Dinoflagellate cyst assemblages of surface sediments from the Beagle Channel, Tierra del Fuego, Argentina-preliminary results

SOLEDAD CANDEL; TAOUFIK RADI; ANNE DE VERNAL

Montréal, Canadá

Conferencia; Eighth International Conference on Modern and Fossil Dinoflagellates; 2008

Universite du Quebec a Montreal-GEOTOP

Abstract Palynological analyses of nine surface sediment samples from the restricted area of the Beagle Channel, Tierra del Fuego, Argentina, were performed in order to investigate the distribution of dinoflagellate cyst assemblages in high latitudes of the Southern Hemisphere and to explore their relationships with sea-surface conditions. Preliminary results show relatively low dinocyst concentrations compared to high latitudes of the Northern Hemisphere. However, dinoflagellate cyst assemblages have relatively high species diversity with 23 taxa identified. Results show also that the assemblages are mostly composed by Protoperidiniale taxa and are dominated by Brigantedinium spp, Echinidinium spp. and Selenopemphix quanta accompanied notably by cysts of Pentapharsodinium dalei, Echinidinium granulatum, Islandinium minutum, Votadinium spinosum, Polykrikos kofoidii, and Polykrikos schwartzii. Such assemblages show some similarities with those of the high latitudes regions of the Northern Hemisphere. However, some taxa, previously suggested as exclusive to warm environments occur with relatively high percentages in the Beagle Channel (e.g. Echinidinium spp. and Votadinium spinosum).