CONICET | Buscador de Institutos y Recursos Humanos

During the late 1950s and early 1960s, thermonuclear testsadded considerable amounts of 14C to the atmosphere. Since that time the amounthas declined, which is owed to the exchange and dispersal of 14C into theEarth's carbon reservoirs, creating an isotopic chronometer (the 14C bomb peak)to all living organisms. In this study, we make use of this alternativeradiometric method to compare dendrochronological ages with the 14C signatureof wood samples, as a way to independently confirm the anual nature of thegrowth rings of Araucaria araucana trees growing in a northern Patagonia site,represented by a forest of old living specimens of ca. 900 years. High precisión14C-AMS of selected tree-rings from two trees confirms the annual frequency ofthe ring formation against an existing dataset of atmospheric 14C values in theSH Zone 1-2, validating these tree specimens for further use on improving thetemporal resolution of the 14C age calibration curve for the SouthernHemisphere.