Late pleistocene-holocene caldera-forming explosive volcanism of the great kuril arc
S.Z. Smirnov1, A.A.Kotov2, O.V. Bergal-Kuvikas3,4, A.V. Degterev5
1V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Science, Novosibirsk, Russia
2Graduate School of Environmental Studies, Tohoku University, Sendai, Japan
3Institute of Volcanology and Seismology, Far Eastern Branch of the Russian Academy of Sciences,
Petropavlovsk-Kamchatsky, Russia
4Vitus Bering Kamchatka State University, Petropavlovsk-Kamchatsky, Russia
5Institute of Marine Geology and Geophysics of the Far Eastern Branch of the Russian Academy of Science, Yuzhno-Sakhalinsk, Russia
Keywords: Great Kuril Arc, caldera, volcano, explosive volcanism, magmatism
Abstract
Caldera-forming explosive volcanism is a most dangerous natural hazard, which have catastrophic consequences to the life, humans and their economic activities. The paper represents a summary of the published and original data on the Late Pleistocene-Holocene caldera-forming volcanism within the Great Kuril Arc (GKA) collected to the recent times. The data available from publications reveal that formation of explosive calderas occurred in all segments of GKA in the Late Pleistocene and Holocene. Most frequent it was in the Southern and Central segments of GKA, where it borders on the back arc basin of Kuril deep-sea depression. The majority of investigated in this study calderas appeared in Late Pleistocene 50-12 Ka and Early Holocene 8-6 Ka. Intensive caldera-forming volcanism in GKA could be contemporaneous to similar volcanism in the East-Kamchatka volcanic belt and Southern Kamchatka. Caldera eruptions of GKA in the Late Pleistocene and Early Holocene were related with evolution of large reservoirs of predominantly dacitic magmas, which were formed due to melting of metabasitic protholiths in the shallow crust (3 – 12 km) at 830 – 890°C. Rhyolitic melts of these magmas were saturated in H2O, CO2, sulfur compounds, and probably by other gaseous species. This caused shallow degassing at the pre-eruptive stages of the magma reservoir evolution. The study rises questions, which solution would provide a basis for more effective prediction of powerful volcanic explosions and monitoring of activity of caldera volcanoes in GKA.
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