| This view shows more detail of Mount Scott (a stratovolcano),
Sentinel Rock and Skull Rock (the remnant of lava flows). The massive
volcano, Mount Mazama, was built up from intermittent eruptions of both lava
flows and ash and cinder falls. In general, lava flows and volcanic stocks
are more resistant to forces of erosion and mass wasting than ash and cinder
beds. As a result, remnants of ancient lava flows typically form the high,
dark, shear cliffs around Crater Lake, whereas the ash and cinder layers
generally form the steep slopes around the lake. Many lava flows, such as
at Sentinel Rock, flowed down ancient glaciated valleys that formed on
the side of Mount Mazama between eruptions (USGS, 2005). |
