Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective

Autores
Frei, Roberto; Poire, Daniel Gustavo; Frei, Karim Margarita
Año de publicación
2014
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
We have investigated the pathway of chromium from its mobilization on land and along its riverine transport in a subtropical region of South America (Misiones Province, Argentina), in an attempt to link Cr stable isotope compositions recently measured in seawater with signals prevailing in rivers and, ultimately, with Cr isotope effects observed during oxidative surface weathering in subtropical red soils. Cr concentrations and stable Cr isotopic compositions (expressed as δ53Cr ‰ values) in two typical and representative surface profiles of weathered basalt show significant depletion of Cr in the soils of up to 50%, together with pronounced negatively fractionated δ53Cr values which are indicative of oxidative mobilization of heavy Cr(VI) into the run-off. The behavior of Cr in the studied weathering profiles is not correlated with that of other redox sensitive elements, such as Ce and U; this is essentially due to the affinity of REE and U, but not Cr with secondary phosphates which form during weathering processes. Smaller tributaries in NW Argentina to the Paraná River (second largest river in South America) carry dissolved Cr in the order of 0.7–1.4 ppb (13–27 nM) with δ53Cr values of + 0.2 to + 0.4‰, balancing the negatively fractionated weathering products. The isotope composition and concentration of dissolved Cr in the ca. 1200 km long Paraná River from Misiones to its estuary and discharge area into the South Atlantic Ocean remains relatively constant with an average Cr concentration around 2.4 ppb (46 nM) and an average δ53Cr value of + 0.32‰. The Cr concentration in the estuary itself drops by ca. 50% but with only minor change in its Cr isotope composition. Results from the Paraná estuary are identical with recently analyzed surface seawater from the Argentine Basin with Cr contents of ~ 0.3 ppb (~ 6 nM) and δ53Cr values ~+ 0.4‰ (Bonnand et al., 2013), and indicate that there is only a minimal Cr isotopic variability during riverine transport, even during long transport distances as shown in our example of the Paraná River. Simple Cr input flux calculations reveal that the Paraná River accounts for ~ 5% of the total yearly Cr flux to the world's oceans today and that its isotopic signature seems to be, at least locally, imparted to the surface seawater of the Argentine Basin. Whether or not this Cr isotope signature is generally exhibited by the world's oceans needs further investigations, particularly the characterization of seawater around the globe.
Fil: Frei, Roberto. Universidad de Copenhagen; Dinamarca
Fil: Poire, Daniel Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentina
Fil: Frei, Karim Margarita. Universidad de Copenhagen; Dinamarca. National Museum of Denmark; Dinamarca
Materia
Cr Isotopes
Weathering Profiles
River Water
Laterite
Paraná River
Misiones
Argentina
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:11336/33118

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oai_identifier_str oai:ri.conicet.gov.ar:11336/33118
network_acronym_str CONICETDig
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network_name_str CONICET Digital (CONICET)
spelling Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspectiveFrei, RobertoPoire, Daniel GustavoFrei, Karim MargaritaCr IsotopesWeathering ProfilesRiver WaterLateriteParaná RiverMisionesArgentinahttps://purl.org/becyt/ford/1.5https://purl.org/becyt/ford/1We have investigated the pathway of chromium from its mobilization on land and along its riverine transport in a subtropical region of South America (Misiones Province, Argentina), in an attempt to link Cr stable isotope compositions recently measured in seawater with signals prevailing in rivers and, ultimately, with Cr isotope effects observed during oxidative surface weathering in subtropical red soils. Cr concentrations and stable Cr isotopic compositions (expressed as δ53Cr ‰ values) in two typical and representative surface profiles of weathered basalt show significant depletion of Cr in the soils of up to 50%, together with pronounced negatively fractionated δ53Cr values which are indicative of oxidative mobilization of heavy Cr(VI) into the run-off. The behavior of Cr in the studied weathering profiles is not correlated with that of other redox sensitive elements, such as Ce and U; this is essentially due to the affinity of REE and U, but not Cr with secondary phosphates which form during weathering processes. Smaller tributaries in NW Argentina to the Paraná River (second largest river in South America) carry dissolved Cr in the order of 0.7–1.4 ppb (13–27 nM) with δ53Cr values of + 0.2 to + 0.4‰, balancing the negatively fractionated weathering products. The isotope composition and concentration of dissolved Cr in the ca. 1200 km long Paraná River from Misiones to its estuary and discharge area into the South Atlantic Ocean remains relatively constant with an average Cr concentration around 2.4 ppb (46 nM) and an average δ53Cr value of + 0.32‰. The Cr concentration in the estuary itself drops by ca. 50% but with only minor change in its Cr isotope composition. Results