Isotopic and Petrologic Investigation, and a Thermomechanical Model of Genesis of Large-Volume Rhyolites in Arc Environments: Karymshina Volcanic Complex, Kamchatka, Russia ...

• Main Authors: Bindeman, Ilya N., Leonov, Vladimir L., Colón, Dylan P., Rogozin, Aleksey N., Shipley, Niccole, Jicha, Brian, Loewen, Matthew W., Gerya, Taras
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2019
• Subjects: Kamchatka; Kamchatka Peninsula
• Online Access: https://dx.doi.org/10.3929/ethz-b-000329418; http://hdl.handle.net/20.500.11850/329418

The Kamchatka Peninsula of eastern Russia is currently one of the most volcanically active areas on Earth where a combination of >8 cm/yr subduction convergence rate and thick continental crust generates large silicic magma chambers, reflected by abundant large calderas and caldera complexes. This study examines the largest center of silicic 4-0.5 Ma Karymshina Volcanic Complex, which includes the 25 × 15 km Karymshina caldera, the largest in Kamchatka. A series of rhyolitic tuff eruptions at 4 Ma were followed by the main eruption at 1.78 Ma and produced an estimated 800 km3 of rhyolitic ignimbrites followed by high-silica rhyolitic post-caldera extrusions. The postcaldera domes trace the 1.78 Ma right fracture and form a continuous compositional series with ignimbrites. We here present results of a geologic, petrologic, and isotopic study of the Karymshina eruptive complex, and present new Ar-Ar ages, and isotopic values of rocks for the oldest pre- 1.78 Ma caldera ignimbrites and intrusions, which ... : Frontiers in Earth Science, 6 ...