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high-pressure metallization of feo and implications for the earth's coreThe phase diagram of FeO has been experimentally determined to pressures of 155 GPa and temperatures of 4000 K using shock-wave and diamond-cell techniques. A metallic phase of FeO is observed at pressures greater than 70 GPa and temperatures exceeding 1000 K. The metallization of FeO at high pressures implies that oxygen can be present as the light alloying element of the earth's outer core, in accord with the geochemical predictions of Ringwood (1977 and 1979). The high pressures necessary for this metallization suggest that the core has acquired its composition well after the initial stages of the earth's accretion. Direct experimental observations at elevated pressures and temperatures indicate that core-forming alloy can react chemically with oxides such as those forming the mantle. The core and mantle may never have reached complete chemical equilibrium, however. If this is the case, the core-mantle boundary is likely to be a zone of active chemical reactions.
Document ID
19870040650
Document Type
Reprint (Version printed in journal)
Authors
Knittle, Elise
(California Univ. Berkeley, CA, United States)
Jeanloz, Raymond
(California, University Berkeley, United States)
Date Acquired
August 13, 2013
Publication Date
December 1, 1986
Publication Information
Publication: Geophysical Research Letters
Volume: 13
ISSN: 0094-8276
Subject Category
GEOPHYSICS
Distribution Limits
Public
Copyright
Other