Environmental inferences based on benthic foraminifera in surface sediments from the Beagle Channel (Argentina): A multiproxy approach

Abstract

Micropaleontological analysis was performed on 22 samples of recent marine sediments from the Beagle Channel (Tierra del Fuego, Argentina) between 10 and 100 m of depth. The most important foraminifera found in the channel were Cibicidoides dispars (d'Orbigny), Buccella peruviana (d'Orbigny), Cibicides aknerianus (d'Orbigny), Cibicides fletcheri Galloway and Wissler, and Neoeponides bradyi (Le Calvez), which inhabit in clayey–sandy marine sediments. The observed variations in diversity and abundance revealed shallow marine conditions, low-energy, and low to moderate salinity, in the west sector and a deeper environment with normal marine conditions, high-energy, highly‑oxygenated and cold seawater in the east sector of the channel. The study area is a complex scenario with numerous landforms that lead to the formation of micro-environments in which patchy distribution of foraminifera was recognized. This study based on foraminifera and the sedimentological analysis supports the previous palynological information from the channel, which also shows an increase in number and diversity of dinocyst species reflecting the eastward changes of the marine environmental conditions due to the influence of the Atlantic.