The geology of this region is governed by ancient crystalline rocks that form the lower units in the now much-eroded eastern Appalachian mountain system.
(The geology of this region; is governed; by ancient crystalline rocks) (ancient crystalline rocks; form; the lower units in the now much-eroded eastern Appalachian mountain system)
The geology of this region ancient crystalline rocks
is governed form
by ancient crystalline rocks
the lower units in the now much-eroded eastern Appalachian mountain system