Limnogeology in Southern South America: On overview

PIOVANO EDUARDO; FRANCISCO CÓRDOBA; SILVINA STUTZ

Latin American Journal of Sedimentology and Basin Research

Asociación Argentina de Sedimentología

Lugar: La Plata; Año: 2015 vol. 21 p. 65 - 75

Received June 16, 2015 - Accepted August 7, 2015Paleoclimatologists reconstruct past conditions of earth´s climate system gathering proxy data from ?natural archives? such as tree rings, ice cores, lake sediments, peat bogs, ocean sediments, corals, and historical data. Climate archives provide information at different time spans, covering from hundreds to millions of years at a large range of temporal resolutions (Fig. 1). One major goal in Quaternary paleoclimatology is to reconstruct and understand past earth system unevenness and feedbacks on longer time scales than the offered by instrumental records, which usually cover the last 100´s years. As underlined by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC; Masson-Delmotte et al., 2013), paleoclimatology provides essential information for the understanding of present and future climate change. Consequently, is highly necessary to evaluate pre-industrial changes in atmospheric composition, and the influence of external solar and volcanic activity to global and regional changes in temperature, cryosphere and hydroclimate conditions during the current interglacial period.Lake environments are one of the most sensitive systems in the continental settings to react to extrinsic and intrinsic forcing changes (Cohen, 2003). Lakes and their deposits provide the opportunity to study both present-day and past lake processes at high temporal resolution (Fig. 1). The life of lakes is greatly variable and they may range from short-lived ephemeral lakes, like in saline mudflats (e.g., Salinas de Ambargasta: Zanor et al., 2012) to extremely long-lasting lakes, as the Lake Tanganyka, which recorded the earth and ecosystem history over the past 9-12 million years at an annual resolution (Cohen et al., 1997).Lake research has fascinated scientists since the latter part of the 19th century. Undoubtedly, the contribution of Gilbert (1890), who identified lake paleoshorelines at 300 m above the present-day Great Salt Lake (USA), is a landmark in this field. These deposits were linked to the Lake Bonneville, which was the largest late Pleistocene pluvial lakes in the North American Great Basin. At the same time, the Swiss naturalist François Forel established the bases for a new discipline named ?Limnology?, and stated that "limnology is the oceanography of lakes" (Forel, 1892). Forel recognized the complexity of lake functioning, considering them as systems in which abiotic and biotic elements are drawn closely together. Regarding southern South America, one of the first lake studies in the Argentinean Patagonia was done by Caldenius (1932) who provided the first systematic study dealing with glaciations and lakes. He had a visionary approach in the analysis of the past climate system trying to establish, for the first time, the existence of ?climate teleconnections? by the comparison of lacustrine varved sediments from Sweden with varved proglacial lake sediments exposed at the terraced walls of the Corintos River in western Patagonia.