Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study
- Autores
- Sola, Alfonso Manuel; Becchio, Raul Alberto; Pimentel, Márcio M.
- Año de publicación
- 2013
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- In Sierra de Molinos, Eastern Cordillera, NW Argentina the relationship between different components of an anatectic system developed in high temperature and low pressure conditions (800 °C and 4_6 kbar) can be observed. This allows the direct insight on the origin of migmatites and granites by anatexis of psammo?pelitic metasedimentary rocks. Four principal rock types have been recognized in Sierra de Molinos 1) metasedimentary rocks, assigned to the Puncoviscana Formation, 2) metatexite migmatites, 3) diatexite migmatites and 4) anatectic granitoids including: leucogranites, trondhjemites and pegmatite/aplitic dykes. The metamorphic grade increases from phyllites and schists at sub-greenschist and greenschist facies in the west, to upper amphibolite facies migmatites in the east. The mineral assemblages indicate a progressive increase in temperature without a significant change in pressure. The ages obtained for granitoids and migmatites are identical within analytical errors and indicate that the metamorphic peak and anatectic granite generation occurred at ca. 470 Ma. We use petrological and geochemical variations to investigate the formation of granite magma from migmatites that derived from metasedimentary protoliths. This provides evidence of the processes that occur during the evolution (melting, segregation and crystallization stages) of partially molten terranes, for which particular components: protolith, residuum and melt fractions are identified. Mass balance calculations are used to estimate the degree of partial melting and the degree of melt extraction in migmatites. Petrological and compositional data suggest that migmatites from this region are the result of open system processes and that fluid-absent melting played a major role in the formation of migmatites and leucogranites. The geochemical evidence suggests that the compositional variation within the anatectic rocks from Molinos can be understood as a result of 1) variable degrees of melt?residuum separation and 2) fractional crystallization of the anatectic melt. Compared to the protolith, most of the migmatites have melt-depleted compositions (up to 0.25 of melt extraction). In the same fashion most of the leucosomes represent cumulate products of fractional crystallization. This means that they have lost some liquid of evolved composition and represent evidence of the melt extraction pathways and linkage to the magma ascent conduits.
Fil: Sola, Alfonso Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Conicet - Salta. Instituto de Investigaciones En Energía No Convencional; Argentina. Universidad Nacional de Salta; Argentina
Fil: Becchio, Raul Alberto. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Conicet - Salta. Instituto de Investigaciones En Energía No Convencional; Argentina
Fil: Pimentel, Márcio M.. Universidade Do Brasilia. Instituto de Geociencias; - Materia
-
Migmatites
Leucogranites
Geochemistry
Partial Melting
Nw Argentina
Famatinian Belt - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
- Repositorio
- Institución
- Consejo Nacional de Investigaciones Científicas y Técnicas
- OAI Identificador
- oai:ri.conicet.gov.ar:11336/1472
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Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical studySola, Alfonso ManuelBecchio, Raul AlbertoPimentel, Márcio M.MigmatitesLeucogranitesGeochemistryPartial MeltingNw ArgentinaFamatinian Belthttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1In Sierra de Molinos, Eastern Cordillera, NW Argentina the relationship between different components of an anatectic system developed in high temperature and low pressure conditions (800 °C and 4_6 kbar) can be observed. This allows the direct insight on the origin of migmatites and granites by anatexis of psammo?pelitic metasedimentary rocks. Four principal rock types have been recognized in Sierra de Molinos 1) metasedimentary rocks, assigned to the Puncoviscana Formation, 2) metatexite migmatites, 3) diatexite migmatites and 4) anatectic granitoids including: leucogranites, trondhjemites and pegmatite/aplitic dykes. The metamorphic grade increases from phyllites and schists at sub-greenschist and greenschist facies in the west, to upper amphibolite facies migmatites in the east. The mineral assemblages indicate a progressive increase in temperature without a significant change in pressure. The ages obtained for granitoids and migmatites are identical within analytical errors and indicate that the metamorphic peak and anatectic granite generation occurred at ca. 470 Ma. We use petrological and geochemical variations to investigate the formation of granite magma from migmatites that derived from metasedimentary protoliths. This