Vegetation and Climate in Southern South America during Marine Isotope Stage 3 (MIS 3): an Overview of Existing Terrestrial Pollen Records

MUSOTTO, L.L.; BORROMEI, A.M.

Marine Isotope Stage 3 in southern South America, 60 ka B.P.-30 ka B.P.

Springer International Publishing

Año: 2016; p. 279 - 298

Data from terrestrial pollen records in the Chilean sector show thatMarine Oxygen Isotope Stage 3 (MIS 3) was characterized by the Heinrich (stadials)/Dansgaard?Oeschger (interstadials) oscillations. At central Chile (32?38° S)an open beech/podocarp woodland was apparently established during the last iceage under cold and humid climates, where nowadays grows a semiarid, broadsclerophyllous vegetation, while episodes of aridity with rise of temperature wereindicated by expansion of chenopods?amaranths. At the Southern Lake District andnorthern Isla Grande de Chiloé (40°?42° 30′ S), the stadial events were characterizedby higher amounts of grasses indicative of the Subantarctic Parkland vegetation.This vegetation implied summer temperatures of  6 °C (8 °C belowpresent). The interstadials were represented by expansion of the Valdivian-NorthPatagonian Evergreen Forest-Subantarctic Evergreen Forest implying summertemperatures of 12 °C. In the Argentine sector, the steppe environmental conditionsprevailed. Interstadial conditions are pointed out at 39° S, in NW Patagonia.Meanwhile, in southern Patagonia at 51°?52° S, and Tierra del Fuego at 54° S, theclimatic conditions during MIS 3 are interpreted as colder and drier than today.