2. Alfred Lothar Wegener
A German polar researcher, geophysicist,
and meteorologist.
Developed a theory to explain his
observation that at one time all the
continents were a part of one large
landmass called PANGAEA.
Suggested that the parts of Pangaea
drifted to their present position. He called
his idea as the CONTINENTAL DRIFT
THEORY.
6. Fossil Evidence
Fossil – are the remains or traces of plant or
animal life, usually preserved in rocks and
sedimentary.
7. Fossil evidence
Same Fossils different continents
Plant fossils in polar region
Coal deposits in polar region
8. Mesosaurus
is known to have been a type of
reptile, similar to the modern
crocodile, which propelled itself
through the water with its long
hind legs and limber tail.
Permian period (286 to 258 million
years ago),
9.
10. Cynognathus
was a mammal-like reptile as
large as a modern wolf.
Triassic period (250 to 240 million
years ago)
18. Seafloor Spreading and Magnetic Reversal
The idea of continental drift circulated in
scientific circles until World War II, when
sounding gear called SONAR produced new
evidence of what the seafloor looked like. The
gear, developed in the 1930s, bounced sound
waves off the seafloor to determine its depth and
features.
19.
20. The command of a attack
transport ship, the USS
Cape Johnson, was given
to Harry Hammond Hess,
a geologist from
Princeton university.
21. Seafloor Spreading
“Hot less dense material from below the
earth’s crust rises towards the surface at the
mid-ocean ridge.”
26. The Mid-Ocean Ridge system, shown above snaking its way between the continents, is more
than 56,000 kilometers (35,000 mi) long. It circles the earth like the stitching on a baseball!
28. Seafloor Spreading and Magnetic Reversal
The idea of continental drift circulated in
scientific circles until World War II, when
sounding gear called SONAR produced new
evidence of what the seafloor looked like. The
gear, developed in the 1930s, bounced sound
waves off the seafloor to determine its depth and
features.
Editor's Notes
At first. Many scientist did not accept Wegener’s theory of continental drift. They do not understand how the continents could have moved. In fact, it took more than 50 years and some very important discoveries before Wegener’s theory was finally accepted by most scientists.
When Alfred Wegener noticed that the edges of South America and Africa in a World Map could be fitted like a jigsaw puzzle his curiosity about the idea of drifted continents started.
It lived during the early Permian period (286 to 258 million years ago), and its remains are found solely in South Africa and Eastern South America.
Its fossils are found only in South Africa and South America. As a dominant land species,
Lystrosaurus fossils are only found in Antarctica, India, and South Africa.
Lystrosaurus fossils are only found in Antarctica, India, and South Africa.
SONAR - sound navigation and ranging
The place where two plates move apart or diverge is called a divergent boundary.
This is a model of sea floor spreading at a divergent boundary called a mid ocean ridge.