A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, Argentina

Autores
Acevedo, Rogelio Daniel
Año de publicación
2018
Idioma
inglés
Tipo de recurso
documento de conferencia
Estado
versión publicada
Descripción
Isolated pods of volcanic breccias with alkalinecomposition are hosted in the metaturbidites of the Yahgan Formation to west ofUshuaia, Isla Grande de Tierra del Fuego, Argentina. The briefly exposed outcropsare almost partially covered by bushy vegetation, whence identification of its scarceapparitions is hampered. Field features display sinuous chilled margins withpinch and swell phenomena or show uneven shape with irregular branching andsegmentation into discrete blobs. Pods of breccias, possibly components of apipe-cluster, seem to represent incipient explosion of the melt that wouldgiven rise to a fully developed vent. Unique horned ends may occur, whichtotally preclude any tectonic explanation for the off-set, even in an Andeanfolded environment. Country rocks are not apparently altered by contact around theigneous boulders. The former may perhaps have acted as a long-lives feeder tolavas, so allowing the hostess to heat up graduatelly. The rock is constituted by macrocrysts of cognatedkaersutite (146 ±5 Ma) and K-feldspar (127 ±4 Ma), phenochrysts of olivine andTi-augite in a groundmass of the same minerals, with plagioclase andfeldspathoids. Texture is mostly aphyric and richly porphyritic both, withfine-grained black matrix. Carbonation is common as secondary alteration. Alkalimetasomatism is marked by developing of kaersutite, feldspathoids and zeolites. The presence of xenoliths, mainly of lherzolitic,pyroxenitic and wehrlitic composition, is the most prominent characteristic ofthese eruptive bodies (Acevedo, 2016). The geochemical plotting of Ce/Yb ratio vs Sm contentsshown these rocks not belong to a specified field in the lamprophyre branches. On the other hand, from a petrographic and petrologic outlook,the mineral arrangement places this rock as a broad volatile-enriched alkalibasalt or camptonite that reflects the mantle upwelling during the stage ofhorizontal extension of the back-arc basin in middle times of the Jurassic-Cretaceoustransition in Tierra del Fuego.
Fil: Acevedo, Rogelio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina
EGU General Assembly
Viena
Austria
European Geosciences Union
Materia
Camptonite
Ushuaia
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:11336/220890
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/220890
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, ArgentinaAcevedo, Rogelio DanielCamptoniteUshuaiahttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1Isolated pods of volcanic breccias with alkalinecomposition are hosted in the metaturbidites of the Yahgan Formation to west ofUshuaia, Isla Grande de Tierra del Fuego, Argentina. The briefly exposed outcropsare almost partially covered by bushy vegetation, whence identification of its scarceapparitions is hampered. Field features display sinuous chilled margins withpinch and swell phenomena or show uneven shape with irregular branching andsegmentation into discrete blobs. Pods of breccias, possibly components of apipe-cluster, seem to represent incipient explosion of the melt that wouldgiven rise to a fully developed vent. Unique horned ends may occur, whichtotally preclude any tectonic explanation for the off-set, even in an Andeanfolded environment. Country rocks are not apparently altered by contact around theigneous boulders. The former may perhaps have acted as a long-lives feeder tolavas, so allowing the hostess to heat up graduatelly. The rock is constituted by macrocrysts of cognatedkaersutite (146 ±5 Ma) and K-feldspar (127 ±4 Ma), phenochrysts of olivine andTi-augite in a groundmass of the same minerals, with plagioclase andfeldspathoids. Texture is mostly aphyric and richly porphyritic both, withfine-grained black matrix. Carbonation is common as secondary alteration. Alkalimetasomatism is marked by developing of kaersutite, feldspathoids and zeolites. The presence of xenoliths, mainly of lherzolitic,pyroxenitic and wehrlitic composition, is the most prominent characteristic ofthese eruptive bodies (Acevedo, 2016). The geochemical plotting of Ce/Yb ratio vs Sm contentsshown these rocks not belong to a specified field in the lamprophyre branches. On the other hand, from a petrographic and petrologic outlook,the mineral arrangement places this rock as a broad volatile-enriched alkalibasalt or camptonite that reflects the mantle upwelling during the stage ofhorizontal extension of the back-arc basin in middle times of the Jurassic-Cretaceoustransition in Tierra del Fuego.Fil: Acevedo, Rogelio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaEGU General AssemblyVienaAustriaEuropean Geosciences UnionCopernicus Publications2018info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/conferenceObjectCongresoJournalhttp://purl.org/coar/resource_type/c_5794info:ar-repo/semantics/documentoDeConferenciaapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/220890A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, Argentina; EGU General Assembly; Viena; Austria; 2018; 1-11029-70061607-7962CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://egu2018.eu/home.htmlinfo:eu-repo/semantics/altIdentifier/url/https://www.geophysical-research-abstracts.net/egu2018.htmlhttps://youtu.be/UmUUOpQosXMInternacionalinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:47:48Zoai:ri.conicet.gov.ar:11336/220890instacron: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:34982025-09-03 09:47:48.713CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, Argentina
title A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, Argentina
spellingShingle A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, Argentina
Acevedo, Rogelio Daniel
Camptonite
Ushuaia
title_short A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, Argentina
title_full A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, Argentina
