La Aguadita Trachyte: new exponent of Triassic alkaline magmatism in the Sierra de Valle Fértil, Western Sierras Pampeanas, Argentina

La Aguadita Trachyte, in Sierra de Valle Fértil, is a new outcrop referring to the Triassic alkaline magmatism. The trachyte body was emplaced along a NNW-trending fault zone overlying the crystalline basement. The trachyte consists mainly of anorthoclase and sanidine as pheno- and microphenocrysts,...

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Autores: Castro de Machuca, B., Morata, D., López, M. G., Pontoriero, S., Conte-Grand, A.
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:Chile
Idioma:inglés
OAI Identifier:oai:repositorio.anid.cl:10533/242157
Acesso em linha:https://hdl.handle.net/10533/242157
Access Level:acceso abierto
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spelling Conte-Grand, A.Pontoriero, S.López, M. G.Morata, D.Castro de Machuca, B.2015s/ihttps://hdl.handle.net/10533/242157http://purl.org/coar/access_right/c_abf2La Aguadita Trachyte: new exponent of Triassic alkaline magmatism in the Sierra de Valle Fértil, Western Sierras Pampeanas, ArgentinaCastro de Machuca, B.Morata, D.López, M. G.Pontoriero, S.Conte-Grand, A.2020-07-29T17:42:15Z2022-07-08T20:13:51Z2020-07-29T17:42:15Z2022-07-08T20:13:51Z2015La Aguadita Trachyte, in Sierra de Valle Fértil, is a new outcrop referring to the Triassic alkaline magmatism. The trachyte body was emplaced along a NNW-trending fault zone overlying the crystalline basement. The trachyte consists mainly of anorthoclase and sanidine as pheno- and microphenocrysts, with lesser amounts of arfvedsonite and ferro-eckermannite in the groundmass. It is moderately evolved in composition with 66.5-69.1 wt.% SiO2 and exhibits a limited compositional range in most of the major elements. The rare earth elements (REE) pattern is somewhat uniform and highly fractionated, being enriched in light REE over heavy REE and showing a prominent negative Eu anomaly. The trachyte is enriched in high field strength elements Nb, Zr, and Y, consistent with typical intraplate alkaline magmatism under extensional tectonic regime. It is proposed to be genetically related with other alkaline volcanic rocks outcropping in the area, and generated from the same parental mantellic source (i.e., asthenospheric mantle source) through open-system fractional crystallization. eNd values of +2.6 are consistent with slightly crustal contamination during trachyte generation. Thus, La Aguadita Trachyte could be the result of a combination of fractional crystallization of mantle-derived basaltic magma and crustal assimilation. Radiometric age dating of 218 ± 7 Ma on the trachyte (K-Ar age, whole rock) expands the range of the Triassic alkaline volcanism known in the area to the Upper Triassic, and confirms a regional volcanic event related to uplift in an extensional tectonic environment.CEGAFONDAPWOSSCOPUSFONDAP1509001315090013virtual::20350-1s/ihttps://hdl.handle.net/10533/242157enginstname: ANIDreponame: Repositorio Digital RI2.0s/ihttp://ppct.caicyt.gov.ar/index.php/raga/article/view/5295Atribución-NoComercial-SinDerivadas 3.0 Chilehttp://creativecommons.org/licenses/by-nc-nd/3.0/cl/info:eu-repo/semantics/openAccessLa Aguadita Trachyte: new exponent of Triassic alkaline magmatism in the Sierra de Valle Fértil, Western Sierras Pampeanas, ArgentinaRevista de la Asociación Geológica de ArgentinaArticuloinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttps://hdl.handle.net/10533/242157FONDAPhttp://purl.org/coar/resource_type/c_2df8fbb1af9f301e-501e-40b1-ba24-0e199f38a218virtual::20350-1af9f301e-501e-40b1-ba24-0e199f38a218virtual::20350-110533/242157oai:repositorio.anid.cl:10533/2421572023-07-24 19:57:09.717https://repositorio.anid.clRepositorio ANIDaletelier@anid.cl
dc.title.none.fl_str_mv La Aguadita Trachyte: new exponent of Triassic alkaline magmatism in the Sierra de Valle Fértil, Western Sierras Pampeanas, Argentina
dc.title.journal.none.fl_str_mv Revista de la Asociación Geológica de Argentina
title La Aguadita Trachyte: new exponent of Triassic alkaline magmatism in the Sierra de Valle Fértil, Western Sierras Pampeanas, Argentina
spellingShingle La Aguadita Trachyte: new exponent of Triassic alkaline magmatism in the Sierra de Valle Fértil, Western Sierras Pampeanas, Argentina
Castro de Machuca, B.
title_short La Aguadita Trachyte: new exponent of Triassic alkaline magmatism in the Sierra de Valle Fértil, Western Sierras Pampeanas, Argentina
title_full La Aguadita Trachyte: new exponent of Triassic alkaline magmatism in the Sierra de Valle Fértil, Western Sierras Pampeanas, Argentina
title_fullStr La Aguadita Trachyte: new exponent of Triassic alkaline magmatism in the Sierra de Valle Fértil, Western Sierras Pampeanas, Argentina
title_full_unstemmed La Aguadita Trachyte: new exponent of Triassic alkaline magmatism in the Sierra de Valle Fértil, Western Sierras Pampeanas, Argentina
title_sort La Aguadita Trachyte: new exponent of Triassic alkaline magmatism in the Sierra de Valle Fértil, Western Sierras Pampeanas, Argentina
dc.creator.none.fl_str_mv Castro de Machuca, B.
Morata, D.
López, M. G.
Pontoriero, S.
Conte-Grand, A.
author Castro de Machuca, B.
author_facet Castro de Machuca, B.
Morata, D.
López, M. G.
Pontoriero, S.
Conte-Grand, A.
author_role author
author2 Morata, D.
López, M. G.
Pontoriero, S.
Conte-Grand, A.
author2_role author
author
author
author
description La Aguadita Trachyte, in Sierra de Valle Fértil, is a new outcrop referring to the Triassic alkaline magmatism. The trachyte body was emplaced along a NNW-trending fault zone overlying the crystalline basement. The trachyte consists mainly of anorthoclase and sanidine as pheno- and microphenocrysts, with lesser amounts of arfvedsonite and ferro-eckermannite in the groundmass. It is moderately evolved in composition with 66.5-69.1 wt.% SiO2 and exhibits a limited compositional range in most of the major elements. The rare earth elements (REE) pattern is somewhat uniform and highly fractionated, being enriched in light REE over heavy REE and showing a prominent negative Eu anomaly. The trachyte is enriched in high field strength elements Nb, Zr, and Y, consistent with typical intraplate alkaline magmatism under extensional tectonic regime. It is proposed to be genetically related with other alkaline volcanic rocks outcropping in the area, and generated from the same parental mantellic source (i.e., asthenospheric mantle source) through open-system fractional crystallization. eNd values of +2.6 are consistent with slightly crustal contamination during trachyte generation. Thus, La Aguadita Trachyte could be the result of a combination of fractional crystallization of mantle-derived basaltic magma and crustal assimilation. Radiometric age dating of 218 ± 7 Ma on the trachyte (K-Ar age, whole rock) expands the range of the Triassic alkaline volcanism known in the area to the Upper Triassic, and confirms a regional volcanic event related to uplift in an extensional tectonic environment.
publishDate 2015
dc.date.issued.none.fl_str_mv 2015
dc.date.accessioned.none.fl_str_mv 2020-07-29T17:42:15Z
2022-07-08T20:13:51Z
dc.date.available.none.fl_str_mv 2020-07-29T17:42:15Z
2022-07-08T20:13:51Z
dc.type.none.fl_str_mv Articulo
dc.type.driver.none.fl_str_mv info:eu-repo/semantics/article
dc.type.openaire.none.fl_str_mv info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.folio.none.fl_str_mv 15090013
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dc.identifier.idwos.none.fl_str_mv s/i
dc.identifier.uri.none.fl_str_mv https://hdl.handle.net/10533/242157
identifier_str_mv 15090013
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url https://hdl.handle.net/10533/242157
dc.language.iso.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv instname: ANID
reponame: Repositorio Digital RI2.0
dc.relation.doi.none.fl_str_mv s/i
dc.relation.uri.none.fl_str_mv http://ppct.caicyt.gov.ar/index.php/raga/article/view/5295
dc.rights.none.fl_str_mv Atribución-NoComercial-SinDerivadas 3.0 Chile
http://creativecommons.org/licenses/by-nc-nd/3.0/cl/
dc.rights.driver.none.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv Atribución-NoComercial-SinDerivadas 3.0 Chile
http://creativecommons.org/licenses/by-nc-nd/3.0/cl/
eu_rights_str_mv openAccess
repository.name.fl_str_mv Repositorio ANID
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