Table 2.

Chemical composition of selected analysed amphiboles

Sample TB59*Sample TB62*Sample TB59†Sample TB61‡
ActinoliteMagnesio-hornblendeActinoliteMagnesio-hornblendeActinoliteMagnesio-hornblendeActinolite
SiO255.0347.1054.0948.4454.2948.4454.98
TiO20.010.460.020.950.000.010.02
Al2O31.614.142.164.141.043.871.15
Cr2O30.040.000.000.030.000.030.00
FeO7.5311.2611.927.855.787.268.95
MnO0.150.120.090.160.070.070.11
MgO18.7914.1716.7416.0117.9717.3316.15
CaO12.3710.5311.9511.0611.6910.5311.76
Na2O0.581.280.521.240.230.250.23
K2O0.080.080.070.130.000.020.05
H22.102.022.102.052.102.092.08
Total98.2997.3299.6697.6698.2197.8399.14
Si7.856.987.736.957.716.957.82
Ti0.000.050.000.100.000.000.00
Al0.270.710.360.710.170.640.20
Cr0.010.000.000.000.000.000.00
Fe3+0.020.230.160.440.000.060.00
Fe2+0.880.891.270.310.620.311.06
Mn2+0.020.020.010.020.010.010.01
Mg3.993.133.573.493.783.693.47
Ca1.891.631.831.731.771.601.78
Na0.160.360.140.340.060.070.06
K0.010.010.010.020.000.000.01
Total cations15.0915.2015.0915.2015.0315.0415.04
Ca+(Na)B1.971.851.901.911.921.641.91
Mg/(Mg + Fe2+)0.820.730.740.780.790.820.71
  • * Found in corona structures.

  • Found along syn-greenschist foliation.

  • Found in veins post-dating the greenschist foliation.

  • § Calculated assuming OH = 2 atoms per unit formula.