Authentic Lessons for 21st Century Learning

As Cold as Ice

Glacial Theory

K20 Center, Quentin Biddy | Published: July 5th, 2022 by K20 Center

  • Grade Level Grade Level 6th, 7th, 8th
  • Subject Subject
  • Course Course
  • Time Frame Time Frame 3-4 class period(s)
  • Duration More 160 minutes


Students will examine evidence for glacial theory and other competing theories of the early 1800s. Students will read field journal excerpts from geologists as well as analyze the data collected from early Alpine expeditions.

Essential Question(s)

Overarching: What is the Nature of Science? Secondary: How can scientists use evidence to form plausible scientific theories and how do those theories change over time?



Students are given a scenario in which they have to make inferences from the evidence at hand and propose plausible theories using the Claims, Evidence, Reasoning (CER) model to explain what occurred.


Students participate in a simulation showing glacial movement and its results. Students view a real glacier flow time-lapse video over a 5-year period.


Students create a T-Chart explaining the similarities and the differences in their glacier model and real glacier movements. Students examine the evidence for modern day Glacial Theory.


Students investigate original glacial evidence from the 1830’s. Students "travel" along with Louis Agassiz on one of his field expeditions into the Alps. Students play the role of William Buckland, a Geologist in the early 1800’s, who was unsure about glacial theory. Students analyze the competing theories (glacial theory, diluvial theory, and drift theory) and test them against the available evidence at hand.


Students write a speech to the British Association for the Advancement of Science to explain why they either support or reject Glacial Theory and cite the evidence for or against the theory.


  • Tricky Tracks Slides

  • Case of the Missing Meatball handout (one per student)

  • Fossil Footprints handout (one per student or class set)

  • GAK (Follow attached instructions for making GAK, makes 3 cups) (1/2 cup – cup per group)

  • Paper towel tubes (one per group or one per class if done as demo)

  • Foil (to line tubes, one per group)

  • Small gravel (aquarium gravel works well, about 10-20 pieces of gravel per group)

  • Food coloring (enough to dye GAK)

  • Black marker (one per group)

  • (optional) iPad or other tablet with time-lapse app

  • Speech/Essay Rubric (1 per student)


Give students the Case of the Missing Meatball handout and have them write a Claim, Evidence, Reasoning (CER) statement for the scenario.

Tell students you are going to show them a series of pictures that tell a story. Explain that they will be making some observations about the pictures and using their observations to make some inferences. Show students the first panel of the footprints (use either the Tricky Track slides or Tricky Tracks student handouts). Have the students write down some observations.

Show students the second panel of the footprints picture. Allow students time to record their observations.

Show students the third panel and completed picture with all three panels.Have the students record their observations

Now ask students to talk with an Elbow Partner to discuss what possible scenarios could account for their observations. Have students write a CER statement for the scenario they think is most likely to have occurred. The students DO NOT have to have the same scenario as other students; there are multiple scenarios that can explain the footprints.


Assign students into groups of 2-4 depending on your available materials. Prepare the GAK ahead of time according to the attached instructions. (Option: If possible students can make the GAK themselves as part of the lesson.)

Cut the paper towel tube in half lengthwise so that you have two "open channels." These will serve as our valley for our glaciers to travel down.

Paper Towel Tube Valley

Cover the channels with foil; this will keep the GAK from sticking to the valley. (Note: As a differentiation you can have groups create obstacles with balls of tape stuck to the cardboard. These would simulate rock and boulder outcroppings. )

Foil Wrapped Paper Towel Tube Valley

Have the students use a marker to draw lines in the bottom of the valley. The marks should be about 1-2 cm apart. These marks will help the students to measure and detect the movement of their GAK glacier.