Deformation patterns, magma supply, and magma storage at Karymsky Volcanic Center, Kamchatka, Russia, 2000–2010, revealed by InSAR

In the summer, studies were carried out on the Tokarev crater (Karymsky Volcanic Center, Kamchatka). The results of three–dimensional electrotomography are obtained, which describe in sufficient detail the topography and heterogeneities of the bottom. The studies were carried out using the author’s floating installation of multi–electrode sounding by the direct current method based on Iris Syscal Pro equipment. The depth of research did not exceed 80 meters, which was enough to describe the structure of the Maar.

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Changes in magma storage conditions following caldera collapse at Okataina Volcanic Center, New Zealand

Contributions to Mineralogy and Petrology ◽

10.1007/s00410-015-1216-6 ◽

2015 ◽

Vol 171 (1) ◽

Cited By ~ 17

Author(s):

Allison Rubin ◽

Kari M. Cooper ◽

Marissa Leever ◽

Josh Wimpenny ◽

Chad Deering ◽

...

Keyword(s):

New Zealand ◽

Storage Conditions ◽

Volcanic Center ◽

Caldera Collapse ◽

Magma Storage ◽

Magma Storage Conditions

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Magma storage and plumbing of adakite-type post-ophiolite intrusions in the Sabzevar ophiolitic zone, NE Iran

Solid Earth Discussions ◽

10.5194/sed-6-2321-2014 ◽

2014 ◽

Vol 6 (2) ◽

pp. 2321-2370

Author(s):

K. Jamshidi ◽

H. Ghasemi ◽

V. R. Troll ◽

M. Sadeghian ◽

B. Dahren

Keyword(s):

High Pressures ◽

Magma Storage ◽

Magma Supply ◽

Intrusive Rocks ◽

Magma System ◽

Rock Suite ◽

High Level ◽

Low Pressures ◽

Crustal Magma ◽

Ne Iran

Abstract. Subduction-related adakite-type intrusive rocks emplaced into the late Cretaceous-Paleocene Sabzevar ophiolite zone, NE Iran, range from Mg-andesite to rhyodacite in composition. Here we investigate the magma supply system to these subvolcanic intrusive rocks by applying thermobarometric mineral and mineral-melt equilibrium models, including amphibole thermobarometry, plagioclase-melt thermobarometry and clinopyroxene-melt barometry. Based on the results of these thermobarometric models, plagioclase crystallized dominantly at pressures of ~ 350 (468–130) MPa, while amphiboles record both low pressures (~ 300 MPa) and very high pressures (> 700 MPa) of crystallization. The latter is supported by the calculated pressures for clinopyroxene crystallization (550 to 730 MPa). The association of amphibole with clinopyroxene and no plagioclase in the most primitive samples (Mg-andesites) is consistent with amphibole fractionation from very hydrous magmas at deep crustal levels of the plumbing system, which may have been a key process to intensify adakite-type affinities in this rock suite. Barometry, combined with frequent disequilibrium features, such as oscillatory-zoned and sieve-textured plagioclase crystals with An-rich overgrowths in more evolved samples, imply final magma differentiation occurred in an open upper crustal magma system that developed progressively stronger compositional modifications during high-level magma storage.

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