from the Paraná estuary are identical with recently analyzed surface seawater from the Argentine Basin with Cr contents of ~ 0.3 ppb (~ 6 nM) and δ53Cr values ~+ 0.4‰ (Bonnand et al., 2013), and indicate that there is only a minimal Cr isotopic variability during riverine transport, even during long transport distances as shown in our example of the Paraná River. Simple Cr input flux calculations reveal that the Paraná River accounts for ~ 5% of the total yearly Cr flux to the world's oceans today and that its isotopic signature seems to be, at least locally, imparted to the surface seawater of the Argentine Basin. Whether or not this Cr isotope signature is generally exhibited by the world's oceans needs further investigations, particularly the characterization of seawater around the globe.Fil: Frei, Roberto. Universidad de Copenhagen; DinamarcaFil: Poire, Daniel Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Frei, Karim Margarita. Universidad de Copenhagen; Dinamarca. National Museum of Denmark; DinamarcaElsevier Science2014-08info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/33118Frei, Karim Margarita; Poire, Daniel Gustavo; Frei, Roberto; Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective; Elsevier Science; Chemical Geology; 381; 8-2014; 110-1240009-2541CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.chemgeo.2014.05.015info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S000925411400254Xinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T10:39:30Zoai:ri.conicet.gov.ar:11336/33118instacron: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 10:39:31.132CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective
title Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective
spellingShingle Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective
Frei, Roberto
Cr Isotopes
Weathering Profiles
River Water
Laterite
Paraná River
Misiones
Argentina
title_short Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective
title_full Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective
title_fullStr Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective
title_full_unstemmed Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective
title_sort Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective
dc.creator.none.fl_str_mv Frei, Roberto
Poire, Daniel Gustavo
Frei, Karim Margarita
author Frei, Roberto
author_facet Frei, Roberto
Poire, Daniel Gustavo
Frei, Karim Margarita
author_role author
author2 Poire, Daniel Gustavo
Frei, Karim Margarita
author2_role author
author
dc.subject.none.fl_str_mv Cr Isotopes
Weathering Profiles
River Water
Laterite
Paraná River
Misiones
Argentina
topic Cr Isotopes
Weathering Profiles
River Water
Laterite
Paraná River
Misiones
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 We have investigated the pathway of chromium from its mobilization on land and along its riverine transport in a subtropical region of South America (Misiones Province, Argentina), in an attempt to link Cr stable isotope compositions recently measured in seawater with signals prevailing in rivers and, ultimately, with Cr isotope effects observed during oxidative surface weathering in subtropical red soils. Cr concentrations and stable Cr isotopic compositions (expressed as δ53Cr ‰ values) in two typical and representative surface profiles of weathered basalt show significant depletion of Cr in the soils of up to 50%, together with pronounced negatively fractionated δ53Cr values which are indicative of oxidative mobilization of heavy Cr(VI) into the run-off. The behavior of Cr in the studied weathering profiles is not correlated with that of other redox sensitive elements, such as Ce and U; this is essentially due to the affinity of REE and U, but not Cr with secondary phosphates which form during weathering processes. Smaller tributaries in NW Argentina to the Paraná River (second largest river in South America) carry dissolved Cr in the order of 0.7–1.4 ppb (13–27 nM) with δ53Cr values of + 0.2 to + 0.4‰, balancing the negatively fractionated weathering products. The isotope composition and concentration of dissolved Cr in the ca. 1200 km long Paraná River from Misiones to its estuary and discharge area into the South Atlantic Ocean remains relatively constant with an average Cr concentration around 2.4 ppb (46 nM) and an average δ53Cr value of + 0.32‰. The Cr concentration in the estuary itself drops by ca. 50% but with only minor change in its Cr isotope composition. Results from the Paraná estuary are identical with recently analyzed surface seawater from the Argentine Basin with Cr contents of ~ 0.3 ppb (~ 6 nM) and δ53Cr values ~+ 0.4‰ (Bonnand et al., 2013), and indicate that there is only a minimal Cr isotopic variability during riverine transport, even during long transport distances as shown in our example of the Paraná River. Simple Cr input flux calculations reveal that the Paraná River accounts for ~ 5% of the total yearly Cr flux to the world's oceans today and that its isotopic signature seems to be, at least locally, imparted to the surface seawater of the Argentine Basin. Whether or not this Cr isotope signature is generally exhibited by the world's oceans needs further investigations, particularly the characterization of seawater around the globe.
