Outback Scenic Byway
Hole-in-the Ground, OR

Hole-in-the-Ground was created from a series of explosions. Rising basaltic magma came into contact with abundant ground water, and rose along the fault line that was exposed in the crater walls. After the initial explosion, repeated slumping along a ring fault led to the closures of the vent, changes in the ground water, and the repeated pressured buildup. Looking at the layering visible in the rim records this pulsing of the eruption.