Practical Aspects of Mineral Thermobarometry
Presenting Thermocalc Average-P-T Results
Many people have asked me about the best format for presenting, in tabular form, the results of P-T calculations from THERMOCALC. Here is a pattern, based on one devised by Malcolm Dransfield, that seems to provide all the necessary information, and still is compact enough to allow several samples to be listed on a single page.
| Sample P-T stage | ZD-24 peak | ZD-26 peak | ZD-28 peak | ZD-29 peak | L477 peak | ||
| Activities Garnet py gr alm Biotite phl ann east naph Muscovite mu pa cel fcel Plagioclase an ab Chlorite clin daph ames Other | at 650°C rim 0.00103 0.00110 0.471 mean 0.0138 0.0968 0.0204 0.00025 mean 0.608 0.447 0.042 0.044 mean 0.19 0.84
- - - q H2O | at 650°C mean rim 0.00052 0.00021 0.580 mean 0.0079 0.107 0.0153 0.00019
0.556 0.349 0.055 0.045
0.085 0.93
- - - q H2O | at 600°C mean 0.0030 0.0122 0.160 mean 0.0628 0.0393 0.0409 0.0012
- - - - mean 0.49 0.65
- - - cz 0.59 q H2O | at 600°C mean rim 0.00011 0.022 0.268 mean 0.0299 0.0825 0.0253 0.0007
- - - - mean 0.376 0.724
- - - cz 0.58 q H2O | at 550°C mean rim 0.00094 0.0051 0.387 mean 0.0326 0.0576 0.0289 0.0007 low-Si 0.663 0.532 0.041 0.039 mean 0.414 0.719 mean 0.021 0.022 0.014 q H2O | ||
| Results aH2O T°C s.d.(T) P kbar s.d.(P) correl. fit NR end members |
1.0 672 46 9.5 1.5 0.670 1.24 7 - |
0.5 624 41 9.0 1.4 0.667 1.24 7 - |
0.25 628 41 11.1 1.6 0.651 1.21 6 fcel |
1.0 578 92 9.0 2.6 0.982 1.13 4 - |
1.0 501 74 7.5 2.3 0.976 0.69 4 - |
1.0 580 14 7.5 0.7 0.409 1.03 10 - |
0.5 536 12 7.1 0.7 0.422 1.03 10 - |
This page last modified 12 October 2004