GSA home

Log In | GSA Community | GSA Store | Join GSA | Donate | Contact Us

GSA home

| GSA Community | GSA Store | Donate | Contact Us

About GSA

Career Resources

Connected Community

Divisions &
Associated Societies

Education & Outreach

GSA Foundation

GSA International




Public Policy



Find Your Science at GSA

GSA Geologic Time Scale

The time scale printed in April/May 2009 GSA Today contained a spelling error (under ORDOVICIAN: HIMANTIAN should be HIRNANTIAN). This page contains the corrected version.
[ read about the changes  |  view printable PDF | buy the poster ]

Note that the authors are still accepting comments on the overall content of time scale. Offer your comments or join in the discussion on GSA's Facebook page.

Geologic Time Scale

updated April 2009

Other versions: 2009 | 1999 | 1983


Get Acrobat Reader

File requires Acrobat Reader (free) to view and print.