DVD: PLATE TECTONICS
Continental Drift: 4 minutes
How the Earth was Made----1.5 Billion Years Ago
Talks about evidence of continental drift like the fresh
water trilobite
Alfred Wegener
CONTINENTAL DRIFT
•Alfred Wegner was one of several people who thought
the continents looked like they fit together, so he
proposed the continental drift theory in 1912.
Wegner was a meteorologist and astronomer so
needless to say other scientists thought he was out of his
field of study.
•His studies concluded that at one time all the continents
were joined together in one land mass called Pangaea.
1. Laurasia was the name given to the northern part
of Pangaea
2. Gondwanaland was the name given to the
southern part of Pangaea
Scientists thought this
theory was outrageous
because even though
Wegner 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.
PANGAEA means “all land”
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 Wegner used to prove his
Continental Drift Theory.
WHERE’S THE EVIDENCE
Wegner had 5 pieces of evidence to prove his
continental drift theory:
1. PUZZLE PIECES:
The continents, especially South America and Africa,
seemed to fit together like a puzzle.
2. FOSSIL EVIDENCE:
Wegner noticed that plant and animal fossils were 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
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
Mountains that disappear
off the coast of
Newfoundland match
mountains in the British Isles
and Scandinavia which
are comparable in age
and structure.
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
Glacial Striations…Scratches glaciers leave
on rocks as they travel
5. CLIMATE EVIDENCE:
DVD on Continental Drift
•Warm weather plants have been found in the
Arctic… but it’s not warm there!
•Glacier deposits have been discovered in tropical
and desert locations…it’s not cold there, either!
•The continents had to have been at different
locations in the geological past.
?????????? ONE QUESTION REMAINED ??????????
WHAT FORCE WAS MAKING THE CONTINENTS MOVE
TOMORROW
FIND OUT
WHAT FINALLY PROVED THAT WEGNER’S
CONTINENTAL DRIFT THEORY
WAS RIGHT?
AMAZING EARTH SCIENCE FACTS
1. The 4 pieces of evidence that support
Continental Drift are
Continents
______________
fit together like puzzle pieces
Fossils
__________
showing the same types of life existed
on the now separated land masses
Rock layers & mountains
___________________________match
up along
coastlines of once joined continents
Glacial
____________
evidence in temperate and hot
climates
Organizing
Topic:
Puzzle
Pieces
Today’s Notes
200 POINTS
Fossil
evidence
100 POINTS
Pangaea
50 POINTS
Appalachian
Mountains
100 POINTS
Continental
Drift
50 POINTS
Wegner
50 POINTS
Organizing
Topic:
Core
Inside of Earth
200 POINTS
Asthenosphere
Basalt
100 POINTS
100 POINTS
Tectonic
plate
50 POINTS
Oceanic
crust
50 POINTS
Lithosphere
50 POINTS