Continental drift is the hypothesis that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed. Wegener argued that there was once a super continent (which he named Pangea -meaning ''all land ) which split up over millions of year and gradually drifted over to their current place on earth at a rate of a few centimeter year.

1. Continental Drift
Under The Guidance of By:- Ramshankar Kirar
Pushpraj Singh Kaurav M.Sc. 1st year
S.O.S Earth Science School Of Studies In Earth Science
Jiwaji University, Gwalior

2. Content
• Introduction
• History
• Significance
• Force for drifting
• Pangea/drift proof
 Shape clues
 Fossil clues
 Climate clues
 Rock clues
• Proof was not enough
• Conclusion
• Bibliography

3. Introduction:-
• The word tectonics came from the Greek word tektov (tekton
–to build ; builder’’).This word is also the origin of other tect
words , such as architect.
• The very first detailed proposal of an idea along these lines as
the plate tectonics theory was made by Alfred Lothar Wegener
in 1911, under the name “Continental Drift”.
• Wegener argued that there was once a supercontinent (which
he named Pangea – meaning “all lands”)which split up over
millions of years and gradually “drifted” over to their current
places on earth ; at a rate of a few centimeters year.

4.  History
• Francis Bacon: In the mid 1600s Bacon noticed that
there’s an odd puzzle piece fit between Africa and
South America.
• Antonio Snider-Pellegrini: In 1858 Antonio enhanced
Bacon’s discovery by comparing the coastlines of Africa
and South America but it was still rejected by most
people.
• F.B Taylor: postulated his concept of “horizontal zontal
displacement of the continent’’ in the year of 1908 but
Published only in the year 1910
The main purpose of his hypothesis was to explain the
Problems of the origin of the folded mountains of
tertiary period

5. Significance
• It describes and explains the motion of portions(plates) of the
earth’s crust.
• It explain the mechanisms that created the continents, mountain
ranges, the ocean floor, earthquakes, and other macro and some
micro events on/in the earth’s crust.
• We can track backward and look at what the earth looked like in past
ages and extrapolate forward to see what could possibly be the
future for our planet.

6. Alfred Wegener, a German meteorologist was the first to make
an exhaustive investigation of the idea of continental Drift and to
convince others to take it seriously.
In his book The origin of the continents and oceans (1915)
He drew a series of map showing three stages in the drift Process
beginning with an original large landmass which He called Pangaea
(meaning “all lands”)

7. continental drift

8. Force For Drifting
• Wegener proposed that the movement accountable for the
drifting of continents was instigated by tidal force and
pole-fleeing force
• The polar-fleeing force relates to the rotation of the earth
• The shape of earth
• The second force that was proposed by Wegener ,the tidal
force
• Though ,most of the scholars considered these force to be
insufficient

9. Pangea/Drift Proof
• Wegener’s idea of continental drift was controversial at the
time.
• People wanted proof that this has and is occurring.
• To prove his idea, Wegener found 4 major pieces of evidence:
 Shape
 Fossils
 Climates
 Rocks

10. Shape Clues
The continents fit together like puzzle pieces.
• Example of Shape:
 The east coast of South American and
west coast of Africa match.

11. Fossil clues
Identical index fossils were found on separate continents.
Fossil e.g. 1: Mesosaurus
An extinct reptile that lived on land and fresh water.
Fossils of Mesosaurus have been found on South America
and in Africa.
These fossils were dated to the same geologic time
frame.
The continents of South American and Africa were one
joined so the reptile could move freely from one landmass
to the next.
Other Index Fossils Include:
-Cynognathus – Land Reptile
-Lystrosaurus – Land Reptile

12. Continues….
Identical index fossils were found on separate continents.
Fossil Example: Glossopteris
Same Plant found on Africa, India, South America and
Antarctica.
The continents were once close together so the plants
seeds were easily able to spread.
It is not possible for the seeds of that plant to spread
across the entire globe.

13. Climate Clues
o Wegener noticed evidence of major climate changes
o Climate Example: Tropical Plants in Arctic Area
o Warm weather plant fossils were found in the Arctic.
o Areas of land that were once in the topics, drifted apart and move toward the arctic.
o Climate Example: Wegener noticed evidence of major Glaciation.
o When a glacier moves, it scratches the land .
o Glacier scratches can be seen in warm tropical areas.
o Glacial evidence is found in area where
there are no glaciers.
o Area of land that were once in the arctic,
drifted apart and moved toward the tropics.

14. Rock Clues
Rock and rocks structures on different are the same where the land was
once joined.
Rock example: North America and Europe
Rock Structures match where the Appalachian
Mountains in the eastern united state once
where jointed against the side of Europe.
How is this possible ?
The continents once were together when the
mountains formed and then they
separated – breaking in the existing mountain
chain as North America and Europe move away from each other.

15. continuous……..
Rock example: Coal Fields
Coal fields in North America and Europe match
up when pieced together.
How is this possible?
When Laurasia formed after the breakup of
Pangea, the continents of North
America and Europe were once joined together.
This supercontinent was located toward the equator
and the type of humid swampy environments that are
needed in order to form coal.
After the coal formed the continent separated breaking
the existing rock layers as North America and Europe moved away from each
other.

17. Proof was not enough….
Despite these 4 major pieces of evidence, geologists of Wegener's time
still did not believe his idea.
The problem was that while Alfred was able to
show evidence that it could have happened ,he
was not able to explain how or why the continents
moved.
He needed to teII people what mechanism was
causing the “so called’’ continental drift.

18. Conclusion
• Paleomagnetic studies appear to provide support for
Wegener’s ideas of continental drift.
• The continents appear to have been joined over 200
million years ago.
• Paleomagnetic evidence also suggests the continents
have moved northwards.

19. Bibliography
 Earth Dynamic Systems(sixth edition)
By: W. Kenneth Hamblin
 Physical geology(second edition)
By: G.B. Mahapatra

20. Thank You