Holocene sea-level change and marine palynology of the Beagle Channel, southern Tierra del Fuego, Argentina. In Press.

BORROMEI, A.M.; QUATTROCCHIO, M.

AMEGHINIANA

Asociación Paleontológica Argentina

Lugar: Buenos Aires; Año: 2007 p. 161 - 171

0002-7014

Abstract. An early-middle Holocene section in Bahía Lapataia (54º 50´ S, 68º 34´ W), Beagle Channel, Tierra del Fuego has been examined for its sporomorphs and organic-walled microplankton. The palynological assemblage suggests nearshore environments. Two relatively higher sea levels were identified by the increased abundance of organic-walled dinoflagellate cysts (Brigantedinium spp., Selenopemphix sp., Operculodinium centrocarpum sensu Wall and Dale, Spiniferites spp.), the acritarch Halodinium sp. and zoomorph remains (test linings of foraminifera and copepod egg-envelopes). The littoral vegetation at the time of the marine incursion was mainly arboreal, as can be seen in the pollen records by significant increase in Nothofagus dombeyi type frequencies, while a forest-steppe vegetational developed regionally. By comparison with a nearby fossil marine terrace, the palynological analysis has demonstrated that these terraces represent the same transgressive-regressive event. The relative altitudinal differences among these terraces in the area may be the result of seismotectonic activity during the Holocene.