Rock sample | Ibity | Tsarasaotra | Antsahakely | |||||||
Granite | Monzonite | Granite dykes | Granite | |||||||
IB-6 | IB-6 | IB-8 | IB-14 | IB-16A | IB-16A | TS-6 | TS-3 | TS-3 | ANH-1 | |
wt% | BI-1 | BI-2 | BI-1 | BI-1 | BI-1 | BI-3 | BI-2 | BI-1 | BI-2 | BI-1 |
SiO2 | 38.4 | 38.0 | 35.7 | 34.2 | 34.5 | 38.1 | 37.5 | 37.2 | 34.9 | 34.8 |
TiO2 | 2.28 | 2.26 | 1.13 | 2.16 | 2.32 | 2.68 | 2.89 | 3.11 | 2.69 | 1.98 |
Al2O3 | 16.9 | 17.3 | 17.4 | 17.0 | 16.9 | 16.7 | 14.9 | 14.9 | 14.6 | 18.8 |
FeO | 19.5 | 19.8 | 23.7 | 25.6 | 20.9 | 17.8 | 17.4 | 18.3 | 18.2 | 24.3 |
MnO | 0.62 | 0.59 | 0.53 | 0.71 | 0.65 | 0.40 | 0.43 | 0.44 | 0.43 | 0.45 |
MgO | 6.03 | 5.71 | 3.68 | 4.56 | 11.6 | 10.2 | 11.6 | 11.2 | 11.3 | 4.83 |
CaO | - | 0.05 | 0.04 | 0.01 | 0.26 | 0.01 | 0.03 | 0.03 | 0.01 | 0.30 |
Na2O | 0.05 | 0.08 | 0.04 | 0.07 | 0.07 | 0.09 | 0.06 | 0.05 | 0.04 | 0.03 |
K2O | 10.7 | 10.6 | 10.0 | 10.6 | 6.06 | 9.91 | 10.6 | 10.4 | 11.1 | 7.7 |
Li2O | 0.59 | 1.32 | 0.66 | 0.23 | 0.08 | 0.12 | 0.08 | 0.09 | 0.08 | 0.39 |
Total | 95.0 | 95.7 | 93.0 | 95.2 | 93.3 | 95.9 | 95.5 | 95.8 | 93.3 | 93.5 |
Number of cations recalculated on the basis of 11 oxygens. | ||||||||||
Si | 5.87 | 5.76 | 5.71 | 5.46 | 5.34 | 5.71 | 5.69 | 5.65 | 5.51 | 5.48 |
AlIV | 2.13 | 2.24 | 2.29 | 2.54 | 2.66 | 2.29 | 2.31 | 2.35 | 2.49 | 2.52 |
AlVI | 0.91 | 0.85 | 1.00 | 0.66 | 0.42 | 0.66 | 0.37 | 0.32 | 0.23 | 0.96 |
Ti | 0.26 | 0.26 | 0.14 | 0.26 | 0.27 | 0.30 | 0.33 | 0.36 | 0.32 | 0.23 |
Fe | 2.49 | 2.51 | 3.18 | 3.42 | 2.71 | 2.23 | 2.21 | 2.33 | 2.40 | 3.20 |
Mn | 0.08 | 0.08 | 0.07 | 0.10 | 0.09 | 0.05 | 0.06 | 0.06 | 0.06 | 0.06 |
Mg | 1.38 | 1.29 | 0.88 | 1.09 | 2.69 | 2.27 | 2.62 | 2.54 | 2.65 | 1.13 |
Ca | - | 0.01 | 0.01 | 0.00 | 0.04 | 0.00 | 0.00 | 0.00 | 0.00 | 0.05 |
Na | 0.01 | 0.02 | 0.01 | 0.02 | 0.02 | 0.02 | 0.02 | 0.01 | 0.01 | 0.01 |
K | 2.08 | 2.05 | 2.04 | 2.17 | 1.20 | 1.90 | 2.05 | 2.02 | 2.23 | 1.55 |
Li | 0.36 | 0.80 | 0.43 | 0.14 | 0.05 | 0.07 | 0.05 | 0.05 | 0.05 | 0.25 |
XMg | 0.36 | 0.34 | 0.22 | 0.24 | 0.50 | 0.50 | 0.54 | 0.52 | 0.53 | 0.26 |
XNa | 0.01 | 0.01 | 0.01 | 0.01 | 0.02 | 0.01 | 0.01 | 0.01 | 0.01 | 0.01 |
Mg-Li | 1.01 | 0.49 | 0.45 | 0.94 | 2.64 | 2.20 | 2.57 | 2.49 | 2.60 | 0.89 |
Fe + Mn + Ti-AlVI | 1.93 | 2.00 | 2.38 | 3.12 | 2.64 | 1.92 | 2.23 | 2.42 | 2.55 | 2.54 |