Repeated debris avalanches on Tenerife and genesis of Las Cañadas caldera wall (Canary Islands)

Abstract

Geologic evidence on Tenerife, Canary Islands, indicates six successive north-directed debris avalanche events, including: the Anaga and Teno (ca. 6 Ma) events that affected the old basaltic series, and the Tigaiga (>2.3 Ma), Roques de García (possibly 0.6–0.7 Ma), Orotava (ca. 0.6 Ma), and Icod (<0.15 Ma) avalanche events that affected the Cañadas and Dorsal volcanic edifices. The approximate total volume (>1000 km3) inferred for these events can account for the volume of previous estimates of offshore volcanic debris. These repeated flank failures can also account for the present morphology of Las Cañadas caldera wall, which partly bounds a multiepisodic lateral-collapse structure 25 km wide.