Table 1 Representative spot and average composition analyses (wt%) of the mineral phases
Sample | 1BAl17-4a1Nuova | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Mineral | Garnet | Omphacite | Jadeite | Titanite | |||||||||||||||||
Wt% | Core | Rim | Spot Hi FeO | Spot Low FeO | Core | Rim | Intergrown with Jd | Spot Low FeO | Spot Hi FeO | Euhedral | Intergrown with Omp | Spot | |||||||||
Spot | Av Comp | σ | Av Comp | σ | Av Comp | σ | Av Comp | σ | Av Comp | σ | Av Comp | σ | Av Comp | σ | |||||||
SiO2 | 37.86 | 38.31 | 0.79 | 38.57 | 0.72 | 54.31 | 55.20 | 53.67 | 1.33 | 53.46 | 1.42 | 53.99 | 0.96 | 58.55 | 57.70 | 57.78 | 1.00 | 57.71 | 0.85 | 29.75 | |
TiO2 | 0.90 | 0.86 | 0.08 | 0.18 | 0.03 | 0.01 | 0.09 | 0.03 | 0.01 | 0.03 | 0.01 | 0.03 | 0.01 | 0.01 | 0.05 | 0.02 | 0.00 | 0.03 | 0.01 | 39.23 | |
Al2O3 | 21.23 | 21.37 | 0.57 | 22.15 | 0.69 | 10.50 | 11.99 | 10.25 | 0.80 | 10.90 | 0.78 | 11.82 | 0.55 | 25.62 | 22.07 | 25.75 | 0.76 | 22.62 | 0.68 | 1.23 | |
FeO | 1.97 | 1.99 | 0.23 | 1.37 | 0.23 | 6.97 | 4.81 | 7.67 | 0.74 | 6.38 | 0.45 | 4.82 | 0.42 | 0.04 | 2.30 | 0.16 | 0.06 | 0.49 | 0.11 | 0.25 | |
MnO | 0.17 | 0.21 | 0.06 | 0.18 | 0.05 | 0.36 | 0.13 | 0.29 | 0.09 | 0.20 | 0.06 | 0.18 | 0.05 | 0.04 | 0.00 | 0.02 | 0.01 | 0.02 | 0.01 | – | |
MgO | 0.01 | 0.02 | 0.01 | 0.02 | 0.00 | 6.57 | 6.97 | 5.53 | 0.38 | 6.05 | 0.40 | 6.59 | 0.35 | 0.04 | 1.32 | 0.12 | 0.05 | 0.46 | 0.04 | 0.01 | |
CaO | 37.96 | 37.98 | 0.92 | 38.39 | 0.68 | 14.03 | 13.16 | 13.62 | 0.92 | 13.39 | 0.79 | 12.84 | 0.63 | 0.15 | 2.44 | 0.29 | 0.13 | 1.21 | 0.14 | 28.90 | |
Na2O | – | – | – | – | – | 6.99 | 7.79 | 7.00 | 0.49 | 7.06 | 0.50 | 7.80 | 0.33 | 15.64 | 14.22 | 15.67 | 0.35 | 13.87 | 0.31 | – | |
K2O | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | |
Total | 100.10 | 100.75 | 1.37 | 100.86 | 1.23 | 99.74 | 100.14 | 98.07 | 1.85 | 97.47 | 1.97 | 98.06 | 1.42 | 100.09 | 100.10 | 99.81 | 1.31 | 96.39 | 1.15 | 99.37 | |
Formulae based | on 12 O | on 6 O | |||||||||||||||||||
Si | 2.86 | 2.89 | 0.04 | 2.90 | 0.04 | 1.95 | 1.95 | 1.97 | 0.03 | 1.97 | 0.03 | 1.96 | 0.02 | 1.96 | 1.96 | 1.97 | 0.02 | 2.00 | 0.00 | ||
Ti | 0.05 | 0.05 | 0.01 | 0.01 | 0.00 | 0.00 | 0.00 | – | – | – | – | – | – | 0.00 | 0.00 | – | – | – | – | ||
Al | 1.89 | 1.90 | 0.05 | 1.96 | 0.05 | 0.45 | 0.50 | 0.45 | 0.06 | 0.47 | 0.06 | 0.51 | 0.04 | 1.01 | 0.88 | 1.03 | 0.02 | 0.95 | 0.02 | ||
Fe3+ | 0.12 | 0.12 | 0.02 | 0.09 | 0.02 | 0.13 | 0.13 | 0.08 | 0.05 | 0.07 | 0.05 | 0.08 | 0.03 | 0.00 | 0.07 | 0.00 | 0.00 | 0.00 | 0.00 | ||
Fe2+ | 0.00 | 0.00 | 0.01 | 0.00 | 0.01 | 0.07 | 0.02 | 0.16 | 0.05 | 0.13 | 0.05 | 0.06 | 0.03 | 0.00 | 0.00 | 0.00 | 0.00 | 0.01 | 0.01 | ||
Mn | 0.01 | 0.01 | 0.00 | 0.01 | 0.00 | – | – | – | – | – | – | – | – | – | – | – | – | – | – | ||
Mg | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.35 | 0.37 | 0.30 | 0.02 | 0.33 | 0.02 | 0.36 | 0.02 | 0.00 | 0.07 | 0.01 | 0.00 | 0.02 | 0.00 | ||
Ca | 3.07 | 3.07 | 0.07 | 3.09 | 0.05 | 0.54 | 0.50 | 0.54 | 0.03 | 0.53 | 0.03 | 0.50 | 0.02 | 0.01 | 0.09 | 0.01 | 0.01 | 0.05 | 0.01 | ||
Na | – | – | – | – | – | 0.49 | 0.53 | 0.50 | 0.03 | 0.50 | 0.03 | 0.55 | 0.02 | 1.02 | 0.94 | 0.98 | 0.01 | 0.93 | 0.02 | ||
K | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | – | ||
∑ cations | 8.00 | 8.05 | – | 8.07 | – | 3.99 | 4.00 | 4.00 | – | 4.00 | – | 4.01 | – | 4.00 | 4.00 | 4.00 | – | 3.96 | – | ||
XAlm | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | XJd | 0.37 | 0.43 | 0.40 | – | 0.41 | – | 0.42 | – | 0.94 | 0.81 | 0.91 | – | 0.95 | – | |
XSps | 0.04 | 0.00 | 0.00 | 0.00 | 0.00 | XAcm | 0.11 | 0.11 | 0.10 | – | 0.09 | – | 0.12 | – | 0.06 | 0.12 | 0.08 | – | 0.00 | – | |
XPrp | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | XAug | 0.51 | 0.47 | 0.50 | – | 0.50 | – | 0.45 | – | 0.00 | 0.06 | 0.00 | – | 0.05 | – | |
XGrs | 0.91 | 0.93 | 0.01 | 0.95 | 0.01 | ||||||||||||||||
XAdr | 0.08 | 0.06 | 0.01 | 0.04 | 0.01 | ||||||||||||||||
