Abstract
During the transformation of olivine (Fo90) to ringwoodite and wadsleyite at 18–20 GPa three transformation microstructures develop: (i) Reaction rims form around olivine by incoherent grain boundary nucleation; the growth rates of these rims decrease strongly with reaction time because the volume decrease causes elastic strain to develop. (ii) Intracrystalline, coherent ringwoodite lamellae nucleate on previously formed (100)α stacking faults. (iii) Polycrystalline ringwoodite and/or wadsleyite lenses develop in the interior of relict olivine crystals by nucleation of incoherent grains on the coherent ringwoodite lamellae. The observed intracrystalline transformation mechanism and the time-dependence of growth have important implications for predicting the depth of the olivine-spinel transformation in subducting lithosphere.
Original language | English (US) |
---|---|
Pages (from-to) | 28-33 |
Number of pages | 6 |
Journal | Review of High Pressure Science and Technology/Koatsuryoku No Kagaku To Gijutsu |
Volume | 7 |
DOIs | |
State | Published - 1998 |
Keywords
- High pressure transformation mechanism
- Intracrystalline nucleation
- Olivine
- Subduction
- Transformational strain
ASJC Scopus subject areas
- Chemistry(all)
- Materials Science(all)
- Condensed Matter Physics