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 This theory was proposed by Alfred Wegener, a German scientist about 100 years ago.  He hypothesized that the continents were not always in the same.

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Presentation on theme: " This theory was proposed by Alfred Wegener, a German scientist about 100 years ago.  He hypothesized that the continents were not always in the same."— Presentation transcript:

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3  This theory was proposed by Alfred Wegener, a German scientist about 100 years ago.  He hypothesized that the continents were not always in the same location that they are today, but that they have “drifted” there over millions of years.  He proposed that millions of years ago – the continents were all attached in one “super-continent” called PANGAEA.  Pan – means “all” and “ Gaea ” means Earth in Greek.

4  His theory of what happened…  250 million years ago, was Pangaea  220 million years ago… it started to drift apart.

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6  #1: He looked at maps of the world and noticed all the continents looked like puzzle pieces that “fit together”. North America South America Africa

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8  #2: He looked at Fossil evidence, geological structures (mountains, valleys, etc…), and evidence of glaciers on different continents.  Mountain Ranges: He noticed that mountain ranges that began on one continent, then ended at the coast-line, seemed to continue on another continent across the Ocean!

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10  Rock structures: such as Folds in the Earth’s crust, and the types of rocks were similar on different continents  Eg. Rocks found in Newfoundland (North American continent) are the same type and age as rocks found in Greenland and Ireland/Scotland (European Continent)

11  Fossils: Wegener found that similar fossils were found on different continents.  One fossil that intrigued him was Mesosaurus (a sharp-toothed freshwater reptile). These fossils have only been found in 2 places – Southeastern “South America” and Southwest “Africa”

12  There were many other fossils where he found the same thing.  Gossopteris (a fern). It’s fossils were found on every continent including Antarctica…It can’t grow in cold temperatures, so Antarctica must have been warmer millions of years ago because it must have been closer to the equator.  Cynognathus and Lystrosaurus (land dwelling creatures) Fossils found on different continents. They could not have swum that far to get onto different continents …so the continents must have been joined.

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14  #3: Paleoglaciation – the extent of ancient glaciers (big masses of ice) and the markings they have left behind.

15  During ice ages, when glaciers covered the lands, they moved and left marks behind them (large U-shaped valleys and deeply scratched rocks)  Glacier evidence has been found in tropical areas (areas that don’t get cold)  The idea seemed to be that if these areas were closer to the South pole at one point – this would make sense….pointing again to the idea of the continents being connected.

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17 17 Coal deposits › coal is formed from decay of tropical plants › coal deposits are found in Antarctica › suggests Antarctica was once a tropical climate that was closer to the equator

18  1) Map show that continents fit together like puzzle pieces  2) Mountain ranges that seem to be split between 2 distant continents  3) Fossils found on different continents  4) Paeoglaciation pattern that makes sense if continents were once connected.


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