Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processing

Autores
Varela, Maria Eugenia; Sylvester, P.; Brandstätter, F.; Engler, A.
Año de publicación
2015
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Sixteen nonporphyritic chondrules and chondrule fragments were studied inpolished thin and thick sections in two enstatite chondrites (ECs): twelve objects fromunequilibrated EH3 Sahara 97158 and four objects from equilibrated EH4 Indarch. Bulkmajor element analyses, obtained with electron microprobe analysis (EMPA) and analyticalscanning electron microscopy (ASEM), as well as bulk lithophile trace element analyses,determined by laser ablation inductively coupled plasma?mass spectrometry (LA-ICP-MS),show that volatile components (K2O + Na2O versus Al2O3) scatter roughly around the CIline, indicating equilibration with the chondritic reservoir. All lithophile trace elementabundances in the chondrules from Sahara 97158 and Indarch are within the range ofprevious analyses of nonporphyritic chondrules in unequilibrated ordinary chondrites(UOCs). The unfractionated (solar-like) Yb/Ce ratio of the studied objects and the mostlyunfractionated refractory lithophile trace element (RLTE) abundance patterns indicate anorigin by direct condensation. However, the objects possess subchondritic CaO/Al2O3 ratios;superchondritic (Sahara 97158) and subchondritic (Indarch) Yb/Sc ratios; and chondriticnormalizeddeficits in Nb, Ti, V, and Mn relative to RLTEs. This suggests a unique nebularprocess for the origin of these ECs, involving elemental fractionation of the solar gas by theremoval of oldhamite, niningerite, and/or another phase prior to chondrule condensation. Alayered chondrule in Sahara 97158 is strongly depleted in Nb in the core compared to therim, suggesting that the solar gas was heterogeneous on the time scales of chondruleformation. Late stage metasomatic events produced the compositional diversity of thestudied objects by addition of moderately volatile and volatile elements. In the equilibratedIndarch chondrules, this late process has been further disturbed, possibly by apostaccretional process (diffusion?) that preferentially mobilized Rb with respect to Cs inthe studied objects.
Fil: Varela, Maria Eugenia. Consejo Nacional de Investigaciones Cienti­ficas y Tecnicas. Centro Cientifico Tecnologico San Juan. Instituto de Ciencias Astronomicas de la Tierra y del Espacio; Argentina
Fil: Sylvester, P.. Memorial University Of Newfoundland; Canadá
Fil: Brandstätter, F.. Naturhistorisches Museum. Mineralogisch-Petrographische Abteilung; Austria
Fil: Engler, A.. University of Graz. Department of Mineralogy and Petrology. Institute of Earth Sciences; Austria
Materia
Condritas a Enstatita
Genesis
Nonphoryritic Chonrules
Secondary Processing
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:11336/4889

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oai_identifier_str oai:ri.conicet.gov.ar:11336/4889
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network_name_str CONICET Digital (CONICET)
spelling Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processingVarela, Maria EugeniaSylvester, P.Brandstätter, F.Engler, A.Condritas a EnstatitaGenesisNonphoryritic ChonrulesSecondary Processinghttps://purl.org/becyt/ford/1.3https://purl.org/becyt/ford/1Sixteen nonporphyritic chondrules and chondrule fragments were studied inpolished thin and thick sections in two enstatite chondrites (ECs): twelve objects fromunequilibrated EH3 Sahara 97158 and four objects from equilibrated EH4 Indarch. Bulkmajor element analyses, obtained with electron microprobe analysis (EMPA) and analyticalscanning electron microscopy (ASEM), as well as bulk lithophile trace element analyses,determined by laser ablation inductively coupled plasma?mass spectrometry (LA-ICP-MS),show that volatile components (K2O + Na2O versus Al2O3) scatter roughly around the CIline, indicating equilibration with the chondritic reservoir. All lithophile trace elementabundances in the chondrules from Sahara 97158 and Indarch are within the range ofprevious analyses of nonporphyritic chondrules in unequilibrated ordinary chondrites(UOCs). The unfractionated (solar-like) Yb/Ce ratio of the studied objects and the mostlyunfractionated refractory lithophile trace element (RLTE) abundance patterns indicate anorigin by direct condensation. However, the objects possess subchondritic CaO/Al2O3 ratios;superchondritic (Sahara 97158) and subchondritic (Indarch) Yb/Sc ratios; and chondriticnormalizeddeficits in Nb, Ti, V, and Mn relative to RLTEs. This suggests a unique nebularprocess for the origin of these ECs, involving elemental fractionation of the solar gas by theremoval of oldhamite, niningerite, and/or another phase prior to chondrule condensation. Alayered chondrule in Sahara 97158 is strongly depleted in