Continental Drift

In the 1960s scientists proposed a theory about the continents on earth. They decided the great plates that make up the continents were not fixed, but rather were drifting; drifting so much that at one time there had been only one supercontinent. They named this supercontinent Pangea. In the interim, the geography of the world has drastically changed over long periods of time until now we have seven distinct continents. Actually, six, Europe and Asia are considered separate continents but are really one land mass.

Image made by Kieff, CC license, Wikimedia.

Of course, this is all theory, there’s no real way, at present at least, to absolutely prove any such thing really happened. But scientists have observed that the Atlantic Ocean gets a little bigger each year and the Pacific a little smaller, by a few millimeters. What put scientists on to the theory though was the coastlines of Africa and South America. They look like they ought to fit together.

There have been other clues supporting continental drift as well, including India pushing into Asia hard enough to form the Himalayas Mountains, the Great Rift Valley in Africa, threatening to become the next continental split, and the great deep valleys and high mountain ranges of the oceans.  There is some fossil evidence too.  Plants that were apparently all present in widely spaced continents in areas that have completely dissimilar climates today.  We can definitely observe that the earth’s plates move, which we call plate tectonics.  When we put all of these ideas together, we can guess that perhaps Pangea was indeed a supercontinent in the earth’s distant past.

Printable Pangea Flip Book

You can print out this Pangea Flip Book to color and assemble to see the continents drifting.

Pangea Flip Book1

A flipbook makes pictures move, by flipping rapidly through the pages with your thumb on the edge of the sheets. It works best on stiff paper like cardstock, but you can also use regular printer paper. Cut apart the sheets on the lines and line them up in order behind the title page. Staple the left side of the book and flip from front to back.

Additional Layers

  • Learn the difference between a scientific theory and a scientific law. A theory is based on observable and testable data and has been substantiated many times over.  It explains a general body of phenomena, rather than one specific thing.  Theories try to explain the mechanism or the process that governs what we see around us in the physical world.  Plate tectonics is the overriding theory that explains everything about the way rocks and continents are formed.   A law, on the other hand, simply describes an observed phenomenon, without trying to connect causes and effects.  Neither a theory nor a law can be proved absolutely, such is the nature of science.  We can only say they have not yet been proven wrong.
  • Read more about Alfred Wegener. He came up with the idea of continental drift in 1912, but nobody paid it any attention until the 1960s when plate tectonics really began to be discussed.
  • The continents only move apart about 50 to 100 mm annually; that’s tiny. Geologists assume that the processes that are happening now are the same processes that happened at the same rate through all the history of the earth. First, do you think that’s a good assumption or a bad one? Why? Second, if this is true, how long ago was it that Africa and South America were actually touching? (Assume the largest movement, 100 mm, and that the continents are 2848 km apart – an approximation)
  • The areas of the world with the most volcanic and earthquake activity are assumed to be the edges of the plates. They look like they fall on plate edges if you see an aerial map of them. Find out more about the earthquake and volcano zones. Do you live in or near one?
  • It’s pretty cool to imagine what it would be like on earth with only one big supercontinent, but think about the one big superocean. Imagine what it would be like to try and cross it. Write or tell about the horrific voyage that would be.
  • Pan means all and gaea means earth. So now you know where the name Pangaea (or Pangea) comes from. What would you name a continent that you discovered?

More From Layers of Learning

This activity and printable are also in Layers of Learning Unit 1-6; this is just a tiny taste of the smorgasbord that is our curriculum.

Cover-1-6

Here are some more things you might like at Layers of Learning.  We hope you’ll check out all of the learning fun in our catalog too!

6 Comments

  1. The evidence for Pangaea goes far beyond what the post described. Geologists have used radiometric dating and other analyses to link volcanic rock from different parts of the world and assign it to a time period. Areas in North America, South America, Africa, and Europe have been linked up in ways that correspond to the boundaries of Pangaea. These are then supported by the fossil evidence that you outlined above. The land I am sitting on right now dates back to the early Jurassic time period, about 200 million years ago.

    Also, there is no “assuming” in figuring out where the plate boundaries are. They are readily observable. Scientists continually measure the movement. At the boundaries, you can observe one plate being pushed underneath another – this is why the Pacific is “getting smaller” – or you can see them spreading apart and new oceanic crust being created, which is why the Atlantic is “getting larger”.

    I’m absolutely fine with keeping it simple for younger students and homeschooling parents who are new to science, but it would be helpful to avoid creating misconceptions that have to be unlearned later. At least in my state, students MUST pass high school Earth Science in order to earn a diploma.

    1. Yes, the evidence is much more extensive than a single blog post. You are right about that. Our model is to give a few facts to give a starting point then have kids and parents go read books and websites written by experts or passionate amateurs on specific subjects. That way kids are reading real books and getting much better, more thorough information. We do not ever attempt to be a text book. The final thing we provide is hands on activities to solidify the information and give greater understanding. Thanks for adding further clarification.

      The assumption is that geologic processes are happening now at the same rate they have always happened. Scientists make these sorts of assumptions all the time, they have to. We have to assume that the physics we experience on earth are the same physics on the other side of the universe, for example. The purpose of the question is not to cast doubt on science but to help kids learn to question things, especially science things. Science is all about questioning, because if we teach kids that science is perfect and perfected then where is the room for curiosity and further discovery?

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