Volcanoes: Lassen Peak & Plate Tectonics

Volcanoes: Lassen Peak

Lassen Peak and Mount Shasta are both volcanoes that are part of the Cascade mountain range, which runs across Northern California, Oregon, and Washington.

Like many other volcanoes, Lassen Peak formed along a convergent plate boundary between an oceanic and a continental plate.

In the case of Lassen Peak, it is the North American plate and the Pacific Plate that are colliding. Because the North American plate is a continental plate and the Pacific Plate is an oceanic plate, this has formed a subduction zone.

Here the Pacific Plate sinks below the North American plate and then part of it melts. The hot melted rock (magma) then rises through the top layers of the Earth, and forms a volcano.

That’s how plate tectonics helped to form Lassen Peak, and the 30 other volcanoes found in Lassen Volcanic National Park!