Transcript 1. shape of the continents

CONTINENTAL DRIFT
http://www.tectonics.caltech.edu/movi
es/outreach/sumatra/pangaea.mov
Alfred L. Wegener
 Geologist Alfred Wegener
noticed similar rocks & fossil
remains were found on
continents which seemed to
fit together
 He called this “super”
continent called Pangaea
 In 1912 Wegener
published the
first version &
died defending
his theory
PANGAEA
the large landmass that included all of Earth’s
present day continents
Support for Continental Drift
1. SHAPE OF THE CONTINENTS
Continents fit together like puzzle pieces
Support for Continental Drift
1. SHAPE OF THE CONTINENTS
 Wegener was not the only
one to notice the fit of the
continents.
 1858: Antonio Pelligrini
depicted Africa and South
America connected.
 He was one of the first
scientists to publish maps
depicting the apparent fit of
the continents.
Support for Continental Drift
2. FOSSIL EVIDENCE
SAME FOSSILS: DIFFERENT CONTINENTS
Mesosaurus was incapable of swimming across a large
ocean.
Support for Continental Drift
3. ROCK EVIDENCE – Mountain ranges
 SAME ROCK:
DIFFERENT RANGE
Existing mountain ranges
separated by vast
oceans contain rocks of
identical mineral content.
 A prime example are the
Appalachian Mountains
in the eastern U.S and
the Caledonian
Mountains in the British
Isles.
Support for Continental Drift
4. GLACIAL SCARS
SAME SCARS:
DIFFERENT CONTINENTS
Support for Continental Drift
5. LOCATION OF COAL DEPOSITS
Coal deposits have been found in temperate and polar
regions; however, coal is formed in tropical regions.
CONTINENTAL DRIFT IN DOUBT
Why didn’t people believe in continental drift?
 People couldn’t image how the earth could
be millions of years old
 People couldn’t image a force great enough
to move the continents
BUT by the 1960’s evidence would prove
continental drift is TRUE and…. The story
continues (as does all good science!)