continental drift theory
TRANSCRIPT
![Page 1: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/1.jpg)
Continental drift theory
![Page 2: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/2.jpg)
According to the hypothesis of continental drift, continents have moved slowly to their current locations.Theory of continental was purposed by alfered wegner in (1912)
![Page 3: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/3.jpg)
![Page 4: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/4.jpg)
Mechanism for Plate Tectonics
Seafloor Spreading provided insight to the mechanism for how the continents moved. The magma which pushes up at the mid-ocean ridge provides the new land pushing the plates, and the subduction zones gobble up the land on the other side of the plates.
The mechanism was convection currents!
![Page 5: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/5.jpg)
Thirteen plate on the world
![Page 6: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/6.jpg)
About 225 million years ago , nearly all the land was united in one large land callled
Pangaea
![Page 7: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/7.jpg)
Pangaea about 200 million years ago, before it began breaking up. The southern portion of Pangaea Gondwana, and the northern portion Laurasia.
![Page 8: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/8.jpg)
The continents about 70 million years ago. Notice that the breakup of Pangaea formed the Atlantic Ocean. India’s eventual collision with Eurasia would form the Himalayan Mountains
![Page 9: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/9.jpg)
![Page 10: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/10.jpg)
The position of the continents today. The continents are still slowly moving, at about the speed your fingernails grow. Satellite measurements have confirmed that every year the Atlantic Ocean gets a few inches wider!
![Page 11: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/11.jpg)
![Page 12: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/12.jpg)
![Page 13: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/13.jpg)
Sea flour spreadingAs the seafloor spreads apart at a mid-ocean ridge, new seafloor is created.
![Page 14: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/14.jpg)
![Page 15: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/15.jpg)
Plate tectonic explainEarthquakes Mountains
volcanoes
![Page 16: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/16.jpg)
Earthquakes and volcanoes occur mostly along or near trenches and mid-ocean ridges...
![Page 17: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/17.jpg)
Mountain formation
![Page 18: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/18.jpg)
Volcanoes
![Page 19: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/19.jpg)
![Page 20: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/20.jpg)
Thawa earthequake ekkak danna
![Page 21: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/21.jpg)
Evidence to support the theory
![Page 22: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/22.jpg)
Continental drift fossil evidence
![Page 23: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/23.jpg)
“Puzzle Pieces”
Continents look like they could be part of a giant jigsaw puzzle
![Page 24: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/24.jpg)
Distribution of fossils of several organisms supported The theory that the continents were once joined together
![Page 25: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/25.jpg)
Francis Bacon (1561-1626) first noted how coasts of Africa and South America fit.
![Page 26: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/26.jpg)
Mesosaurus, a fresh water reptile that couldn’t swim across the open sea
![Page 27: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/27.jpg)
Sequence of RocksSame rock patterns found in South America, India, Africa, Antarctica and Australia
![Page 28: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/28.jpg)
Mountains in South America and Antarctica are believed to have formed as part of the same mountain chain.
![Page 29: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/29.jpg)
Ancient ClimatesTropical plant remains (coal deposits) found in AntarcticaGlaciations in Africa, South America, India, and Australia during the same time
![Page 30: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/30.jpg)
Coal
Deposits found in Antarctica.
Coal requires a warm, lush climate
===>
What’s Antarctica like today? ===>
![Page 31: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/31.jpg)
Glossopteris, a seed fern whose seeds
are too large to be carried far by wind
![Page 32: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/32.jpg)
Fossils of Glossopteris are found in Permian rocks of South Africa, India, Australia, South America, and Antarctica—all regions that were once part of Gondwanaland.
![Page 33: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/33.jpg)
Problems With The Theory
•No mechanism for movement of continents
•Wind and currents could possibly move fossils
•Theory was not accepted by scientists
![Page 34: Continental drift theory](https://reader033.vdocument.in/reader033/viewer/2022052223/55776143d8b42a472c8b48e7/html5/thumbnails/34.jpg)