Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristics

Autores
O'Leary, M. S.; Lira, Raul; Dorais, M. J.; Tassinari, C. C. G.
Año de publicación
2009
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Over 20 lamprophyre dykes, varying in width between a few centimeters and several meters, have been identified in central Sierra Norte - Eastern Pampean Ranges, Córdoba, Argentina. Their mineralogy and chemistry indicate that they are part of the calc-alkaline lamprophyres clan (CAL). They contain phenocrysts of magnesiohornblende ± augite set in a groundmass of magnesiohornblende, calcic-plagioclase, alkali feldspar, and opaque minerals, which designate them as spessartite-type lamprophyres. Alteration products include chlorite, calcite and iron oxides after mafic phenocrysts, though some are partially replaced by actinolite. Feldspars are replaced by carbonate and clay minerals. The dykes are relatively primitive, and show restricted major element variation (SiO2 51.1-55.3 wt.%, Al2O3 12-16.6 wt.%, total alkalies 1.5-4.7 wt.%), high Mg# (55-77), high Cr contents (27-988 ppm) and moderate to high Ni contents (60-190 ppm). Lamprophyre LILE (e.g. Rb averages 110 ppm, Sr 211-387 ppm, Ba 203-452 ppm) are high relative to HFSE (e.g., Ta 0.2-1.6 ppm, Nb 4-11 ppm, Y 17-21 ppm), and are enriched in LREE (30-70 times chondrite). They are characterized by relatively high 208Pb/204Pb (38.8-39.9), 207Pb/204Pb (∼15.7), and 206Pb/204Pb (18.7-20.1), combined with low (epsilon)εNd (-4.69 to -1.52) and a relative moderately high (87Sr/86Sr)i of 0.7055-0.7074. The Rb-Sr whole rock isochron indicates an Early Ordovician age of 485 ± 25 Ma. The calculated TDM (1.7 Ga) suggests that these rocks appear to have originated from a reservoir that was created during a mantle metasomatism event related to the Pampean orogeny. The Sierra Norte lamprophyres show affinities with a subduction-related magma in an active continental margin. Their geochemical and isotopic features suggest a multicomponent source, composed of enriched mantle material variably contaminated by crustal components. The lamprophyric suite emplacement occurred at the dawning stage of the Pampean orogeny, in a regional post-collisional extensional setting developed in the Sierra Norte-Ambargasta batholith (SNAB) in Early Ordovician times.
Fil: O'Leary, M. S.. Universidad Nacional del Comahue; Argentina
Fil: Lira, Raul. Universidad Nacional de Córdoba. Facultad de Cs.exactas Físicas y Naturales. Museo de Geología y Miner."dr.a.stelzner"; Argentina
Fil: Dorais, M. J.. Brigham Young University; Estados Unidos
Fil: Tassinari, C. C. G.. Universidade de Sao Paulo; Brasil
Materia
Argentina
Petrology And Geochemistry
Post-Collisional
Rb/Sr Age
Sierra Norte
Spessartites
Sr-Nd-Pb Isotopes
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/55367

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network_name_str CONICET Digital (CONICET)
spelling Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristicsO'Leary, M. S.Lira, RaulDorais, M. J.Tassinari, C. C. G.ArgentinaPetrology And GeochemistryPost-CollisionalRb/Sr AgeSierra NorteSpessartitesSr-Nd-Pb Isotopeshttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1Over 20 lamprophyre dykes, varying in width between a few centimeters and several meters, have been identified in central Sierra Norte - Eastern Pampean Ranges, Córdoba, Argentina. Their mineralogy and chemistry indicate that they are part of the calc-alkaline lamprophyres clan (CAL). They contain phenocrysts of magnesiohornblende ± augite set in a groundmass of magnesiohornblende, calcic-plagioclase, alkali feldspar, and opaque minerals, which designate them as spessartite-type lamprophyres. Alteration products include chlorite, calcite and iron oxides after mafic phenocrysts, though some are partially replaced by actinolite. Feldspars are replaced by carbonate and clay minerals. The dykes are relatively primitive, and show restricted major element variation (SiO2 51.1-55.3 wt.%, Al2O3 12-16.6 wt.%, total alkalies 1.5-4.7 wt.%), high Mg# (55-77), high Cr contents (27-988 ppm) and moderate to high Ni contents (60-190 ppm). Lamprophyre LILE (e.g. Rb averages 110 ppm, Sr 211-387 ppm, Ba 203-452 ppm) are high relative to HFSE (e.g., Ta 0.2-1.6 ppm, Nb 4-11 ppm, Y 17-21 ppm), and are enriched in LREE (30-70 times chondrite). They are characterized by relatively high 208Pb/204Pb (38.8-39.9), 207Pb/204Pb (∼15.7), and 206Pb/204Pb (18.7-20.1), combined with low (epsilon)εNd (-4.69 to -1.52) and a relative moderately high (87Sr/86Sr)i of 0.7055-0.7074. The Rb-Sr whole rock isochron indicates an Early Ordovician age of 485 ± 25 Ma. The calculated TDM (1.7 Ga) suggests that these rocks appear to have originated from a reservoir that was created during a mantle metasomatism event related to the Pampean orogeny. The