Recent Benthic Foraminifers from the South Atlantic Shelf of Argentina

Abstract

Abstract The aim of this study was to determine foraminiferal associations from recent sediments of Argentina's continental shelf (39–41ºS, 59–61ºW; 11–70 m) and assess their relationship to physicochemical parameters. From 20 samples, all dominated by sandy sediments (>80% sand), 44 species of foraminifers were identified, most commonly Buccella peruviana. Recovered foraminiferal tests were generally well preserved, with morphologies indicating predominantly epifaunal, free-living detritivores from well-oxygenated waters. Multivariate analyses showed a strong correlation between foraminiferal assemblages and four zones related to physicochemical parameters. Zone I included the offshore samples from depths of 40–70 m where waters were slightly colder and more saline. Zone II samples were all collected from depths of 30–40 m that were intermediate in temperature. Zone III occurred at 20–40 m depth where sediments were characterized by some gravel content. Zone IV included the inshore sites (<20 m) offshore from the Rio Colorado delta. This work contributes to the knowledge of foraminifers on Argentina's continental shelf, complementing earlier studies of foraminiferal distributions and ecology from the region.