This programme calculates pressures and temperatures for garnet - cordierite - spinel - sillimanite/kyanite - quartz anhydrous or hydrous pelitic assemblages. It is derived from the shareware NICHOLS programme, which is available in either Macintosh or PC friendly formats. This version additionally allows the P vs T graphical representation of the calculated isopleths.
Experimental and thermodynamic data as well as the derived temperature and pressure equations are published in
Nichols, G.T., Berry, R.F. and Green, D.H. 1992. Internally consistent gahnitic spinel-cordierite-garnet equilibria in the FMASHZn system: geothermobarometry and applications. Contributions to Mineralogy and Petrology, 111:362-377.
Before starting thermobarometry, please note that mineral-cation data will be required. Cations are assumed to be calculated on the basis of 12 O for garnet, 18 O for cordierite, and 4 O for spinel.
Enter your cation values (divided by relevant denominator) for selected minerals, then click calculate to receive either graphical or tabulated results.
To calculate pressures and temperatures select your desired assemblage
| Created : March 23rd 1997 | Last Updated : April 3rd 1997 |
| Front end designer : Sean Noble | Queries : snoble@penman.es.mq.edu.au |