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Historical Geology
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Georgia is divided into four geologic provinces the Valley and Ridge in northwest Georgia, the Blue Ridge Province in north and northeast Georgia, the Piedmont Province in central Georgia, and the Coastal Plain in south Georgia.  The only province that we will not visit during this field study is the Coastal Plain.  The Valley and Ridge Province is composed of Paleozoic sedimentary rocks that have been folded and faulted into valleys and ridges that run from the northeast to southwest.  After the deposition of this sediment, the weight of the overlying material compacted the sediment into rock.  The rocks of the Blue Ridge Province are low to moderate-grade Precambrian and Paleozoic metamorphic rocks.  Most of these rocks were the same type of sedimentary rocks that made up the Valley and Ridge Province (some were extrusive igneous from submarine volcanic flows and some were intrusive igneous), but when the Appalachian Mountains were formed, they were subjected to great heat and pressure.  The Piedmont Province is made up of moderate to high-grade Precambrian and Paleozoic metamorphic rocks. 

The location of these regions is due to the collision that occurred about 300 million years ago and built the Appalachian Mountains.  When the North American and African continents collided to make Pangaea, the compression moved sheets of sedimentary rock over each other to form the Valley and Ridge.  At the heart of the collision, intense metamorphism occurred creating the Piedmont.  Lower intensity metamorphism combined with folding created the Blue Ridge.  The rocks of the Blue Ridge and Piedmont were buried during the collision, but millions of years of erosion leaves them exposed today.