A comparison of some mixing models for crystalline silicate solid solutions

✍ Scribed by Roger Powell

• Publisher: Springer
• Year: 1974
• Tongue: English
• Weight: 505 KB
• Volume: 46
• Category: Article
• ISSN: 0010-7999
• DOI: 10.1007/bf00370967

✦ Synopsis

Activity-composition relations for silicate solid solutions, which are necessary for equilibrium calculations on mineral assemblages, can be calculated from the compositions of coexisting minerals with ~ suitable mixing model. Three mixing models are considered; the subregular model, the Van Laar model and Green's model. The mixing properties calculated from solvi are compared with experimentally measured mixing properties for the systems NaC1--KC1 and Zn--Co olivines for the different models. Green's model appears to be the most reliable, ~nd the subregular model the least reliable. An equilibrium calculation on the assemblage alkali fcldspar--pyroxene--quartz using activities calculated from the alkali feldspar solvus shows the considerable difference between the results from the different models.