La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment

Autores
Moreira, Pilar; Fernandez, Raul Roberto
Año de publicación
2015
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The La Josefina Jurassic epithermal Au-Ag deposit located in Patagonia, Argentina, developed in an extensional setting of a back-arc environment, associated with a widespread Middle-Late Jurassic calc-alkaline volcanism. Block faulting has juxtaposed shallow level features evidenced by hot spring manifestations, hydrothermal eruption breccias and Au-rich veins, which suggest that mineralization in these veins, could extend far below the depths already tested by core drilling. Veins are filled by quartz, chalcedony, opal and minor adularia and barite with massive, comb, cockade, colloform-crustiform bandings and lattice-bladed textures. Ore minerals include electrum, Ag-rich sulfosalts (freibergite), pyrite, galena, sphalerite, chalcopyrite and specular hematite with minor arsenopyrite, marcasite, tetrahedrite and bornite. Four mineralizing stages have been identified, the first two (S1 and S2) are Au and Ag-rich, with temperatures ranging from 225 to 290° and salinities from up to 15 wt.% in S1 decreasing to ~1 wt.% NaCl in S2. The third stage (S3) displays higher base metal contents at lower temperatures (~200 °C). Finally, the last stage (S4) is barren with temperatures lower than 100 °C. Veins are surrounded by a proximal alteration halo of quartz + pyrite ± adularia ± illite followed outwards by illite/smectite interstratified clays and smectites (with less chlorite) to a propylitic zone. Stable isotope values calculated for the fluids show a mostly meteoric origin for mineralization fluids. Such distinct features place the La Josefina deposits in a hot spring environment with evidences of being formed at a proximal position of the Jurassic paleosurface and paleowater level.
Fil: Moreira, Pilar. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Fernandez, Raul Roberto. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Materia
Au-Ag Veins
Epithermal
Jurassic
Paleohot Spring Occurrences
Patagonia Argentina
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/37776

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network_name_str CONICET Digital (CONICET)
spelling La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environmentMoreira, PilarFernandez, Raul RobertoAu-Ag VeinsEpithermalJurassicPaleohot Spring OccurrencesPatagonia Argentinahttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1The La Josefina Jurassic epithermal Au-Ag deposit located in Patagonia, Argentina, developed in an extensional setting of a back-arc environment, associated with a widespread Middle-Late Jurassic calc-alkaline volcanism. Block faulting has juxtaposed shallow level features evidenced by hot spring manifestations, hydrothermal eruption breccias and Au-rich veins, which suggest that mineralization in these veins, could extend far below the depths already tested by core drilling. Veins are filled by quartz, chalcedony, opal and minor adularia and barite with massive, comb, cockade, colloform-crustiform bandings and lattice-bladed textures. Ore minerals include electrum, Ag-rich sulfosalts (freibergite), pyrite, galena, sphalerite, chalcopyrite and specular hematite with minor arsenopyrite, marcasite, tetrahedrite and bornite. Four mineralizing stages have been identified, the first two (S1 and S2) are Au and Ag-rich, with temperatures ranging from 225 to 290° and salinities from up to 15 wt.% in S1 decreasing to ~1 wt.% NaCl in S2. The third stage (S3) displays higher base metal contents at lower temperatures (~200 °C). Finally, the last stage (S4) is barren with temperatures lower than 100 °C. Veins are surrounded by a proximal alteration halo of quartz + pyrite ± adularia ± illite followed outwards by illite/smectite interstratified clays and smectites (with less chlorite) to a propylitic zone. Stable isotope values calculated for the fluids show a mostly meteoric origin for mineralization fluids. Such distinct features place the La Josefina deposits in a hot spring environment with evidences of being formed at a proximal position of the Jurassic paleosurface and paleowater level.Fil: Moreira, Pilar. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernandez, Raul Roberto. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaElsevier Science2015-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/37776Moreira, Pilar; Fernandez, Raul Roberto; La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment; Elsevier Science; Ore Geology Reviews; 67; 1-2015; 297-3130169-1368CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.oregeorev.2014.12.012info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0169136814003680info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-03T09:57:58Zoai:ri.conicet.gov.ar:11336/37776instacron: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 09:57:58.737CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment
title La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment
spellingShingle La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment
Moreira, Pilar
Au-Ag Veins
Epithermal
Jurassic
Paleohot Spring Occurrences
Patagonia Argentina
title_short La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment
title_full La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment
