The Malvern Hills are composed of igneous rocks, most of which cooled and crystallised deep below the surface.

On Broad Down, south and east of British Camp, there were volcanoes which erupted in an island arc which existed more than 600 million years ago. All these rocks have been uplifted by earth movements along a line of weakness in the earth's crust. Rocks such as diorites, granites, and volcanic lavas can be seen in quarries around the Malverns.

To the west are the hills of Herefordshire underlain by Silurian rocks.