Metastable transformations of eclogite to garnetite in subducting oceanic crust

Masayuki Nishi, Tomoaki Kubo, Takumi Kato

研究成果: ジャーナルへの寄稿レター

12 引用 (Scopus)

抄録

The eclogite-garnetite transformation experiments were conducted at 11 GPa and 1000-1550 °C using synthesized polycrystalline eclogite with MORB composition as a starting material. We found that the eclogite-garnetite transformation proceeds by two stages, (1) precipitation of majoritic garnet from clinopyroxene and (2) formation of majoritic garnet from original pyropic garnet by absorption of clinopyroxene. The 1st stage in the transformation proceeds at 1000 °C for 180 minutes, however the 2nd stage was not observed even at the high temperature of 1550 °C on the same time scale. The differences in kinetics are due to contrasting diffusivities between clinopyroxene and garnet. The kinetic effect would modify the mineralogy and rock microstructures in MORB, which provides important implications for dynamics of subducting oceanic crust by changing the density and viscosity relation.

元の言語英語
ページ(範囲)192-198
ページ数7
ジャーナルJournal of Mineralogical and Petrological Sciences
104
発行部数3
DOI
出版物ステータス出版済み - 6 1 2009

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eclogite
garnets
oceanic crust
crusts
garnet
clinopyroxene
mid-ocean ridge basalt
rock microstructure
kinetics
mineralogy
diffusivity
viscosity
rocks
timescale
microstructure
experiment

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Geology

これを引用

Metastable transformations of eclogite to garnetite in subducting oceanic crust. / Nishi, Masayuki; Kubo, Tomoaki; Kato, Takumi.

:: Journal of Mineralogical and Petrological Sciences, 巻 104, 番号 3, 01.06.2009, p. 192-198.

研究成果: ジャーナルへの寄稿レター

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