A multiproxy approach to reconstruct the environmental changes in Lago Toncek (Patagomia, Argentina): Preliminary studies

GORGORZA; IRURZUN; QUINTANA; MAYR; MASSAFERRO

Lisboa

Congreso; 14th Castle Meeting NEW TRENDS ON PALEO, ROCK AND ENVIRONMENTAL MAGNETISM; 2014

Universidad de Cs de Lisboa

Lake sediments are excellent sources of palaeoenvironmental andpalaeoclimatic information because they provide continuous and high-resolutionrecords. They are also first class recorders of magnetic parameters widely used aroundthe world as proxies for paleoenvironmental variations, because every change in thecatchment area (rainfall and drought periods, temperature changes, differences insedimentation rates) is likewise reflected in variations of the magnetic parameters.This study was carried out on cores collected from the Laguna Toncek (41°11´52.72"S,71°29´17.45" W, 1750 m asl), a small lake with 0.03 km2 surface area and 12mmaximum depth of glacial origin, situated in Catedral mountain in the Nahuel HuapiNational Park of northern Patagonia. Lake Toncek watershed is dominated by rockyground deposits, and scattered timberline forest (Nothofagus pumilio ) and high-Andean vegetation (Gaultheria pumila, Baccharis magellanica, among others). Thiswork is part of a multidisciplinary project which aim is to provide paleoenvironmentalinformation about the almost unexplored remote wetland areas of the Nahuel HuapiNational Park in Patagonia. A combination of rock magnetic parameters withpaleolimnological analysis (diatoms, chironomids, ostracods, and geochemistry) fromremote lakes such as Laguna Toncek will be used to develop a detailed history ofenvironmental changes during the past hundred years in the area of Bariloche(Patagonia, Argentina).