Tree cast near Ape Cave (1988). During an effusive eruption some 1900 years ago a lava flow engulfed a tree. Lava of low viscosity was necessary to create this and the nearby lava tunnels, illustrating changes in eruptive style of Mount St. Helens. |
Tree cast near Ape Cave (1988). During an effusive eruption some 1900 years ago a lava flow engulfed a tree. Lava of low viscosity was necessary to create this and the nearby lava tunnels, illustrating changes in eruptive style of Mount St. Helens. |