In the Coastal Plain in the east, younger sediments are denoted by beige or orange (Tertiary, 65 to 2 million years) and light yellow (Quaternary, less than 2 m.y.). In the southeast is a large area of older sedimentary rocks of Cretaceous age (140 to 65 m.y.). All of these are little disturbed. This region is mined for sand and phosphate minerals. The Coastal Plain is home to hundreds, perhaps thousands, of the mysterious oval basins called Carolina bays.
Between the Blue Ridge and Coastal Plain is a complex set of mostly metamorphosed, mostly Paleozoic rocks (550 to 200 m.y.) called the Piedmont. Granite, gneiss, schist and slate are the typical rocks here. North Carolina's famous gem mines and gold district, America's first, are in the Piedmont. Exactly in the middle is a former rift valley of Triassic age (200 to 180 m.y.), marked olive-gray, filled with mudstone and conglomerate. Similar Triassic basins exist in states to the north, all of them made during the initial opening of the Atlantic Ocean.
This little map does not do the state justice, even when you click it for the larger image. See the 2000x1300 pixel version (700 KB), which includes a key to the different colors.
More North Carolina resources on About.com:
North Carolina Maps
North Carolina Geography, State Symbols & Facts
North Carolina National Parks
North Carolina State Parks, Winter
North Carolina State Parks, Spring
North Carolina Campgrounds
North Carolina Scenic Roads
North Carolina Fishing