Pre-caldera Pyroclastic deposits of Deception Island (South Shetland Islands)

• Published in: Antarctic Science
• Main Authors: Martí, J., Baraldo, A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1990
• Subjects: Geology; Ecology, Evolution, Behavior and Systematics; Oceanography; South Shetland Islands; Deception Island; Antarctic Science
• Online Access: http://dx.doi.org/10.1017/s0954102090000475; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102090000475

The youngest pre-caldera volcanism of Deception Island is represented by a thick sequence of subaerial pyroclastic deposits which has been grouped as the Yellow Tuff Formation. Most of these deposits were related to the explosive activity of a central vent which was destroyed during the formation of the caldera. Two members can be distinguished in this formation. The lower member is mainly composed of 1 to 12 m thick massive pyroclastic flow deposits with interbedded air-fall and surge deposits. The upper member is in stratigraphical continuity with the lower member and consists of base surge deposits with minor air-fall and thin pyroclastic flow deposits. The pre-caldera deposits have undergone a palagonitic alteration which produced crystallization of smectites, Fe-oxides, zeolites and calcite.