Diatoms as indicators of hydrological and climatic changes in Laguna Potrok Aike (Patagonia) since the Late Pleistocene

RECASENS, C.; ARIZTEGUI, D.; MAIDANA N. I.; ZOLITSCHKA, B.; PASADO SCIENCE TEAM

PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 427 p. 309 - 319

0031-0182

SouthernSouth America is a key site to study climate variability in the SouthernHemisphere, allowing for a wide variety of climatic archives. Recently, severalinvestigations using lacustrine sediments have provided an enormous amount ofinformation to reconstruct past environmental changes. In the framework of thePotrok Aike Maar Lake Sediment Archive Drilling Project (PASADO) more than 500m of sediment cores were retrieved from the center of this lake. Thiscontribution is centered in the diatom record of a core covering over the last50 cal. ka BP. Nine statistically significant zones were determined based onchanges in the assemblages of more than 200 species of diatoms, showing changesin productivity throughout time. Although it appears that he presence of masswaste events may have triggered some peaks in productivity, large fluctuationsin diatom abundance and changes in species assemblages coincide withdistinctive Antarctic warm events, A2 and A1, described for Antarctic ice coresat around 44.5 and 38.5 kyr BP respectively (Blunier and Brook, 2001).Furthermore, a smaller diatom peak may account for the A3 event compatible witha new OSL-based chronological model. Up to now they have only been describedfor Antarctica, but the fact that these events are recorded in southernPatagonia indicates their magnitude and importance for climate in the SouthernHemisphere