EVIDENCE OF PLATE TECTONICS
FIT OF THE CONTINENTS
AGENDA
When was the Continental Drift Theory rejected?
History of the Idea and How the Idea started
Timeline of Alfred Wegener’s Study
Alfred Wegener’s Discoveries
Fit of the Continents
EVIDENCE OF PLATE TECTONICS
FIT OF THE CONTINENTS
EVIDENCE OF PLATE TECTONICS
FIT OF THE CONTINENTS
ALFRED
WEGENER
ALFRED
WEGENER
ALFRED
WEGENER
Continental drift was a revolutionary scientific theory developed in the
years 1908-1912 by Alfred Wegener (1880-1930).
- He is a German meteorologist, climatologist,
and geophysicist, that put forth the hypothesis
that the continents had all originally been a pa
rt of one enormous landmass or supercontine
nt about 240 million years ago before breakin
g apart and drifting to their current locations.
ALFRED
WEGENER
(1924–1930)
Continental drift was a revolutionary scientific theory developed in the
years 1908-1912 by Alfred Wegener (1880-1930).
- He is a German meteorologist, climatologist,
and geophysicist, that put forth the hypothesis
that the continents had all originally been a pa
rt of one enormous landmass or supercontine
nt about 240 million years ago before breakin
g apart and drifting to their current locations.
When was the
Continental Drift
Theory rejected?
Evidence of Plate Tectonics:
Fit of the Continents
Rejection of Wegener’s
theory,
1910s–1950s.
Although now accepted,
the theory of continental
drift was rejected for man
y years, with evidence in
its favor considered insuff
icient. One problem was
that a plausible driving
force was missing.
The main reason that Wegen
er's hypothesis was not
accepted was because he
suggested no mechanism for
moving the continents. He
thought the force of Earth’s
spin was sufficient to cause
continents to move, but geolo
gists knew that rocks are too
strong for this to be true.
His idea was quickly rejected by the
scientific community primarily because the
actual forces generated by the rotation of
the earth were calculated to be insufficient
to move continents. Wegener also tried to
explain the westward drift of the Americas
by invoking the gravitational forces of the
sun and the moon, this idea was also
quickly rejected. Wegener's inability to
provide an adequate explanation of the
forces responsible for continental drift and
the prevailing belief that the earth was
solid and immovable resulted in the
scientific dismissal of his theories.
Evidence of Plate Tectonics:
Fit of the Continents
Extra facts on time frame:
The 1910s were known for
the
discovery
of
refrigerators
and
air
conditioners. As well as the
debut of Neon Lighting in
Paris. It was also called
the Edwardian Era.
And ending on the 1950s
with new products. From
photocopy machines to
oral
contraceptive birth
control
pills, long-playing
record
s (LPs) to Liquid
Paper. The
earliest video game was even
invented in 1958.
History of the
Idea and How
the Idea started
Evidence of Plate Tectonics:
Fit of the Continents
History of the Idea:
Wegener eventually proposed a mechanism for continental
drift that focused on his assertion that the rotation of the
earth created a centrifugal force towards the equator. He
believed that Pangaea originated near the South Pole and
that the centrifugal force of the planet caused the protoconti
nent to break apart and the resultant continents to drift
towards the equator. He called this the "pole-fleeing force".
Evidence of Plate Tectonics:
Fit of the Continents
How the Idea started:
Close examination of a globe often results in the observation that most of the continents
seem to fit together like a puzzle: the west African coastline seems to snuggle nicely into
the east coast of South America and the Caribbean sea; and a similar fit appears across
t he Pacific. The fit is even more striking when the submerged continental shelves are
compared rather than the coastlines. In 1912 Alfred Wegener (1880-1930) noticed the
same thing and proposed that the continents were once compressed into a single protocon
tinent which he called Pangaea (meaning "all lands"), and over time they have drifted
apart into their current distribution. He believed that Pangaea was intact until the late
Carboniferous period, about 300 million years ago, when it began to break up and drift
apart. However, Wegener's hypothesis lacked a geological mechanism to explain how the
continents could drift across the earth’s surface as he proposed.
Evidence of Plate Tectonics:
Fit of the Continents
How the Idea started:
Carboniferous period (from about 360 million to
300 million years ago) were its dense and
swampy forests, which gave rise to large deposits
of
peat. Over the eons the peat transformed
into
rich coal stores in Western Europe and
North America.
Timeline of
Alfred Wegener’s
study
December
3, 1910
January
14, 1915
Alfred Wegener realizes
that continents fit together
Alfred Wegener publishes
a book
The concept of continental drift first came to me as
far back as 1910, when considering the map of the
world, under the direct impression produced by the
congruence of the coastlines on either side of the
Atlantic. At first I did not pay attention to the idea
because I regarded it as improbable. In 1911, I
came quite accidentally upon a report in which I
learned of paleontological evidence for a former
land bridge between Brazil and Africa.
In 1915, Alfred Wegener (1880–1930)
published hypothesis of continental
drift in his book ,The Origin of the
Continents and Oceans. He was not
the first to observe that certain
continental coastlines fit together like
pieces of a puzzle.
Evidence of Plate Tectonics:
Fit of the Continents
February
3, 1916
December
3, 1916
Scientists reject Wegener’s
hypothesis
Wegener proposes his
Continental-Drift hypothesis
Most scientists found serious flaws in Wegener’s
hypothesis, and many dismissed it outright. One
major weakness was that Wegener failed to
provide a mechanism, or an explanation for how
the continents moved. Still, some scientists thought
that the continental-drift hypothesis could be very
important and needed to be explored further.
