ISSN:
1432-0967
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
Notes:
Abstract The miscibility gap between rhodonite and bustamite has been experimentally determined at temperatures between 600° and 1,100° C. For temperatures below 700° C the resulting limbs have been extrapolated on T-X-diagram as at such low temperatures equilibrium could not be attained. According to microprobe analyses for the natural assemblages of Ravinella di Sotto (Ivrea zone, Italy) and Broken Hill (N.S.W., Australia) equilibrium temperatures are estimated to be at 500° to 550° C. However these assemblages are thought to have re-equilibrated during cooling and the compositions of equilibrium assemblages are also pressure dependent. According to experiments and to molar volume data the rhodonite structure is stabilized by high pressures whereas bustamite by high temperatures. Based on available experimental results and natural data an isobaric T-X Ca diagram and two isotherm $$X_{CO_2 }$$ -X Ca diagrams (for T=400° C and T=600° C) are given.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00371696
