25,000,000,000 mya - 542,000,000 mya
Neoproterozoic - 10,000,000,000 mya:
The land under North Carolina was pulled apart, and inland seas emerged. Island volcanoes developed, first along the North Carolina-Virginia border, then in an arc from Virginia to Georgia. Rocks formed by those volcanoes extend today over a wide area of the Piedmont and Coastal Plain.
Mesoproterozoic - 13,000,000,000 mya
bout 1,300 million years ago, the first mountains were formed in North Carolina. Called the Grenville Mountains, they eroded long ago, but rocks formed at this time lie underneath the Appalachians and are exposed in parts of the Piedmont and Coastal Plain.
Paleoproterozoic - 17,000,000,000 BC
About 1700 million years ago, the land that would become North Carolina began to form.
By this time, the eastern coast of North America lay somewhere in middle Tennessee; except for islands and volcanoes, North Carolina was under water. About 750 million years ago, the landmasses of North America and Europe/Africa had begun moving towards each other again. The Kings Mountain Belt was formed about 540 million years ago as the Piedmont slowly moved into the rest of the continent.
As the continents of North America and Europe/Africa moved together, more rock was pushed upwards, and over the next 100 million years, the Appalachian mountains were formed. As the Appalachians rose, streams carried sand and mud westward and filled the sea.
In wetland forests, ferns thrived and primitive trees called scale trees grew more than 100 feet high. Their decayed remains became coal. The portions of the Appalachian region where coal is mined today were then covered in such forests.
About 320 million years ago, the North American and Euro-African continents collided, resulting in the last period of Appalachian mountain building. The land under the Piedmont and Coastal Plain was also pushed upward. The continents were united in a "supercontinent" that geologists call Pangaea.
A mass extinction occurred 251 million years ago, marking the end of the Permian period. Some 95 percent of life on Earth became extinct, including 75 percent of amphibian species and 80 percent of reptiles. No one knows why this extinction occurred, but some scientists speculate that changing climate and massive mountain building as the continents collided caused great changes to the environment, in which highly specialized species could no longer survive.
As soon as they had formed, the Appalachians began to erode. Wind and rain wore away the rock and carried it as sediment to lower-lying land or to the sea. Meanwhile, the continents began to move apart again.
At this time, North Carolina probably lay near the equator, and had a tropical climate in which a great diversity of life must have flourished.
As the North American continent drifted to the northwest, its trailing edge sank under water, and the Atlantic Ocean formed between North America and Africa. The shore was located near the present Outer Banks.
The Appalachians continued to erode, leaving the flat land that now exists in the eastern Piedmont.
The eastern portion of the modern Coastal Plain of North Carolina again lay under water, but the ocean receded late in this period. Elsewhere, the southern landmasses broke up, creating the continents of Africa and South America as well as the southern Atlantic Ocean. The youngest ranges of the Rocky Mountains formed.
66.5 mya: Paleocene
By the end of the Paleocene, the entire Coastal Plain of North Carolina was again above sea level.
55.8 mya: Eocene
The crust under the Coastal Plain began to sink again, and the ocean pushed as far west as the modern Piedmont. The calcium-rich shells of microscopic algae sank to the ocean floor, where over time they became limestone. By the end of the Eocene, the seas had again retreated.
33.9 mya: Oligocene
About 31 million years ago, the ocean advanced west as far as present-day New Bern.