Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern...

Autores
Verdecchia, Sebastián Osvaldo; Collo, Gilda; Zandomeni, Priscila Soledad; Wunderlin, Cecilia Ayelén; Fehrmann, Mariano
Año de publicación
2019
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
In this work, crystallochemical indexes and geothermobarometric calculations are used together to estimate the P-T condition in low-grade metamorphic units of the San Luis Formation from Sierra de San Luis (Eastern Sierras Pampeanas of Argentina). Phyllites and slates from this formation record at least two episodes of white mica (Wm) and chlorite (Chl) growth associated with main D1-S1 (Wm2-Chl1) and local D2-S2 (Wm3-Chl2) stages. Mean KICIS values of 0.30 (Western Belt) and 0.23 Δ°2θ (Eastern Belt) were determined for the <2 μm fraction. Moreover, since the average grain size of the Wm2 exceeds 10 μm, KICIS values were also measured for the 10–20 μm fraction ranging between 0.22 and 0.24 Δ°2θ for both belts. For those fractions, the KICIS values indicate epizone conditions, associated with temperatures higher than 300 °C. These values are comparable to temperatures obtained from chlorite thermometers, 316°–416 °C in Western Belt and 261°-403 °C in the Eastern Belt. Pressure values for D1 stage constrained from chlorite – white mica – quartz – H2O equilibrium are 2.5–5.1 kbar in the Western Belt, and at 3.3–4.7 kbar in Eastern Belt. The pressures are consistent with white mica b parameter values measured in samples from Western Belt (9.006 to 9.025 Å) and Eastern Belt (9.003 to 9.020 Å), linked to intermediate thermal gradients (25–35 °C/km). The identification of increasing P-T condition paths in low-grade metasedimentary successions is not easy in the absence of higher grade rocks; in these situations, a systematic sampling and analysis of dozens of samples must be carried out. The very good correlation between crystallochemical index values (Kübler index and white mica b parameter) and thermobarometric calculations (empirical and semi-empirical chlorite thermometers and thermobarometry for chlorite – white mica – quartz – H2O equilibrium) presented in this work argues in favor of the development of a multiproxy study strategy in this type of low-grade metasedimentary successions that involve: (1) a systematic sampling of metapelite levels for X-ray diffraction study (mineralogical and crystallochemical indexes with a rapid implementation allowing a dense systematic sampling); (2) the recognition of variations in the P-T conditions from KI and b parameter values and the consequent selection of metapelitic samples for analyzing mineral chemistry and thermobarometric calculations. In order to facilitate these calculations, a user-friendly spreadsheet for crystallochemical indexes and chlorite thermometry calculations is also provided.
Fil: Verdecchia, Sebastián Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Fil: Collo, Gilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Fil: Zandomeni, Priscila Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Fil: Wunderlin, Cecilia Ayelén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Fil: Fehrmann, Mariano. Universidad Nacional de Córdoba; Facultad de Ciencias Exactas, Físicas y Naturales; Argentina
Materia
Kübler Index
White mica b parameter
Chlorite thermometry
Multi-equilibrium thermobarometry
Central-WesternArgentina
Nivel de accesibilidad
acceso abierto
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https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
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CONICET Digital (CONICET)
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Consejo Nacional de Investigaciones Científicas y Técnicas
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oai:ri.conicet.gov.ar:11336/121165
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network_name_str CONICET Digital (CONICET)
spelling Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern Sierras Pampeanas of ArgentinaVerdecchia, Sebastián OsvaldoCollo, GildaZandomeni, Priscila SoledadWunderlin, Cecilia AyelénFehrmann, MarianoKübler IndexWhite mica b parameterChlorite thermometryMulti-equilibrium thermobarometryCentral-WesternArgentinahttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1In this work, crystallochemical indexes and geothermobarometric calculations are used together to estimate the P-T condition in low-grade metamorphic units of the San Luis Formation from Sierra de San Luis (Eastern Sierras Pampeanas of Argentina). Phyllites and slates from this formation record at least two episodes of white mica (Wm) and chlorite (Chl) growth associated with main D1-S1 (Wm2-Chl1) and local D2-S2 (Wm3-Chl2) stages. Mean KICIS values of 0.30 (Western Belt) and 0.23 Δ°2θ (Eastern Belt) were determined for the <2 μm fraction. Moreover, since the average grain size of the Wm2 exceeds 10 μm, KICIS values were also measured for the 10–20 μm fraction ranging between 0.22 and 0.24 Δ°2θ for both belts. For those fractions, the KICIS values indicate epizone conditions, associated with temperatures higher than 300 °C. These values are comparable to temperatures obtained from chlorite thermometers, 316°–416 °C in Western Belt and 261°-403 °C in the Eastern Belt. Pressure values for D1 stage constrained from chlorite – white mica – quartz – H2O equilibrium are 2.5–5.1 kbar in the Western Belt, and at 3.3–4.7 kbar in Eastern Belt. The pressures are consistent with white mica b parameter values measured in samples from Western Belt (9.006 to 9.025 Å) and Eastern Belt (9.003 to 9.020 Å), linked to intermediate thermal gradients (25–35 °C/km). The identification of increasing P-T condition paths in low-grade metasedimentary successions is not easy in the absence of higher grade rocks; in these situations, a systematic sampling and analysis of dozens of samples must be carried out. The very good correlation between crystallochemical index values (Kübler index and white mica b parameter) and thermobarometric calculations (empirical and semi-empirical chlorite thermometers and thermobarometry for chlorite – white