TY - JOUR
AU - TUTTLE, O., F.
AB - Abstract The system MgO-CO2-H2O 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 MgCO3÷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 CO2. The maximum percentage of CO2 in a vapor that can coexist with brucite increases with decreasing pressure and with increasing temperature: 6 weight per cent CO2 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, H2O and CO2. Applications to metamorphism are briefly discussed. This content is only available as a PDF. Author notes 1Mineral Industries Experiment Station Contribution No. 60–76. © Oxford University Press
TI - The System MgO-CO2-H2O at High Pressures and Temperatures
JO - Journal of Petrology
DO - 10.1093/petrology/3.1.49
DA - 1962-01-01
UR - https://www.deepdyve.com/lp/oxford-university-press/the-system-mgo-co2-h2o-at-high-pressures-and-temperatures-i6Q67C0BsV
SP - 49
EP - 64
VL - 3
IS - 1
DP - DeepDyve
ER -