Table 1 Calculated density and water contents of pyrophyllite and its breakdown products at different P-T conditions
From: A role for subducting clays in the water transportation into the Earth’s lower mantle
Depth (km) | Pressure (GPa) | Temperature (°C) | Phase assemblages | Phases | Density (g/cm3) | Net crystalline density (g/cm3) | Net water contents (wt% H2O) with SiO2 | Net water contents without SiO2 | Net crystalline and fluid volume (ratio, cm3) |
|---|---|---|---|---|---|---|---|---|---|
0 | 0 | 25 | prl | pyrophyllite | 2.82(1) | 2.82 | 5.0 | 5.0 | 1000:1000 |
~170 | 5.5(3) | 570 ± 35 | gbs + dsp + 4 coe | gibbsite | 2.37(2) | 2.97 | 9.5 | 26.1 | 1020:859 |
diaspore | 3.37(1) | ||||||||
coesite | 3.01(1) | ||||||||
~215 | 6.9(3) | 700 ± 45 | 2 dsp + 4 coe | diaspore | 3.41(1) | 3.15 | 5.0 | 15.0 | 897:1000 |
coesite | 3.02(1) | ||||||||
~240 | 7.6(4) | 850 ± 50 | 1/2 toz + dsp + 7/2 coe | topaz | 3.40(1) | 3.14 | 5.0 | 12.0 | 887:1000 |
diaspore | 3.41(1) | ||||||||
coesite | 3.03(1) | ||||||||
~400 | 13.6(10) | 725 ± 75 | 1/2 toz + dsp + 7/2 stv | topaz | 3.56(1) | 4.10 | 5.0 | 12.0 | 710:1000 |
diaspore | 3.51(1) | ||||||||
stishovite | 4.34(1) | ||||||||
~585 | 20.7(10) | 790 ± 110 | del + egg + 3 stv | δ-AlOOH | 3.82(1) | 4.21 | 5.0 | 10.0 | 676:1000 |
phase Egg | 4.00(1) | ||||||||
stishovite | 4.41(1) | ||||||||
~670 | 24.0(10)* | 790 ± 110 | del + egg + 3 stv | δ-AlOOH | 3.89(2) | 4.29 | 5.0 | 10.0 | 663:1000 |
phase Egg | 4.06(2) | ||||||||
stishovite | 4.50(4) | ||||||||
~195 | 6.3(4) | 900 ± 50 | 1/2 ky + 1/2 toz + 3 coe (ky + 3coe) | kyanite | 3.70(1) | 3.41 | 2.3 | 5.3-10.0 | 846:1070 (811:1141) |
topaz | 3.42(1) | ||||||||
coesite | 3.00(1) |
