How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW Argentina

Autores
Wolfram, L. C.; Weinberg, Roberto F.; Hasalová, Pavlína; Becchio, Raul Alberto
Año de publicación
2017
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Compositional variability of crustal-derived granites has been attributed to a multitude of processes. Although there has been much discussion on the entrainment of residuum and its effect on granite magma chemistry, the exact nature of what is entrained and when entrainment is efficient remain unclear. We describe the relationship between granulite-facies migmatites and granites in the Sierra de Quilmes, NW Argentina, focusing on how the style of melt segregation affects its ability to disaggregate the source and carry residual minerals, and therefore control granite chemistry. The north-south-trending mountains that define the region known as the Sierras Pampeanas are characterized by variably metamorphosed turbidites of the Neoproterozoic-Cambrian Puncoviscana Formation. Early Ordovician subduction on the western Gondwana margin produced widespread high-T, low-P metamorphism of the turbidites during the Famatinian orogeny (~500- 440 Ma), resulting in extensive anatexis and granite plutonism. The Tolombón complex of the northern Sierra de Quilmes is a tilted metamorphic sequence in the northern Sierras Pampeanas, providing near-complete exposure from granulite-facies magma source rocks in the SW to granite emplacement levels in amphibolite- and greenschist-facies rocks in the NE. Anatexis is associated with fluid-absent incongruent breakdown of biotite in granulite-facies rocks, evidenced by the presence of peritectic Grt±Crd±Opx. The western Tolombón complex is separated from the Ovejeria complex by a shear zone. The Ovejeria complex is distinguished by a generally higher melt fraction, and is dominated by gradational contacts from metatexites to diatexites and granites. In contrast, in the Tolombón complex, with few examples of diatexites, magmas are more commonly extracted from metatexites, and migrate to feed stocks and plutons at higher crustal levels. Granites derived from diatexites tend to remain close to the source and retain strong compositional similarities to the Puncoviscana Formation protolith, indicating significant mobilization of residuum, and defining the Ovejeria style of granite formation. Granites derived dominantly from melt extraction from metatexites tend to be leucogranites with compositions approaching those of experimental melts, defining the Tolombón style of granite formation. Magma derived through either mechanism undergoes further differentiation, giving rise to the compositionally diverse suite of rocks common to most anatectic terranes. Magmas derived through the Tolombón style of melt extraction are leucocratic and impoverished in light rare earth elements (LREE), Th, and Zr compared with both the sedimentary source rocks and residuum-rich magmas derived through the Ovejeria style of granite formation. The low solubility of zircon and monazite in relatively dry, peraluminous leucogranite melts guarantees that Zr, Th, and LREE behave as compatible elements during dehydration melting of metasedimentary packages. Therefore, neither style of granite formation contributed to the transfer of many of the typical trace elements enriched in the upper crust. Instead, biotite dehydration melting in the Sierra de Quilmes had the opposite effect of typical crustal differentiation, concentrating these trace elements in the residual source, possibly reflecting the lack of a pressure gradient driving extraction of residuum-rich magmas.
