Ishimaru Satoko, Arai Shoji Highly silicic glasses in peridotite xenoliths from Avacha volcano, Kamchatka arc; implications for melting and metasomatism within the sub-arc mantle // Lithos. 2009. Vol. 107. № 1–2. P. 93 - 106. doi: 10.1016/j.lithos.2008.07.005.
Silicate glasses in peridotite xenoliths from Avacha volcano have high SiO2 (up to 72 wt.) and highly SiO2-oversaturated characteristics; normative quartz content is up to 50 wt.. The glasses represent secondary melts solidified after interaction with mantle peridotite, i.e. crystallization of secondary orthopyroxene at the expense of olivine. We identified two kinds of silicate glasses in Avacha peridotites; one is higher in K2O and enriched in Rb, Ba, U, and Pb than the other. The glasses show basically similar chemical characteristics to the host basaltic andesite to andesite of the Avacha volcano. These chemical characteristics are inherited from slab-derived fluids/melts, which metasomatize the mantle wedge and induce partial melting. The differences of chemical features among the Avacha glasses are attributed to chemical difference of the slab-derived fluids/melts, possibly due to the difference of sediments/basalt ratio of the relevant slab. The low-degree partial melt of peridotite assisted by these fluids/melts, is primarily SiO2-oversaturated, and can conduct silicate metasomatism, evolving through interaction with surrounding mantle peridotite, i.e. formation of orthopyroxene at the expense of olivine. Highly silicic glasses, also reported from peridotite xenoliths from oceanic hotspots and continental rift zones, mostly result from assimilation of orthopyroxene by SiO2-undersaturated melts, which crystallize clinopyroxene and olivine. The glasses also show similar trace-element patterns to their host alkali basaltic magmas, as in the case of arc glasses/calc-alkali magmas. If the glasses in peridotite xenoliths are of silicate metasomatism origin, they are similar in chemistry to host magmas. Reaction between carbonatite melts and peridotites shows the same petrographical feature as that of SiO2-undersaturated silicate melts with peridotites. The glasses originated from carbonatite metasomatism, however, exhibit clearly different trace-element patterns from their host alkali basaltic magmas.
Ishimaru Satoko, Arai Shoji, Shukuno Hiroshi Metal-saturated peridotite in the mantle wedge inferred from metal-bearing peridotite xenoliths from Avacha volcano, Kamchatka // Earth and Planetary Science Letters. 2009. Vol. 284. № 3–4. P. 352 - 360. doi: 10.1016/j.epsl.2009.04.042.
Lithospheric mantle is inferred to be more oxidized than the asthenosphere, and mantle-wedge peridotites are characterized by high oxidation state relative to abyssal and continental peridotites due to addition of slab-derived fluids or melts. We found metals (native Ni, Fe silicides, native Fe and possible native Ti) from otherwise oxidized sub-arc mantle peridotite xenoliths from Avacha volcano, Kamchatka. This is contrary to the consensus and experimental results that the metals are stable only in deeper parts of the mantle (> 250 km). The metals from Avacha are different in chemistry and petrography from those in serpentinized peridotites. The Avacha metals are characteristically out of chemical equilibrium between individual grains as well as with surrounding peridotite minerals. This indicates their independent formation from different fluids. Some of the Avacha metals form inclusion trails with fluids and pyroxenes, leading to the inference that very local metal saturation resulted from rapid supply (‘flashing’) of reducing fluids from deeper levels. The fluids, possibly rich in H2, are formed by serpentinization at the cold base of the mantle wedge just above the slab, and they reduce overlying peridotites. We propose a metal-saturated peridotite layer, underlying the main oxidized portion, within the mantle wedge beneath the volcanic front to fore-arc region.