Sierra Norte lamprophyres show affinities with a subduction-related magma in an active continental margin. Their geochemical and isotopic features suggest a multicomponent source, composed of enriched mantle material variably contaminated by crustal components. The lamprophyric suite emplacement occurred at the dawning stage of the Pampean orogeny, in a regional post-collisional extensional setting developed in the Sierra Norte-Ambargasta batholith (SNAB) in Early Ordovician times.Fil: O'Leary, M. S.. Universidad Nacional del Comahue; ArgentinaFil: Lira, Raul. Universidad Nacional de Córdoba. Facultad de Cs.exactas Físicas y Naturales. Museo de Geología y Miner."dr.a.stelzner"; ArgentinaFil: Dorais, M. J.. Brigham Young University; Estados UnidosFil: Tassinari, C. C. G.. Universidade de Sao Paulo; BrasilPergamon-Elsevier Science Ltd2009-10info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/55367O'Leary, M. S.; Lira, Raul; Dorais, M. J.; Tassinari, C. C. G.; Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristics; Pergamon-Elsevier Science Ltd; Journal of South American Earth Sciences; 28; 10-2009; 277-2870895-9811CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0895981108000849info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2008.08.005info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:39:24Zoai:ri.conicet.gov.ar:11336/55367instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 09:39:24.775CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristics
title Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristics
spellingShingle Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristics
O'Leary, M. S.
Argentina
Petrology And Geochemistry
Post-Collisional
Rb/Sr Age
Sierra Norte
Spessartites
Sr-Nd-Pb Isotopes
title_short Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristics
title_full Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristics
title_fullStr Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristics
title_full_unstemmed Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristics
title_sort Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristics
dc.creator.none.fl_str_mv O'Leary, M. S.
Lira, Raul
Dorais, M. J.
Tassinari, C. C. G.
author O'Leary, M. S.
author_facet O'Leary, M. S.
Lira, Raul
Dorais, M. J.
Tassinari, C. C. G.
author_role author
author2 Lira, Raul
Dorais, M. J.
Tassinari, C. C. G.
author2_role author
author
author
dc.subject.none.fl_str_mv Argentina
Petrology And Geochemistry
Post-Collisional
Rb/Sr Age
Sierra Norte
Spessartites
Sr-Nd-Pb Isotopes
topic Argentina
Petrology And Geochemistry
Post-Collisional
Rb/Sr Age
Sierra Norte
Spessartites
Sr-Nd-Pb Isotopes
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Over 20 lamprophyre dykes, varying in width between a few centimeters and several meters, have been identified in central Sierra Norte - Eastern Pampean Ranges, Córdoba, Argentina. Their mineralogy and chemistry indicate that they are part of the calc-alkaline lamprophyres clan (CAL). They contain phenocrysts of magnesiohornblende ± augite set in a groundmass of magnesiohornblende, calcic-plagioclase, alkali feldspar, and opaque minerals, which designate them as spessartite-type lamprophyres. Alteration products include chlorite, calcite and iron oxides after mafic phenocrysts, though some are partially replaced by actinolite. Feldspars are replaced by carbonate and clay minerals. The dykes are relatively primitive, and show restricted major element variation (SiO2 51.1-55.3 wt.%, Al2O3 12-16.6 wt.%, total alkalies 1.5-4.7 wt.%), high Mg# (55-77), high Cr contents (27-988 ppm) and moderate to high Ni contents (60-190 ppm). Lamprophyre LILE (e.g. Rb averages 110 ppm, Sr 211-387 ppm, Ba 203-452 ppm) are high relative to HFSE (e.g., Ta 0.2-1.6 ppm, Nb 4-11 ppm, Y 17-21 ppm), and are enriched in LREE (30-70 times chondrite). They are characterized by relatively high 208Pb/204Pb (38.8-39.9), 207Pb/204Pb (∼15.7), and 206Pb/204Pb (18.7-20.1), combined with low (epsilon)εNd (-4.69 to -1.52) and a relative moderately high (87Sr/86Sr)i of 0.7055-0.7074. The Rb-Sr whole rock isochron indicates an Early Ordovician age of 485 ± 25 Ma. The calculated TDM (1.7 Ga) suggests that these rocks appear to have originated from a reservoir that was created during a mantle metasomatism event related to the Pampean orogeny. The Sierra Norte lamprophyres show affinities with a subduction-related magma in an active continental margin. Their geochemical and isotopic features suggest a multicomponent source, composed of enriched mantle material variably contaminated by crustal components. The lamprophyric suite emplacement occurred at the dawning stage of the Pampean orogeny, in a regional post-collisional extensional setting developed in the Sierra Norte-Ambargasta batholith (SNAB) in Early Ordovician times.
