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A uniform isotopic and chemical signature of dust exported from Patagonia: Rock sources and occurrence in southern environments

Gaiero, Diego M. and Brunet, Frédéric and Probst, Jean-Luc and Depetris, Pedro J. A uniform isotopic and chemical signature of dust exported from Patagonia: Rock sources and occurrence in southern environments. (2007) Chemical Geology, 238 (1-2). 107-120. ISSN 0009-2541

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Official URL: http://dx.doi.org/10.1016/j.chemgeo.2006.11.003


Patagonia is considered to be the most important source of dust from South America that is deposited in surrounding areas, and we present here a systematic Sr and Nd isotopic study of sediment currently being exported. Eolian and suspended riverine sediments from Patagonia have a homogeneous chemical and isotopic composition that results from the mixing of by-products from explosive Andean volcanism, derived from the extensive Jurassic silicic Province of Chon Aike and pyroclastic materials from the basic to intermediate southern Andean Quaternary arc, which are easily denudated and dispersed. The main Andean uplift and the glaciations that began in the Late Tertiary account for the extensive distribution of these sediments in the extra-Andean region. The present geochemical signature of Patagonian sediments was produced during the Pleistocene, along with the onset of the southern Andean explosive arc volcanism. Previously published compositions of sediments from other southern South American source regions, assumed to be representative of Patagonia, are distinct from our data. Considering the alleged importance of Patagonia as a dust source for different depositional environments in southern latitudes, it is surprising to verify that the chemical and isotopic signatures of Patagonian-sourced sediments are different from those of sediments from the Southern Ocean, the Pampean Region or the Antarctic ice. Sediments from these areas have a crustal-like geochemical signature reflecting a mixed origin with sediment from other southern South American sources, whereas Patagonian sediments likely represent the basic to intermediate end-member composition.

Item Type:Article
Additional Information:Thanks to Elsevier editor. The definitive version is available at http://www.sciencedirect.com The original PDF of the article can be found at Chelical Geology Website : http://www.sciencedirect.com/science/journal/00092541
HAL Id:hal-03592061
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
French research institutions > Institut de Recherche pour le Développement - IRD (FRANCE)
Other partners > Universidad Nacional de Cordoba - UNC (ARGENTINA)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
Other partners > University of Ottawa (CANADA)
Laboratory name:
Deposited On:15 Apr 2010 12:10

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