Paleoclimatic Variations During the Holocene Through Magnetic Proxies on Sediments from Laguna Potrok Aike (51°57’S, 70°24’W, Argentina)

IRURZUN, M.A.; GOGORZA, C.S.G.; SINITO, A.M.; AGUILAR, D.; OLHENDORF,C.; ZOLITSCHKA, B

Buenos Aires

Workshop; 1ª Reunión Internodos del Proyecto Interdisciplinario Patagonia Austral y 1er Workshop Argentino del Proyecto Potrok Aike Maar Lake Sediment Archive Drilling Project; 2010

Proyecto PIPA

Lake sediments are excellent sources for many different paleoenvironmental and paleoclimatic information as they provide continuous and high-resolution records. They are also first class recorders of magnetic parameters widely used around the world as proxies for paleoenvironmental variations, because every change in the catchment area (rainfall and drought periods, temperature changes, differences in sedimentation rates) is likewise reflected in variations of the magnetic parameters. Relationships between magnetic parameters, total organic carbon, total inorganic carbon, different elements, gastropods (Haberzettl et al., 2007), pollen (Wille et al., 2001) and diatom frustules (Mayr et al., 2009) were analysed to infer lake level changes and to suggest related hydrological and climate fluctuations. The results from these previous studies suggest a dry period around 11600 cal BP and periods of moister environment at the beginning of the Holocene followed by drier conditions between 8700 and 6000 cal BP, and then an increase of available moisture. A lower lake level event was recognized around 7000 cal BP and periodic changes among low and high lake levels were identified for the last 1500 cal BP with a particular high lake level between 500 and 150 cal BP which is attributed to the “Little Ice Age (LIA)”.