Ivanov A.V., Perepelov A.B., Puzankov M.Yu., Yasnygina T.A., Malykh Yu.M., Rasskazov S.V. Rift- and arc-type basaltic volcanism of the Sredinny Ridge, Kamchatka: case study of the Payalpan volcano-tectonic structure / Metallogeny of the Pacific Northwest: Tectonics, Magmatism and Metallogeny of Active Continental Margins. Vladavostok: Dalnauka. 2004. P. 345-349.
Trace element data for volcanic rocks of the Payalpan volcano-tectonic structure (Sredinny ridge, Kamchatka) allows distinguishing typical island-arc, rift and transitional series of rocks. Island-arc basaltic and differentiated magmas erupted in the Late Miocene and Pliocene. In the Late Pliocene – Early Pleistocene, there was a voluminous event dominated by the basaltic magmas of rift-type series. This event followed by voluminous eruptions of mainly basaltic andesites of transitional series. At the end of the Pleistocene and probably during the Holocene volume of eruptions diminished and composition of magmas shifted towards rift-type basaltic series. Practically in the same area in the Pleistocene and Holocene the Icha volcano produced basaltic andesite to rhyolite magmas of the island-arc and transitional series. Reasons for spatial overlapping and temporal evolution of the island-arc and rift magma types are also discussed.
Ivanov B.V., Chirkov A.M., Dubik Y.M., Khrenov A.P., Dvigalo V.N., Razina A.A., Stepanov V.V., Chubarova O.S. Active Volcanoes of Kamchatka and Kuril Islands: Status in 1982 // Volcanology and Seismology. 1988. Vol. 6. № 4. P. 623-634.
Ivanov B.V., Gavrilenko G.M., Dvigalo V.N., Ovsyannikov A.A., Ozerov A.Yu., Razina A.A., Tokarev P.I., Khrenov A.P., Chirkov A.M. Activity of Volcanoes in Kamchatka and the Kuril Islands in 1983 // Volcanology and Seismology. 1988. Vol. 6. № 6. P. 959-972.
A new Klyuchevskoy volcano eruptive cycle encompasses terminal (March 30, 1972 to August 23, 1974) and lateral (August 23, 1974 to December, 1974) eruption stages. The terminal eruption stage resulted in lava flows and parasitic cones that formed on the south-western flank of the volcano.
Eruption products are moderately alkalic high-alumina olivine-bearing andesite-basalts. The terminal eruption stage was accompanied by volcanic earthquakes and volcanic tremor. The lateral eruption was accompanied by explosive earthquakes. Volcanic tremor was the most useful prognostic sign indicating the onset of the lateral eruption. Eruptive mechanisms are discussed.
Ivanov B.V., Kadik A.A., Maksimov A.P. Conditions of the crystallization of andesites from the Klyuchevskaya volcanic group (Kamchatka) Arc volcanism (abstr.).. // Arc Volcanism: Physics and Tectonics. Proceedings of a 1981 IAVCEI Symposium, Arc Volcanism, August-September, 1981, Tokyo and Hakone. Tokyo: Terra Scientific Pub. Co.. 1983.
Izbekov P., Eichelberger J., Belousova M., Ozerov A. Post-collapse trends at Bezymianny Volcano, Kamchatka, Russia and the May 6, 2006 eruption // AGU Fall Meeting 2006. Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstracts. 2006. P. V11B-0576.
Izbekov P., Eichelberger J., Ivanov B., Maximov A. Variations of Volcanic Glass Composition Show Possible Mixing Event at the Beginning of 1996 Eruption of Karymsky Volcano, Kamchatka, Russia // Trans. American Geophys. Union, Fall Meet. Suppl, Abstract . 1998. Vol. 79(45). P. V22B-10.
Izbekov P., Koloskov A., Maximov A., Khabunaya S. The 2012 Fissure Tolbachik Eruption: Preliminary Results of Petrological Investigation // Geophysical Research Abstracts. EGU General Assembly, Vienna, 2014. Vienna, Austria: EGU General Assembly 2014. 2014. Vol. 16. P. 11710