title_fullStr A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, Argentina
title_full_unstemmed A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, Argentina
title_sort A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, Argentina
dc.creator.none.fl_str_mv Acevedo, Rogelio Daniel
author Acevedo, Rogelio Daniel
author_facet Acevedo, Rogelio Daniel
author_role author
dc.subject.none.fl_str_mv Camptonite
Ushuaia
topic Camptonite
Ushuaia
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Isolated pods of volcanic breccias with alkalinecomposition are hosted in the metaturbidites of the Yahgan Formation to west ofUshuaia, Isla Grande de Tierra del Fuego, Argentina. The briefly exposed outcropsare almost partially covered by bushy vegetation, whence identification of its scarceapparitions is hampered. Field features display sinuous chilled margins withpinch and swell phenomena or show uneven shape with irregular branching andsegmentation into discrete blobs. Pods of breccias, possibly components of apipe-cluster, seem to represent incipient explosion of the melt that wouldgiven rise to a fully developed vent. Unique horned ends may occur, whichtotally preclude any tectonic explanation for the off-set, even in an Andeanfolded environment. Country rocks are not apparently altered by contact around theigneous boulders. The former may perhaps have acted as a long-lives feeder tolavas, so allowing the hostess to heat up graduatelly. The rock is constituted by macrocrysts of cognatedkaersutite (146 ±5 Ma) and K-feldspar (127 ±4 Ma), phenochrysts of olivine andTi-augite in a groundmass of the same minerals, with plagioclase andfeldspathoids. Texture is mostly aphyric and richly porphyritic both, withfine-grained black matrix. Carbonation is common as secondary alteration. Alkalimetasomatism is marked by developing of kaersutite, feldspathoids and zeolites. The presence of xenoliths, mainly of lherzolitic,pyroxenitic and wehrlitic composition, is the most prominent characteristic ofthese eruptive bodies (Acevedo, 2016). The geochemical plotting of Ce/Yb ratio vs Sm contentsshown these rocks not belong to a specified field in the lamprophyre branches. On the other hand, from a petrographic and petrologic outlook,the mineral arrangement places this rock as a broad volatile-enriched alkalibasalt or camptonite that reflects the mantle upwelling during the stage ofhorizontal extension of the back-arc basin in middle times of the Jurassic-Cretaceoustransition in Tierra del Fuego.
Fil: Acevedo, Rogelio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina
EGU General Assembly
Viena
Austria
European Geosciences Union
description Isolated pods of volcanic breccias with alkalinecomposition are hosted in the metaturbidites of the Yahgan Formation to west ofUshuaia, Isla Grande de Tierra del Fuego, Argentina. The briefly exposed outcropsare almost partially covered by bushy vegetation, whence identification of its scarceapparitions is hampered. Field features display sinuous chilled margins withpinch and swell phenomena or show uneven shape with irregular branching andsegmentation into discrete blobs. Pods of breccias, possibly components of apipe-cluster, seem to represent incipient explosion of the melt that wouldgiven rise to a fully developed vent. Unique horned ends may occur, whichtotally preclude any tectonic explanation for the off-set, even in an Andeanfolded environment. Country rocks are not apparently altered by contact around theigneous boulders. The former may perhaps have acted as a long-lives feeder tolavas, so allowing the hostess to heat up graduatelly. The rock is constituted by macrocrysts of cognatedkaersutite (146 ±5 Ma) and K-feldspar (127 ±4 Ma), phenochrysts of olivine andTi-augite in a groundmass of the same minerals, with plagioclase andfeldspathoids. Texture is mostly aphyric and richly porphyritic both, withfine-grained black matrix. Carbonation is common as secondary alteration. Alkalimetasomatism is marked by developing of kaersutite, feldspathoids and zeolites. The presence of xenoliths, mainly of lherzolitic,pyroxenitic and wehrlitic composition, is the most prominent characteristic ofthese eruptive bodies (Acevedo, 2016). The geochemical plotting of Ce/Yb ratio vs Sm contentsshown these rocks not belong to a specified field in the lamprophyre branches. On the other hand, from a petrographic and petrologic outlook,the mineral arrangement places this rock as a broad volatile-enriched alkalibasalt or camptonite that reflects the mantle upwelling during the stage ofhorizontal extension of the back-arc basin in middle times of the Jurassic-Cretaceoustransition in Tierra del Fuego.
publishDate 2018
dc.date.none.fl_str_mv 2018
dc.type.none.fl_str_mv info:eu-repo/semantics/publishedVersion
info:eu-repo/semantics/conferenceObject
Congreso
Journal
http://purl.org/coar/resource_type/c_5794
info:ar-repo/semantics/documentoDeConferencia
status_str publishedVersion
format conferenceObject
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/220890
A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, Argentina; EGU General Assembly; Viena; Austria; 2018; 1-1
1029-7006
1607-7962
CONICET Digital
CONICET
url http://hdl.handle.net/11336/220890
identifier_str_mv A megacryst- and xenolith-rich camptonite basalt from Ushuaia, Tierra del Fuego, Argentina; EGU General Assembly; Viena; Austria; 2018; 1-1
1029-7006
1607-7962
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://egu2018.eu/home.html
info:eu-repo/semantics/altIdentifier/url/https://www.geophysical-research-abstracts.net/egu2018.html
https://youtu.be/UmUUOpQosXM
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.coverage.none.fl_str_mv Internacional
dc.publisher.none.fl_str_mv Copernicus Publications
publisher.none.fl_str_mv Copernicus Publications
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
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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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