- The Statherian Period ( /stəˈθɪəriən/; Ancient Greek: σταθερός, romanized: statherós, meaning “stable, firm”) is the final geologic period in the Paleoproterozoic Era and lasted from 1800 Mya to 1600 Mya (million years ago). Instead of being based on stratigraphy, these dates are defined chronometrically.
