Transcript The Continental Drift

The Continental Drift
»
By: Reese Wells
Continental Drift Theory
 Alfred
Wegner
developed the
theory in 1912
 Theory suggested
all continents
move
Alfred Wegner
 Published
The Origins of
Continents
 Called the big
super-continent
“Pangea”
 Suggested continents
move because of the
convective flow
Controversy
 Harrold
Jeffrey said that
continents couldn’t move
because the inner core was very
strong and no rock could move
Discussion
 David
Griggs
proved that
rock flows in
high
temperature
and pressure.
Why Continents Move
 Continents
move because of the
liquid rock that flows under
the plate, making the plate
move, bringing the continent
move.
Movement was Proven
 Proven
in 1969 when
Glomar Challenger
drilled over the
Atlantic, looking
for the age of the
ocean
 Drill picked up
sediment and
experts looked for
the age
Movement Was Proven
 Proven
by analysis of sea-floor
spreading
 Age of ocean was 150 million
years old,which is extremely
young for a 4 billion year old
Earth
Arthur Holmes
 Proposed
the
first geological
time scale
 Used convection
to test the idea
of the drift
 Came close to
getting the idea
of Earth’s
tectonic plates
correct
Continental Drift
 Continents
fit
together using
their continental
shelves as
borders.
 This
“super
continent” was
called “Pangea.”
Proof of Continental Drift
 Tropical
fossils have
been found
in the
Arctic
 South Africa
and Brazil
match up
Rock/Fossils Evidence
 Most
continents
have the same
fossils
 Gold
& iron are
found in South
Africa and
Brazil
Plate Tectonics
 Theory
developed in 1960’s
 Continents rest on larger
plates
 Plates move over time, causing
continents to change position
John Milne
 First
geologist to
develop a
seismograph
 Helped track
earthquakes
 Before his death,
140 stations of
global pattering of
earthquakes were
set up
Extra Info
 When
plates spread, cracks form
 In Iceland, there are many
cracks
 The Atlantic Ocean plate spreads
to the west about .75 inches
each year.
About Myself

I am Reese
Wells. I love
baseball, music
and a lot of
other things. I
play baseball
for the
Carolina
Angels, and my
favorite band
is Guns n’
Roses.
Bibliography




Mark Cloos. “History of tectonic theory” The
World Book Encyclopedia. 1999 ed.
(No Name). Continental Drift. (No date last
revised). 29 April 2004
<http://library.thinkquestafrica.org/TQA00091/c
ondrift.htm>
(No Name).Plate Tectonics. (No date last
revised). Earth Science Austria & Prof. Stephen
A. Nelson’s notes. 30 April 2004
<http://earthsci.org/teacher/basicgeol/platec.h
tml#Plate%20Tectonics>
(No Name).Rockhounding Arkansas. October 1998.
Rockhounding Arkansas. 27 April. 2004.
<http://rockhoundingar.com/geology/condrift.htm
l>.
Bibliography


(No Name). Science Odyssey:People and
Discoveries. (No date last revised). A
Science Odyssey. 27 April. 2004
<http://www.pbs.org/wgbh/aso/databank/e
ntries/boholm.html>.
(No Name). The National Academies: From
Earthquakes to Continental Drift. (No
date last revised). National Academy of
Sciences. 27 April. 2004
<http://www.beyonddiscovery.org/content
/view.page.asp?I=230>.