Caracterización taxonómica y paleoecológica de la ingresión del Holoceno en el Canal Beagle (Tierra del Fuego), en base a las asociaciones de dinoquistes y otros palinomorfos acuáticos.

MARIA SOLEDAD CANDEL; ANA MARIA BORROMEI

REVISTA BRASILEIRA DE PALEONTOLOGIA

SOC BRASILEIRA PALEONTOLOGIA

Lugar: Porto Alegre; Año: 2013 vol. 16 p. 245 - 262

1519-7530

ABSTRACT. TAXONOMIC AND PALEOECOLOGICAL CHARACTERIZATION OF HOLOCENE INGRESSION IN THE BEAGLE CHANNEL (TIERRA DEL FUEGO), BASED ON DINOCYST ASSEMBLAGES AND OTHER AQUATIC PALYNOMORPHS. On the southern coast of Tierra del Fuego, Argentina, the Holocene marine ingression took place around 8,000 C14 years BP, and it is represented by several discontinuous marine terraces along the north coast of the Beagle Channel. During the beginning of the marine incursion, the aquatic assemblages developed in Bahía Lapataia and Río Varela localities, were characterized by a scarce participation of marine components, especially of dinofl agellate cysts. After 6,000 C14 years BP, in Río Ovando and Albufera Lanushuaia localities, an increase in the number of aquatic species was observed with a major participation of Peridiniales dinocysts in the associations, suggesting the establishment of marginal marine environments with low to moderate salinities and high nutrient content in the water. The analysis of the dinofl agellate cysts and other aquatic palynomorphs assemblages recorded in the marine sediments from northern coast of the Beagle Channel, indicate that the environmental conditions during the middle-late Holocene correspond to fjord (estuarine) environments close to ice fields affected by glacier meltwater discharge with anomalously low salinities. These aquatic assemblages identifi ed have a similar composition to those observed in modern sediments of the Beagle Channel.