Fil: Wolfram, L. C.. Monash University; Australia
Fil: Weinberg, Roberto F.. Monash University; Australia
Fil: Hasalová, Pavlína. Czech Geological Survey; República Checa
Fil: Becchio, Raul Alberto. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Materia
CRUSTAL DIFFERENTIATION
MONAZITE DISSOLUTION
PARTIAL MELTING
RESIDUUM ENTRAINMENT
ZIRCON
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:11336/98462

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network_name_str CONICET Digital (CONICET)
spelling How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW ArgentinaWolfram, L. C.Weinberg, Roberto F.Hasalová, PavlínaBecchio, Raul AlbertoCRUSTAL DIFFERENTIATIONMONAZITE DISSOLUTIONPARTIAL MELTINGRESIDUUM ENTRAINMENTZIRCONhttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1Compositional variability of crustal-derived granites has been attributed to a multitude of processes. Although there has been much discussion on the entrainment of residuum and its effect on granite magma chemistry, the exact nature of what is entrained and when entrainment is efficient remain unclear. We describe the relationship between granulite-facies migmatites and granites in the Sierra de Quilmes, NW Argentina, focusing on how the style of melt segregation affects its ability to disaggregate the source and carry residual minerals, and therefore control granite chemistry. The north-south-trending mountains that define the region known as the Sierras Pampeanas are characterized by variably metamorphosed turbidites of the Neoproterozoic-Cambrian Puncoviscana Formation. Early Ordovician subduction on the western Gondwana margin produced widespread high-T, low-P metamorphism of the turbidites during the Famatinian orogeny (~500- 440 Ma), resulting in extensive anatexis and granite plutonism. The Tolombón complex of the northern Sierra de Quilmes is a tilted metamorphic sequence in the northern Sierras Pampeanas, providing near-complete exposure from granulite-facies magma source rocks in the SW to granite emplacement levels in amphibolite- and greenschist-facies rocks in the NE. Anatexis is associated with fluid-absent incongruent breakdown of biotite in granulite-facies rocks, evidenced by the presence of peritectic Grt±Crd±Opx. The western Tolombón complex is separated from the Ovejeria complex by a shear zone. The Ovejeria complex is distinguished by a generally higher melt fraction, and is dominated by gradational contacts from metatexites to diatexites and granites. In contrast, in the Tolombón complex, with few examples of diatexites, magmas are more commonly extracted from metatexites, and migrate to feed stocks and plutons at higher crustal levels. Granites derived from diatexites tend to remain close to the source and retain strong compositional similarities to the Puncoviscana Formation protolith, indicating significant mobilization of residuum, and defining the Ovejeria style of granite formation. Granites derived dominantly from melt extraction from metatexites tend to be leucogranites with compositions approaching those of experimental melts, defining the Tolombón style of granite formation. Magma derived through either mechanism undergoes further differentiation, giving rise to the compositionally diverse suite of rocks common to most anatectic terranes. Magmas derived through the Tolombón style of melt extraction are leucocratic and impoverished in light rare earth elements (LREE), Th, and Zr compared with both the sedimentary source rocks and residuum-rich magmas derived through the Ovejeria style of granite formation. The low solubility of zircon and monazite in relatively dry, peraluminous leucogranite melts guarantees that Zr, Th, and LREE behave as compatible elements during dehydration melting of metasedimentary packages. Therefore, neither style of granite formation contributed to the transfer of many of the typical trace elements enriched in the upper crust. Instead, biotite dehydration melting in the Sierra de Quilmes had the opposite effect of typical crustal differentiation, concentrating these trace elements in the residual source, possibly reflecting the lack of a pressure gradient driving extraction of residuum-rich magmas.Fil: Wolfram, L. C.. Monash University; AustraliaFil: Weinberg, Roberto F.. Monash University; AustraliaFil: Hasalová, Pavlína. Czech Geological Survey; República ChecaFil: Becchio, Raul Alberto. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaOxford University Press2017-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/98462Wolfram, L. C.; Weinberg, Roberto F.; Hasalová, Pavlína; Becchio, Raul Alberto; How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW Argentina; Oxford University Press; Journal Of Petrology; 58; 12; 12-2017; 2339-23640022-3530CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1093/petrology/egy010info:eu-repo/semantics/altIdentifier/url/https://academic.oup.com/petrology/article/58/12/2339/4857452info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:41:14Zoai:ri.conicet.gov.ar:11336/98462instacron: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 09:41:15.01CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW Argentina
title How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW Argentina
spellingShingle How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW Argentina
Wolfram, L. C.
CRUSTAL DIFFERENTIATION
MONAZITE DISSOLUTION
PARTIAL MELTING
RESIDUUM ENTRAINMENT
ZIRCON
title_short How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW Argentina
title_full How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW Argentina
title_fullStr How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW Argentina
title_full_unstemmed How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW Argentina
title_sort How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW Argentina
dc.creator.none.fl_str_mv Wolfram, L. C.