title_fullStr La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment
title_full_unstemmed La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment
title_sort La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment
dc.creator.none.fl_str_mv Moreira, Pilar
Fernandez, Raul Roberto
author Moreira, Pilar
author_facet Moreira, Pilar
Fernandez, Raul Roberto
author_role author
author2 Fernandez, Raul Roberto
author2_role author
dc.subject.none.fl_str_mv Au-Ag Veins
Epithermal
Jurassic
Paleohot Spring Occurrences
Patagonia Argentina
topic Au-Ag Veins
Epithermal
Jurassic
Paleohot Spring Occurrences
Patagonia Argentina
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv The La Josefina Jurassic epithermal Au-Ag deposit located in Patagonia, Argentina, developed in an extensional setting of a back-arc environment, associated with a widespread Middle-Late Jurassic calc-alkaline volcanism. Block faulting has juxtaposed shallow level features evidenced by hot spring manifestations, hydrothermal eruption breccias and Au-rich veins, which suggest that mineralization in these veins, could extend far below the depths already tested by core drilling. Veins are filled by quartz, chalcedony, opal and minor adularia and barite with massive, comb, cockade, colloform-crustiform bandings and lattice-bladed textures. Ore minerals include electrum, Ag-rich sulfosalts (freibergite), pyrite, galena, sphalerite, chalcopyrite and specular hematite with minor arsenopyrite, marcasite, tetrahedrite and bornite. Four mineralizing stages have been identified, the first two (S1 and S2) are Au and Ag-rich, with temperatures ranging from 225 to 290° and salinities from up to 15 wt.% in S1 decreasing to ~1 wt.% NaCl in S2. The third stage (S3) displays higher base metal contents at lower temperatures (~200 °C). Finally, the last stage (S4) is barren with temperatures lower than 100 °C. Veins are surrounded by a proximal alteration halo of quartz + pyrite ± adularia ± illite followed outwards by illite/smectite interstratified clays and smectites (with less chlorite) to a propylitic zone. Stable isotope values calculated for the fluids show a mostly meteoric origin for mineralization fluids. Such distinct features place the La Josefina deposits in a hot spring environment with evidences of being formed at a proximal position of the Jurassic paleosurface and paleowater level.
Fil: Moreira, Pilar. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Fernandez, Raul Roberto. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
description The La Josefina Jurassic epithermal Au-Ag deposit located in Patagonia, Argentina, developed in an extensional setting of a back-arc environment, associated with a widespread Middle-Late Jurassic calc-alkaline volcanism. Block faulting has juxtaposed shallow level features evidenced by hot spring manifestations, hydrothermal eruption breccias and Au-rich veins, which suggest that mineralization in these veins, could extend far below the depths already tested by core drilling. Veins are filled by quartz, chalcedony, opal and minor adularia and barite with massive, comb, cockade, colloform-crustiform bandings and lattice-bladed textures. Ore minerals include electrum, Ag-rich sulfosalts (freibergite), pyrite, galena, sphalerite, chalcopyrite and specular hematite with minor arsenopyrite, marcasite, tetrahedrite and bornite. Four mineralizing stages have been identified, the first two (S1 and S2) are Au and Ag-rich, with temperatures ranging from 225 to 290° and salinities from up to 15 wt.% in S1 decreasing to ~1 wt.% NaCl in S2. The third stage (S3) displays higher base metal contents at lower temperatures (~200 °C). Finally, the last stage (S4) is barren with temperatures lower than 100 °C. Veins are surrounded by a proximal alteration halo of quartz + pyrite ± adularia ± illite followed outwards by illite/smectite interstratified clays and smectites (with less chlorite) to a propylitic zone. Stable isotope values calculated for the fluids show a mostly meteoric origin for mineralization fluids. Such distinct features place the La Josefina deposits in a hot spring environment with evidences of being formed at a proximal position of the Jurassic paleosurface and paleowater level.
publishDate 2015
dc.date.none.fl_str_mv 2015-01
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/11336/37776
Moreira, Pilar; Fernandez, Raul Roberto; La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment; Elsevier Science; Ore Geology Reviews; 67; 1-2015; 297-313
0169-1368
CONICET Digital
CONICET
url http://hdl.handle.net/11336/37776
identifier_str_mv Moreira, Pilar; Fernandez, Raul Roberto; La Josefina Au-Ag deposit (Patagonia, Argentina): A Jurassic epithermal deposit formed in a hot spring environment; Elsevier Science; Ore Geology Reviews; 67; 1-2015; 297-313
0169-1368
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1016/j.oregeorev.2014.12.012
info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0169136814003680
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
application/pdf
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dc.publisher.none.fl_str_mv Elsevier Science
publisher.none.fl_str_mv Elsevier Science
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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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