Geologic regions of the Appalachains

Map of the Appalachian Mountains region showing the outcrop belts of the "Sedimentary Appalachians" (also called the Appalachian Basin, and represents a vast region underlain by Paleozoic sedimentary rocks), and the "Crystalline Appalachians" (underlain chiefly by Precambrian and Early Paleozoic metamorphic and igneous rocks).

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