The limnogeological record of Melincué Lake (central argentina) through the last millennium in the South American hydro-climate context

LUCÍA GUERRA; EDUARDO LUIS PIOVANO

Zaragoza

Congreso; 5th PAGES Open Science Meeting; 2017

PAGES

Regional paleoclimatic reconstructions are fundamental to emplace the present-day climate in a long-term context. The reconstruction of climate in the region of southeastern South America (SESA) can supply information to validate the paleoclimate models at a continental level and to understand the past patterns of atmospheric circulation. The South American Monsoon (SAM) system controls the precipitations in the tropics and subtropics of South America at the east of the Andes. Recently, an increasing number of climate reconstructions from SESA has been developing for the Common Era, using multiple continental proxies, including paleolimnological records. Melincué Lake, located in central Argentina (33°S/61°W), is shallow and closed system, highly sensitive to changes in regional waterbudget and has a record of the last 1000 years climate variability. In this contribution, the sedimentary record from Melincué Lake is compared with different paleolimnological records from central Argentina and eastern Uruguay during contrasting climatic periods comprising the Medieval Climate Anomaly (MCA), the Little Ice Age (LIA) and the 20th century. These reconstructions are also compared with available paleoclimatic archives from different sites of South America, which are also under the SAM domain, including glacial, lacustrine records and speleothemes. Sedimentological and chemical analyses from Melincué indicate significant wet periods during the MCA-LIA transition and after the LIA, with increasing humidity during the last part of the century. Conversely, part of the MCA and the LIA periods are represented by very low lake-level records. The regional and subcontinental comparison depicts regional hydro-climatic differences during warm and cold periods along South America, which reflect the past dynamics of the SAM. Future research taking part in the eastern part of the Andes in northwestern Argentina will provide further information to complete the latitudinal climate variability in the SESA region associated to the monsoon.