Transformation in Garnet from Orthorhombic Perovskite to LiNbO 3 Phase on Release of Pressure
- 24 January 1997
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 275 (5299), 513-515
- https://doi.org/10.1126/science.275.5299.513
Abstract
High-pressure in situ x-ray diffraction and transmission electron microscopy on quenched samples show that natural garnet transforms to orthorhombic perovskite (and minor coexisting phases) containing increasing amounts of aluminum with increasing pressure. This suggests that the perovskite is the dominant host mineral for aluminum in Earth's lower mantle. Orthorhombic perovskite is quenched from ∼35 gigapascals but, because of the increased aluminum content, transforms to the LiNbO 3 structure upon quenching from ∼60 gigapascals.Keywords
This publication has 15 references indexed in Scilit:
- An experimental study of the garnet-perovskite transformation in the system MgSiO3Mg3Al2Si3O12Physics of the Earth and Planetary Interiors, 1996
- MgSiO3‐FeSiO3‐Al2O3 in the Earth's lower mantle: Perovskite and garnet at 1200 km depthJournal of Geophysical Research, 1994
- Absence of an aluminous phase in the upper part of the Earth's lower mantleNature, 1994
- Unquenchable high-pressure perovskite polymorphs of MnSnO3 and FeTiO3Physics and Chemistry of Minerals, 1991
- Experimental petrology of the lower mantle: A natural peredottte taken to 54 GPAGeophysical Research Letters, 1990
- Synthesis and crystal-chemical characterization of MgSiO3 perovskiteEarth and Planetary Science Letters, 1978
- Structure and crystal chemistry of perovskite-type MgSiO3Physics and Chemistry of Minerals, 1978
- The high-pressure phases of MgSiO3Earth and Planetary Science Letters, 1976
- Silicate perovskite from phase transformations of pyrope‐garnet at high pressure and temperatureGeophysical Research Letters, 1974
- Effective ionic radii in oxides and fluoridesActa Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 1969