A paleopedological approach to understanding Eocene environmental conditions in southern Patagonia, Argentina

M. SOL RAIGEMBORN; LIZZOLI SABRINA; ETHAN HYLAND; JENNIFER COTTON; LUCÍA GÓMEZ PERAL; ELISA BEILINSON; MARCELO KRAUSE

PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY

ELSEVIER SCIENCE BV

Año: 2022 vol. 61 p. 1 - 25

0031-0182

The Eocene Las Flores and Koluel-Kaike formations in southern Patagonia (~48° S,Golfo San Jorge Basin, Argentina) are strongly pedogenically modified fluvial and fluvio- eolian successions, respectively, which document early–middle Eocene environments atmid-paleolatitudes in the Southern Hemisphere. In order to reconstruct thepaleoenvironment and paleoclimate for the Las Flores and Kolul-Kaike formations, weperformed a multiproxy and coordinated study of sediments and paleosols of both units,considering abiotic components. Using detailed sedimentology and paleopedology (macro-and micromorphology), bulk paleosol geochemistry and clay mineralogy, and organiccarbon concentrations and stable isotope (δ13Corg) compositions, we show that these units document a broadly warm–temperate and humid climate punctuated by periods of tropicalwarmth and distinct seasonality. Changing paleosol features and conditions further revealan established and likely complex paleoenvironment in the Golfo San Jorge Basin duringearly Paleogene. Overall, these combined data record long-term environmentalconditions during the early Paleogene (early−middle Eocene), and may preserve one of themost comprehensive records of Eocene terrestrial climate in the Southern Hemisphere