A multi-proxy approach to paleoenvironmental changes in the southwestern Río de la Plata area (Argentina) during Late Pleistocene

BEILINSON, ELISA; SOIBELZON, ESTEBAN; CUSMINSKY, GABRIELA C.; SOIBELZON, LEOPOLDO HÉCTOR; RODRIGUEZ, SERGIO GABRIEL; CALVO-MARCILESE, LYDIA; IACONA, FACUNDO; RAIGEMBORN, MARÍA SOL; GASPARINI, GERMÁN MARIANO; MARI, FLORENCIA

QUATERNARY INTERNATIONAL

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2019 vol. 512 p. 6 - 17

1040-6182

In the southwestern margin of the Río de la Plata (Argentina), mining works have uncovered deposits thatcorrespond to the last glacio-eustatic cycle (< 120 Ky). Because deposits of this cycle are rare in the area, thestudied succession provides an opportunity to study the paleoenvironmental and paleoclimatic evolution of thearea during that time. Sedimentary analysis reveal an inner estuarine environment impacted by storm surges,followed by fluvial and eolian depositional environments. The paleontological record of the terrestrial depositsindicates open grasslands and semi-arid climatic conditions that can be biostratigraphically assigned to theLujanian Stage (late Pleistocene). Nevertheless, the chronology of the succession is hereby modified based onOSL ages and geomorphological evidence suggesting that the lower levels of the studied succession are olderthan previously thought (i.e. MIS 5e instead of MIS 3). Relative changes of sea level are inferred: the estuarinedeposits are related to a period of relative high sea-level (i.e. MIS 5e), and the subsequent fluvial system isassociated to a global sea-level fall that reached its lowest point during MIS 2.