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Main Sections

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



Docs and downloads

Activity coding



Bugs and quirks

Bulk compositions

Modal proportions

Spreadsheet tools

Practical Aspects of Mineral Thermobarometry

Computer programs for activity calculation

To make the calculation of activities from mineral data more efficient, we currently have a utility program AX, written by Tim Holland, for use with THERMOCALC, and a selection of spreadsheet implementations of models for certain mineral species. The latter can be accessed from the tools page.

Documentation for AX (axnotes.pdf) is included with the suite of PDF documents supplied with THERMOCALC. However, since it is important not to treat activity calculation software as a "black box", this page will be used to summarise some of the recommended activity models for use with THERMOCALC in both P-T and phase diagram calculation modes.

For the time being, consult the PDF document axnotes.pdf.

For those minerals which can be treated as ideal multisite solutions, such as micas, amphiboles, chlorite, see the table of activity expressions in part 3.

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This page last modified 12 October 2004