DO THE DO NOW
What is a fossil?
•Anything left from
something that
used to be alive.
Objectives
• WWBAT define lithosphere
and lithospheric plate.
• WWBAT analyze evidence
that lithospheric plates
move.
Activity
• Cut out the continents
along the lines
• Try to fit them all
together like a puzzle
Can you fit them together like this?
Now glue them down.
VOCABULARY
• Lithosphere: The crust
and very top of the mantle.
• Lithospheric plate: Large
pieces of the crust that
move along the earth's
surface.
The plates are slowly moving and
bump into each other.
The Continents are Doing What?
• The Theory of
Plate
Tectonics:
The continents
are not fixed in
place, they
move around
on the surface
of the earth.
300 Million Years Ago
Prove It
• 1. The shapes
of our
continents fit
together. This
makes it
possible that
the continents
used to all fit
together.
Prove It!
• AND THEY DID. It was one giant
continent called: Pangaea.
Prove It!
• 2. The eastern coast of South America
and western coast of Africa have matching
fossils and rocks,
• 3. The east coast of Africa and
Madagascar also have matching fossils
and rocks.
Continental Drift:
• Where did Wegener noticed identical plant and
animal fossils?
– He noticed identical plant and animal fossils on opposite
sides of the Atlantic.
• What did Wegener notice next?
– Wegener then noticed that all the continents fit together like
puzzle pieces
• What did Wegener name his super continent?
– Pangaea (“All Earth” in Greek) is the name of the super
continent.
• What did he call his theory?
– Continental drift is the name for Wegener’s Theory..
• Did people listen to Wegener?
– The public thought he was crazy.
Sea Floor Spreading
• What did Harry Hess discover about the ocean floor?
– Its not flat, there are mountains there.
• How long is the Mid-Atlantic Ridge?
– 12,000 miles!
• What is the Mid-Atlantic Ridge?
– A long mountain range of volcanoes.
• What did Hess discover next?
– That the ocean floor gets older away from the midAtlantic ridge.
• Does making new crust mean the earth is getting
bigger?
– No!
Plate Tectonics
• Plate tectonics combines what 2 theories?
– Continental drift and Sea floor spreading.
• How fast to plates move?
– As fast as our fingernails grow.
• How long ago was Pangaea together?
– 250 million years ago.
• What's the next crazy thing that's going to happen?
– The continents are going to collide again!
• How did scientists figure out where the plate
boundaries are?
– Earthquakes