Nb in the core compared to therim, suggesting that the solar gas was heterogeneous on the time scales of chondruleformation. Late stage metasomatic events produced the compositional diversity of thestudied objects by addition of moderately volatile and volatile elements. In the equilibratedIndarch chondrules, this late process has been further disturbed, possibly by apostaccretional process (diffusion?) that preferentially mobilized Rb with respect to Cs inthe studied objects.Fil: Varela, Maria Eugenia. Consejo Nacional de Investigaciones Cienti­ficas y Tecnicas. Centro Cientifico Tecnologico San Juan. Instituto de Ciencias Astronomicas de la Tierra y del Espacio; ArgentinaFil: Sylvester, P.. Memorial University Of Newfoundland; CanadáFil: Brandstätter, F.. Naturhistorisches Museum. Mineralogisch-Petrographische Abteilung; AustriaFil: Engler, A.. University of Graz. Department of Mineralogy and Petrology. Institute of Earth Sciences; AustriaWiley2015-08info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/4889Varela, Maria Eugenia; Sylvester, P.; Brandstätter, F.; Engler, A.; Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processing; Wiley; Meteoritics & Planetary Science; 50; 8; 8-2015; 1338-13611086-9379enginfo:eu-repo/semantics/altIdentifier/url/http://onlinelibrary.wiley.com/doi/10.1111/maps.12468/abstractinfo:eu-repo/semantics/altIdentifier/doi/10.1111/maps.12468info:eu-repo/semantics/altIdentifier/doi/info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:37:11Zoai:ri.conicet.gov.ar:11336/4889instacron: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 09:37:12.048CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processing
title Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processing
spellingShingle Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processing
Varela, Maria Eugenia
Condritas a Enstatita
Genesis
Nonphoryritic Chonrules
Secondary Processing
title_short Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processing
title_full Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processing
title_fullStr Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processing
title_full_unstemmed Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processing
title_sort Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processing
dc.creator.none.fl_str_mv Varela, Maria Eugenia
Sylvester, P.
Brandstätter, F.
Engler, A.
author Varela, Maria Eugenia
author_facet Varela, Maria Eugenia
Sylvester, P.
Brandstätter, F.
Engler, A.
author_role author
author2 Sylvester, P.
Brandstätter, F.
Engler, A.
author2_role author
author
author
dc.subject.none.fl_str_mv Condritas a Enstatita
Genesis
Nonphoryritic Chonrules
Secondary Processing
topic Condritas a Enstatita
Genesis
Nonphoryritic Chonrules
Secondary Processing
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Sixteen nonporphyritic chondrules and chondrule fragments were studied inpolished thin and thick sections in two enstatite chondrites (ECs): twelve objects fromunequilibrated EH3 Sahara 97158 and four objects from equilibrated EH4 Indarch. Bulkmajor element analyses, obtained with electron microprobe analysis (EMPA) and analyticalscanning electron microscopy (ASEM), as well as bulk lithophile trace element analyses,determined by laser ablation inductively coupled plasma?mass spectrometry (LA-ICP-MS),show that volatile components (K2O + Na2O versus Al2O3) scatter roughly around the CIline, indicating equilibration with the chondritic reservoir. All lithophile trace elementabundances in the chondrules from Sahara 97158 and Indarch are within the range ofprevious analyses of nonporphyritic chondrules in unequilibrated ordinary chondrites(UOCs). The unfractionated (solar-like) Yb/Ce ratio of the studied objects and the mostlyunfractionated refractory lithophile trace element (RLTE) abundance patterns indicate anorigin by direct condensation. However, the objects possess subchondritic CaO/Al2O3 ratios;superchondritic (Sahara 97158) and subchondritic (Indarch) Yb/Sc ratios; and chondriticnormalizeddeficits in Nb, Ti, V, and Mn relative to RLTEs. This suggests a unique nebularprocess for the origin of these ECs, involving elemental fractionation of the solar gas by theremoval of oldhamite, niningerite, and/or another phase prior to chondrule condensation. Alayered chondrule in Sahara 97158 is strongly depleted in Nb in the core compared to therim, suggesting that the solar gas was heterogeneous on the time scales of chondruleformation. Late stage metasomatic events produced the compositional diversity of thestudied objects by addition of moderately volatile and volatile elements. In the equilibratedIndarch chondrules, this late process has been further disturbed, possibly by apostaccretional process (diffusion?) that preferentially mobilized Rb with respect to Cs inthe studied objects.
