Most of these rocks range in age from Proterozoic to Paleozoic and form the internal core of the ancient Appalachian mountain belt.
(Most of these rocks; range; from Proterozoic to Paleozoic) (Most of these rocks; form; the internal core of the ancient Appalachian mountain belt)
Most of these rocks Most of these rocks
range form
from Proterozoic to Paleozoic
the internal core of the ancient Appalachian mountain belt