Abstract

SILVA, Maria Luísa Gomes da  and  CORREA, Antônio Carlos de Barros. Continental dunes of Brazil as geocronometers of paleoclimate variations: A review of the state of the art of knowledge. Finisterra [online]. 2023, n.123, pp.149-169.  Epub Sep 30, 2023. ISSN 0430-5027.  https://doi.org/10.18055/finis28868.

Continental dunes are key features for the study of climatic oscillations that occurred during the Quaternary. These deposits occur in different spatial contexts in Brazil and reflect their formative paleoenvironmental and paleoclimatic conditions. The present work proposes a synthesis of the literature on the subject over the last 30 years, integrating geochronological and environmental information on the continental dunes present in the Brazilian territory. The data from dating by LOE and TL indicate the occurrence of wind deposition from the Middle Pleistocene (253.8±19.0ka) to the present (0.165±0.025ka) with alternation between periods of lower and higher activity. Parabolic dunes, sand sheets, and deflation basins (blowouts) predominate in the studied areas. Cyclical and anomalous mechanisms, such as Palei-ENSO, appear to have been responsible for the onset of drier phases, leadind to a greater supply of sediments and the consequent formation of dune deposits. The good resolution of the chronological data also suggests that the dunes act as important geo-archives for studying environmental changes with medium to short recurrence intervals.

Keywords : Climatic geomorphology; palaeoclimatology; interior dunes.

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