TWQ or TWEEQU (Thermobarometry With Estimation of Equilibration State) is an interactive program for calculation of mineral-fluid equilibria. It has been developed & maintained by Rob Berman of 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.

At present, there is no Apple Macintosh version of this software.

A new Windows version, winTWQ, supercedes earlier DOS versions (1 and 2) described below. It includes updated thermodynamic data described in part in

• Reversed phase equilibrium constraints on the stability of Mg-Fe-Al biotite

as well as updated documentation and these main programs:

The winTWQ software will be released in Fall 2006 as a GSC Open File and will be available to the public.

If you would like to test a beta-version of winTWQ for Windows, or if you would like to become a registered TWQ user and receive update/revision information, please register with Rob Berman. If you have questions or comments, please contact Rob Berman.

Thermobarometry With Estimation of Equilibration State [TWEEQU]: a Software Package For IBM or Compatible Personal Computers:

TWQ (version 1.02, June, 1992)

Thermodynamic data of Berman (1988), Berman (1990) with amphibole thermobarometry capabilities from Mader et al. (1994)

Released as Geological Survey of Canada Open File 2534 and available as a free download from GeoPub.

TWQ (versions 2.01 and 2.02)

Released as Geological Survey of Canada Open File 5408 and available as a free download from GeoPub.

• TWQ2.01 (version 2.01, October, 1996)

  Thermodynamic data of Berman (1988) updated with internally consistent solid solution and end-member data for garnet, olivine, orthopyroxene, cordierite, ilmenite from (Berman & Aranovich, 1996)

  Described in these publications :

  • Optimized standard state and solution properties of minerals: I. model calibration for olivine, orthopyroxene, cordierite, garnet, and ilmenite in the system FeO-MgO-CaO-Al₂O₃-TiO₂-SiO₂

  • Optimized standard state and solution properties of minerals, II. comparisons, predictions, and applications

  • A new garnet-orthopyroxene thermometer based on reversed Al2O3 solubility in FeO-Al₂O₃-SiO₂ orthopyroxene

• TWQ2.02 (version 2.02, January, 1997)

  Thermodynamic data of Berman (1988) updated with internally consistent solid solution and end-member data for:

  • garnet, olivine, orthopyroxene, cordierite, ilmenite from (Berman & Aranovich, 1996)
  • clinopyroxene (Berman et al., 1995)
  • biotite, spinel (Berman & Aranovich, unpublished data)

  Described in the above publications and in the following:

  • Reassessment of the garnet-clinopyroxene, Fe-Mg exchange thermometer: II. thermodynamic analysis

Other files that are included with the above downloads include:

• GTCPX.ZIP - program for calculating gt-cpx temperatures (CMP, 119, 30-42)
• B88.MIN - TWQ format thermodynamic data of Berman (1998; J Pet, 29, 445-522)
• Ge0TAB.EXE - program for making tables of thermodynamic data