The signature of river- and wind-borne materials exportedfrom Patagonia to the southern latitudes: a view from REEsand implications for paleoclimatic interpretations

• Published in: Earth and Planetary Science Letters
• Main Authors: Gaiero, Diego M., Depetris, Pedro J., Probst, Jean-Luc, Bidart, Susana M., Leleyter, Lydia
• Other Authors: Facultad de Ciencias Exactas, Físicas y Naturales Córdoba (FCEFyN), Universidad Nacional de Córdoba Argentina, Laboratoire des Mécanismes et Transfert en Géologie (LMTG), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS), Universidad Nacional del Sur Argentina (UNS), Equipe de Recherche en Physico-Chimie et Biotechnologie (ERPCB), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2004
• Subjects: Rare earth elements; Eolian dust; Patagonia; South Atlantic Ocean; Antarctica; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; [SDV.EE]Life Sciences [q-bio]/Ecology; environment; Antarc*; East Antarctica; Scotia Sea
• Online Access: https://hal.science/hal-04256976; https://doi.org/10.1016/S0012-821X(03)00686-1

International audience Riverine and wind-borne materials transferred from Patagonia to the SW Atlantic exhibit a homogeneous rareearth element (REE) signature. They match well with the REE composition of Recent tephra from the Hudson volcano,and hence this implies a dominance of material supplied by this source and other similar Andean volcanoes. Due to the trapping effect of proglacial and reservoir lakes,the larger Patagonian rivers deliver to the ocean a suspended load with a slightly modified Andean signature,that shows a REE composition depleted in heavy REEs. In this paper we redefine Patagonia as a source of sediments,which is in contrast with other sources located in southern South America. Quaternary sediments deposited in the northern and,to a lesser extent, in the southern Scotia Sea, and most of the dust in ice cores of east Antarctica have REE compositions very similar to the loess from Buenos Aires Province and to Patagonian eolian dust. However,we rule out Buenos Aires province as a Holocene major source of sediments. Similarly to Buenos Aires loess (a proximal facies),it is likely that the REE compositions of mostsediment cores of the Scotia Sea and Antarctica reflect a distal transport of dust with an admixed composition fromtwo main sources: a major contribution from Patagonia,and a minor proportion from source areas containing sediments with a clear upper crustal signature (e.g.,western Argentina) or from Bolivia’s Altiplano. Evidence indicatesthat only during the Last Glacial Maximum,Patagonian materials were the predominant sediment source to thesouthern latitudes.