winTWQ is an interactive program for calculation of mineral-fluid equilibria developed by Rob Berman at the Geological Survey of Canada. Although it can calculate many types of phase diagrams, its primary application is geothermobarometry using internally consistent thermodynamic data for endmembers and solid solutions that have been derived simultaneously from relevant experimental constraints. The philosophy of this approach to thermobarometry is described by Berman (1991).
Two implementations of the software are available for download:
Both implementations can be used with either of two internally consistent thermodynamic databases:
- Version 1 database (JUN92): Berman (1988) endmember properties with internally consistent solid solution and end-member data for:
- garnet, orthopyroxene (Berman, 1990)
- amphiboles (Mader et al., 1994)
- additional solution models in JUN92.bs (de Capitani, unpublished data)
- Version 2 database (DEC06): Berman (1988) endmember properties updated with internally consistent solid solution and end-member data for:
- Fe-Mg garnet, olivine, cordierite, ilmenite, & Fe-Mg-Al orthopyroxene, (Berman & Aranovich, 1996, CMP 119:30-42)
- Mn-Fe-Mg mixing properties of garnet, and endmember properties of spessartine based on the experimental data of Feenstra and Peters (1996, CMP, 126, 109-120) and Feenstra and Engi (1998, CMP, 131, 379-392), along with natural datasets of Williams & Grambling (1990, AMin, 75, 886-908)
- revised properties for biotite endmembers (phl, annite, siderophyllite, eastonite) and Fe-Mg-Al-Ti mixing, based on:
- Al solubility data for Fe-Al, Mg-Al, Fe-Mg-Al biotite (Berman et al. 2007)
- ol-bi Fe-Mg exchange data for Fe-Mg-Ti biotite (Zhou, 1994)
- analysis of gt-bi and gt-bi-plg-qz/GASP applications to natural assemblages
- Fe-Mg clinopyroxene (Berman et al., 1995)
Instructions for using the winTWQ software, as well as auxiliary programs, are included in the downloads. If you have questions or comments, please contact Rob Berman.