Metasomatized hazburgite xenoliths from Avacha volcano as fragments of mantle wedge of the Kamchatka arc: Implication for the metasomatic agent
スポンサーリンク
概要
- 論文の詳細を見る
Abundant peridotite xenoliths have been found in pyroclasitics of Avacha (Avachinsky) volcano, the south Kamchatka arc, Russia. They are mostly refractory harzburgite with or without clinopyroxene: the Fo of olivine and Cr/(Cr+Al) atomic ratio of spinel range from 91 to 92 and from 0.5 to 0.7, respectively. They are metasomatized to various extents, and the metasomatic orthopyroxene has been formed at the expense of olivine. The metasomatic orthopyroxene, free of deformation and exsolution, is characterized by low contents of CaO and Cr2O3. The complicated way of replacement possibly indicates low viscosity of the metasomatic agent, namely hydrous fluids released from the relatively cool slab beneath the south Kamchatka arc. This is a good contrast to the north Kamchatka arc, where the slab has been hot enough to provide slab-derived melts. High content of total orthopyroxene, 40 vol% on average, in metasomatized harzburgite from Avacha suggests silica enrichment of the mantle wedge, and is equivalent to some subcratonic harzburgite. Some subcratonic harzburgites therefore could have been formed by transportation of subarc metasomatized peridotites to a deeper part of the upper mantle.
- Blackwell Publishingの論文
- 2003-06-01
著者
-
ARAI Shoji
Department of Earth Sciences, Kanazawa University
-
ISHIMARU SATOKO
Department of Earth Sciences, Kanazawa University
-
OKRUGIN VICTOR
Department of Physical-Chemical Methods of Research and Mineralogy, Institute of Volcanology, Russia
-
Ishimaru Satoko
Department Of Earth Sciences Faculty Of Science Kanazawa University
-
Arai Shoji
Department Of Earth Sciences Faculty Of Science Kanazawa University
関連論文
- Unraveling sub-arc melt-peridotite reactions in the Sibuyan Ultramafics, Romblon, Central Philippines
- Origin of spinel-free dunites associated with podiform chromitites from northern Oman ophiolite
- Melt-impregnated plagioclase lherzolites of the Nain melange, central Iran, as a recorder of continental rifting
- Post-deformational impregnation of depleted MORB in Nain lherzolite (Central Iran)
- Petrologic profile of peridotite layers under a possible Moho in the northern Oman ophiolite : an example from Wadi Fizh
- Unusual ultra-depleted dunite from Sibuyan Island (the Philippines) : a residue for ultra-depleted MORB?
- Origin of graphite in glimmerite and spinellite in Achankovil Shear Zone, southern India
- Metasomatized hazburgite xenoliths from Avacha volcano as fragments of mantle wedge of the Kamchatka arc: Implication for the metasomatic agent
- Geochemistry of metasomatized peridotites above subducting slab : a case study of hydrous metaperidotites from Happo-O'ne complex, central Japan
- Petrology and geochemistry of prograde peridotites from Happo-O'ne, Japan : evidence of element mobility during deserpentinization