This Geological Society of America (GSA) site contains a detailed geologic time scale as an educational resource. It may be downloaded to a larger size, and includes all Eras, Eons, Periods, Epochs and ages as well as magnetic polarity information.
This description of a site outside SERC has not been vetted by SERC staff and may be incomplete or incorrect. If you
have information we can use to flesh out or correct this record let us know.