These passages represent some of the discussion
scientists had about Wegener’s hypothesis.
Alfred Wegener proposed a
theory that the continents
had once been joined, and
over time had drifted apart.
This was the Continental
Drift Theory.
Evidence of Plate Tectonics:
Fit of the Continents
December 1916December1950
Following the initial controver
sy over Wegener’s continental
-drift hypothesis, there was lit
tle written about it for several
decades.
December
1959
Scientists realize that the
plates did move
In 1959, a U.S. Navy officer and Princeton geology
professor named Harry Hess, who had used sonar
during World War II to map vast areas of the Pacific
bottom, wrote a paper explaining a process he
called seafloor spreading: molten rock seeps up
from the Earth’s interior through mid-ocean ridges
(undersea mountain chains), spreads out to create n
ew ocean floor, and then sinks back into the Earth’s
interior through oceanic trenches. This would end up
being the discovery that proved Wegener’s theory.
Evidence of Plate Tectonics:
Fit of the Continents
Evidence of Plate Tectonics:
Fit of the Continents
December
1960
Scientists accept Continental Drift theory
The advent of new and independent evidence suggestive of drift,
from paleomagnetic studies, resuscitated the idea in the late
fifties and sixties, and subsequently the post-war investment in
marine geology and geophysics paid off in the form of providing
compelling evidence for seafloor spreading and hence continental
drift. By the late 1960s the vast majority of geologists and geophy
sicists were convinced that continental drift was a reality.
Alfred Wegener’s
Discoveries
Evidence of Plate Tectonics:
Fit of the Continents
In 1910, Wegener noticed the match
ing coastlines of the Atlantic contine
nts -- they looked on maps like they
had once been fit together. He was
not the first to notice this, but it
was an idea that would never leave
his thoughts.
Evidence of Plate Tectonics:
Fit of the Continents
Wegener noticed the similarity in the coas
tlines of eastern South America and west
ern Africa and speculated that those land
s had once formed a supercontinent, Pan
gaea, which had split and slowly moved
many miles apart over geologic time. He
also pointed to closely related fossil orga
nisms and similar rock strata that occurre
d on widely separated continents.
Evidence of Plate Tectonics:
Fit of the Continents
Alfred Wegener collected diverse pieces of evidence to support his theory,
including geological “fit” and fossil evidence. It is important to know that
the following specific fossil evidence was not brought up by Wegener to sup
port his theory. Wegener himself did not collect the fossils but he called att
ention to the idea of using these scientific documents stating there were fos
sils of species present in separate continents in order to support his claim.
Newly discovered exploration techniques were employed to prove this
theory and ultimately, the correctness of Wegener's chief idea as well.
Fit of the
Continents
Fit of the continents around the Atlantic
The best fit is found to be at the 500 fm contour which
lies on the steep part of the continental edge . The root
- mean - square errors for fitting Africa to South
America , Greenland to Europe and North America to
Greenland and Europe are 30 to 90 km . These fits are
thought not to be due to chance , though no reliable
statistical criteria are available . The fit of the block
assembled from South America and Africa to that form
ed from Europe , North America and Greenland is much
poorer . The root - mean - square misfit is about 130
km .
(source: Edward Bullard, J. E. Everett and A. Gilbert Smith)
Fit of the continents around the Atlantic
Fit of the continents around the Atlantic
Periods or Timeline of the Evolution:
Permian, Triassic, Jurassic, Cretaceous, Present Day
The Continental Drift Theory is defined as the movement
of the Earth’s continents relative to each other, thereby
appearing to drift together across the oceanic bed. This
theory states that the world was once made up of one big
supercontinent called the Pangaea, around 250 million
years ago (Permian Period). Then in the Triassic period
(200 million years ago), Pangaea fragmented, and parts
started to move away from each other. 145 million years
ago (Jurassic period), Pangaea split into two major
continents: Laurasia and Gondwana or Gondwanaland.
Fit of the continents around the Atlantic
Cretaceous period (65 million years ago
) - During this period, oceans formed
as land shifted and broke out of one big
supercontinent into smaller ones.
Continents were on the move in the
Cretaceous, busy remodeling the shape
and tone of life on Earth.
(Source: https://www.nationalgeographic.com/science/article/cretaceous)
Fit of the continents around the Atlantic
Fit of the continents around the Atlantic
The Eastern South
American
and
West
African
coastlines
show
the best jigsaw fit
among the continent
s. The best fit of the
coastlines show if
they matched at a
depth of 1,000.
Ever since the question about the
mechanism for the moving of the
continents was answered by the
Plate Tectonic Theory, the fit of the
continents made more sense to the
Continental Drift Theory. Disregardi
ng the current sea level, you can
really see how the coastlines of
some continents fit perfectly
together. South America and Africa
are the greatest example for this,
although there are more coastline
that fits together.
Each continent has a
very
specific
and
unique shape that the
fitting of South America
and Africa’s coastlines wo
uld not make sense if
they were not once one
big single landmass.
Our verdict is accepted!
Alfred Wegener’s Continental Drift Theory
Thank you for
listening !
Group 1:
SHAIRA
LEYNE
PALAD
ALEXI
GREY
GALANG
FRANCHESKA
TULILIS
MIKAELA
MUNGCAL
PRINCESS
SHANEEN
PECSON
10- OLAS
MARCO
KYLE
GUDA
Fit of the Continents
ERICKA
LANA
ESTANDIAN