New study challenges drought theory for Cahokia exodus

Nine hundred years ago, the Cahokia Mounds settlement just across the Mississippi River from present-day St. Louis bustled with roughly 50,000 people in the metropolitan area, making it one of the largest communities in the ...

Sediments reveal the ancient ocean during a mass extinction event

About 183 million years ago, volcanic activity in modern South Africa unleashed an estimated 20,500 gigatons of carbon dioxide (CO2) into the ocean–atmosphere system over a period of 300 to 500 thousand years. Known as ...