Homework: Pangea Worksheet Science Warm Up #29 1. What is

Homework: Pangea Worksheet
Science Warm Up #29
1. What is continental drift?
2. What was Pangea?
3. What happened to Pangea?
Objective: Scholars will be able to describe the
different types of boundaries and the theory of
• The lithosphere (outer layer of Earth’s crust) is
broken into many pieces called the tectonic
• They resemble the cracked shell of a hard
boiled egg.
Theory of Continental Drift
In the 1800s, Alfred
Wegner developed the
Theory of Continental
He used the following
• In the 1950's, with more modern technology, the
ocean floor could be explored. Evidence that the
continents move came from the discovery of the
mid ocean ridges.
• 1950= better technology, discovery of mid ocean
ridges (show that continents move).
• Shows sea floor spreading, ocean trenches
But if mid ocean
ridges are adding
to the sea floor,
shouldn't Earth be
getting bigger??
No, at the other
side of the Earth
trenches allow
the plates to
flow back under.
• The theory of plate tectonics states that
Earth's lithosphere is made up of huge plates
that move over the surface of the Earth.
3 Ways Plates Move
• Divergent Boundaries--plates move apart
• Convergent boundaries--plates move together
• Transform boundaries--plates slide past each
Divergent Boundaries
• Divergent boundaries are called spreading
centers because they move apart and new
crust is formed.
When this
happen on the
crust, volcanoes
are formed.