Preliminary Dendrogeomorphological Results Showing Past Eruptions in the Andes

SHEPPARD, P.; CASTELLER, A.; MUÑOZ, A.; GONZÁLEZ, M.

Tucson, Arizona

Conferencia; Ameridendro 2013; 2013

Universidad de Arizona

Tree-ring samples were collected from trees growing on the flanks of various volcanoes of the central Andes Volcanic Range, on the border of Argentina and Chile. The species sampled were Araucaria, which appear to be up to 800 years in age, and Australcedrus, which are about 150 years in age. The Araucaria samples have extremely narrow rings forhundreds of years in a row, and strictly speaking crossdating those samples will be difficult, if not impossible. The Australcedrus samples have much wider rings, and those samples are crossdatable. The intention is to analyze these tree-ring samples both for ring width and for ring chemistry to ascertain possible eruptions of the past. For example, manyAustralcedrus samples show an abrupt increase in ring growth beginning in 1960, which might be evidence of an eruption and ash fall at that time. Salvaging the Araucaria samples with dendrochemistry is proposed.