Published February 1972
| public
Journal Article
A shock-induced phase change in iron-silicate garnet
- Creators
- Ahrens, Thomas J.
- Graham, E. K.
Abstract
Hugoniot measurements on iron-silicate garnet (Fe_(0.79), Mg_(0.14), Ca_(0.04), Mn_(0.03))_3 Al_2Si_3O_(12) initial density 4.18 g/cm^3, demonstrate that above a shock pressure of 205 ± 20 kbar transition to a high-pressure phase(s), having an apparent zero-pressure density and bulk modulus of 4.44 ± 0.06g/cm^3 and 3.3 ± 0.3 Mbar, occurs. Crystal chemical systematics and Debye-Scherrer X-ray patterns of a recovered phase(s), which may be the shock-induced high-pressure form, suggest possible formation of a phase with a density of∼ 4.48/cm^3. Occurrence of such a polymorph of garnet in the mantle would give rise to an increase in density and seismic velocity below ∼ 600km in the earth.
Additional Information
© 1972 Published by Elsevier B.V. Received 6 September 1971; Revised version received 22 November 1971. We appreciate the assistance of John F Lower and Rex V. Gibbons in carrying out the Hugomot and shock recovery experiments Rex V Gibbons' review of the manuscript is also appreciated This research was supported under NSF Grant GA 21396 and NASA Grant NGL 05-002-105.Additional details
- Eprint ID
- 53292
- Resolver ID
- CaltechAUTHORS:20150107-133724965
- GA 21396
- NSF
- NGL 05-002-105
- NASA
- Created
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2015-01-08Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Division of Geological and Planetary Sciences
- Other Numbering System Identifier
- 2049