Calymmian

The Calymmian is the first geologic period in the Mesoproterozoic Era, lasting from 1600 to 1400 million years ago (Ma) and spanning 200 million years. It follows the Statherian Period from the Paleoproterozoic Era, and precedes the Ectasian Period. Instead of being based on stratigraphy, these dates are defined chronometrically.

← Geological time scale