See this and learn about Continental Drift Theory

Grade 9 topic continental drift theory lesson

1. THE EARTH`S MECHANISM:
Continental Drift

2. CONTINENTAL DRIFT
•Alfred Wegenerwas one of several people who thought
the continents looked like they fit together,so he
proposed the continental drift theoryin 1912.
•Wegener was a meteorologist and astronomerso
needless to say other scientists thought he was out of his
field of study.

3. •His studies concluded that at one time all the continents
were joined together in one land mass called Pangaea.
1. Laurasiawas the name given to the northern part
of Pangaea
2. Gondwanalandwas the name given to the
southern partof Pangaea

4. •Scientists thought this
theory was outrageous
because even though
Wegener had evidence
of one large land mass,
he didn’t have the
answers to what force
(engine)“floated the
plates”. He was laughed
at and did not live to see
his theory accepted.
This animation begins with the
continents in their present
location, and then moving back
in time to form PANGAEA. The
circles represent fossil evidence
that Wegener used to prove his
Continental Drift Theory.
PANGAEA means “all land”

5. WHERE’S THE EVIDENCE
Wegener had pieces of evidenceto prove his
continental drift theory:
1.PUZZLE PIECES:
The continents, especially South America and Africa,
seemed to fit together like a puzzle.

6. 2.FOSSIL EVIDENCE:
Wegner noticed that plant and animal fossilswere found
on different continents.
•Do you think they swam all the way across the oceans?
NO!
•This would lead people to believe that the continents
were once joined.
Glossopteris…seed much to
large to be windblown
Mesosaurus…lived in fresh
water and could not have
lived in salt water

8. 3. ROCK EVIDENCE:
Huge belts of rocks found in
Africa and South America
were identical. Not only
were they the same, but
they would match up (age,
thickness, types)if the
continents were put
together.
Matching Mountains
The Appalachian
Mountainsthat disappear
off the coast of
Newfoundland match
mountains in the British Isles
and Scandinavia which
are comparable in age
and structure.

9. 4. GLACIER EVIDENCE:
There is proof that glaciers moved from Africa, through
the Atlantic Ocean, and then on towards South
America. This would be much easier if the Atlantic
Ocean were not there

10. Glacial Striations…Scratches glaciers leave
on rocks as they travel

11. 5. COAL DEPOSITS:
•Coal beds were formed from the compaction
and decomposition of swamp plants that lived
million years ago
•How is a coal bed formation possible in
Antarctica?
•Antarctica once experienced a tropical
climate, thus, it might have been closer before to
the equator.

12. 6. CLIMATE EVIDENCE:
•Warm weather plantshave been found in the
Arctic… but it’s not warm there!
•Glacier depositshave been discovered in tropical
and desertlocations…it’s not cold there, either!
•The continents had to have been at different
locations in the geological past.