:digital.cic.gba.gob.ar:11746/8096
Acceder
id CICBA_1befbd86a5b8834bcf1a447c2d4ff30a
oai_identifier_str oai:digital.cic.gba.gob.ar:11746/8096
network_acronym_str CICBA
repository_id_str 9441
network_name_str CIC Digital (CICBA)
spelling Basamento paleoproterozoico del área de San Miguel, Sierras Septentrionales de la provincia de Buenos Aires: registro de una cuenca de retroarco en el margen sur del cratón del Río de La PlataLajoinie, María FlorenciaLanfranchini, Mabel ElenaEtcheverry, Ricardo O.Geologíaciclo transamazónicoprocesos metamórficosNew information obtained from the characterization of biotite gneises and migmatites from the San Miguel area allowed the interpretation of metamorphic processes that formed a portion of the Paleoproterozoic basement of the Tandilia Belt. Biotite gneiss shows a compositional Sj banding (N35°E/60°NW) and a mineral composition: microcline, (oligoclase-andesine), quartz and biotite. Migmatites oc- cur as differentiated bodies with stromatic structure with Sj orientation and quartz, oligoclase, microcline leucoso- mes. Also almandine gamet appears in voluminous leucosomes. Chemical analyses indícate that the gneiss derived from a sedimentary protolith (wacke) while the migmatites would have formed from partial melting of the gneiss through decomposition of biotite in presence of quartz and plagioclase. This fact must have generated the gametife- rous phase with potassic feldspar and a peraluminous granitic melt in imbalance: low ratio (La/Yb)N <55.85 and low Th and Zr contents. Migmatization must have started during the Transamazonian Cycle (~2200Ma) considering that most of the leucosomes are concordant with the banding gneiss orientation, formed during the mentioned Cycle. Thus, the pressure gradient favoured the migration and the intrusión of the melt (before to rebalance) into the gneiss and also in marbles generating metasomatism and skamification. This metamorphic evolution scheme matches with a tectonic context of back-arc basin associated with an oceanic-continental crust subduction that occu- rred during the Archaean-Paleoproterozoic period, and finished with the amalgamation of Tandilia Terrane to the Rio de la Plata Craton.2017-08-07info:eu-repo/semantics/conferenceObjectinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_5794info:ar-repo/semantics/documentoDeConferenciaapplication/pdfhttps://digital.cic.gba.gob.ar/handle/11746/8096spaTandilia (Buenos Aires, Argentina)info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-nd/4.0/reponame:CIC Digital (CICBA)instname:Comisión de Investigaciones Científicas de la Provincia de Buenos Airesinstacron:CICBA2025-09-04T09:42:55Zoai:digital.cic.gba.gob.ar:11746/8096Institucionalhttp://digital.cic.gba.gob.arOrganismo científico-tecnológicoNo correspondehttp://digital.cic.gba.gob.ar/oai/snrdmarisa.degiusti@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:94412025-09-04 09:42:55.499CIC Digital (CICBA) - Comisión de Investigaciones Científicas de la Provincia de Buenos Airesfalse
dc.title.none.fl_str_mv Basamento paleoproterozoico del área de San Miguel, Sierras Septentrionales de la provincia de Buenos Aires: registro de una cuenca de retroarco en el margen sur del cratón del Río de La Plata
title Basamento paleoproterozoico del área de San Miguel, Sierras Septentrionales de la provincia de Buenos Aires: registro de una cuenca de retroarco en el margen sur del cratón del Río de La Plata
spellingShingle Basamento paleoproterozoico del área de San Miguel, Sierras Septentrionales de la provincia de Buenos Aires: registro de una cuenca de retroarco en el margen sur del cratón del Río de La Plata
Lajoinie, María Florencia
Geología
ciclo transamazónico
procesos metamórficos
title_short Basamento paleoproterozoico del área de San Miguel, Sierras Septentrionales de la provincia de Buenos Aires: registro de una cuenca de retroarco en el margen sur del cratón del Río de La Plata
title_full Basamento paleoproterozoico del área de San Miguel, Sierras Septentrionales de la provincia de Buenos Aires: registro de una cuenca de retroarco en el margen sur del cratón del Río de La Plata
title_fullStr Basamento paleoproterozoico del área de San Miguel, Sierras Septentrionales de la provincia de Buenos Aires: registro de una cuenca de retroarco en el margen sur del cratón del Río de La Plata
title_full_unstemmed Basamento paleoproterozoico del área de San Miguel, Sierras Septentrionales de la provincia de Buenos Aires: registro de una cuenca de retroarco en el margen sur del cratón del Río de La Plata
title_sort Basamento paleoproterozoico del área de San Miguel, Sierras Septentrionales de la provincia de Buenos Aires: registro de una cuenca de retroarco en el margen sur del cratón del Río de La Plata
dc.creator.none.fl_str_mv Lajoinie, María Florencia
Lanfranchini, Mabel Elena
Etcheverry, Ricardo O.