provides evidence of the processes that occur during the evolution (melting, segregation and crystallization stages) of partially molten terranes, for which particular components: protolith, residuum and melt fractions are identified. Mass balance calculations are used to estimate the degree of partial melting and the degree of melt extraction in migmatites. Petrological and compositional data suggest that migmatites from this region are the result of open system processes and that fluid-absent melting played a major role in the formation of migmatites and leucogranites. The geochemical evidence suggests that the compositional variation within the anatectic rocks from Molinos can be understood as a result of 1) variable degrees of melt?residuum separation and 2) fractional crystallization of the anatectic melt. Compared to the protolith, most of the migmatites have melt-depleted compositions (up to 0.25 of melt extraction). In the same fashion most of the leucosomes represent cumulate products of fractional crystallization. This means that they have lost some liquid of evolved composition and represent evidence of the melt extraction pathways and linkage to the magma ascent conduits.Fil: Sola, Alfonso Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Conicet - Salta. Instituto de Investigaciones En Energía No Convencional; Argentina. Universidad Nacional de Salta; ArgentinaFil: Becchio, Raul Alberto. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Conicet - Salta. Instituto de Investigaciones En Energía No Convencional; ArgentinaFil: Pimentel, Márcio M.. Universidade Do Brasilia. Instituto de Geociencias;Elsevier Science Bv2013-09info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/1472Sola, Alfonso Manuel; Becchio, Raul Alberto; Pimentel, Márcio M.; Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study; Elsevier Science Bv; Lithos; 177; 9-2013; 470-4910024-4937enginfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.lithos.2013.07.025info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:54:33Zoai:ri.conicet.gov.ar:11336/1472instacron: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 09:54:33.382CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse |
dc.title.none.fl_str_mv |
Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study |
title |
Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study |
spellingShingle |
Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study Sola, Alfonso Manuel Migmatites Leucogranites Geochemistry Partial Melting Nw Argentina Famatinian Belt |
title_short |
Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study |
title_full |
Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study |
title_fullStr |
Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study |
title_full_unstemmed |
Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study |
title_sort |
Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study |
dc.creator.none.fl_str_mv |
Sola, Alfonso Manuel Becchio, Raul Alberto Pimentel, Márcio M. |
author |
Sola, Alfonso Manuel |
author_facet |
Sola, Alfonso Manuel Becchio, Raul Alberto Pimentel, Márcio M. |
author_role |
author |
author2 |
Becchio, Raul Alberto Pimentel, Márcio M. |
author2_role |
author author |
dc.subject.none.fl_str_mv |
Migmatites Leucogranites Geochemistry Partial Melting Nw Argentina Famatinian Belt |
topic |
Migmatites Leucogranites Geochemistry Partial Melting Nw Argentina Famatinian Belt |
purl_subject.fl_str_mv |
https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 |
dc.description.none.fl_txt_mv |
In Sierra de Molinos, Eastern Cordillera, NW Argentina the relationship between different components of an anatectic system developed in high temperature and low pressure conditions (800 °C and 4_6 kbar) can be observed. This allows the direct insight on the origin of migmatites and granites by anatexis of psammo?pelitic metasedimentary rocks. Four principal rock types have been recognized in Sierra de Molinos 1) metasedimentary rocks, assigned to the Puncoviscana Formation, 2) metatexite migmatites, 3) diatexite migmatites and 4) anatectic granitoids including: leucogranites, trondhjemites and pegmatite/aplitic dykes. The metamorphic grade increases from phyllites and schists at sub-greenschist and greenschist facies in the west, to upper amphibolite facies migmatites in the east. The mineral assemblages indicate a progressive increase in temperature without a significant change in pressure. The ages obtained for granitoids and migmatites are identical within analytical errors and indicate that the metamorphic peak and anatectic granite generation occurred at ca. 470 Ma. We use petrological and geochemical variations to investigate the formation of granite magma from migmatites that derived from metasedimentary protoliths. This provides evidence of the processes that occur during the evolution (melting, segregation and crystallization stages) of partially molten