The Western Sierras Pampeanas: Protracted Grenville-age history (1330-1030 Ma) of intra-oceanic arcs, subduction-accretion at continental-edge and AMCG intraplate magmatism

Autores
Rapela, Carlos Washington; Pankhurst, Robert J.; Casquet, César; Baldo, Edgardo G.; Galindo, Carmen; Fanning, Christopher; Dahlquist, Juan A.
Año de publicación
2010
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
New U–Pb SHRIMP zircon ages combined with geochemical and isotope investigation in the Sierra de; Maz and Sierra de Pie de Palo and a xenolith of the Precordillera basement (Ullun), provides insight into; the identification of major Grenville-age tectonomagmatic events and their timing in the Western Sierras; Pampeanas. The study reveals two contrasting scenarios that evolved separately during the 300 Ma long; history: Sierra de Maz, which was always part of a continental crust, and the juvenile oceanic arc and; back-arc sector of Sierra de Pie de Palo and Ullun. The oldest rocks are the Andino-type granitic orthogneisses; of Sierra de Maz (1330–1260 Ma) and associated subalkaline basic rocks, that were part of an; active continental margin developed in a Paleoproterozoic crust. Amphibolite facies metamorphism; affected the orthogneisses at ca. 1175 Ma, while granulite facies was attained in neighbouring meta-sediments; and basic granulites. Interruption of continental-edge magmatism and high-grade metamorphism; is interpreted as related to an arc–continental collision dated by zircon overgrowths at 1170–1230 Ma.; The next event consisted of massif-type anorthosites and related meta-jotunites, meta-mangerites; (1092 ± 6 Ma) and meta-granites (1086 ± 10 Ma) that define an AMCG complex in Sierra de Maz. The; emplacement of these mantle-derived magmas during an extensional episode produced a widespread; thermal overprint at ca. 1095 Ma in neighbouring country rocks. In constrast, juvenile oceanic arc and; back-arc complexes dominated the Sierra de Pie de Palo–Ullun sector, that was fully developed ca.; 1200 Ma (1196 ± 8 Ma metagabbro). A new episode of oceanic arc magmatism at 1165 Ma was roughly; coeval with the amphibolite high-grade metamorphism of Sierra de Maz, indicating that these two sectors; underwent independent geodynamic scenarios at this age. Two more episodes of arc subduction are; registered in the Pie de Palo–Ullun sector: (i) 1110 ± 10 Ma orthogneisses and basic amphibolites with; geochemical fingerprints of emplacement in a more mature crust, and (ii) a 1027 ± 17 Ma TTG juvenile; suite, which is the youngest Grenville-age magmatic event registered in the Western Sierras Pampeanas.; The geodynamic history in both study areas reveals a complex orogenic evolution, dominated by convergent; tectonics and accretion of juvenile oceanic arcs to the continent.
Centro de Investigaciones Geológicas
Materia
Geología
Sierras Pampeanas
Grenville-age orogeny
Intra-oceanic arc
Arc–continent collision
AMCG complex
U–Pb SHRIMP dating
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/128518

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oai_identifier_str oai:sedici.unlp.edu.ar:10915/128518
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network_name_str SEDICI (UNLP)
spelling The Western Sierras Pampeanas: Protracted Grenville-age history (1330-1030 Ma) of intra-oceanic arcs, subduction-accretion at continental-edge and AMCG intraplate magmatismRapela, Carlos WashingtonPankhurst, Robert J.Casquet, CésarBaldo, Edgardo G.Galindo, CarmenFanning, ChristopherDahlquist, Juan A.GeologíaSierras PampeanasGrenville-age orogenyIntra-oceanic arcArc–continent collisionAMCG complexU–Pb SHRIMP datingNew U–Pb SHRIMP zircon ages combined with geochemical and isotope investigation in the Sierra de; Maz and Sierra de Pie de Palo and a xenolith of the Precordillera basement (Ullun), provides insight into; the identification of major Grenville-age tectonomagmatic events and their timing in the Western Sierras; Pampeanas. The study reveals two contrasting scenarios that evolved separately during the 300 Ma long; history: Sierra de Maz, which was always part of a continental crust, and the juvenile oceanic arc and; back-arc sector of Sierra de Pie de Palo and Ullun. The oldest rocks are the Andino-type granitic orthogneisses; of Sierra de Maz (1330–1260 Ma) and