Transcript Plate Tectonics Unit(poster)

The Story of the
Discovery of Plate
Tectonics
All Continents had been joined
together in a supercontinent, Pangaea
and has since drifted apart
In 1915 a German
scientist named Alfred
Wegener proposed
hypothesis called
CONTINENTAL DRIFT
The same fossils
were found on
different
continents
This plant fossil
Glossopteris
was found on 5
different
continents
The same
mountains
were found on
different
continents
Circle is where
mountains
split, half are
found in East
US, the other
half in Europe
Scratches from
ice were found
in deserts in
India and
Africa
Scratches left
by ice show
that India and
africa were
much farther
South on Globe
WEGENER’S HYPOTHESIS WAS REJECTED BECAUSE HE COULDN”T PROVE WHY CONTINENTS MOVED!
Mid-Ocean
Ridges
Or
During World War II scientists
began to use sonar to map the ocean
floor
Underwater
volcanic
mountain ranges
Deep Ocean
Trenches
Or
Deep holes where plates
slide under eachother
In 1963 Harry Hess created the idea
of Sea-Floor Spreading
New ocean floor forms at the mid-ocean ridges,
slowly spreads out to form new ocean basins
before sinking below lighter plates
With Sonar Scientists
Discovered:
Other Observations
*1 Youngest Rock was Found
at the ridge and oldest the
farthest away from the ridge
*2 Basalt rock was found at the
mid-ocean ridge, it comes from
Volcanoes and makes the ocean
floor of every ocean
* 3 Ocean floor was found to be
sinking below continents or other
crust at the trenches… this
process was named subduction
WarmUp (3-19-13)
• What is going to happen to all of our
continents within the next 250 million years?
– They will collide to form another supercontinent
WarmUp (3-20-13)
• Who developed the concept of Continental
Drift and what was his evidence to support it?
– Alfred Wegener: same fossils on different
continents, and same rocks from mountains, and
how continents fit together like a puzzle
WarmUp (3-21-13)
• Describe the process of sea-floor spreading.
Agenda:
1.WarmUp
2.How It’s Made
3.Finish Poster
4.Watch Video
WarmUp (3-25-13)
• Name the three different types of plate
boundaries.
– Convergent boundary (plates collide with each
other)
– Divergent boundary (plates move away from each
other)
– Transform boundary (plates slide past each other)
Agenda:
1.WarmUp
2.How It’s Made
3.Plate Tectonic
Activity