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1. Microprobe analyses

2. Mineral groups

3. Solid solutions

Energy of mixing

Mixing on sites

Non-ideal solutions

Reciprocal solutions

Simple models, DQF

Activity calculations

4. Thermobarometers

5. Uncertainties

6. P-T calculations

7. Phase diagrams



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Bulk compositions

Modal proportions

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Practical Aspects of Mineral Thermobarometry

Reciprocal solutions

In multi-site solid solutions, it may be necessary to consider non-ideal interactions between cations in different sites as well as, or rather than, interactions in the same site. This is entirely understandable in terms of mineral structure: for any cation site of interest, its nearest cation neighbours are quite likely to sit in a crystallographically different site. Such relations are called reciprocal, and they are described in Spear, chapter 7, pp. 205-213. An activity model for disordered sodic pyroxenes involving reciprocal solution parameters is given in Holland (1990) Contrib Min Pet 105, 446-453.

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This page last modified 12 October 2004