Alfred Wegener first proposed his theory of continental drift in 1910. He noticed that the continents seemed to fit together like puzzle pieces. Wegener also presented three lines of evidence to support his theory: landforms on different continents matched up, matching plant and animal fossils were found on separated continents, and patterns of past climates did not match the continents' current positions. However, Wegener's theory was initially rejected because he could not explain how or why the continents would move. Wegener believed that evidence from all earth sciences was needed to understand the planet's past configurations and that new discoveries could alter conclusions.

1. Continental Drift TheoryContinental Drift Theory
No need to take notesNo need to take notes
I have taken them for youI have taken them for you

2. "Doesn't the east coast of South
America fit exactly against the west
coast of Africa, as if they had once
been joined?" wrote Wegener to
his future wife in December 1910.
"This is an idea I'll have to pursue."
Alfred was trying to get his
girlfriend’s father to like him. Her
father was a well-known geologist!!

3. Alfred Wegener (Vegener)Alfred Wegener (Vegener)
• As a young scientist,As a young scientist,
Wegener was curiousWegener was curious
about Earth’s continents.about Earth’s continents.
• In 1910, Mr. WegenerIn 1910, Mr. Wegener
formed a hypothesisformed a hypothesis
which stated all thewhich stated all the
continents were oncecontinents were once
joined together in a giantjoined together in a giant
landmass.landmass.
• He named this landmassHe named this landmass
PANGAEA.PANGAEA.

4. Wegener used 3 types of evidenceWegener used 3 types of evidence
to prove his theory!to prove his theory!
1.Evidence from landforms1.Evidence from landforms
2.Evidence from fossils2.Evidence from fossils
3.Evidence from climate3.Evidence from climate

5. Evidence from landformsEvidence from landforms
• The shapes of theThe shapes of the
continents seemed tocontinents seemed to
fit together.fit together.
• Mountain ranges andMountain ranges and
other features alsoother features also
lined up.lined up.

6. The ‘jig-saw’ puzzle
EvidenceEvidence from landformsfrom landforms

7. The ‘jig-saw’ puzzle
Evidence from landformsEvidence from landforms

8. The ‘jig-saw’ puzzle
Evidence from landformsEvidence from landforms

9. Evidence from FossilsEvidence from Fossils
• Fossils from oneFossils from one
continent matchedcontinent matched
fossils from otherfossils from other
continents.continents.
• Wegener used bothWegener used both
plant and animalplant and animal
fossils.fossils.
Glossopteris: a fern
found on the southern
continents
Mesosaurus: a
freshwater swimming
reptile found in Africa
and South America

10. fossil matches
Evidence from Fossils

11. fossil matches
Evidence from Fossils

12. Evidence from ClimateEvidence from Climate
• Wegener looked atWegener looked at
certain areas on Earthcertain areas on Earth
and their climatesand their climates
• He noted that theHe noted that the
fossils he found onfossils he found on
certain sections ofcertain sections of
Earth did not matchEarth did not match
the current climatethe current climate
• Glacier scratches inGlacier scratches in
S. AfricaS. Africa

13. Antarctic ice
Evidence from ClimateEvidence from Climate

14. Ice could not have extended this far.
So...continents MUST have moved..
Evidence from ClimateEvidence from Climate

15. Drift awayDrift away
Continental Drift Theory
At first
nobody
believed
Alfred
Wegener’s
theory…..
WHY YOU
ASK!
He could
not prove
how or
why the
continents
moved.

16. Scientists still do not appear to understand sufficiently that all
earth sciences must contribute evidence toward unveiling the
state of our planet in earlier times, and that the truth of the
matter can only be reached by combing all this evidence. . .
It is only by combing the information furnished by all the
earth sciences that we can hope to determine 'truth' here,
that is to say, to find the picture that sets out all the known
facts in the best arrangement and that therefore has the
highest degree of probability. Further, we have to be
prepared always for the possibility that each new discovery,
no matter what science furnishes it, may modify the
conclusions we draw."
Alfred Wegener.
The Origins of Continents and Oceans (4th edition)