Late Pleistocene mollusc assemblages and inferred paleoenvironments from the Andean piedmont of Mendoza, Argentina

DE FRANCESCO, C.G.; ZÁRATE, M.A.; MIQUEL, S.E.

Palaeogeography, Palaeoclimatology, Palaeoecology

Elsevier

Año: 2007 p. 461 - 469

This paper is focussed on the paleoecological analysis of a mollusc seccession cropping out on the right margin of The Estacada stream in the Andean piedmont of Mendoza, Argentina (33º281 S, 69º031 W). The stratigraphic section, mainly composed of fine sands, interbedded with levels of silty clays and organic matter, records the interval between 35.2-35.5 C14 ka. B.P. and 31.5-31.6 C14 ka B.P. The mollusc succession is represented by freshwater and land snails: Biomphalaria peregrina (Planorbidae), Lymnaea viator (Lymnaeidae), Succinea meridionalis (Succineidae), Rotadiscus amancaezensis (Charopidae) and Radiodiscus sp. aff. R. quillajicola (Charopidae). The dominance of semi-aquatic and hygrophilus land sanials, suggests the development of a vegeted shallow water body, probably a damp habitat occasionally submerged, with four main stages of evolution related to fluctuating water levels. The abundance of shells togethet with the stable isotope composition of carbonate shalles of L. viator and the presence of Radiodiscus sp. aff. R. quillajicola and R. amancaezensis suggest relatively warm and interval corresponding to an interstadial (Marine isotope stage 3) of the last glacial cycle. .