Geochemistry of the Mamil Choique granitoids at Rio Chico, Río Negro, Argentina: Late Paleozoic crustal melting in the North Patagonian Massif

The Mamil Choique granitoids located in the SW border of the North Patagonian Massif consist of three peraluminous units: the banded Huenchuquil tonalites and granodiorites (HTG) and the Cerro Mojón biotite-muscovite monzogranites (CMG), which are intruded by the Nahuelfil monzogranites (NG). Accord...

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Autores principales: López de Luchi, M.G., Cerredo, M.E.
Formato: JOUR
Materias:
Geochemistry
Mamil Choique granitoids
North Patagonian Massif
Partial melting
Upper Paleozoic
emplacement
granitoid
granodiorite
igneous geochemistry
igneous intrusion
Paleozoic
partial melting
source rock
tonalite
trace element
Argentina
Patagonia
Rio Negro [Argentina]
South America
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_08959811_v25_n4_p526_LopezdeLuchi
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_08959811_v25_n4_p526_LopezdeLuchi2023-10-03T15:42:47Z Geochemistry of the Mamil Choique granitoids at Rio Chico, Río Negro, Argentina: Late Paleozoic crustal melting in the North Patagonian Massif López de Luchi, M.G. Cerredo, M.E. Geochemistry Mamil Choique granitoids North Patagonian Massif Partial melting Upper Paleozoic emplacement granitoid granodiorite igneous geochemistry igneous intrusion Paleozoic partial melting source rock tonalite trace element Argentina Patagonia Rio Negro [Argentina] South America The Mamil Choique granitoids located in the SW border of the North Patagonian Massif consist of three peraluminous units: the banded Huenchuquil tonalites and granodiorites (HTG) and the Cerro Mojón biotite-muscovite monzogranites (CMG), which are intruded by the Nahuelfil monzogranites (NG). According to their major and trace element relations, as well as a comparison with experimentally produced melts, HTG are compatible with partial melting of mafic source rocks at variable H2O contents; residual garnet is suggested by HREE depletion that indicates a minimum P of 9-10 kbar during melting. The CMG would have formed from partial melting of supracrustal fertile lithologies (biotite-bearing) in the presence of H2O-bearing volatile phase that resulted in Sr-rich, moderately depressed HREE melts, likely produced within the garnet stability field (7-10 kbar). The intrusive NG display distinct geochemical signatures (low Sr, no HREE depletion) and general major element ratios akin to the experimentally produced melt at low P (≈5 kbar). Regional constraints indicate that coeval HTG and CMG emplacement took place along a decompressing path slightly postdating the climax of regional metamorphism in the host Cushamen Formation. Later NG intrusion would have occurred at upper crustal levels. © 2007 Elsevier Ltd. All rights reserved. Fil:Cerredo, M.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_08959811_v25_n4_p526_LopezdeLuchi
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Geochemistry
Mamil Choique granitoids
North Patagonian Massif
Partial melting
Upper Paleozoic
emplacement
granitoid
granodiorite
igneous geochemistry
igneous intrusion
Paleozoic
partial melting
source rock
tonalite
trace element
Argentina
Patagonia
Rio Negro [Argentina]
South America
spellingShingle Geochemistry
Mamil Choique granitoids
North Patagonian Massif
Partial melting
Upper Paleozoic
emplacement
granitoid
granodiorite
igneous geochemistry
igneous intrusion
Paleozoic
partial melting
source rock
tonalite
trace element
Argentina
Patagonia
Rio Negro [Argentina]
South America
López de Luchi, M.G.
Cerredo, M.E.
Geochemistry of the Mamil Choique granitoids at Rio Chico, Río Negro, Argentina: Late Paleozoic crustal melting in the North Patagonian Massif
topic_facet Geochemistry
Mamil Choique granitoids
North Patagonian Massif
Partial melting
Upper Paleozoic
emplacement
granitoid
granodiorite
igneous geochemistry
igneous intrusion
Paleozoic
partial melting
source rock
tonalite
trace element
Argentina
Patagonia
Rio Negro [Argentina]
South America
description The Mamil Choique granitoids located in the SW border of the North Patagonian Massif consist of three peraluminous units: the banded Huenchuquil tonalites and granodiorites (HTG) and the Cerro Mojón biotite-muscovite monzogranites (CMG), which are intruded by the Nahuelfil monzogranites (NG). According to their major and trace element relations, as well as a comparison with experimentally produced melts, HTG are compatible with partial melting of mafic source rocks at variable H2O contents; residual garnet is suggested by HREE depletion that indicates a minimum P of 9-10 kbar during melting. The CMG would have formed from partial melting of supracrustal fertile lithologies (biotite-bearing) in the presence of H2O-bearing volatile phase that resulted in Sr-rich, moderately depressed HREE melts, likely produced within the garnet stability field (7-10 kbar). The intrusive NG display distinct geochemical signatures (low Sr, no HREE depletion) and general major element ratios akin to the experimentally produced melt at low P (≈5 kbar). Regional constraints indicate that coeval HTG and CMG emplacement took place along a decompressing path slightly postdating the climax of regional metamorphism in the host Cushamen Formation. Later NG intrusion would have occurred at upper crustal levels. © 2007 Elsevier Ltd. All rights reserved.
format JOUR
author López de Luchi, M.G.
Cerredo, M.E.
author_facet López de Luchi, M.G.
Cerredo, M.E.
author_sort López de Luchi, M.G.
title Geochemistry of the Mamil Choique granitoids at Rio Chico, Río Negro, Argentina: Late Paleozoic crustal melting in the North Patagonian Massif
title_short Geochemistry of the Mamil Choique granitoids at Rio Chico, Río Negro, Argentina: Late Paleozoic crustal melting in the North Patagonian Massif
title_full Geochemistry of the Mamil Choique granitoids at Rio Chico, Río Negro, Argentina: Late Paleozoic crustal melting in the North Patagonian Massif
title_fullStr Geochemistry of the Mamil Choique granitoids at Rio Chico, Río Negro, Argentina: Late Paleozoic crustal melting in the North Patagonian Massif
title_full_unstemmed Geochemistry of the Mamil Choique granitoids at Rio Chico, Río Negro, Argentina: Late Paleozoic crustal melting in the North Patagonian Massif
title_sort geochemistry of the mamil choique granitoids at rio chico, río negro, argentina: late paleozoic crustal melting in the north patagonian massif
url http://hdl.handle.net/20.500.12110/paper_08959811_v25_n4_p526_LopezdeLuchi
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