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Pangea

Pangea. How It All Began.

hayley-ryan
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Pangea

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  1. Pangea

  2. How It All Began • Looking at a globe reveals coincidences that are difficult to ignore. The Eastern coast of South America seems to fit perfectly, almost like a puzzle, into the Western coast of Africa. At the same time, North America can be rotated slightly, and made to fit comfortably next to Europe, and Asia.

  3. These clues have lead geologists and other scientists to examine the relationships of other clues. Ancient fossil records show that the same plants and animals lived along the Eastern coast of South America, as did along the Western coast of Africa, as did other plants and animals along the coasts of North America and Europe.

  4. With this over whelming evidence, it became clear that at some point many millions of years ago, these continents must have in fact been connected.

  5. Scientists now believe that about 250 million years ago, a supercontinent known as Pangaea existed. • This supercontinent was made up of all the continents on Earth. • Over time, these continents have broken apart, and slowly drifted away from one another.

  6. Pangaea was created when all the continents we know today smashed together like some giant car wreck. • This crashing together was not a gentle process. The Appalachian Mountains in North America and the Ural Mountains on the boundary of Europe and Asia are the results of some of these collisions. • If you lived at the time of Pangaea, you could walk from the North Pole to the South Pole without getting your feet wet... well, unless you had to wade in a river or something.

  7. Pangaea started to break up into the continents that we know now during the middle of the Jurassic time period, about 175 million years ago. • Have you ever noticed that the east coast of South America and the west coast of Africa look like they could fit together like a giant jig saw puzzle? That's because they used to be stuck together. At one point North America, Greenland and Europe were all connected; because North America and Europe were connected, you can find the same rock formations in New York and in Scotland

  8. The rifting of Pangaea started with North America and Africa, and rifting continues on the east side of Africa near the Red Sea in an area called the Great Rift Valley. • The land mass that would become North America was twisted so that the Mississippi River Valley would have been running east and west, not north and south. In fact, the Mississippi River Valley is the result of a failed rift. • North America and Africa tried to split apart along what we now call the Mississippi River Valley. When North America finally rifted away from Africa, it formed the beginning of what is now the Atlantic Ocean.

  9. The continents wouldn't reach their current arrangement until 35 million years ago when India crashed into Asia forming the Himalayan Mountains.

  10. Pangaea took a really long time to crash together (340 million years), was really big, and took a really long time to break apart (140 million years). Did you know that in about 250 million years all the continents will have crashed together forming another supercontinent? Scientists already have a name for the new supercontinent. They are calling it Pangaea Ultima.

  11. Thinking Question • What force on Earth could possibly have enough energy to cause the continents to move as far as they have?

  12. Vocabulary • Plate-rigid blocks of crust and upper mantle rock. • These plated move in three ways: • Toward each other - convergent • Away from each other - divergent • Sliding past each other - transforming

  13. Destructive Zone Subduction Divergent Convergent

  14. Plate Techtonics • Using modern equipment, scientists known as oceanographers have been able to measure and map out the ocean floor. What these scientists have discovered has helped explain how it is that continents are able to move around on the Earth’s crust.

  15. Located deep beneath the waves on the ocean floor almost exactly halfway between the continents are raised areas known as ridges. These ridges are similar to under-water mountain ranges. At other locations we find extremely deep trenches, some reaching many thousands of feet in depth.

  16. Many scientists believe that the ridges represent areas where new crust is being formed as hot magma escapes from the Earth’s core and spreads outward. As the seafloor spreads outward away from the area where magma is being released, the continents are carried across the sea, riding on top of the sima crust.

  17. Geologists refer to this process as plate tectonics. As we study plate tectonics, a picture emerges of very old continents riding on top of much younger and ever moving plates. These plates move extremely slowly, at a rate of only about 10 cm per year.

  18. http://www.kidsgeo.com/geology-for-kids/0044-plate-boundaries.phphttp://www.kidsgeo.com/geology-for-kids/0044-plate-boundaries.php • http://www.teachertube.com/viewVideo.php?video_id=230989

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