Transcript Class Starter

What makes the plates of the crust
move?
 Continental
Drift
 Pangea
 Mid-Ocean
Ridge
 Convection
 Theory
of plate tectonics
 Earth’s
continents were once joined in a
single landmass and gradually moved, or
drifted apart.
 Alfred Wegener first proposed the theory
of continental drift.
 Fossils:
Discoveries of organisms on different
continents suggest they were once together.
 Climate:
Fossils such as, tropical plants, are
found on continents that are not tropical.
 Geology:
Finding of rocks found on other
continents shows that the continents were
once together
 What
is the theory of Continental Drift?
 What was the scientist name that came up
with the theory of Continental Drift?
 What are the 3 evidences of continental
drift?
Pangaea
 Continents
had once been joined in a huge
supercontinent called Pangea.
 Pangea started to splitting apart about 200
million years ago.
 What scientist came up with the pangea
theory?
 Alfred Wagner
 Underwater
mountain ranges.
 The mid-ocean ridge is the longest chain of
mountains.
 Hess proposed that the ocean floors move,
carrying the continents along with them.
The movement begins at the mid-ocean
ridge.
 Energy
transfer by the movement of a
material.
 Example: Boling water, the water at the
bottom of the pot heats up, becoming less
dense, and rises. At the surface, it cools,
becomes denser, and sinks, only to be heated
and rise again.
 PG.
14 IN SCIENCE BOOK