Table T2. Mean compositions of nine garnet sand grains, Sample 183-1137A-33R-3, 50-53 cm.


Grain ID:
gn1
gn2
gn3
gn4
gn5
gn6
gn7
gn8
gn10
Major element oxides (wt%):              
SiO2 37.60 37.25 38.30 36.95 37.12 38.45 37.42 37.71 37.36
TiO2 0.02 0.02 0.03 0.04 0.03 0.05 0.03 0.02 0.06
Al2O3 20.86 21.31 22.06 21.37 21.36 21.43 21.46 21.74 21.54
FeO 31.82 32.86 26.70 34.77 33.23 28.27 33.45 30.59 32.28
MnO 0.63 0.84 1.46 0.51 0.68 1.56 0.89 0.45 1.03
MgO 7.12 5.59 9.86 4.24 5.42 9.32 5.61 8.09 5.88
CaO 2.57 2.17 1.02 1.99 1.45 2.12 1.60 2.24 2.04
K2O 0.01 0.03 0.01 0.01 0.02 0.02 0.00 0.02 0.01
Na2O 0.00 0.01 0.00 0.02 0.01 0.01 0.01 0.00 0.01
Total: 100.62 100.06 99.45 99.88 99.32 101.22 100.48 100.87 100.21
Number of ions on the basis of 12 O:            
Si 2.96 2.96 2.96 2.96 2.97 2.96 2.96 2.93 2.95
Al 0.04 0.04 0.04 0.04 0.03 0.04 0.04 0.07 0.05
Al 1.89 1.95 1.98 1.98 1.98 1.90 1.96 1.92 1.96
Ti 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Fe+3 0.11 0.05 0.02 0.02 0.02 0.10 0.04 0.08 0.04
Fe+2 1.98 2.14 1.71 2.31 2.20 1.72 2.18 1.91 2.10
Mn 0.04 0.06 0.10 0.03 0.05 0.10 0.06 0.03 0.07
Mg 0.83 0.66 1.14 0.51 0.65 1.07 0.66 0.94 0.69
Ca 0.22 0.18 0.08 0.17 0.12 0.17 0.14 0.19 0.17
Molecular percent:                
Almandine 64.5 70.3 56.5 76.5 73.0 56.1 71.7 62.4 69.2
Andradite 3.6 1.5 0.5 0.6 0.6 3.3 1.2 2.5 1.2
Grossular 3.4 4.6 2.0 5.0 3.5 2.4 3.3 3.6 4.5
Pyrope 27.1 21.8 37.7 16.8 21.4 34.9 21.8 30.6 22.8
Spessartine 1.4 1.9 3.2 1.1 1.5 3.3 2.0 1.0 2.3