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The System MgO-CO_2-H_2O at High Pressures and Temperatures

Walter, L. S. and Wyllie, P. J. and Tuttle, O. F. (1962) The System MgO-CO_2-H_2O at High Pressures and Temperatures. Journal of Petrology, 3 (1). pp. 49-64. ISSN 0022-3530. doi:10.1093/petrology/3.1.49.

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The system MgO-CO_2-H_2O has been studied up to 1,400° C and 4,000 bars pressure using the sealed-capsule quenching technique. No melting was observed. At 1,000 bars pressure magnesite dissociates at 780° C, and brucite at 635° C, to periclase and vapor. The univariant reaction MgCO_3÷Mg(OH)_2 ⇌ MgO + V proceeds at 630° C, at 1,000 bars and at 700° C, at 4,000 bars. Solubility measurements show that, at 1,000 bars and temperatures up to 1,000° C, less than 1.5 weight per cent MgO is dissolved in the vapor phase. Brucite is unstable in the presence of vapors containing more than a small amount of CO_2. The maximum percentage of CO_2 in a vapor that can coexist with brucite increases with decreasing pressure and with increasing temperature: 6 weight per cent CO_2 is the maximum at 630° C, 1,000 bars, and 4 weight per cent at 700° C, 4,000 bars. The phase relations in the isobaric TX prism for 1,000 bars pressure are described. The results illustrate two dissociation reactions, decarbonation and dehydration, occurring in the presence of a vapor phase containing two volatile components, H_2O and CO_2. Applications to metamorphism are briefly discussed.

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Alternate Title:The System MgO-CO2-H2O at High Pressures and Temperatures
Additional Information:© 1962 Oxford University Press. Mineral Industries Experiment Station Contribution No. 60-76. This work was supported by the National Science Foundation and the Mineral Industries Experiment Station, The Pennsylvania State University.
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Pennsylvania State UniversityUNSPECIFIED
Issue or Number:1
Record Number:CaltechAUTHORS:20160112-133601833
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Official Citation:L. S. WALTER, P. J. WYLLIE, and O. F. TUTTLE The System MgO-CO2-H2O at High Pressures and Temperatures J. Petrology (1962) 3 (1): 49-64 doi:10.1093/petrology/3.1.49
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:63598
Deposited By: Tony Diaz
Deposited On:12 Jan 2016 22:15
Last Modified:10 Nov 2021 23:18

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