Early to middle Holocene palaeoenvironmental reconstruction of the Beagle Channel (southernmost Argentina) based on terrestrial and marine palynomorphs

MARIA SOLEDAD CANDEL; ANA MARIA BORROMEI; STEPHEN LOUWYE

BOREAS

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2018 vol. 47 p. 1072 - 1083

0300-9483

This paper presents the main palaeoenvironmental results obtained from a site located in the western sector of the Beagle Channel, Isla Grande de Tierra del Fuego, southernmost Argentina. The palynological analysis performed on marine sediments from Aserradero-Lapataia 2 (54º51?22.7?? S; 68º34?22.8?? W) allowed us to document the evolution of palaeoenvironmental conditions during the beginning of the Holocene marine transgression into the Beagle Channel. The results indicate that, prior to the marine incursion, the coastal areas were characterized by the presence of open-grown shrubs and herbs along with woodland palaeocommunities. The aquatic environments were dominated exclusively by freshwater taxa. Around 8300 cal. a BP, the seawater gradually flooded the channel while cold and high effective moisture conditions favoured the development of an arboreal vegetation with dominance of Nothofagus forest and scarcity of shrub and herbaceous communities. Gradual increasing salinities allowed the development of freshwater/marine transitional environments indicated by aquatic palynomorphs able to tolerate stressed conditions under fluctuating salinities. The increasing dinocyst diversification with dominance of heterotrophic taxa corroborate the establishment of a fully marine environment during the middle-late Holocene into the Beagle Channel.