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d13C tracing of dissolved inorganic carbon sources in Patagonian rivers (Argentina)

Brunet, Frédéric and Gaiero, Diego M. and Probst, Jean-Luc and Depetris, Pedro J. and Gauthier-Lafaye, François and Stille, Peter d13C tracing of dissolved inorganic carbon sources in Patagonian rivers (Argentina). (2005) Hydrological Processes, 1 (17). 3321-3344. ISSN 0885-6087

(Document in English)

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Official URL: http://dx.doi.org/10.1002/hyp.5973


The main Patagonian rivers (Colorado, Negro, Chubut, Deseado, Coyle, Chico, Santa Cruz and Gallegos) were sampled between September 1995 and November 1998 to determine their chemical and isotopic compositions, the origins of the suspended and dissolved river loads and their inputs to the South Atlantic Ocean. This paper focuses on the dissolved inorganic carbon (DIC) transport and its υ13C isotopic signature. The υ13CDIC values vary between 12Ð8 and 1Ð8‰ and allow one to distinguish two river groups: (i) the Colorado, Negro, Chubut and Santa Cruz, which display the highest values and the lowest seasonal variations; (ii) the Deseado, Coyle, Chico and Gallegos, which show the lowest values and the highest seasonal variations. For the first group, υ13CDIC is mainly controlled by important exchanges between the river waters and atmospheric CO2, due to the presence of lakes and dams. For the second group, υ13CDIC also appears to be controlled by the oxidation of organic carbon, showing a negative relationship between υ13CDIC and the dissolved organic carbon. These biogeochemical processes interfere with the contribution of carbonate and silicate weathering to the riverine DIC and do not allow use of υ13CDIC alone to distinguish these contributions. The annual DIC flux exported by Patagonian Rivers to the South Atlantic Ocean averages 621 ð 109 g. of C, i.e. a specific yield of 2Ð7 g m2 year1. The mean υ13CDIC can be estimated to 4Ð9‰, which is high compared with other rivers of the world.

Item Type:Article
Additional Information:Thanks to Wiley editor. The definitive version is available at http://www3.interscience.wiley.com/ The original PDF of the article can be found at Hydrological Processes website : http://www3.interscience.wiley.com/journal/4125/home
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:Other partners > Universidad Nacional de Cordoba - UNC (ARGENTINA)
Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
French research institutions > Institut de Recherche pour le Développement - IRD (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Other partners > Université Louis Pasteur-Strasbourg I - ULP (FRANCE)
Laboratory name:
Deposited On:15 Apr 2010 16:13

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