Research Article

Thermal Liability of Hyaloclastite in the Krafla Geothermal Reservoir, Iceland: The Impact of Phyllosilicates on Permeability and Rock Strength

Table 2

Mineralogy for the as-collected material and for each treatment temperature quantified from the QEMSCAN image analysis at 20 μm resolution (see Supplementary Figures 2-7). Note that changes to mineral structure, such as dissolution, are not captured by QEMSCAN. Values are normalised by the background (pore space) of each image.

Temperature experienced:20°C130°C185°C400°C600°C

Glass (%)53.851.453.057.957.6
Smectite (Fe Mg) (%)26.826.323.622.023.4
Zeolite (%)8.89.28.28.08.3
Anorthite (%)6.08.811.88.76.9
Augite (%)2.62.62.12.52.3
Quartz (%)0.30.30.30.30.4
Actinolite (%)0.30.30.20.20.1
Others (%)1.21.00.70.20.6
Unclassified (%)0.20.10.20.20.4
Total (%)100100100100100