Asociaciones de moluscos bentónicos marinos del Cuatemario tardío en el noreste bonaerense

Abstract

The paíaeoecologíc study of Holocene benthic macroinvertebrates (mainly gastropods and bivalves) from northeastern Buenos Aires Province enabled the characterization of the environment where theywere deposited as well as the proposition of a general pattem of their probable evolution up to the presento By means of multivariate analysis (Cluster Analysis, Principal Coordinate Analysis and Principal Component Analysis) of the fauna from'27localities, mostly littoral beach ridges, scattered along 400 km, an objective discrimination of the studied deposits can be established. Thus, two main Biofacies (comprising five and six Sub-biofacies each), and six faunal associations were recognized. The analysis of the ecologic requirements of the species from each association reveals that the studied area corresponds to an estuarine or mixed palaeoenvironment, with salinity ranging from mixo to poly-haline gradients. Northem and southem regions of this arca differed in the extent of the littoral zone, kind of substrate, and water depth, energy and salinity.