Phase relations and their petrological implications in the system MgO-SiO_2-H_2O-CO_2 at pressures up to 100 kbar
- Creators
- Ellis, David E.
- Wyllie, Peter J.
Abstract
A comprehensive model has been developed for phase relations in the system MgO-SiO_2-H_2O-CO_2 on the basis of Schreinemakers' rules and subsolidus thermodynamic data. The assemblage forsterite plus enstatite can melt in the presence of vapor of any H_2O/CO_2 ratio at low pressures, in the presence of vapor whose H_2O/CO_2 ratio is buffered by magnesite at intermediate pressures, and at a vapor-absent eutectic at high pressures. Forsterite and H_2O-CO_2 vapor cannot coexist at pressures greater than 90 kbar. A thermal maximum is postulated to exist on the reaction Fo + En + V → L at pressures greater than 35 kbar. Thermal maxima on vapor-present melting reactions may be responsible for the eruption of kimberlitic magma from the upper mantle.
Additional Information
© 1980 Mineralogical Society of America. Manuscript received, April 9, 1979; accepted for publication, January 15, 1980. This research was supported by NSF grant EAR 76-20410 (Earth Sciences Section).Additional details
- Alternative title
- Phase relations and their petrological implications in the system MgO-SiO2-H2O-CO2 at pressures up to 100 kbar
- Eprint ID
- 64083
- Resolver ID
- CaltechAUTHORS:20160129-085241942
- EAR 76-20410
- NSF
- Created
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2016-01-29Created from EPrint's datestamp field
- Updated
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2019-10-03Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences