Period
Sd
Siderian
2500.0000 – 2300.0000 Ma
The Siderian is the first geologic period in the Paleoproterozoic Era and Proterozoic Eon. It lasted from 2500 to 2300 million years ago (Ma), spanning 200 million years, and is followed by the Rhyacian Period. Instead of being based on tectonic layers, these dates are defined chronometrically.
← Geological time scale
Parent interval
Paleoproterozoic
Era