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The upper three-phase region in the system SiO_2 - H_2O

Kennedy, G. C. and Wasserburg, G. J. and Heard, H. C. and Newton, R. C. (1962) The upper three-phase region in the system SiO_2 - H_2O. American Journal of Science, 260 (7). pp. 501-521. ISSN 0002-9599. doi:10.2475/ajs.260.7.501.

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Melting relations in the system SiO_2 – H_2O were studied at high temperatures and pressures. A quadruple point for the equilibrium among quartz, tridymite, and 2 fluids was found at 1160° C. and 1500 bars. A second quadruple point for tridymite, 2 fluids, and cristobalite is estimated to be near 1470° C. and 400 bars. The freezing point of SiO_2 in equilibrium with 2 fluid phases is depressed from 1720° C. at one bar to 1130° C. at 2000 bars. This freezing point is diminished by only an additional 50° C. with a further increase in pressure to 9700 bars. The compositions of coexisting fluids along the upper 3-phase boundary have been determined. A critical end point for the univariant equilibrium curve was found at 1080° C. and 9700 bars with a composition of approximately 75 wt% SiO_2 to 25 wt% H_2O.

Item Type:Article
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Wasserburg, G. J.0000-0002-7957-8029
Additional Information:© 1962 American Journal of Science. Partial financial support for this investigation stemmed from Mineral Synthesis Contract. ONR 233(28), and Pressure Effects on Metals Contract, ONR 233(53), as well as a National Science Foundation Grant.
Funding AgencyGrant Number
Office of Naval Research (ONR)233(28)
Office of Naval Research (ONR)233(53)
Issue or Number:7
Record Number:CaltechAUTHORS:20150728-073827459
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Official Citation:G. C. Kennedy, G. J. Wasserburg, H. C. Heard, and R. C. Newton The upper three-phase region in the system SiO2-H2O Am J Sci September 1, 1962 260:501-521; doi:10.2475/ajs.260.7.501
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:59020
Deposited By: Tony Diaz
Deposited On:28 Jul 2015 16:48
Last Modified:10 Nov 2021 22:13

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