author Lajoinie, María Florencia
author_facet Lajoinie, María Florencia
Lanfranchini, Mabel Elena
Etcheverry, Ricardo O.
author_role author
author2 Lanfranchini, Mabel Elena
Etcheverry, Ricardo O.
author2_role author
author
dc.subject.none.fl_str_mv Geología
ciclo transamazónico
procesos metamórficos
topic Geología
ciclo transamazónico
procesos metamórficos
dc.description.none.fl_txt_mv New information obtained from the characterization of biotite gneises and migmatites from the San Miguel area allowed the interpretation of metamorphic processes that formed a portion of the Paleoproterozoic basement of the Tandilia Belt. Biotite gneiss shows a compositional Sj banding (N35°E/60°NW) and a mineral composition: microcline, (oligoclase-andesine), quartz and biotite. Migmatites oc- cur as differentiated bodies with stromatic structure with Sj orientation and quartz, oligoclase, microcline leucoso- mes. Also almandine gamet appears in voluminous leucosomes. Chemical analyses indícate that the gneiss derived from a sedimentary protolith (wacke) while the migmatites would have formed from partial melting of the gneiss through decomposition of biotite in presence of quartz and plagioclase. This fact must have generated the gametife- rous phase with potassic feldspar and a peraluminous granitic melt in imbalance: low ratio (La/Yb)N <55.85 and low Th and Zr contents. Migmatization must have started during the Transamazonian Cycle (~2200Ma) considering that most of the leucosomes are concordant with the banding gneiss orientation, formed during the mentioned Cycle. Thus, the pressure gradient favoured the migration and the intrusión of the melt (before to rebalance) into the gneiss and also in marbles generating metasomatism and skamification. This metamorphic evolution scheme matches with a tectonic context of back-arc basin associated with an oceanic-continental crust subduction that occu- rred during the Archaean-Paleoproterozoic period, and finished with the amalgamation of Tandilia Terrane to the Rio de la Plata Craton.
description New information obtained from the characterization of biotite gneises and migmatites from the San Miguel area allowed the interpretation of metamorphic processes that formed a portion of the Paleoproterozoic basement of the Tandilia Belt. Biotite gneiss shows a compositional Sj banding (N35°E/60°NW) and a mineral composition: microcline, (oligoclase-andesine), quartz and biotite. Migmatites oc- cur as differentiated bodies with stromatic structure with Sj orientation and quartz, oligoclase, microcline leucoso- mes. Also almandine gamet appears in voluminous leucosomes. Chemical analyses indícate that the gneiss derived from a sedimentary protolith (wacke) while the migmatites would have formed from partial melting of the gneiss through decomposition of biotite in presence of quartz and plagioclase. This fact must have generated the gametife- rous phase with potassic feldspar and a peraluminous granitic melt in imbalance: low ratio (La/Yb)N <55.85 and low Th and Zr contents. Migmatization must have started during the Transamazonian Cycle (~2200Ma) considering that most of the leucosomes are concordant with the banding gneiss orientation, formed during the mentioned Cycle. Thus, the pressure gradient favoured the migration and the intrusión of the melt (before to rebalance) into the gneiss and also in marbles generating metasomatism and skamification. This metamorphic evolution scheme matches with a tectonic context of back-arc basin associated with an oceanic-continental crust subduction that occu- rred during the Archaean-Paleoproterozoic period, and finished with the amalgamation of Tandilia Terrane to the Rio de la Plata Craton.
publishDate 2017
dc.date.none.fl_str_mv 2017-08-07
dc.type.none.fl_str_mv info:eu-repo/semantics/conferenceObject
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_5794
info:ar-repo/semantics/documentoDeConferencia
format conferenceObject
status_str publishedVersion
dc.identifier.none.fl_str_mv https://digital.cic.gba.gob.ar/handle/11746/8096
url https://digital.cic.gba.gob.ar/handle/11746/8096
dc.language.none.fl_str_mv spa
language spa
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-nd/4.0/
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-nd/4.0/
dc.format.none.fl_str_mv application/pdf
dc.coverage.none.fl_str_mv Tandilia (Buenos Aires, Argentina)
dc.source.none.fl_str_mv reponame:CIC Digital (CICBA)
instname:Comisión de Investigaciones Científicas de la Provincia de Buenos Aires
instacron:CICBA
reponame_str CIC Digital (CICBA)
collection CIC Digital (CICBA)
instname_str Comisión de Investigaciones Científicas de la Provincia de Buenos Aires
instacron_str CICBA
institution CICBA
repository.name.fl_str_mv CIC Digital (CICBA) - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires
repository.mail.fl_str_mv marisa.degiusti@sedici.unlp.edu.ar
_version_ 1842340394657906688
score 12.623145

Publicaciones similares