A LONG, LONG time ago: geologic timescales
James Madison University
This activity was selected for the On the Cutting Edge Exemplary Teaching Collection
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This activity has benefited from input from faculty educators beyond the author through a review and suggestion process.
This review took place as a part of a faculty professional development workshop where groups of faculty reviewed each others' activities and offered feedback and ideas for improvements. To learn more about the process On the Cutting Edge uses for activity review, see http://serc.carleton.edu/NAGTWorkshops/review.html.
This page first made public: May 21, 2008
Used this activity? Share your experiences and modifications
Students compare their pre-conceived impressions of events on the geologic time with the actual positions of these events on a 45.5' geologic timescale.
This activity, or a similar version, is used in many introductory, general education courses at JMU including Physical Geology and Earth Systems and Climate
Skills and concepts that students must have mastered
None. Understanding the concept of scale helps, but it is not necessary.
How the activity is situated in the course
A stand-alone exercise as part of a brief (1-2 lecture) discussion of geologic time.
Content/concepts goals for this activity
Students learn about the relative and absolute timing of a set of geologic events, and contrast geologic timescales and human timescales.
Higher order thinking skills goals for this activity
Developing scale models
Other skills goals for this activity
Working in groups
Description of the activity/assignment
Each student randomly picks a card with a geologic event (written description and an image) on it. A timeline has 11 events, not including the formation of the Earth and today. Students attach their event where they think it should go on a 45.5' timeline (in the hallway) made out of paper adding tape and mark the location on the timeline. They return to the classroom and receive a list of age dates for each event. Each group figures out the scale (1 foot = 100 million years) and then moves their events to the correct locations. Students are asked how the position of the events changed, and answer other questions that reinforce the difference between human timescales and geologic timescales.
The powerpoint file below contains a template for making geologic event labels for the index cards. Instructors can tailor the geologic event list to fit their course.
Determining whether students have met the goals
I check each timeline after the "correction" phase to make sure all events are placed correctly. We go over the answers to the thought questions in class after they are finished with the assignment. Questions from this exercise are fair game as test questions.
More information about assessment tools and techniques.
Download teaching materials and tips