Table 2.

Electron microprobe analyses of minerals in sample 55-D

Mineralg-cg-cg-rg-rbi-gbi-gBipl-gplplksp
SiO238.0937.8337.9637.9237.0336.8937.0660.0462.0063.4266.29
TiO20.030.020.040.073.833.823.310.020.000.010.00
Al2O320.7720.6520.5820.9514.9715.0815.3025.0623.2922.3018.00
Cr2O30.080.080.080.080.070.080.100.000.030.040.01
FeO25.5825.6029.0528.7019.2919.1418.750.280.070.000.00
MnO1.100.971.491.480.110.070.110.020.020.010.00
MgO4.825.005.135.0010.5110.6110.650.000.000.020.00
CaO9.319.405.305.150.010.000.037.156.104.650.13
Na2O0.010.030.010.040.120.150.637.037.608.181.96
K2O0.000.020.010.019.189.209.300.330.290.5113.49
Total99.7899.6099.6599.3895.1295.0495.2299.9499.4099.1399.88
O121212121111118888
Si2.982.973.003.002.822.812.822.682.772.833.03
Ti0.000.000.000.000.220.220.190.000.000.000.00
Al1.921.911.921.961.351.361.371.321.221.170.97
Cr0.010.010.010.010.000.010.010.000.000.000.00
Fe3+0.110.160.080.030.000.000.000.010.000.000.00
Fe2+1.571.521.851.871.231.221.190.000.000.000.00
Mn0.070.060.100.100.010.010.010.000.000.000.00
Mg0.560.580.600.591.191.211.210.000.000.000.00
Ca0.780.790.450.440.000.000.000.340.290.220.01
Na0.000.010.000.010.020.020.090.610.660.710.17
K0.000.000.000.000.890.900.900.020.020.030.79
XFe0.520.510.620.62XMg0.490.500.50XAn0.350.300.23XAn0.01
XMn0.020.020.030.03Ti0.220.220.19XAb0.630.680.74XAb0.18
XMg0.190.200.200.20XKsp0.020.020.03XKsp0.81
XCa0.260.270.150.15
  • Garnet (g): XFe = Fe2+/(Fe2+ + Mn + Mg + Ca), XCa, XMg and XMn are defined accordingly to XFe; biotite (bi): XMg = Mg/(Fe2+ + Mg); feldspar (pl & ksp): XAn = Ca/(Ca + Na + K), XAb and XKsp are defined accordingly to XAn; K-feldspar (ksp): XNa = Na/(Ca + Na + K). c, core; r, rim; phase A–phase B, phase A included in phase B. Total iron is reported as FeO. The mineral formulae were calculated with the program AX (Holland: www.esc.cam.ac.uk/research/research-groups/holland/ax).