Notes – Continental Drift
Theory of Continental Drift
Who came up with the Theory of Continental Drift?
________________________________
What is a Continental Drift?
It is the idea or Theory …….. that the continents
_________________________ move over Earth’s surface.
All continents had once been joined together in a ____________
land mass (PANGEA) and later began to drift apart.
Wegener’s 3 main pieces of
evidence
1. Landforms___________________ – They appeared to ‘fit’ South America and
Africa.
_____________- In North America and Europe match up when
pieced together (also ‘fit’ as well)
___________________ – In North America and Europe match
up when the continents are pieced together (similar rocks)
2. Fossil Evidence - Fossils of the ________ animals were found
on many different continents, now separated by oceans:
Glossopteris = plant
Cynognathus = land reptile
Lystrosaurus = land reptile
Mesosaurus = freshwater reptile
These organisms had no way to travel across such oceans to
cross that exists today.
Notes – Continental Drift
3. Climate Evidence –
__________________ - Found in areas that are considered
Arctic (frozen) today.
_______________ - Evidence of glaciers found in areas
that have temperatures far too mild to have glaciers.
Evidence shows that climate must have been much
different in the past
Why didn’t Wegener’s
fellow scientists accept his
theory?
Wegener could not provide an explanation for the force that
pushes or pulls the continents.
Most scientists believed that the Earth was cooling and shrinking,
which created Earth’s mountain ranges. (like the dried up,
wrinkled skin of an apple)
Notes – Continental Drift
Wegener said that if this was true,
Mountains should be found all
over Earth, but they usually occur
in bands along the edges of
continents.
Unfortunately, Wegener died
before his theory was ever
accepted.