Weinberg, Roberto F.
Hasalová, Pavlína
Becchio, Raul Alberto
author Wolfram, L. C.
author_facet Wolfram, L. C.
Weinberg, Roberto F.
Hasalová, Pavlína
Becchio, Raul Alberto
author_role author
author2 Weinberg, Roberto F.
Hasalová, Pavlína
Becchio, Raul Alberto
author2_role author
author
author
dc.subject.none.fl_str_mv CRUSTAL DIFFERENTIATION
MONAZITE DISSOLUTION
PARTIAL MELTING
RESIDUUM ENTRAINMENT
ZIRCON
topic CRUSTAL DIFFERENTIATION
MONAZITE DISSOLUTION
PARTIAL MELTING
RESIDUUM ENTRAINMENT
ZIRCON
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Compositional variability of crustal-derived granites has been attributed to a multitude of processes. Although there has been much discussion on the entrainment of residuum and its effect on granite magma chemistry, the exact nature of what is entrained and when entrainment is efficient remain unclear. We describe the relationship between granulite-facies migmatites and granites in the Sierra de Quilmes, NW Argentina, focusing on how the style of melt segregation affects its ability to disaggregate the source and carry residual minerals, and therefore control granite chemistry. The north-south-trending mountains that define the region known as the Sierras Pampeanas are characterized by variably metamorphosed turbidites of the Neoproterozoic-Cambrian Puncoviscana Formation. Early Ordovician subduction on the western Gondwana margin produced widespread high-T, low-P metamorphism of the turbidites during the Famatinian orogeny (~500- 440 Ma), resulting in extensive anatexis and granite plutonism. The Tolombón complex of the northern Sierra de Quilmes is a tilted metamorphic sequence in the northern Sierras Pampeanas, providing near-complete exposure from granulite-facies magma source rocks in the SW to granite emplacement levels in amphibolite- and greenschist-facies rocks in the NE. Anatexis is associated with fluid-absent incongruent breakdown of biotite in granulite-facies rocks, evidenced by the presence of peritectic Grt±Crd±Opx. The western Tolombón complex is separated from the Ovejeria complex by a shear zone. The Ovejeria complex is distinguished by a generally higher melt fraction, and is dominated by gradational contacts from metatexites to diatexites and granites. In contrast, in the Tolombón complex, with few examples of diatexites, magmas are more commonly extracted from metatexites, and migrate to feed stocks and plutons at higher crustal levels. Granites derived from diatexites tend to remain close to the source and retain strong compositional similarities to the Puncoviscana Formation protolith, indicating significant mobilization of residuum, and defining the Ovejeria style of granite formation. Granites derived dominantly from melt extraction from metatexites tend to be leucogranites with compositions approaching those of experimental melts, defining the Tolombón style of granite formation. Magma derived through either mechanism undergoes further differentiation, giving rise to the compositionally diverse suite of rocks common to most anatectic terranes. Magmas derived through the Tolombón style of melt extraction are leucocratic and impoverished in light rare earth elements (LREE), Th, and Zr compared with both the sedimentary source rocks and residuum-rich magmas derived through the Ovejeria style of granite formation. The low solubility of zircon and monazite in relatively dry, peraluminous leucogranite melts guarantees that Zr, Th, and LREE behave as compatible elements during dehydration melting of metasedimentary packages. Therefore, neither style of granite formation contributed to the transfer of many of the typical trace elements enriched in the upper crust. Instead, biotite dehydration melting in the Sierra de Quilmes had the opposite effect of typical crustal differentiation, concentrating these trace elements in the residual source, possibly reflecting the lack of a pressure gradient driving extraction of residuum-rich magmas.
