Chapter 5 Plate Tectonics Section 3 Drifting Continents
Do you think the scientists of Wegener's time should have accepted his hypothesis? Why or Why not?
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Why did most scientists rejet Wegener's hypothesis of continental drift?
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Which coastlines of continents seem to match up like jigsaw-puzzle pieces?
.......(figure 12 in book) Eurasis (Europe and Asia) Nothe America, South America, Africa, Antarcrica, India, Australia
What coasts look like they could fit together like a jigsaw puzzle
Africa and South Africa.
Who proposed the concept of continental drift?
Alfred Wegener
Alfred Wegener
Although scientist rejected his theory, Wegener continued to collect evidence on continental drift and to update his book. He died in 1930 on an expedition to explore Greenland's continetal glacier.
According to Wegener, the continents drifted together to form the supercontinent
Pangaea (pan jeeuh)
How did fossils provide evidence for continental drift?
Similar fossils occur on different continents. Because many of these organisms could not have crossed an ocean, this provides evidence that the continents were once connected.
Deposits of coal have been found beneath the ice of Antarctica. But coal only forms in warm swamps. Use Wegener's hypothesis to explain how coal could be found so near the South Pole.
Unfortunately, Wegener could not provide a satisfactory explanation for the force that pushes or pulls the continents. Because Wegener could not identify the cause of continental drift, most geologists rejected his idea.
Why was Wegener's hypothesis rejected by most scientists of his day?
Wegener could not provide a satisfactory explanation for the force that pushes or pulls the continents
What evidence supported Wegener's hypothesis?
Wegener gathered evidence from different scientific fields to support his ideas about continental drift. He studied land features, fossils, and evidence of climate change.
In 1910, a young German scientist named Alfred Wegner became curious about the relationship of the continents. He hypothesixed that Earth's continents had moved!
Wegener's hypothesis was that all the continents were once joined together in a single landmass and have since drifted apart.
What was Alfred Wegener's hypothesis about the continents?
Wegener's hypothesis was that all the continents were once joined together in a single landmass and have since drifted apart.
fossil
a trace of an ancient organism that has been preserved in rock.
Pangaea means
all lands.
Why did most geologists reject Wegener's idea on continental drift?
because he could not identify the cause of continental drift.
According to Wegener, how do mountains form?
when continents collide their edges crumple and fold. The folding continents push up huge mountains
How would continental drift affect a continent's climate?
when the land mass was attached and was in one climate and then drifted to a warmer or colder climate things that could once live in these areas could no longer survive
Wegener's idea that the continents slowly moved over Earth's surface became known as
continental drift.
What do the matching mountain ranges in Africa and South America show, according to Wegener's hypothesis?
he noticed that mountain ranges of both continents line up and that European coal fiels match up with coal fields in North America.
As a continent moves toward the poles,
it's climate becomes colder.
As a continent moves toward the equator,
it's climate becomes warmer
Glossopteris
organism , fernlike plant whose fossil provided evidence for continental drift, fossilized leaves of an extinct plant found in rocks in South America, Africa, Australia, India and Antarctica
Fossils and rocks found on different continents provide evidence that Earth's landmasses once were joined together in the
supercontinent Pangaea
Pangaea
the name of the single landmass that broke apart 200 million years ago and gave rise to today's continents.
Mesosaurus and Lytrosaurus
these fossisls have been found in places now seperated by oceans. Neither reptile could have swum great distances across salt water. Wegener inferred that these reptiles lived on a single landmass that has since split apart.
In the early 1900 what did many geologists believe how mountains form?
they thought mountains formed because Earth was slowly cooling and shrinking. According to this hypothesis, mountains formed when the crust wrinkled like the skin of a dried- up apple.
What evidence supported the hypothesis of continental drift?
Matching coastlines of continents Similar land features across continents Evidence from fossils Evidence from climate
In 1915 Wegener published his evidence for continental drift in a book callled
The Origin of Continents and Oceans
According to the hypothesis of continental drift, how would a world map have changed over the last 250 million years?
The continents have slowly separated to their current positions.
True/False Today's continents provide clues about Earth's history.
True
Wegener attempted to explain how continental drift took place. He suggested that the continents plowed actoss the ocean floors.
Unfortunately, Wegener could not provide a satisfactory explanation for the force that pushes or pulls the continents.