Fil: Varela, Maria Eugenia. Consejo Nacional de Investigaciones Cienti­ficas y Tecnicas. Centro Cientifico Tecnologico San Juan. Instituto de Ciencias Astronomicas de la Tierra y del Espacio; Argentina
Fil: Sylvester, P.. Memorial University Of Newfoundland; Canadá
Fil: Brandstätter, F.. Naturhistorisches Museum. Mineralogisch-Petrographische Abteilung; Austria
Fil: Engler, A.. University of Graz. Department of Mineralogy and Petrology. Institute of Earth Sciences; Austria
description Sixteen nonporphyritic chondrules and chondrule fragments were studied inpolished thin and thick sections in two enstatite chondrites (ECs): twelve objects fromunequilibrated EH3 Sahara 97158 and four objects from equilibrated EH4 Indarch. Bulkmajor element analyses, obtained with electron microprobe analysis (EMPA) and analyticalscanning electron microscopy (ASEM), as well as bulk lithophile trace element analyses,determined by laser ablation inductively coupled plasma?mass spectrometry (LA-ICP-MS),show that volatile components (K2O + Na2O versus Al2O3) scatter roughly around the CIline, indicating equilibration with the chondritic reservoir. All lithophile trace elementabundances in the chondrules from Sahara 97158 and Indarch are within the range ofprevious analyses of nonporphyritic chondrules in unequilibrated ordinary chondrites(UOCs). The unfractionated (solar-like) Yb/Ce ratio of the studied objects and the mostlyunfractionated refractory lithophile trace element (RLTE) abundance patterns indicate anorigin by direct condensation. However, the objects possess subchondritic CaO/Al2O3 ratios;superchondritic (Sahara 97158) and subchondritic (Indarch) Yb/Sc ratios; and chondriticnormalizeddeficits in Nb, Ti, V, and Mn relative to RLTEs. This suggests a unique nebularprocess for the origin of these ECs, involving elemental fractionation of the solar gas by theremoval of oldhamite, niningerite, and/or another phase prior to chondrule condensation. Alayered chondrule in Sahara 97158 is strongly depleted in Nb in the core compared to therim, suggesting that the solar gas was heterogeneous on the time scales of chondruleformation. Late stage metasomatic events produced the compositional diversity of thestudied objects by addition of moderately volatile and volatile elements. In the equilibratedIndarch chondrules, this late process has been further disturbed, possibly by apostaccretional process (diffusion?) that preferentially mobilized Rb with respect to Cs inthe studied objects.
publishDate 2015
dc.date.none.fl_str_mv 2015-08
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/11336/4889
Varela, Maria Eugenia; Sylvester, P.; Brandstätter, F.; Engler, A.; Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processing; Wiley; Meteoritics & Planetary Science; 50; 8; 8-2015; 1338-1361
1086-9379
url http://hdl.handle.net/11336/4889
identifier_str_mv Varela, Maria Eugenia; Sylvester, P.; Brandstätter, F.; Engler, A.; Nonporphyritic chondrules and chondrule fragments in enstatite chondrites: Insights into their origin and secondary processing; Wiley; Meteoritics & Planetary Science; 50; 8; 8-2015; 1338-1361
1086-9379
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/http://onlinelibrary.wiley.com/doi/10.1111/maps.12468/abstract
info:eu-repo/semantics/altIdentifier/doi/10.1111/maps.12468
info:eu-repo/semantics/altIdentifier/doi/
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Wiley
publisher.none.fl_str_mv Wiley
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
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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