Fil: Wolfram, L. C.. Monash University; Australia
Fil: Weinberg, Roberto F.. Monash University; Australia
Fil: Hasalová, Pavlína. Czech Geological Survey; República Checa
Fil: Becchio, Raul Alberto. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
description Compositional variability of crustal-derived granites has been attributed to a multitude of processes. Although there has been much discussion on the entrainment of residuum and its effect on granite magma chemistry, the exact nature of what is entrained and when entrainment is efficient remain unclear. We describe the relationship between granulite-facies migmatites and granites in the Sierra de Quilmes, NW Argentina, focusing on how the style of melt segregation affects its ability to disaggregate the source and carry residual minerals, and therefore control granite chemistry. The north-south-trending mountains that define the region known as the Sierras Pampeanas are characterized by variably metamorphosed turbidites of the Neoproterozoic-Cambrian Puncoviscana Formation. Early Ordovician subduction on the western Gondwana margin produced widespread high-T, low-P metamorphism of the turbidites during the Famatinian orogeny (~500- 440 Ma), resulting in extensive anatexis and granite plutonism. The Tolombón complex of the northern Sierra de Quilmes is a tilted metamorphic sequence in the northern Sierras Pampeanas, providing near-complete exposure from granulite-facies magma source rocks in the SW to granite emplacement levels in amphibolite- and greenschist-facies rocks in the NE. Anatexis is associated with fluid-absent incongruent breakdown of biotite in granulite-facies rocks, evidenced by the presence of peritectic Grt±Crd±Opx. The western Tolombón complex is separated from the Ovejeria complex by a shear zone. The Ovejeria complex is distinguished by a generally higher melt fraction, and is dominated by gradational contacts from metatexites to diatexites and granites. In contrast, in the Tolombón complex, with few examples of diatexites, magmas are more commonly extracted from metatexites, and migrate to feed stocks and plutons at higher crustal levels. Granites derived from diatexites tend to remain close to the source and retain strong compositional similarities to the Puncoviscana Formation protolith, indicating significant mobilization of residuum, and defining the Ovejeria style of granite formation. Granites derived dominantly from melt extraction from metatexites tend to be leucogranites with compositions approaching those of experimental melts, defining the Tolombón style of granite formation. Magma derived through either mechanism undergoes further differentiation, giving rise to the compositionally diverse suite of rocks common to most anatectic terranes. Magmas derived through the Tolombón style of melt extraction are leucocratic and impoverished in light rare earth elements (LREE), Th, and Zr compared with both the sedimentary source rocks and residuum-rich magmas derived through the Ovejeria style of granite formation. The low solubility of zircon and monazite in relatively dry, peraluminous leucogranite melts guarantees that Zr, Th, and LREE behave as compatible elements during dehydration melting of metasedimentary packages. Therefore, neither style of granite formation contributed to the transfer of many of the typical trace elements enriched in the upper crust. Instead, biotite dehydration melting in the Sierra de Quilmes had the opposite effect of typical crustal differentiation, concentrating these trace elements in the residual source, possibly reflecting the lack of a pressure gradient driving extraction of residuum-rich magmas.
publishDate 2017
dc.date.none.fl_str_mv 2017-12
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/11336/98462
Wolfram, L. C.; Weinberg, Roberto F.; Hasalová, Pavlína; Becchio, Raul Alberto; How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW Argentina; Oxford University Press; Journal Of Petrology; 58; 12; 12-2017; 2339-2364
0022-3530
CONICET Digital
CONICET
url http://hdl.handle.net/11336/98462
identifier_str_mv Wolfram, L. C.; Weinberg, Roberto F.; Hasalová, Pavlína; Becchio, Raul Alberto; How melt segregation affects granite chemistry: Migmatites from the Sierra de Quilmes, NW Argentina; Oxford University Press; Journal Of Petrology; 58; 12; 12-2017; 2339-2364
0022-3530
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1093/petrology/egy010
info:eu-repo/semantics/altIdentifier/url/https://academic.oup.com/petrology/article/58/12/2339/4857452
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 Oxford University Press
publisher.none.fl_str_mv Oxford University Press
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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