Late Pleistocene Littoral Deposits from 33° to 40° S, Argentine Republic: Blake and Probable Lake Mungo Events-Magnetostratigraphic Geochronology

Abstract

Geochronological data are presented on a basis of magnetostratigraphic evidence from old lagoonal deposits and younger estuarine deposits from Irazusta Quarry (33° S and 58° W). The Virtual Geomagnetic Pole Position (VGP) recorded in the lagoonal deposits, corresponds to the Blake Event and confirms its previous tentative correlations with the Sangamon (Eemian) Interglacial. An "excursion," or "transition interval" of the earth's magnetic field recorded in the younger estuarine deposits, previously dated between 35,400 ± 1800 BP and 26,600 ± 720 BP (¹⁴C ages), could indicate the Lake Mungo Event. On the other hand, littoral deposits from 38° S, dated in 30,500 ± 1400 BP, also recorded an "excursion" that could coincide with the Lake Mungo Event. If this Lake Mungo Event is confirmed, then the reliability of the ¹⁴C ages for these estuarine and littoral deposits from 33° to 40° S at the present time above modern mean sea level will be definitively supported.