associated subalkaline basic rocks, that were part of an; active continental margin developed in a Paleoproterozoic crust. Amphibolite facies metamorphism; affected the orthogneisses at ca. 1175 Ma, while granulite facies was attained in neighbouring meta-sediments; and basic granulites. Interruption of continental-edge magmatism and high-grade metamorphism; is interpreted as related to an arc–continental collision dated by zircon overgrowths at 1170–1230 Ma.; The next event consisted of massif-type anorthosites and related meta-jotunites, meta-mangerites; (1092 ± 6 Ma) and meta-granites (1086 ± 10 Ma) that define an AMCG complex in Sierra de Maz. The; emplacement of these mantle-derived magmas during an extensional episode produced a widespread; thermal overprint at ca. 1095 Ma in neighbouring country rocks. In constrast, juvenile oceanic arc and; back-arc complexes dominated the Sierra de Pie de Palo–Ullun sector, that was fully developed ca.; 1200 Ma (1196 ± 8 Ma metagabbro). A new episode of oceanic arc magmatism at 1165 Ma was roughly; coeval with the amphibolite high-grade metamorphism of Sierra de Maz, indicating that these two sectors; underwent independent geodynamic scenarios at this age. Two more episodes of arc subduction are; registered in the Pie de Palo–Ullun sector: (i) 1110 ± 10 Ma orthogneisses and basic amphibolites with; geochemical fingerprints of emplacement in a more mature crust, and (ii) a 1027 ± 17 Ma TTG juvenile; suite, which is the youngest Grenville-age magmatic event registered in the Western Sierras Pampeanas.; The geodynamic history in both study areas reveals a complex orogenic evolution, dominated by convergent; tectonics and accretion of juvenile oceanic arcs to the continent.Centro de Investigaciones Geológicas2010info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf105-127http://sedici.unlp.edu.ar/handle/10915/128518enginfo:eu-repo/semantics/altIdentifier/issn/0895-9811info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2009.08.004info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:31:07Zoai:sedici.unlp.edu.ar:10915/128518Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:31:08.013SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv The Western Sierras Pampeanas: Protracted Grenville-age history (1330-1030 Ma) of intra-oceanic arcs, subduction-accretion at continental-edge and AMCG intraplate magmatism
title The Western Sierras Pampeanas: Protracted Grenville-age history (1330-1030 Ma) of intra-oceanic arcs, subduction-accretion at continental-edge and AMCG intraplate magmatism
spellingShingle The Western Sierras Pampeanas: Protracted Grenville-age history (1330-1030 Ma) of intra-oceanic arcs, subduction-accretion at continental-edge and AMCG intraplate magmatism
Rapela, Carlos Washington
Geología
Sierras Pampeanas
Grenville-age orogeny
Intra-oceanic arc
Arc–continent collision
AMCG complex
U–Pb SHRIMP dating
title_short The Western Sierras Pampeanas: Protracted Grenville-age history (1330-1030 Ma) of intra-oceanic arcs, subduction-accretion at continental-edge and AMCG intraplate magmatism
title_full The Western Sierras Pampeanas: Protracted Grenville-age history (1330-1030 Ma) of intra-oceanic arcs, subduction-accretion at continental-edge and AMCG intraplate magmatism
title_fullStr The Western Sierras Pampeanas: Protracted Grenville-age history (1330-1030 Ma) of intra-oceanic arcs, subduction-accretion at continental-edge and AMCG intraplate magmatism
title_full_unstemmed The Western Sierras Pampeanas: Protracted Grenville-age history (1330-1030 Ma) of intra-oceanic arcs, subduction-accretion at continental-edge and AMCG intraplate magmatism
title_sort The Western Sierras Pampeanas: Protracted Grenville-age history (1330-1030 Ma) of intra-oceanic arcs, subduction-accretion at continental-edge and AMCG intraplate magmatism
dc.creator.none.fl_str_mv Rapela, Carlos Washington
Pankhurst, Robert J.
Casquet, César
Baldo, Edgardo G.
Galindo, Carmen
Fanning, Christopher
Dahlquist, Juan A.
author Rapela, Carlos Washington
author_facet Rapela, Carlos Washington
Pankhurst, Robert J.
Casquet, César
Baldo, Edgardo G.
Galindo, Carmen
Fanning, Christopher
Dahlquist, Juan A.
author_role author
author2 Pankhurst, Robert J.
Casquet, César
Baldo, Edgardo G.
Galindo, Carmen
Fanning, Christopher
Dahlquist, Juan A.
