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Presenting the Geologic Timescale

Laura Guertin, Catherine Nguyen (Pennsylvania State University Delaware County) - Starting Point Page by Rebecca Teed (SERC)

This material is replicated on a number of sites as part of the SERC Pedagogic Service Project


This project has students model the geologic timescale using distance as a metaphor for time. Each student writes a summary of a major event or fossil organism. The students would station themselves and their summaries along a path within a gymnasium, and present their information to visitors from the community and the campus. Each student's position along the path was a function of how long ago their organism had lived or the event had occurred, so students could appreciate the scale of geologic time. Visitors were asked to donate money to a charity fundraiser. The authors felt that students worked harder because they were presenting their work to the public and because it served the cause of charity.

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Learning Goals

This project will allow students to:
  • Gain a good perspective of the scale of geologic time
  • Accept outside motivation to learn materials and skills well
  • Research a topic in detail, gain deep knowledge of one aspect of Earth history
  • Raise money for charity
  • Develop presentation skills

Context for Use

This project is intended to take place early in an introductory course that involves Earth history. It gives students a perspective on the scale of geologic time and involves them in the past by having them work on a particular organism or time period of their own, which they will present to other people.

Teaching Materials

The instructor provides fossil samples and a list of geologic time periods for the students to choose between early in the course. Students provided contact to a campus charity fund-raiser. Student volunteers publicized the event across the campus and the community to encourage people to visit the presentations. Visitors were asked to donate a certain amount of change for each presentation: pennies for the Hadean, nickels for the Archaen, dimes for the Proterozoic, and quarters for the Phanerozoic.

Teaching Notes and Tips

The authors mention providing fossil examples of organisms to display. Instructors may want to consider having students create posters instead of summaries and to study specific events (such as the breakup of Pangea or the Cambrian Explosion) rather than whole time-periods.


The project involves three assignments:
  1. Summary of the assigned geologic time period or fossil organism due 1 week before the presentation. (11x17 inch sheet) - Authors recommend changing this to a short paper, as the original summary was intended to be used in the presentation but was not very practical.
  2. Participation in the walking tour of geologic time as a presenter
  3. Post-project writeup due one-week after the presentation consisting of five references (not all websites) for the summary and an evaluation of the project, including:
    • Student's overall impressions of the project
    • Ease/difficulty of researching the summary
    • The most interesting feature of the student's topic time period or organism
    • How the student's perspective of geologic time has changed
    • The most interesting part of geologic time overall

References and Resources

This exercise is taken from Guertin and Nguyen, 2003 . Combining a historical geology project with a campus student organization's fundraising efforts. Journal of Geoscience Education 51 (4) 378-380.

An introductory warm-up or pre-test activity is Starting Out with Earth History.

Useful tools for students include: