how is the cascade mountain range formed
The Cascade mountains were formed by a subduction zone with the Juan De Fuca plate went under the North American plate why the Juan De Fuca went under was because its more den â¦ se than the North American plate.he arc has formed due to subduction along the Cascadia subduction zone. Western Cascades: These mountains formed roughly 40 million years ago as a chain of volcanoes on the then-coastline of Oregon. By 500,000 years ago, the magma had shifted eastward to form the younger High Cascades.