author2_role author
author
author
author
author
author
dc.subject.none.fl_str_mv Geología
Sierras Pampeanas
Grenville-age orogeny
Intra-oceanic arc
Arc–continent collision
AMCG complex
U–Pb SHRIMP dating
topic Geología
Sierras Pampeanas
Grenville-age orogeny
Intra-oceanic arc
Arc–continent collision
AMCG complex
U–Pb SHRIMP dating
dc.description.none.fl_txt_mv New U–Pb SHRIMP zircon ages combined with geochemical and isotope investigation in the Sierra de; Maz and Sierra de Pie de Palo and a xenolith of the Precordillera basement (Ullun), provides insight into; the identification of major Grenville-age tectonomagmatic events and their timing in the Western Sierras; Pampeanas. The study reveals two contrasting scenarios that evolved separately during the 300 Ma long; history: Sierra de Maz, which was always part of a continental crust, and the juvenile oceanic arc and; back-arc sector of Sierra de Pie de Palo and Ullun. The oldest rocks are the Andino-type granitic orthogneisses; of Sierra de Maz (1330–1260 Ma) and associated subalkaline basic rocks, that were part of an; active continental margin developed in a Paleoproterozoic crust. Amphibolite facies metamorphism; affected the orthogneisses at ca. 1175 Ma, while granulite facies was attained in neighbouring meta-sediments; and basic granulites. Interruption of continental-edge magmatism and high-grade metamorphism; is interpreted as related to an arc–continental collision dated by zircon overgrowths at 1170–1230 Ma.; The next event consisted of massif-type anorthosites and related meta-jotunites, meta-mangerites; (1092 ± 6 Ma) and meta-granites (1086 ± 10 Ma) that define an AMCG complex in Sierra de Maz. The; emplacement of these mantle-derived magmas during an extensional episode produced a widespread; thermal overprint at ca. 1095 Ma in neighbouring country rocks. In constrast, juvenile oceanic arc and; back-arc complexes dominated the Sierra de Pie de Palo–Ullun sector, that was fully developed ca.; 1200 Ma (1196 ± 8 Ma metagabbro). A new episode of oceanic arc magmatism at 1165 Ma was roughly; coeval with the amphibolite high-grade metamorphism of Sierra de Maz, indicating that these two sectors; underwent independent geodynamic scenarios at this age. Two more episodes of arc subduction are; registered in the Pie de Palo–Ullun sector: (i) 1110 ± 10 Ma orthogneisses and basic amphibolites with; geochemical fingerprints of emplacement in a more mature crust, and (ii) a 1027 ± 17 Ma TTG juvenile; suite, which is the youngest Grenville-age magmatic event registered in the Western Sierras Pampeanas.; The geodynamic history in both study areas reveals a complex orogenic evolution, dominated by convergent; tectonics and accretion of juvenile oceanic arcs to the continent.
Centro de Investigaciones Geológicas
description New U–Pb SHRIMP zircon ages combined with geochemical and isotope investigation in the Sierra de; Maz and Sierra de Pie de Palo and a xenolith of the Precordillera basement (Ullun), provides insight into; the identification of major Grenville-age tectonomagmatic events and their timing in the Western Sierras; Pampeanas. The study reveals two contrasting scenarios that evolved separately during the 300 Ma long; history: Sierra de Maz, which was always part of a continental crust, and the juvenile oceanic arc and; back-arc sector of Sierra de Pie de Palo and Ullun. The oldest rocks are the Andino-type granitic orthogneisses; of Sierra de Maz (1330–1260 Ma) and associated subalkaline basic rocks, that were part of an; active continental margin developed in a Paleoproterozoic crust. Amphibolite facies metamorphism; affected the orthogneisses at ca. 1175 Ma, while granulite facies was attained in neighbouring meta-sediments; and basic granulites. Interruption of continental-edge magmatism and high-grade metamorphism; is interpreted as related to an arc–continental collision dated by zircon overgrowths at 1170–1230 Ma.; The next event consisted of massif-type anorthosites and related meta-jotunites, meta-mangerites; (1092 ± 6 Ma) and meta-granites (1086 ± 10 Ma) that define an AMCG complex in Sierra de Maz. The; emplacement of these mantle-derived magmas during an extensional episode produced a widespread; thermal overprint at ca. 1095 Ma in neighbouring country rocks. In constrast, juvenile oceanic arc and; back-arc complexes dominated the Sierra de Pie de Palo–Ullun sector, that was fully developed ca.; 1200 Ma (1196 ± 8 Ma metagabbro). A new episode of oceanic arc magmatism at 1165 Ma was roughly; coeval with the amphibolite high-grade metamorphism of Sierra de Maz, indicating that these two sectors; underwent independent geodynamic scenarios at this age. Two more episodes of arc subduction are; registered in the Pie de Palo–Ullun sector: (i) 1110 ± 10 Ma orthogneisses and basic amphibolites with; geochemical fingerprints of emplacement in a more mature crust, and (ii) a 1027 ± 17 Ma TTG juvenile; suite, which is the youngest Grenville-age magmatic event registered in the Western Sierras Pampeanas.; The geodynamic history in both study areas reveals a complex orogenic evolution, dominated by convergent; tectonics and accretion of juvenile oceanic arcs to the continent.
publishDate 2010
dc.date.none.fl_str_mv 2010
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
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format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/128518
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language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0895-9811
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2009.08.004
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
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