Article contents
Equilibria in the Mg-rich part of the pyroxene quadrilateral
Published online by Cambridge University Press: 05 July 2018
Abstract
Pyroxene phase relations in the Mg-rich corner of the pyroxene quadrilateral, at 1 atmosphere, have been reinvestigated. Experimental studies on sixteen selected compositions in the systems CMS and CFMS were undertaken in the temperature range 1100–1400 °C. The results of this study clarify our understanding of the pyroxene stability relations at low pressure. In particular, the demonstration that there is a high-temperature stability field of orthoenstatite denies the existence of a stable (or real) invariant point defined by the reactions OE = PE + DI, PE + DI = PI, and OE + DI = PI, in the system CaMgSi2O6-Mg2Si2O6. New phase relations, consistent with the experimental findings of this and other studies, for the Mg-rich corner of the pyroxene quadrilateral are presented. These new phase relations may be of use in interpreting the origin of volcanic rocks containing magnesian pigeonite.
- Type
- Research Article
- Information
- Copyright
- Copyright © The Mineralogical Society of Great Britain and Ireland 1983
Footnotes
Present address: Max-Planck Institut für Chemie, Saarstrasse 23, Postfach 3060, D-6500 Mainz, West Germany.
References
- 13
- Cited by