Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective
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 an...
Published in: | Chemical Geology |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier Science
|
Subjects: | |
Online Access: | http://hdl.handle.net/11336/33118 |
id |
ftconicet:oai:ri.conicet.gov.ar:11336/33118 |
---|---|
record_format |
openpolar |
spelling |
ftconicet:oai:ri.conicet.gov.ar:11336/33118 2023-10-09T21:55:57+02:00 Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective Frei, Roberto Poire, Daniel Gustavo Frei, Karim Margarita application/pdf http://hdl.handle.net/11336/33118 eng eng Elsevier Science 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 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 info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ Cr Isotopes Weathering Profiles River Water Laterite Paraná River Misiones Argentina https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion ftconicet https://doi.org/10.1016/j.chemgeo.2014.05.015 2023-09-24T20:21:17Z 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 ... Article in Journal/Newspaper South Atlantic Ocean CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas) Argentina Argentine Misiones ENVELOPE(-63.900,-63.900,-64.450,-64.450) Chemical Geology 381 110 124 |
institution |
Open Polar |
collection |
CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas) |
op_collection_id |
ftconicet |
language |
English |
topic |
Cr Isotopes Weathering Profiles River Water Laterite Paraná River Misiones Argentina https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 |
spellingShingle |
Cr Isotopes Weathering Profiles River Water Laterite Paraná River Misiones Argentina https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 Frei, Roberto Poire, Daniel Gustavo Frei, Karim Margarita Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective |
topic_facet |
Cr Isotopes Weathering Profiles River Water Laterite Paraná River Misiones Argentina https://purl.org/becyt/ford/1.5 https://purl.org/becyt/ford/1 |
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 ... |
format |
Article in Journal/Newspaper |
author |
Frei, Roberto Poire, Daniel Gustavo Frei, Karim Margarita |
author_facet |
Frei, Roberto Poire, Daniel Gustavo Frei, Karim Margarita |
author_sort |
Frei, Roberto |
title |
Weathering on land and transport of chromium to the ocean in a subtropical region (Misiones, NW Argentina): A chromium stable isotope perspective |
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 |
publisher |
Elsevier Science |
url |
http://hdl.handle.net/11336/33118 |
long_lat |
ENVELOPE(-63.900,-63.900,-64.450,-64.450) |
geographic |
Argentina Argentine Misiones |
geographic_facet |
Argentina Argentine Misiones |
genre |
South Atlantic Ocean |
genre_facet |
South Atlantic Ocean |
op_relation |
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 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 |
op_rights |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ |
op_doi |
https://doi.org/10.1016/j.chemgeo.2014.05.015 |
container_title |
Chemical Geology |
container_volume |
381 |
container_start_page |
110 |
op_container_end_page |
124 |
_version_ |
1779320210254200832 |