Compaction of Hyaloclastite from the Active Geothermal System at Krafla Volcano, Iceland

Figure 1

Photographs of representative sample cores of hyaloclastite from different depths within the hydrothermal reservoir at Krafla volcano, NE Iceland. (a) The surface hyaloclastite is matrix supported, containing dark, glassy basaltic scoria clasts. (b) The subsurface 70 m hyaloclastite sample contains a higher volume of prominent dark scoria clasts. (c) The subsurface hyaloclastite from 556 m is matrix supported and contains some scoria clasts which appear compacted, and overall, the material appears denser. (d) The subsurface 732 m hyaloclastite sample contains matrix-supported light grey basaltic clasts.