From: Hydrous Na-garnet from Garnet Ridge; products of mantle metasomatism underneath the Colorado Plateau
(A) Cr-rich pyrope | (B) Cr-poor pyrope | ||||
---|---|---|---|---|---|
B1 | B2 | B3 | B4 | ||
Wt.% | Amp | Ilm-only | Dense lamellae | Cpx-Amp | |
SiO2 | 41.91 | 42.24 | 41.02 | 41.32 | 40.40 |
TiO2 | 0.09 | 0.05 | 0.14 | 0.10 | 0.06 |
Al2O3 | 22.30 | 23.36 | 21.66 | 23.01 | 22.72 |
Cr2O3 | 1.71 | 0.13 | 1.46 | 0.01 | 0.04 |
FeOa | 8.80 | 9.26 | 13.82 | 14.49 | 19.7 |
MnO | 0.36 | 0.38 | 0.54 | 0.41 | 0.45 |
MgO | 19.31 | 18.75 | 15.81 | 15.85 | 13.33 |
CaO | 5.43 | 5.99 | 5.43 | 4.93 | 3.41 |
Na2O | 0.02 | 0.02 | 0.03 | 0.05 | 0.05 |
K2O | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
Total | 99.92 | 100.18 | 99.91 | 100.17 | 100.15 |
Cations | Number of cations on the basis of 12 oxygen | ||||
Si | 3.000 | 3.009 | 3.007 | 3.007 | 3.001 |
Ti | 0.005 | 0.003 | 0.008 | 0.006 | 0.003 |
Al | 1.881 | 1.961 | 1.871 | 1.974 | 1.989 |
Cr | 0.097 | 0.008 | 0.085 | 0.001 | 0.002 |
Fe3+ | 0.019 | 0.023 | 0.034 | 0.016 | 0.004 |
Fe2+ | 0.498 | 0.517 | 0.797 | 0.857 | 1.218 |
Mn | 0.022 | 0.023 | 0.034 | 0.025 | 0.029 |
Mg | 2.060 | 1.991 | 1.728 | 1.719 | 1.476 |
Ca | 0.416 | 0.457 | 0.426 | 0.384 | 0.271 |
Na | 0.002 | 0.002 | 0.004 | 0.007 | 0.006 |
K | 0.000 | 0.000 | 0.000 | 0.000 | 0.000 |
Total | 7.999 | 7.994 | 7.992 | 7.996 | 8.001 |