SECUENCIA POLÍNICA DE LA LAGUNA LA COLORADA, PARTIDO DE GENERAL MADARIAGA, PROVINCIA DE BUENOS AIRES, ARGENTINA

This paper presents the results of a palynological study from a pond sediment core obtained at Laguna La Colorada (37o 04' S 56o 58' O). A total of 54 pollen taxa were identified along a 140 cm long sediment sequence where 15 pollen samples were collected at regular intervals. The zonation of the obtained pollen diagram was based on an stratigraphycal constrained Cluster Analysis preformed to pollen taxa with values highest than 2% of pollen sum. Two zones were identified in the sequence: a bottom section, with prevalence of Poaceae and low values of Chenopodiineae and Myriophyllum. These taxa indicate extension of the grassland and reduction of the body water that corresponds to a drier period. The top section, with prevalence of aquatic plants, indicates a moister period. In the most upper section both palynological taxa and sediment characteristics evidence human activity. KEY WORDS. Palinology. Pond core. Late Holocen. Buenos Aires Province. Argentina.