PDF Exploring Geologic Time Poster Illustrated Teacher's Guide Worksheet # 1 - The Geologic Time Scale (Expected Results) Answer the questions in the spaces provided. 1. Explain the relationships among eons, eras, epochs and periods of the geologic time scale. Eons are the largest spans of time in the geologic time scale. Eons are divided into smaller units called eras. Eras are subdivided into periods.