The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionation

Autores
Heimann, Adriana; Yonts, Jason A.; Galliski, Miguel Angel
Año de publicación
2015
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Gahnite from LCT granitic pegmatites of the Comechingones (Blanca Dora, Juan Román, Magdalena, La Ona, and Sin Nombre pegmatites) and Conlara (Nancy pegmatite) pegmatite districts, Argentina, was analyzed to investigate the relationship between its chemistry, pegmatite mineralogy, and pegmatite melt evolution. Based on the molecular proportions of endmembers (gahnite, hercynite, spinel, and galaxite) the composition of gahnite in these pegmatites is defined by the ranges Ghn77.7– 91.0Hc7.4–20.0Spl0.25–3.37Glx0.7–2.4, which fall within the previously defined field for granitic pegmatites. Gahnite from the Nancy pegmatite has higher Mg and Mn contents than gahnite from the pegmatites of the Comechingones pegmatite district. Chemical variation within gahnite crystals is characterized by higher Zn (∼2.8 wt.% ZnO) and lower Fe (∼2.6 wt.% FeO) contents near the edge compared to inner portions, reflecting the evolution of the pegmatite melt via simple fractional crystallization. Other crystals show a complex zoning pattern of oscillations in Fe and Zn contents within the crystal and higher Zn and lower Fe near the rim compared to the core. A plot of molecular Fe2+ + Mg versus Zn + Mn yields a strong negative correlation and best displays the substitutions within the gahnite crystal structure and is the best to determine relative pegmatite melt evolution. Without implying a co-magmatic origin of the pegmatites, based on pegmatite mineralogy, Zn contents, Zn/Fe2+ ratios, and coupled Fe2++Mg and Zn+Mn values in gahnite, the relative degree of evolution of the pegmatites increases in the order: Sin Nombre → Magdalena → Juan Román → Blanca Dora → Nancy → La Ona. Based on the composition of gahnite in worldwide granitic pegmatites reported in the literature and those obtained here, the composition of gahnite in these rocks is defined by the endmember ranges Ghn50–98Hc1–50Spl0–7. This study shows that the major element composition of gahnite in granitic pegmatites can effectively be used to determine the relative degree of evolution of pegmatite-forming melts.
Fil: Heimann, Adriana. East Carolina University; Estados Unidos
Fil: Yonts, Jason A.. East Carolina University; Estados Unidos
Fil: Galliski, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina
Materia
ARGENTINA
CHEMISTRY
GAHNITE
GRANITIC PEGMATITES
MELT EVOLUTION
PAMPEAN PEGMATITE PROVINCE
ZN
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:11336/182845

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oai_identifier_str oai:ri.conicet.gov.ar:11336/182845
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionationHeimann, AdrianaYonts, Jason A.Galliski, Miguel AngelARGENTINACHEMISTRYGAHNITEGRANITIC PEGMATITESMELT EVOLUTIONPAMPEAN PEGMATITE PROVINCEZNhttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1Gahnite from LCT granitic pegmatites of the Comechingones (Blanca Dora, Juan Román, Magdalena, La Ona, and Sin Nombre pegmatites) and Conlara (Nancy pegmatite) pegmatite districts, Argentina, was analyzed to investigate the relationship between its chemistry, pegmatite mineralogy, and pegmatite melt evolution. Based on the molecular proportions of endmembers (gahnite, hercynite, spinel, and galaxite) the composition of gahnite in these pegmatites is defined by the ranges Ghn77.7– 91.0Hc7.4–20.0Spl0.25–3.37Glx0.7–2.4, which fall within the previously defined field for granitic pegmatites. Gahnite from the Nancy pegmatite has higher Mg and Mn contents than gahnite from the pegmatites of the Comechingones pegmatite district. Chemical variation within gahnite crystals is characterized by higher Zn (∼2.8 wt.% ZnO) and lower Fe (∼2.6 wt.% FeO) contents near the edge compared to inner portions, reflecting the evolution of the pegmatite melt via simple fractional crystallization. Other crystals show a complex zoning pattern of oscillations in Fe and Zn contents within the crystal and higher Zn and lower Fe near the rim compared to the core. A plot of molecular Fe2+ + Mg versus Zn + Mn yields a strong negative correlation and best displays the substitutions within the gahnite crystal structure and is the best to determine relative pegmatite melt evolution. Without implying a co-magmatic origin of the pegmatites, based on pegmatite mineralogy, Zn contents, Zn/Fe2+ ratios, and coupled Fe2++Mg and Zn+Mn values in gahnite, the relative degree of evolution of the pegmatites increases in the order: Sin Nombre → Magdalena → Juan Román → Blanca Dora → Nancy → La Ona. Based on the composition of gahnite in worldwide granitic pegmatites reported in the literature and those obtained here, the composition of gahnite in these rocks is defined by the endmember ranges Ghn50–98Hc1–50Spl0–7. This study shows that the major element composition of gahnite in granitic pegmatites can effectively be used to determine the relative degree of evolution of pegmatite-forming melts.Fil: Heimann, Adriana. East Carolina University; Estados UnidosFil: Yonts, Jason A.. East Carolina University; Estados UnidosFil: Galliski, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaMineralogical Association of Canada2015-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/182845Heimann, Adriana; Yonts, Jason A.; Galliski, Miguel Angel; The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionation; Mineralogical Association of Canada; Canadian Mineralogist; 53; 6; 12-2015; 991-10130008-44761499-1276CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.3749/canmin.1400100info:eu-repo/semantics/altIdentifier/url/https://pubs.geoscienceworld.org/canmin/article/53/6/991/521457/The-Composition-of-Gahnite-in-Granitic-Pegmatitesinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T10:11:43Zoai:ri.conicet.gov.ar:11336/182845instacron: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 10:11:44.709CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionation
title The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionation
spellingShingle The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionation
Heimann, Adriana
ARGENTINA
CHEMISTRY
GAHNITE
GRANITIC PEGMATITES
MELT EVOLUTION
PAMPEAN PEGMATITE PROVINCE
ZN
title_short The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionation
title_full The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionation
title_fullStr The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionation
title_full_unstemmed The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionation
title_sort The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionation
dc.creator.none.fl_str_mv Heimann, Adriana
Yonts, Jason A.
Galliski, Miguel Angel
author Heimann, Adriana
author_facet Heimann, Adriana
Yonts, Jason A.
Galliski, Miguel Angel
author_role author
author2 Yonts, Jason A.
Galliski, Miguel Angel
author2_role author
author
dc.subject.none.fl_str_mv ARGENTINA
CHEMISTRY
GAHNITE
GRANITIC PEGMATITES
MELT EVOLUTION
PAMPEAN PEGMATITE PROVINCE
ZN
topic ARGENTINA
CHEMISTRY
GAHNITE
GRANITIC PEGMATITES
MELT EVOLUTION
PAMPEAN PEGMATITE PROVINCE
ZN
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Gahnite from LCT granitic pegmatites of the Comechingones (Blanca Dora, Juan Román, Magdalena, La Ona, and Sin Nombre pegmatites) and Conlara (Nancy pegmatite) pegmatite districts, Argentina, was analyzed to investigate the relationship between its chemistry, pegmatite mineralogy, and pegmatite melt evolution. Based on the molecular proportions of endmembers (gahnite, hercynite, spinel, and galaxite) the composition of gahnite in these pegmatites is defined by the ranges Ghn77.7– 91.0Hc7.4–20.0Spl0.25–3.37Glx0.7–2.4, which fall within the previously defined field for granitic pegmatites. Gahnite from the Nancy pegmatite has higher Mg and Mn contents than gahnite from the pegmatites of the Comechingones pegmatite district. Chemical variation within gahnite crystals is characterized by higher Zn (∼2.8 wt.% ZnO) and lower Fe (∼2.6 wt.% FeO) contents near the edge compared to inner portions, reflecting the evolution of the pegmatite melt via simple fractional crystallization. Other crystals show a complex zoning pattern of oscillations in Fe and Zn contents within the crystal and higher Zn and lower Fe near the rim compared to the core. A plot of molecular Fe2+ + Mg versus Zn + Mn yields a strong negative correlation and best displays the substitutions within the gahnite crystal structure and is the best to determine relative pegmatite melt evolution. Without implying a co-magmatic origin of the pegmatites, based on pegmatite mineralogy, Zn contents, Zn/Fe2+ ratios, and coupled Fe2++Mg and Zn+Mn values in gahnite, the relative degree of evolution of the pegmatites increases in the order: Sin Nombre → Magdalena → Juan Román → Blanca Dora → Nancy → La Ona. Based on the composition of gahnite in worldwide granitic pegmatites reported in the literature and those obtained here, the composition of gahnite in these rocks is defined by the endmember ranges Ghn50–98Hc1–50Spl0–7. This study shows that the major element composition of gahnite in granitic pegmatites can effectively be used to determine the relative degree of evolution of pegmatite-forming melts.
