"As long as this cognitive process is acknowledged as the pragmatic basis of stratigraphy, both local and global sections can be treated as chronologies without

"As long as this cognitive process is acknowledged as the pragmatic basis of stratigraphy, both local and global sections can be treated as chronologies without reproach." (American Journal of Science 276:55). –J. E. O’Rourke The paper you cited actually goes on to show why the type of dating used is as accurate as it can be. Index fossil ages have been used to calibrate radiometric dating and vice versa. Not all rock formations have radioactive elements we can use to give rocks an "absolute age" meaning relative aging often is as good as we can get.