terranes, for which particular components: protolith, residuum and melt fractions are identified. Mass balance calculations are used to estimate the degree of partial melting and the degree of melt extraction in migmatites. Petrological and compositional data suggest that migmatites from this region are the result of open system processes and that fluid-absent melting played a major role in the formation of migmatites and leucogranites. The geochemical evidence suggests that the compositional variation within the anatectic rocks from Molinos can be understood as a result of 1) variable degrees of melt?residuum separation and 2) fractional crystallization of the anatectic melt. Compared to the protolith, most of the migmatites have melt-depleted compositions (up to 0.25 of melt extraction). In the same fashion most of the leucosomes represent cumulate products of fractional crystallization. This means that they have lost some liquid of evolved composition and represent evidence of the melt extraction pathways and linkage to the magma ascent conduits. Fil: Sola, Alfonso Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Conicet - Salta. Instituto de Investigaciones En Energía No Convencional; Argentina. Universidad Nacional de Salta; Argentina Fil: Becchio, Raul Alberto. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Conicet - Salta. Instituto de Investigaciones En Energía No Convencional; Argentina Fil: Pimentel, Márcio M.. Universidade Do Brasilia. Instituto de Geociencias; |
description |
In Sierra de Molinos, Eastern Cordillera, NW Argentina the relationship between different components of an anatectic system developed in high temperature and low pressure conditions (800 °C and 4_6 kbar) can be observed. This allows the direct insight on the origin of migmatites and granites by anatexis of psammo?pelitic metasedimentary rocks. Four principal rock types have been recognized in Sierra de Molinos 1) metasedimentary rocks, assigned to the Puncoviscana Formation, 2) metatexite migmatites, 3) diatexite migmatites and 4) anatectic granitoids including: leucogranites, trondhjemites and pegmatite/aplitic dykes. The metamorphic grade increases from phyllites and schists at sub-greenschist and greenschist facies in the west, to upper amphibolite facies migmatites in the east. The mineral assemblages indicate a progressive increase in temperature without a significant change in pressure. The ages obtained for granitoids and migmatites are identical within analytical errors and indicate that the metamorphic peak and anatectic granite generation occurred at ca. 470 Ma. We use petrological and geochemical variations to investigate the formation of granite magma from migmatites that derived from metasedimentary protoliths. This provides evidence of the processes that occur during the evolution (melting, segregation and crystallization stages) of partially molten terranes, for which particular components: protolith, residuum and melt fractions are identified. Mass balance calculations are used to estimate the degree of partial melting and the degree of melt extraction in migmatites. Petrological and compositional data suggest that migmatites from this region are the result of open system processes and that fluid-absent melting played a major role in the formation of migmatites and leucogranites. The geochemical evidence suggests that the compositional variation within the anatectic rocks from Molinos can be understood as a result of 1) variable degrees of melt?residuum separation and 2) fractional crystallization of the anatectic melt. Compared to the protolith, most of the migmatites have melt-depleted compositions (up to 0.25 of melt extraction). In the same fashion most of the leucosomes represent cumulate products of fractional crystallization. This means that they have lost some liquid of evolved composition and represent evidence of the melt extraction pathways and linkage to the magma ascent conduits. |
publishDate |
2013 |
dc.date.none.fl_str_mv |
2013-09 |
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/11336/1472 Sola, Alfonso Manuel; Becchio, Raul Alberto; Pimentel, Márcio M.; Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study; Elsevier Science Bv; Lithos; 177; 9-2013; 470-491 0024-4937 |
url |
http://hdl.handle.net/11336/1472 |
identifier_str_mv |
Sola, Alfonso Manuel; Becchio, Raul Alberto; Pimentel, Márcio M.; Petrogenesis of migmatites and leucogranites from Sierra de Molinos, Salta, Northwest Argentina: A petrologic and geochemical study; Elsevier Science Bv; Lithos; 177; 9-2013; 470-491 0024-4937 |
dc.language.none.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.lithos.2013.07.025 |
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 |
Elsevier Science Bv |
publisher.none.fl_str_mv |
Elsevier Science Bv |
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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1844613656073994240 |
score |
13.070432 |