Here's why:
* Converging Plates: The Pacific Plate is subducting (sliding) beneath the North American Plate at the Cascade Range. This is a classic example of a convergent plate boundary.
* Volcanic Arcs: As the oceanic plate (Pacific) dives beneath the continental plate (North American), it melts, creating magma that rises to the surface and forms volcanoes. The Cascade Range is a volcanic arc formed by this process.
* Mt. Mazama: Mt. Mazama is one of many volcanoes in this volcanic arc. Its eruption, which created Crater Lake, was a massive event caused by the pressure of rising magma.
Therefore, Mt. Mazama is a result of the interaction of converging plates, not diverging plates.
