Выбрать:     Все     A     B     C     D     E     F     G     H     I     J     K     L     M     N     O     P     R     S     T     V     W     Y     Z     А     Б     В     Г     Д     Е     Ж     З     И     К     Л     М     Н     О     П     Р     С     Т     У     Ф     Х     Ц     Ч     Ш     Щ     Э     Я     
Записей: 2683
Nishizawa Tatsuji, Nakamura Hitomi, Churikova T., Gordeychik B., Ishizuka Osamu, Iwamori Hikaru Genesis of Quaternary volcanism of high-Mg andesitic rocks in the northeast Kamchatka Peninsula // Japan Geoscience Union Meeting. 22-26 May 2016, Makuhari, Messe. 2016. P. SVC48-02.
Arc magmatism is a product of subduction factory, involving thermal and chemical interactions
between a subducted slab as a material input and mantle wedge as a processing factory. In turn, the
compositions of arc magma provide invaluable information concerning the material input and the
interactions. The northeast Kamchatka Peninsula is an ideal field to examine such interactions and
relationships, being characterized by (1) subduction of the Emperor Seamount Chain (Davaille and
Lees, 2004), and (2) possible material and thermal interaction among the subducted slab, the
overlying mantle wedge and the sub-slab mantle via the edge of subducted Pacific slab (Portnyagin
and Manea, 2008). Within this area, a monogenetic volcanic group occurs along the east coast,
including high-Mg andesitic rocks and relatively primitive basalts (East Cones, EC (Fedorenko,
1969)). We have conducted geochemical studies of the EC lavas, with bulk rock major and trace
elements, and K-Ar and Ar-Ar ages, based on which a possible contribution of subducted seamounts
and its relation to the tectonic setting are discussed.
The elemental compositions indicate that the lavas from individual cones have distinct mantle
sources with different amounts and/or compositions of slab-derived fluids. Based on mass balance,
water content and melting phase relations, we estimate the melting P-T conditions to bet ~1200 ℃
at 1.5 GPa, while the slab surface temperature is 620 –730 ℃ (at 50-80 km depth). Compared with
the southern part of Kamchatka, the slab surface temperature beneath EC seems to be high due to the
thinner Pacific slab associated with the seamount chain and/or the plate rejuvenation from a mantle
plume impact (Davaille and Lees, 2004; Manea and Manea, 2007).
The K-Ar and Ar-Ar ages of the Middle Pleistocene are consistent with the tephrochronological
study (Uspensky and Shapiro, 1984) and the present tectonic setting after 2 Ma (Lander and Shapiro,
2007). The high-Mg andesite with the highest SiO2 content in the EC lavas shows the oldest age
(0.73 ±0.06 Ma) within not only EC but also the northeast part of Kamchatka (e.g., Churikova et
al., 2015, IAVCEI). On the other hand, the rest of EC lava samples show relatively younger ages to
0.18 ±0.07 Ma. These results suggest that the EC lavas including high-Mg andesite and basalt were
generated by mantle flux-melting induced by dehydration of a subducted seamount inheriting a local
thermal anomaly (Nishizawa et al., 2014, JpGU; 2015, JpGU).
Ostorero L., Balcone-Boissard H., Boudon G., Shapiro N., Belousov A., Belousova M., Droznina S. Correlated petrology and seismicity indicate rapid magma accumulation prior to eruption of Kizimen volcano, Kamchatka // Communications Earth & Environment. 2022. Vol. 3. № 290. P. 1-14. https://doi.org/10.1038/s43247-022-00622-3.
Ovsyannikov A.A., Khrenov A.P., Muravyev Y.D. Recent Fumarole Activity on Dal'nii Ploskii Volcano // Volcanology and Seismology. 1989. Vol. 7. № 5. P. 815-817.
Ozerov A. Gas-hydrodynamic model of basalt explosions (based on experimental data) // 33rd International Geological Congress. Oslo, Norway. Abstracts. 2008.
Ozerov A. Types and Mechanisms of Basaltic Explosions: Environmental Observations and Experimental Data // IAVCEI 2008 - General Assembly, Reykjavik, Iceland. Abstracts. 2008. P. 7
Ozerov A. Yu. Experimental modeling of the explosion mechanism of basaltic magmas // Petrology. 2009. Vol. 17. № 7. P. 653-668. doi:10.1134/S0869591109070029.
Ozerov A., Ispolatov I., Lees J. Modeling Strombolian eruptions of Karymsky volcano, Kamchatka, Russia // Journal of Volcanology and Geothermal Research. 2003. Vol. 122. № 3–4. P. 265 - 280. doi: 10.1016/S0377-0273(02)00506-1.
A model is proposed to explain temporal patterns of activity in a class of periodically exploding Strombolian-type andesite volcanoes. These patterns include major events (explosions) which occur every 3–30 min and subsequent tremor with a typical period of 1 s. This two-periodic activity is thought to be caused by two distinct mechanisms of accumulation of the elastic energy in the moving magma column: compressibility of the magma in the conduit and viscoelastic response of the almost solid magma plug on the top. A release of the elastic energy occurs during a stick–slip dynamic phase transition in a boundary layer along the walls of the conduit; this phase transition is driven by the shear stress accumulated in the boundary layer. The intrinsic hysteresis of this first-order phase transition explains the long periods of inactivity in the explosion cycle. Temporal characteristics of the model are found to be qualitatively similar to the acoustic and seismic signals recorded at Karymsky volcano in Kamchatka.
Ozerov A., Lees J., Ispolatov J. Long and Short Term Periodic Activity at Karymsky Volcano // AGU Spring Meeting 1999. Eos Trans. AGU, xx (xx), Spring Meet. Suppl., Abstract. Boston, Massachusetts: AGU. 1999. P. V11D-09.
Ozerov A.Yu. A New Cluster Regime Of Gas-Liquid Flow In Vertical Columns (Physical Modeling) // Сборник тезисов Международной конференции «Потоки и Структуры в Жидкостях: Физика Геосфер». М.: ИПМех РАН. 2009. Vol. 1. P. 178-181.
Ozerov A.Yu. Cluster Regime – The New Regime Of Flowing Of Gas-Liquid Mixture In Vertical Columns (Based On Experimental Data) // 6th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion. Xi’an, China, 11-15 July 2009. 2009. P. FG-30.