View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Institute of Volcanology and Seismology FEB RAS Repository ISSN 07420463, Journal of Volcanology and Seismology, 2011, Vol. 5, No. 5, pp. 312–334. © Pleiades Publishing, Ltd., 2011. Original Russian Text © A.V. Koloskov, G.B. Flerov, A.B. Perepelov, I.V. Melekestsev, M.Yu. Puzankov, T.M. Filosofova, 2011, published in Vulkanologiya i Seismologiya, 2011, No. 5, pp. 17–41. Evolution Stages and Petrology of the Kekuknai Volcanic Massif as Reflecting the Magmatism in Backarc Zone of Kuril–Kamchatka Island Arc System. Part 1. Geological Position and Geochemistry of Volcanic Rocks A. V. Koloskova, G. B. Flerova, A. B. Perepelovb, I. V. Melekestseva, M. Yu. Puzankova, and T. M. Filosofovaa a Institute of Volcanology and Seismology, Far East Branch, Russian Academy of Sciences, Piipa boulevard, 9, PetropavlovskKamchatskii, 683006 Russia email:
[email protected] b A. P. Vinogradov Institute of Geochemistry, Siberian Branch, Russian Academy of Sciences, ul. Favorskogo, 1A, Irkutsk, 664033 Russia email:
[email protected] Received October 25, 2010 Abstract—The evolution of the Quaternary Kekuknai volcanic massif (the western flank of the Sredinnyi Range in Kamchatka) has been subdivided into five stages: (1) the precaldera trachybasalt– basaltic andes ite, (2) the extrusive trachyandesite–trachydacite, (3) the early trachybasalt, (4) the middle hawaiite– mugearite (with occasional occurrences of basaltic andesites), and (5) the late trachybasalt–hawaiite– mugearite (with occasional andesites) of areal volcanism. On the basis of petrologic data we identified the island arc and the intraplate geochemical types of rocks in the massif.