Fil: Frei, Roberto. Universidad de Copenhagen; Dinamarca
Fil: Poire, Daniel Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentina
Fil: Frei, Karim Margarita. Universidad de Copenhagen; Dinamarca. National Museum of Denmark; Dinamarca
description We have investigated the pathway of chromium from its mobilization on land and along its riverine transport in a subtropical region of South America (Misiones Province, Argentina), in an attempt to link Cr stable isotope compositions recently measured in seawater with signals prevailing in rivers and, ultimately, with Cr isotope effects observed during oxidative surface weathering in subtropical red soils. Cr concentrations and stable Cr isotopic compositions (expressed as δ53Cr ‰ values) in two typical and representative surface profiles of weathered basalt show significant depletion of Cr in the soils of up to 50%, together with pronounced negatively fractionated δ53Cr values which are indicative of oxidative mobilization of heavy Cr(VI) into the run-off. The behavior of Cr in the studied weathering profiles is not correlated with that of other redox sensitive elements, such as Ce and U; this is essentially due to the affinity of REE and U, but not Cr with secondary phosphates which form during weathering processes. Smaller tributaries in NW Argentina to the Paraná River (second largest river in South America) carry dissolved Cr in the order of 0.7–1.4 ppb (13–27 nM) with δ53Cr values of + 0.2 to + 0.4‰, balancing the negatively fractionated weathering products. The isotope composition and concentration of dissolved Cr in the ca. 1200 km long Paraná River from Misiones to its estuary and discharge area into the South Atlantic Ocean remains relatively constant with an average Cr concentration around 2.4 ppb (46 nM) and an average δ53Cr value of + 0.32‰. The Cr concentration in the estuary itself drops by ca. 50% but with only minor change in its Cr isotope composition. Results from the Paraná estuary are identical with recently analyzed surface seawater from the Argentine Basin with Cr contents of ~ 0.3 ppb (~ 6 nM) and δ53Cr values ~+ 0.4‰ (Bonnand et al., 2013), and indicate that there is only a minimal Cr isotopic variability during riverine transport, even during long transport distances as shown in our example of the Paraná River. Simple Cr input flux calculations reveal that the Paraná River accounts for ~ 5% of the total yearly Cr flux to the world's oceans today and that its isotopic signature seems to be, at least locally, imparted to the surface seawater of the Argentine Basin. Whether or not this Cr isotope signature is generally exhibited by the world's oceans needs further investigations, particularly the characterization of seawater around the globe.
publishDate 2014
dc.date.none.fl_str_mv 2014-08
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/11336/33118
Frei, Karim Margarita; Poire, Daniel Gustavo; Frei, Roberto; Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective; Elsevier Science; Chemical Geology; 381; 8-2014; 110-124
0009-2541
CONICET Digital
CONICET
url http://hdl.handle.net/11336/33118
identifier_str_mv Frei, Karim Margarita; Poire, Daniel Gustavo; Frei, Roberto; Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective; Elsevier Science; Chemical Geology; 381; 8-2014; 110-124
0009-2541
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.chemgeo.2014.05.015
info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S000925411400254X
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
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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