Abstract
Experimental data on phase relations in the CaCO3-MgCO3-FeCO3 ternary by Goldsmith et al. (1962) are inconsistent with those of Rosenberg (1967). These inconsistencies cannot be reconciled by the pressure or temperature differences between the two sets of experiments. Available reversed experiments on the binary systems have been re-evaluated to yield consistent binary solvi. These data have been combined with analyses of natural carbonates to yield approximate ternary phase diagrams at 250,400,550, and 700 °C, and 4 to model ternary activity/composition relations for calcite- and dolomite-structure carbonates. An empirical model for thermometry with calcite-ferroan dolomite was derived from the ternary solvus by fitting an empirical equation to the calcite limb of the ternary solvus. This model appears to extend reliably to higher iron contents than the models of Bickle * Powell (1977) and Powell et al. (1984).
Original language | English |
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Pages (from-to) | 389-415 |
Number of pages | 27 |
Journal | Journal of Petrology |
Volume | 28 |
Issue number | 2 |
DOIs | |
State | Published - Apr 1987 |
Externally published | Yes |
Funding
The authors thank Dr. D. R. Peacor for a critical reading of this manuscript, and Dr. C. Klein for helpful conversations about iron-carbonates. J. R. Goldsmith, R. Powell, R. Reeder, J. M. Rice, R. Sack, S. K. Saxena, and B. J. Wood, provided helpful critical reviews. Dr. Sack's comments on the ankerite/siderite KD problem were especially helpful. NSF grant EAR-8009538 to EJ.E. is acknowledged for support of some of this work. The Geological Society of America, Sigma Xi, and the Scott Turner Fund provided research support, and the University of Michigan provided microprobe and computing facilities. We also thank Mr. Ed Berdusco and the Algoma Ore Co. at Wawa, Ontario for providing access to their properties. Ms. Mary Schatz is gratefully thanked for her patience during repeated retypings of the manuscript.