mica – quartz – H2O equilibrium) presented in this work argues in favor of the development of a multiproxy study strategy in this type of low-grade metasedimentary successions that involve: (1) a systematic sampling of metapelite levels for X-ray diffraction study (mineralogical and crystallochemical indexes with a rapid implementation allowing a dense systematic sampling); (2) the recognition of variations in the P-T conditions from KI and b parameter values and the consequent selection of metapelitic samples for analyzing mineral chemistry and thermobarometric calculations. In order to facilitate these calculations, a user-friendly spreadsheet for crystallochemical indexes and chlorite thermometry calculations is also provided.Fil: Verdecchia, Sebastián Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Collo, Gilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Zandomeni, Priscila Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Wunderlin, Cecilia Ayelén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Fehrmann, Mariano. Universidad Nacional de Córdoba; Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaElsevier Science2019-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/121165Verdecchia, Sebastián Osvaldo; Collo, Gilda; Zandomeni, Priscila Soledad; Wunderlin, Cecilia Ayelén; Fehrmann, Mariano; Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern Sierras Pampeanas of Argentina; Elsevier Science; Lithos; 324-325; 1-2019; 385-4010024-4937CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://linkinghub.elsevier.com/retrieve/pii/S0024493718304420info:eu-repo/semantics/altIdentifier/doi/10.1016/j.lithos.2018.11.021info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T10:39:49Zoai:ri.conicet.gov.ar:11336/121165instacron: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 10:39:49.557CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern Sierras Pampeanas of Argentina
title Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern Sierras Pampeanas of Argentina
spellingShingle Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern Sierras Pampeanas of Argentina
Verdecchia, Sebastián Osvaldo
Kübler Index
White mica b parameter
Chlorite thermometry
Multi-equilibrium thermobarometry
Central-WesternArgentina
title_short Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern Sierras Pampeanas of Argentina
title_full Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern Sierras Pampeanas of Argentina
title_fullStr Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern Sierras Pampeanas of Argentina
title_full_unstemmed Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern Sierras Pampeanas of Argentina
title_sort Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern Sierras Pampeanas of Argentina
dc.creator.none.fl_str_mv Verdecchia, Sebastián Osvaldo
Collo, Gilda
Zandomeni, Priscila Soledad
Wunderlin, Cecilia Ayelén
Fehrmann, Mariano
author Verdecchia, Sebastián Osvaldo
author_facet Verdecchia, Sebastián Osvaldo
Collo, Gilda
Zandomeni, Priscila Soledad
Wunderlin, Cecilia Ayelén
Fehrmann, Mariano
author_role author
author2 Collo, Gilda
Zandomeni, Priscila Soledad
Wunderlin, Cecilia Ayelén
Fehrmann, Mariano
author2_role author
author
author
author
dc.subject.none.fl_str_mv Kübler Index
White mica b parameter
Chlorite thermometry
Multi-equilibrium thermobarometry
Central-WesternArgentina
topic Kübler Index
White mica b parameter
Chlorite thermometry
Multi-equilibrium thermobarometry
Central-WesternArgentina
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 this work, crystallochemical indexes and geothermobarometric calculations are used together to estimate the P-T condition in low-grade metamorphic units of the San Luis Formation from Sierra de San Luis (Eastern Sierras Pampeanas of Argentina). Phyllites and slates from this formation record at least two episodes of white mica (Wm) and chlorite (Chl) growth associated with main D1-S1 (Wm2-Chl1) and local D2-S2 (Wm3-Chl2) stages. Mean KICIS values of 0.30 (Western Belt) and 0.23 Δ°2θ (Eastern Belt) were determined for the <2 μm fraction. Moreover, since the average grain size of the Wm2 exceeds 10 μm, KICIS values were also measured for the 10–20 μm fraction ranging between 0.22 and 0.24 Δ°2θ for both belts. For those fractions, the KICIS values indicate epizone conditions, associated with temperatures higher than 300 °C. These values are comparable to temperatures obtained from chlorite thermometers, 316°–416 °C in Western Belt and 261°-403 °C in the Eastern Belt. Pressure values for D1 stage constrained from chlorite – white mica – quartz – H2O equilibrium are 2.5–5.1 kbar in the Western Belt, and at 3.3–4.7 kbar in Eastern Belt. The pressures are consistent with white mica b parameter values measured in samples from Western Belt (9.006 to 9.025 Å) and Eastern Belt (9.003 to 9.020 Å), linked to intermediate thermal gradients (25–35 °C/km). The identification of increasing P-T condition paths in low-grade metasedimentary successions is not easy in the absence of higher grade rocks; in these situations, a systematic sampling and analysis of dozens of samples must be carried out. The very good correlation between crystallochemical index values (Kübler index and white mica b parameter) and thermobarometric calculations (empirical and semi-empirical chlorite thermometers and thermobarometry for chlorite – white mica – quartz – H2O equilibrium) presented in this work argues in favor of the development of a multiproxy study strategy in this type of low-grade metasedimentary successions that involve: (1) a systematic sampling of metapelite levels for X-ray diffraction study (mineralogical and crystallochemical indexes with a rapid implementation allowing a dense systematic sampling); (2) the recognition of variations in the P-T conditions from KI and b parameter values and the consequent selection of metapelitic samples for analyzing mineral chemistry and thermobarometric calculations. In order to facilitate these calculations, a user-friendly spreadsheet for crystallochemical indexes and chlorite thermometry calculations is also provided.
