Deception Island (South Shetland Islands, Antarctica): an example of a tectonically induced collapse caldera

Abstract

Deception Island is: The most active volcano of the South Shetland Islands Antarctic Peninsula group, with more than twenty eruptions in the last two centuries. A <0.75Ma (Smellie et al., 1984) horseshoe-shaped stratovolcano 25 km in submerged basal diameter (Barclay et al., 2009) and about 15 km in diameter of the emerged zone. A field revision carried out during the 2010-2011 austral summer has allowed a re-interpretation of the formation of this caldera. The stratigraphy of the deposits cut by the caldera episode and the nature of lithic clasts found in the post-caldera pyroclastic deposits have allowed the reconstructions of the eruptive sequence of the caldera forming eruption and the distribution of intra- and extracaldera deposits.