Multibioproxy reconstruction of environmental changes during the Lateglacial-Holocene transition in northern Patagonia east of the Andes

MASSAFERRO, J., MANCA, M., SYLVESTRE, F. ARIZTEGUI

Valdivia

Congreso; PAGES; 2010

Universidad de Valdivia

The transition from the Last Glacial Maximum to the present interglacial period is the last major global climate change event and thus crucial for our understanding of modern climate processes and the validation of climate models (Lamy and Kaiser, 2009) Despite the recent increase of paleoproxies work from both marine and terrestrial archives in the southern hemisphere , the relationships between deglacial climate change in the Northern and Southern Hemispheres remain clouded by uncertainties in the absolute timing and magnitude of the events recorded in the two hemispheres In southern South America, the debate is primarily focused on the existence of a ACR-like , a YD-like or a mixture of both, cooling events at the end of the LGM. In this paper we explore climate changes occurred during the Late Glacial/ Early Holocene transition (between 15,000 and 11,000 cal yr BP) in Lake Mascardi, a glacial lake located eastern of the Andes in Argentinean Patagonia. This multiproxy study provides high-resolution postglacial chironomid, cladoceran and diatom records which combined with radiocarbon dating reveals the suitability of the bioproxy data in helping to pinpoint the onset and timing of cold/warm dry/wet episodes and.to produce more robust interpretations of climate change in southern South America This paper, along with previously published records from the southern mid-latitudes (Massaferro et al., 2009 )suggest a more complex relationship in temperature trends between the polar hemispheres than the widespread notion of in-phase versus climatic anti-phase during the Last Glacial-Interglacial Transition.