| This entrance to the "Catacombs" lava tube is relatively
small compared to the others in the park. Note the blocky character of the
lava flow above the entrance to the lava tube. This is typical of an "a'a"
type lava flow. The blocky texture forms from the accumulation of congealed
lava on the surface of a moving lava flow. Lava tubes typically form in
lava flows where the surface material has solidified and became stabilized,
whereas molten lava continues to flow or drain in the subsurface (Grimes, 2005). |
