Materials:

• At least one prepared leader, preferably one that knows the basic geology of Northfield
• *Handout of cars
• *Puzzle (handout & answer key)
• Scissors
• Paper
• *Fossils & sandstone

*Available in hard copy in Mudd 71 or from link above

Concepts Used:

• Plate tectonics and supercontinents
• Geologic time scale of Minnesota
• Review of the scientific method
• Understand dynamic earth & natural climate fluctuations

Skills Emphasized:

• Geology
• Environmental Science
• Problem Solving

Background:

Did you know that the continents move? They split apart and ram together and never get tired of it. It's called plate tectonics. The continents are "floating" on top of the rest of the earth and can move around it. Sometimes they are all mashed together in a supercontinent, while other times they are all spread out (like now). Mountains are made when continents smash together, just like two cars that have collided (handout). Ocean is formed in between continents that break apart (Example: Red Sea on handout).

Plate tectonics is a cycle where the continents all crash together, and then all break apart. They are different shapes and sizes after every cycle! But, how in the world do we know that the continents used to be connected? One man named Alfred Wegener noticed many interesting facts about why the continents might have fit together in the past. First, when a plant or animal dies it is sometimes preserved in the rock record. Have you been to the science museum and seen the dinosaur bones? If you find animal bones in the rocks in Minnesota, then you know that that animal lived in Minnesota when it was alive. So, what does it mean if you find the same fossil in South America that you do in Africa? (they might have been touching)

Description of activity:

* Estimated prep time (before student arrival): 20

* Estimated activity time: 20-60 min depending on complexity and number of students.

1) Give each student a Pangea puzzle sheet. Have them color each pattern a different color. Cut out the continents and then try to fit them together. (NOTE: let them know that they won't fit together exactly, but that they can come close.)

2) Once they have “solved” the puzzle, have them look more closely at the fossils drawn on the puzzle. Discuss the importance of the fact that the same fossils are found in both South America and Africa. Tell the students that this is how scientists first found out that the continents moved across the earth's surface. The puzzle shows how the continents once fit together to form a super-continent (emphasize the idea that North America was once at the equator). CAN STOP HERE (go on if there is more time)

3) Have the students then draw pictures on a piece of paper of what they think Minnesota looked like 260 million years ago (the time when MN was near the equator). After a couple different interpretations tell them that we don't know who's right and we'll have to do a couple experiments and look for evidence to find out.

4) One way to figure out what MN was like is to look at what kind of rocks we have. Around Northfield there is a lot of sandstone and limestone. Show them some fossils and some sandstone. Ask the students how sandstone forms. Ask the students where they might find both sand and animals that live in the ocean. They might suggest an ocean. Since these are both found in Minnesota, what does this mean? (there was an ocean here) How could there have been an ocean in Minnesota? (change in sea-level due to glaciers, Minnesota wasn't always where it is now) There are changes in the earth that may cause sections of the earth to move in plates. Remember the moving plates? Could MN have been under an ocean when it was near the equator?

5) To conclude, ask the students what they think Minnesota will look like 260 million years from now!

Review and Questions:

The world hasn't always looked like it does today. The land moves around and smashes into other land, and breaks up into smaller pieces. Also, the ocean can get deeper or shallower depending on the amount of ice caught up in glaciers.

What is plate tectonics?

How did scientists figure out that the continents used to touch? (remember the fossils?)

Has Minnesota always been cold in the winter? Why or why not? (no, it used be near the equator)

What do we know about climate change and sea level fluctuation? (when it's warmer, there is less ice and the sea level can rise. That means Minnesota was under water!)

Additional Resources:

• Review of plate tectonics : http://www.platetectonics.com/book/index.asp
• Cool animation of breakup : http://www.scotese.com/pangeanim.htm
• History of Alfred Wegener (how scientists came to understand plate tectonics) http://www.ucmp.berkeley.edu/history/wegener.html
• Africa map from: http://www.hrw.com/science/si-science/earth/tectonics/volcano/volcano/region02/

Alternatives for older/younger ages:

• Younger students could focus on the different fossils and the animals they came from.

• Older students can discuss more about climate change.

Idea for game:

came from Kids for Conservation