Aseries of volcanoes make up the range.
a.
sierra nevada
b.
appalachian
c.
alaskan
d.
cascade

A series of volcanoes make up the Cascade Range. To be more specific, it includes the notable volcanoes known as the High Cascades. It also includes non-volcanic mountains such as the North Cascades. The Cascade Range is a major mountain range of western North America extending from southern British Columbia through Washington and Oregon to Northern California.

Answermost of the time it would be ground into fine sediment,and sometimes they are carried away from the original location;