Review of the Palaeoenvironmental Reconstruction of Late Quaternary Marine Sequences, Tierra Del Fuego (Argentina)

Abstract

Abstract. This work is an updated review of the knowledge on the evolution and development of palaeoenvironments during the holocene marine ingression and posterior regressive event in Tierra del Fuego. During the beginning of the marine transgression, ca. 8,000 cal yr BP, the vegetation in the southern coastal areas along the Beagle Channel was mainly arboreal with dominance of Nothofagus forest and scarcity of shrub and herbaceous communities, while in the northeastern atlantic coast, the treeless steppe was replaced by a relatively open Nothofagus forest. The early-Middle holocene aquatic assemblages were characterized by a scarce occurrence of marine components, especially dinoflagellate cysts, suggesting the development of low energy estuarine environments with low-salinities caused by glacier meltwater discharge. after 6,000 cal yr BP, an increase in the number of aquatic species was observed with dominance of Peridiniales dinoflagellate cysts, indicating the establishment of marginal marine environments with low to moderate salinities and high nutrient levels. During the last 1,000 cal yr BP, the littoral vegetation along the Beagle Channel showed an open Nothofagus forest and the development of peatlands, while in the northeastern atlantic coast the steppe vegetation developed under less humid environmental conditions related to the marine regressive event. These assemblages have a similar composition to those observed in modern sediments of the Beagle Channel and suggest palaeoenvironmental conditions comparable to today.

Post‐Last Glacial Maximum evolution of a “fjord‐type” lake based on high‐resolution seismic data: the Lago Roca/Acigami (southern Tierra del Fuego, Argentina/Chile)

“…The increase in the diversity of microfaunal assemblages typical of environments with high salinity (Candel et al , ) is in line with the increase in water density inferred from the interpretation of the seismic data. Although the palynological studies argue for a gradual salinisation, with the establishment of an estuarine environment (Candel and Borromei, ) followed by a fully marine environment (Gordillo et al ., ), the seismic data suggest a sudden lake level fall and a rapid invasion of the basin by marine waters, producing the basin‐wide erosive unconformity D4.…”

“…Whenever possible, the radiocarbon ages discussed in the text are given as calibrated ages (cal a BP). The old published conventional dates were converted to calibrated ages by Candel and Borromei (2016) and Hall et al (2013). Otherwise, we will refer to the original conventional (14 C a BP) ages.…”

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

“…Model of coast evolution during the Holocene marine event in the Beagle Channel (modified after Candel & Borromei ). A. Open‐grown communities of grasses and herbs, scarce presence of Nothofagus trees.…”

Palinología Del Meso-Cenozoico en Argentina. Volumen en Homenaje a Mirta Elena Quattrocchio

“…Patagonia, were largely based on palynological records from terrestrial sediments (heusser and Rabassa, 1987Rabassa, , 1995heusser, 1989Quattrocchio and Borromei, 1998;Musotto, 2013;Waldmann et al, 2014;Musotto et al, 2016a, in press; among others works). Studies on dinocyst assemblages and palynofacies from Late Quaternary deposits of the southern South america are still limited to a few contributions Quattrocchio, 2001, 2007;Candel et al, 2009Candel et al, , 2011Candel et al, , 2012Rabassa et al, 2009;Candel, 2010;Fernández et al, 2014).…”