South Carolina's rocks represent the Appalachian foldbelt starting at the western border with a thin sliver of its deep, contorted heart, the Blue Ridge province. The rest of northwestern South Carolina, left of the dark green strip, is in the Piedmont belt, which is a series of rocks that have been piled up here by ancient plate collisions throughout Paleozoic time. The beige stripe across the eastern edge of the Piedmont is the Carolina slate belt, site of gold mining in the early 1800s and again today. It also coincides with the famous Fall Line, where rivers rushing down to the Coastal Plain afforded water power for the early settlers.
The Coastal Plain includes all of South Carolina from the sea to the dark green strip of Cretaceous-age rocks. The rocks generally get older with distance from the coast, and all of them were laid down under the Atlantic at times when it was much higher than today.
South Carolina is rich in mineral resources, starting with crushed stone, limestone for cement production, and sand and gravel. Other notable minerals include kaolinite clay in the Coastal Plain and vermiculite in the Piedmont. The metamorphic mountain rocks are also known for gemstones.
The South Carolina Geological Survey has a free geologic map that shows these rock units labeled as packages, or terranes.
More about South Carolina Geology
More South Carolina resources on About.com:
South Carolina Maps
South Carolina Geography, State Symbols & Facts
South Carolina National Parks
South Carolina State Parks, Winter
South Carolina State Parks, Spring
South Carolina Campgrounds
South Carolina Scenic Roads
South Carolina Bed & Breakfasts
South Carolina Fishing
South Carolina Saltwater Fishing
South Carolina Archaeology
