Creating a Time Scale: Relative Dating Principles A. Importance of a Time Scale Rocks record geological events + changing life forms of the past; however, many pages (especially earlier ones) are missing or incomplete. Geologiests can unravel complexity of the past Earth by studying rocks Geologic events have little meaning until put into perspective. Geologic time scale = major contribution of geology (Earth?s age = huge) B. Numerical and Relative Dates Geologists have learned that Earth is much older than people thought, and it has been changed over and over again by the same geologic principles I. Numerical Dates