Preliminary geochemical data on shallow marine mollusc from middle Pleistocene-Holocene beach ridges in the Gulf S.Jorge (Patagonia, Argentina)

Viena

Otro; Geophysical Research General Assembly 2010; 2010

The Patagonia coast comprised between ca 45° S and 43° S preserves a spectacular succession of Quaternary raised beach deposits mostly composed by gravelly beach-ridge successions containing abundant storm accumulations of mollusc remains. Currently, this coastal area is interested by the competing action of the warm Brazilian current from north and the Falkland (Malvinas) current from the south, and roughly it corresponds to the boundary of the Magellanean and Argentinean zooprovinces. Although paleontological studies have been conducted in the recent past (e.g. Aguirre, 2003) there are not practically geochemical studies on these natural archives to infer local paleoceanographic and paleoclimate changes. Preliminary geochemical studies (petrography, stable isotopes, trace elements) on the aragonitic shell Prototaqua antiqua collected in various localities spanning from Holocene to Middle Pleistocene (MIS 9 to MIS 1, e.g. Schellmann and Radke, 2000) successions indicate that this species is relatively well preserved and can be used for the reconstruction of the past coastal oceanographic changes in the area.