Fil: O'Leary, M. S.. Universidad Nacional del Comahue; Argentina
Fil: Lira, Raul. Universidad Nacional de Córdoba. Facultad de Cs.exactas Físicas y Naturales. Museo de Geología y Miner."dr.a.stelzner"; Argentina
Fil: Dorais, M. J.. Brigham Young University; Estados Unidos
Fil: Tassinari, C. C. G.. Universidade de Sao Paulo; Brasil
description Over 20 lamprophyre dykes, varying in width between a few centimeters and several meters, have been identified in central Sierra Norte - Eastern Pampean Ranges, Córdoba, Argentina. Their mineralogy and chemistry indicate that they are part of the calc-alkaline lamprophyres clan (CAL). They contain phenocrysts of magnesiohornblende ± augite set in a groundmass of magnesiohornblende, calcic-plagioclase, alkali feldspar, and opaque minerals, which designate them as spessartite-type lamprophyres. Alteration products include chlorite, calcite and iron oxides after mafic phenocrysts, though some are partially replaced by actinolite. Feldspars are replaced by carbonate and clay minerals. The dykes are relatively primitive, and show restricted major element variation (SiO2 51.1-55.3 wt.%, Al2O3 12-16.6 wt.%, total alkalies 1.5-4.7 wt.%), high Mg# (55-77), high Cr contents (27-988 ppm) and moderate to high Ni contents (60-190 ppm). Lamprophyre LILE (e.g. Rb averages 110 ppm, Sr 211-387 ppm, Ba 203-452 ppm) are high relative to HFSE (e.g., Ta 0.2-1.6 ppm, Nb 4-11 ppm, Y 17-21 ppm), and are enriched in LREE (30-70 times chondrite). They are characterized by relatively high 208Pb/204Pb (38.8-39.9), 207Pb/204Pb (∼15.7), and 206Pb/204Pb (18.7-20.1), combined with low (epsilon)εNd (-4.69 to -1.52) and a relative moderately high (87Sr/86Sr)i of 0.7055-0.7074. The Rb-Sr whole rock isochron indicates an Early Ordovician age of 485 ± 25 Ma. The calculated TDM (1.7 Ga) suggests that these rocks appear to have originated from a reservoir that was created during a mantle metasomatism event related to the Pampean orogeny. The Sierra Norte lamprophyres show affinities with a subduction-related magma in an active continental margin. Their geochemical and isotopic features suggest a multicomponent source, composed of enriched mantle material variably contaminated by crustal components. The lamprophyric suite emplacement occurred at the dawning stage of the Pampean orogeny, in a regional post-collisional extensional setting developed in the Sierra Norte-Ambargasta batholith (SNAB) in Early Ordovician times.
publishDate 2009
dc.date.none.fl_str_mv 2009-10
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/55367
O'Leary, M. S.; Lira, Raul; Dorais, M. J.; Tassinari, C. C. G.; Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristics; Pergamon-Elsevier Science Ltd; Journal of South American Earth Sciences; 28; 10-2009; 277-287
0895-9811
CONICET Digital
CONICET
url http://hdl.handle.net/11336/55367
identifier_str_mv O'Leary, M. S.; Lira, Raul; Dorais, M. J.; Tassinari, C. C. G.; Post-collisional lamprophyric event in Sierra Norte, Córdoba, Argentina: Mineralogical, geochemical and isotopic characteristics; Pergamon-Elsevier Science Ltd; Journal of South American Earth Sciences; 28; 10-2009; 277-287
0895-9811
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0895981108000849
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.jsames.2008.08.005
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
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eu_rights_str_mv openAccess
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dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Pergamon-Elsevier Science Ltd
publisher.none.fl_str_mv Pergamon-Elsevier Science Ltd
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repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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