Lithology and Stratigraphy of the Quaternary Sediments from the Ameghino Segment of the Atlantic Patagonian Margin

The paper provides the first lithological and age data from the Ameghino segment of the Atlantic Patagonian Margin. The multiproxy study, which involves lithology, microfossils, magnetic susceptibility, color reflectance, and accelerator mass spectrometry radiocarbon (AMS-C-14) dating, made it possible to establish the litho- and chronostratigraphic frame of six short (<1 m) sediment cores from the continental margin from a water depth range of 2-2.3 km. The units corresponding to marine oxygen-isotope stages (MIS) 1-3 are identified and distantly correlated with simultaneous units of reference core AI-3327 from the Piedra Buena Terrace. The unit thickness and sedimentation rates are estimated. The occurrence of glauconite in coarse-grained sediments of the last glacial, described earlier from coeval sediments on the Piedra Buena Terrace, has now been confirmed within the Ameghino segment of the continental margin. The occurrence of contourites in the sediment cores is also confirmed, suggesting that bottom currents were involved in sedimentation.