Post-Glacial tephrochronology of Nahuel Huapi National Park, Northern Patagonia

GUSTAVO VILLAROSA; VALERIA OUTES; BRENT ALLOWAY; HÉCTOR PANARELLO

Ciudad de Mendoza

Congreso; XVIII International Sedimentological Congress; 2010

IAS

Nahuel Huapi National Park (41°S, 71°40’W) is under the strong influence of the numerous active volcanoes from the Central Southern Volcanic Zone (CSVZ). This portion of the volcanic arc extends from latitudes 37° to 41,5° S, following the Liquiñe–Ofqui fault zone. Strong westerly winds drive volcanic plumes to the east, depositing tephras in Nahuel Huapi area. Sedimentary records from lakes, exposures and archaeological sites preserve evidence of several explosive Late Glacial to Holocene eruptions from multiple sources. Lago Mascardi (41º 20’S–71º 30’W) and laguna El Trébol (41°04’S, 71°29’W), have been selected as reference records because of their continuity, time span (ca. 18,000 years) and good chronological control.