Mid-Holocene tephra on Tierra del Fuego (54°S) derived from the Hudson volcano (46°S): evidence for a large explosive eruption

Abstract

The Hudson volcano (46°8) is identified, on the basis of chemical data, as the source of a characteristically green-brown tephra within Holocene deposits on Tierra del Fuego. The 10-15 cm thicknesses of these ash layers, found over 900 km from their source volcano, suggest an explosive eruption of significant magnitude. This eruption has been dated as between 6,625 and 6,930 years B.P. Younger Hudson-derived tephra in Aisen, Chile, and Santa Cruz, Argentina, indicate another explosive eruption of this volcano occurred shortly after 4,830 years B.P. RESUMEN. El volcan Hudson (46°S) se identifico, sobre la base de informacion quimica, como la fuente de una tefra, de tipico color verde-pardusco, intercalada en los depositos del Holoceno en Tierra del Fuego. Estos niveles de ceniza, con espesores de 10-15 cm, situados a distancias mayores que 900 km de su fuente volcanica, sugieren una erupcion explosiva de gran magnitud, datada entre 6.625 y 6.930 anos A.P. Tefras mas jovenes en Aisen, Chile, y 8anta Cruz, Argentina, indican otra erupcion explosiva del volcan Hudson poco despues de 4.830 anos A.P.