|
Mineral:
|
Spinel
|
Staurolite
|
Magnetite
|
Ilmenite
|
Cordierite
|
|---|---|---|---|---|---|
|
Rock type:
|
St-HGS
|
St-HGS
|
Gneiss
|
St-HGS
|
Gneiss
|
|
Sample:
|
976B-74X-1, 30-34 cm
|
76R-1, 45-49 cm
|
98R-1, 96-101 cm
|
76R-1, 03-07 cm
|
95R-2, 24-28 cm
|
|
Textural position:
|
Included in andalusite
|
Matrix
|
Matrix
|
Included in andalusite
|
Rim
|
|
Analytic point:
|
A-22
|
C-3
|
84d
|
C-24
|
5-per 1
|
| SiO2 | 3.37 | 27.24 | 0.02 | 0.03 | 48.64 |
| Al2O3 | 57.05 | 55.92 | 0.42 | 0.06 | 32.43 |
| TiO2 | 0.11 | 0.47 | 0.17 | 52.29 | 0.01 |
| Cr2O3 | 0.24 | 0.07 | 0.03 | 0.04 | 0.02 |
| MgO | 1.90 | 0.59 | 0.00 | 0.02 | 9.09 |
| FeO | 30.41 | 13.45 | 45.61 | 43.84 | 6.71 |
Fe2O3 ( ) |
— | 0.54 | 50.56 | 0.00 | — |
| MnO | 0.48 | 0.24 | 0.04 | 2.30 | 0.35 |
| ZnO | 0.00 | 0.23 | 0.00 | 0.00 | n.d. |
| CaO | n.d. | n.d. | n.d. | n.d. | 0.02 |
| Na2O | n.d. | n.d. | n.d. | n.d. | 0.29 |
| K2O | n.d. | n.d. | n.d. | n.d. | 0.01 |
| H2O (#) | — | 3.35 | — | — | — |
| Total (-H2O) | 93.55 | 98.75 | 96.85 | 98.60 | 97.55 |
| Cations normalized to 32 oxygens (Mag, Spl), 6 oxygens (Ilm), 46.5 oxygens (St) | |||||
| Si | 0.788 | 7.271 | 0.006 | 0.002 | 5.020 |
| Al | 15.737 | 17.594 | 0.206 | 0.004 | 3.944 |
| Ti | 0.019 | 0.095 | 0.053 | 2.007 | 0.001 |
| Cr | 0.044 | 0.014 | 0.009 | 0.002 | 0.002 |
|
Fe3+ () |
0.000 | 0.109 | 7.874 | 0.000 | — |
 [B], [Al]vi |
16.589 | 17.082 | 8.149 | 2.014 | 8.967 |
| Mg | 0.663 | 0.233 | 0.000 | 0.002 | 1.398 |
| Fe2+ | 5.955 | 3.002 | 15.787 | 1.873 | 0.579 |
| Mn | 0.094 | 0.054 | 0.015 | 0.099 | 0.030 |
| Zn | 0.000 | 0.044 | 0.000 | 0.000 | n.d. |
|
[A], [Fe]vi |
6.713 | 3.334 | 15.802 | 1.974 | 2.007 |
| Ca | n.d. | n.d. | n.d. | n.d. | 0.002 |
| Na | n.d. | n.d. | n.d. | n.d. | 0.058 |
| K | n.d. | n.d. | n.d. | n.d. | 0.001 |
|
total Cat |
23.302 | 28.416 | 23.952 | 3.988 | 11.036 |
|
|
|
|
|
|
|
| Spinel | 9.882 | Li | 0.200 | X Mg | 0.697 |
| Hercynite | 88.715 | H | 5.919 |
CC |
0.062 |
| Galaxite | 1.403 | XMg | 0.071 |
|
|
| Gahnite | 0.000 | XFe | 0.915 |
|
|
|
|
|
XZn | 0.014 |
|
|
Notes: End-member fractions of spinel are calculated as (100 x Mg/[A]) = spinel; (100 x Fe/[A]) = hercynite; (100 x Mn/[A]) = galaxite; and (100 x Zn/[A]) = gahnite. Li and H contents are determined by the staurolite-normalization procedure (Hawthorne et al., 1993) (46.5 Ox; Li = 0.2 and H = 3.06 apfu; Fe3+ = 3.5 wt% total Fe). Subsequently, H2O (#) and Fe2O3 () are back-calculated. For the other minerals, Fe3+ contents () are calculated as described by Droop (1987). X Mg = Mg/(Mg + Mn + Fe2+) and CC= (Ca + Na + K) in cordierite. St-HGS = Staurolite-bearing high-grade schist. Mineral abbreviations are from Kretz (1983); n.d. = not determined; — = not calculated.