Fil: Verdecchia, Sebastián Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Fil: Collo, Gilda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Fil: Zandomeni, Priscila Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Fil: Wunderlin, Cecilia Ayelén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
Fil: Fehrmann, Mariano. Universidad Nacional de Córdoba; Facultad de Ciencias Exactas, Físicas y Naturales; Argentina
description In this work, crystallochemical indexes and geothermobarometric calculations are used together to estimate the P-T condition in low-grade metamorphic units of the San Luis Formation from Sierra de San Luis (Eastern Sierras Pampeanas of Argentina). Phyllites and slates from this formation record at least two episodes of white mica (Wm) and chlorite (Chl) growth associated with main D1-S1 (Wm2-Chl1) and local D2-S2 (Wm3-Chl2) stages. Mean KICIS values of 0.30 (Western Belt) and 0.23 Δ°2θ (Eastern Belt) were determined for the <2 μm fraction. Moreover, since the average grain size of the Wm2 exceeds 10 μm, KICIS values were also measured for the 10–20 μm fraction ranging between 0.22 and 0.24 Δ°2θ for both belts. For those fractions, the KICIS values indicate epizone conditions, associated with temperatures higher than 300 °C. These values are comparable to temperatures obtained from chlorite thermometers, 316°–416 °C in Western Belt and 261°-403 °C in the Eastern Belt. Pressure values for D1 stage constrained from chlorite – white mica – quartz – H2O equilibrium are 2.5–5.1 kbar in the Western Belt, and at 3.3–4.7 kbar in Eastern Belt. The pressures are consistent with white mica b parameter values measured in samples from Western Belt (9.006 to 9.025 Å) and Eastern Belt (9.003 to 9.020 Å), linked to intermediate thermal gradients (25–35 °C/km). The identification of increasing P-T condition paths in low-grade metasedimentary successions is not easy in the absence of higher grade rocks; in these situations, a systematic sampling and analysis of dozens of samples must be carried out. The very good correlation between crystallochemical index values (Kübler index and white mica b parameter) and thermobarometric calculations (empirical and semi-empirical chlorite thermometers and thermobarometry for chlorite – white mica – quartz – H2O equilibrium) presented in this work argues in favor of the development of a multiproxy study strategy in this type of low-grade metasedimentary successions that involve: (1) a systematic sampling of metapelite levels for X-ray diffraction study (mineralogical and crystallochemical indexes with a rapid implementation allowing a dense systematic sampling); (2) the recognition of variations in the P-T conditions from KI and b parameter values and the consequent selection of metapelitic samples for analyzing mineral chemistry and thermobarometric calculations. In order to facilitate these calculations, a user-friendly spreadsheet for crystallochemical indexes and chlorite thermometry calculations is also provided.
publishDate 2019
dc.date.none.fl_str_mv 2019-01
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/11336/121165
Verdecchia, Sebastián Osvaldo; Collo, Gilda; Zandomeni, Priscila Soledad; Wunderlin, Cecilia Ayelén; Fehrmann, Mariano; Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern Sierras Pampeanas of Argentina; Elsevier Science; Lithos; 324-325; 1-2019; 385-401
0024-4937
CONICET Digital
CONICET
url http://hdl.handle.net/11336/121165
identifier_str_mv Verdecchia, Sebastián Osvaldo; Collo, Gilda; Zandomeni, Priscila Soledad; Wunderlin, Cecilia Ayelén; Fehrmann, Mariano; Crystallochemical indexes and geothermobarometric calculations as a multiproxy approach to P-T condition of the low-grade metamorphism: The case of the San Luis Formation, Eastern Sierras Pampeanas of Argentina; Elsevier Science; Lithos; 324-325; 1-2019; 385-401
0024-4937
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/https://linkinghub.elsevier.com/retrieve/pii/S0024493718304420
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.lithos.2018.11.021
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
application/pdf
dc.publisher.none.fl_str_mv Elsevier Science
publisher.none.fl_str_mv Elsevier Science
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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score 13.070432

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