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 ...

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 ...