Institute of Volcanology and Seismology FEB RAS Repository
IVS FEB RAS
Поиск
Browse
IVS FEB RAS Items
Statistics
Instruction
Links

Highly silicic glasses in peridotite xenoliths from Avacha volcano, Kamchatka arc; implications for melting and metasomatism within the sub-arc mantle

Ishimaru Satoko, Arai Shoji (2009) Highly silicic glasses in peridotite xenoliths from Avacha volcano, Kamchatka arc; implications for melting and metasomatism within the sub-arc mantle // Lithos. Vol. 107, No. 1–2. pp. 93 - 106. doi: 10.1016/j.lithos.2008.07.005.

Full text not available from this repository.

Official URL: http://www.sciencedirect.com/science/article/pii/S...

Abstract

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.
Item Type: Article
Title: Highly silicic glasses in peridotite xenoliths from Avacha volcano, Kamchatka arc; implications for melting and metasomatism within the sub-arc mantle
Language: English
Journal or Publication Title: Lithos
ISSN Print: 0024-4937
Uncontrolled Keywords: Peridotite xenoliths, Silicate glasses, Arc setting, Metasomatism, Partial melting, Slab-derived fluids
Subjects: State scientific and technical information rubricator (ГРНТИ) > 38 ГЕОЛОГИЯ > 38.37 Петрография > 38.37.25 Вулканология
Volcanoes > 1 Volcanoes of the Kurile-Kamchatka Region > 1.1 Kamchatka > Avachinsky
Additional Information: Subduction vs Intraplate Lithospheric Mantle: Agents and ProcessesSubduction vs Intraplate Lithospheric Mantle: Agents and Processes
Depositing User: И.М. Романова
Date Deposited: 17 Dec 2015 05:46
Last Modified: 17 Dec 2015 05:46
URI: http://repo.kscnet.ru/id/eprint/2558

Actions (login required)

View Item View Item