Dating quimper pottery
The Gulf of Mexico did not exist 250 million years ago when there was but one supercontinent, Pangea.As Pangea split apart, the Atlantic Ocean and Gulf of Mexico opened.Much of the state's lands were formed from sediment washed down the Mississippi River, leaving enormous deltas and vast areas of coastal marsh and swamp.These contain a rich southern biota; typical examples include birds such as ibis and egrets.In the uplands and hills, the elevations rise to Driskill Mountain, the highest point in the state at only 535 feet (163 m) above sea level. The state also has political jurisdiction over the approximately 3-mile (4.8 km)-wide portion of subsea land of the inner continental shelf in the Gulf of Mexico.
There are several hundred salt domes in the state; one of the most familiar is Avery Island.
The breadth of the alluvial region along the Mississippi is from 10 to 60 miles (15 to 100 km), and along the other rivers, the alluvial region averages about 10 miles (15 km) across.