Fil: Heimann, Adriana. East Carolina University; Estados Unidos
Fil: Yonts, Jason A.. East Carolina University; Estados Unidos
Fil: Galliski, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina
description Gahnite from LCT granitic pegmatites of the Comechingones (Blanca Dora, Juan Román, Magdalena, La Ona, and Sin Nombre pegmatites) and Conlara (Nancy pegmatite) pegmatite districts, Argentina, was analyzed to investigate the relationship between its chemistry, pegmatite mineralogy, and pegmatite melt evolution. Based on the molecular proportions of endmembers (gahnite, hercynite, spinel, and galaxite) the composition of gahnite in these pegmatites is defined by the ranges Ghn77.7– 91.0Hc7.4–20.0Spl0.25–3.37Glx0.7–2.4, which fall within the previously defined field for granitic pegmatites. Gahnite from the Nancy pegmatite has higher Mg and Mn contents than gahnite from the pegmatites of the Comechingones pegmatite district. Chemical variation within gahnite crystals is characterized by higher Zn (∼2.8 wt.% ZnO) and lower Fe (∼2.6 wt.% FeO) contents near the edge compared to inner portions, reflecting the evolution of the pegmatite melt via simple fractional crystallization. Other crystals show a complex zoning pattern of oscillations in Fe and Zn contents within the crystal and higher Zn and lower Fe near the rim compared to the core. A plot of molecular Fe2+ + Mg versus Zn + Mn yields a strong negative correlation and best displays the substitutions within the gahnite crystal structure and is the best to determine relative pegmatite melt evolution. Without implying a co-magmatic origin of the pegmatites, based on pegmatite mineralogy, Zn contents, Zn/Fe2+ ratios, and coupled Fe2++Mg and Zn+Mn values in gahnite, the relative degree of evolution of the pegmatites increases in the order: Sin Nombre → Magdalena → Juan Román → Blanca Dora → Nancy → La Ona. Based on the composition of gahnite in worldwide granitic pegmatites reported in the literature and those obtained here, the composition of gahnite in these rocks is defined by the endmember ranges Ghn50–98Hc1–50Spl0–7. This study shows that the major element composition of gahnite in granitic pegmatites can effectively be used to determine the relative degree of evolution of pegmatite-forming melts.
publishDate 2015
dc.date.none.fl_str_mv 2015-12
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/11336/182845
Heimann, Adriana; Yonts, Jason A.; Galliski, Miguel Angel; The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionation; Mineralogical Association of Canada; Canadian Mineralogist; 53; 6; 12-2015; 991-1013
0008-4476
1499-1276
CONICET Digital
CONICET
url http://hdl.handle.net/11336/182845
identifier_str_mv Heimann, Adriana; Yonts, Jason A.; Galliski, Miguel Angel; The composition of gahnite in granitic pegmatites from the Pampean Pegmatite Province, Argentina: Implications for pegmatite fractionation; Mineralogical Association of Canada; Canadian Mineralogist; 53; 6; 12-2015; 991-1013
0008-4476
1499-1276
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.3749/canmin.1400100
info:eu-repo/semantics/altIdentifier/url/https://pubs.geoscienceworld.org/canmin/article/53/6/991/521457/The-Composition-of-Gahnite-in-Granitic-Pegmatites
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 Mineralogical Association of Canada
publisher.none.fl_str_mv Mineralogical Association of Canada
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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