Prehistoric Tennessee

Geology & Fossils

Many millions of years ago, there were no Appalachian Mountains and Tennessee was covered by the sea. This ancient sea drained away as North America began to collide with Africa and Europe.

As the continents continued to slam together, the land buckled, forming massive mountains. West of these mountains — in what is now central Tennessee — lush forests of exotic plants flourished.

When the climate became more arid and dinosaurs began to stalk the land, these coal forests disappeared. Over millions of years the Appalachians eroded as the dinosaurs flourished then disappeared.

Then the sea invaded again, this time from the South. The rolling hills and flatlands of western Tennessee are a souvenir of this ancient sea in which whales swam.

Today, fossils of unimaginably ancient marine animals can be found in the Appalachians. In central Tennessee, marine animals are recalled by oil and gas, while coal is a souvenir of ancient coal forests.

But the earth beneath Tennessee has not fallen asleep. Tennessee’s only really large lake is a reminder of the titanic forces that are still at work beneath us.

In the northwest corner of the state, Reelfoot Lake was formed by the New Madrid earthquakes of 1811-1812. One eyewitness recalled the spectacle: “Groves of trees disappeared and fissures in the earth vomited forth sand water . . . the atmosphere was so saturated with sulphurous vapors as to cause total darkness; trees cracked and fell into the roaring Mississippi.”

Some people said the Mississippi River flowed backward three days to fill the 45-square-mile basin that was formed. Reelfoot National Wildlife Refuge now occupies part of the basin. Geologists say another major earthquake can be expected in the early twentieth century.