plate tectonics. what is the theory of continental drift?
TRANSCRIPT
![Page 1: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/1.jpg)
Plate Tectonics
![Page 3: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/3.jpg)
What is the Theory of Continental Drift?• Alfred Wegner, 1915• The continents were once a super-
continent called Pangea• the continents are plowing through
the ocean floors---most people didn’t believe this
![Page 4: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/4.jpg)
What evidence supports this theory?
• Africa & South America look like they fit together
• similar fossils, rocks, and glacial striations
![Page 5: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/5.jpg)
What is the Theory of Plate Tectonics?
• Earth's crust is made up of plates that ride on top of the asthenosphere
• The plates move due to convection currents in the mantle
![Page 6: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/6.jpg)
What evidence supports this theory?
• distribution of earthquakes and volcanoes
• sea-floor spreading
![Page 7: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/7.jpg)
![Page 8: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/8.jpg)
![Page 9: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/9.jpg)
![Page 10: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/10.jpg)
How do oceanic and continental crust compare with regard to thickness and density?
continental oceanic
Density(ESRTspg 10)
thickness
![Page 11: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/11.jpg)
What are the primary rocks which make up the continental and oceanic crusts?
continental crust
oceanic crust
High density, dark-
colored, fine-grained,
mafic igneous rock
Low-density, light-
colored, coarse-
grained, felsic, igneous
rock
![Page 12: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/12.jpg)
What are these types of plate boundaries?
What are the key characteristics for each?
Give an example of where each can be found.
![Page 13: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/13.jpg)
![Page 14: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/14.jpg)
![Page 15: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/15.jpg)
![Page 16: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/16.jpg)
![Page 17: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/17.jpg)
What happens to the age of oceanic crust as distance increases from a ridge?
![Page 18: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/18.jpg)
![Page 19: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/19.jpg)
Explain how magnetic data can be used to show that oceanic crust is diverging at ridges. Use the diagram below to help explain your answer.
• as new crust is made at ridges, the ferrous minerals (Fe) align according to where the magnetic poles are located
• same pattern on opposite sides of the ridge
• proves sea-floor spreading
![Page 20: Plate Tectonics. What is the Theory of Continental Drift?](https://reader036.vdocuments.net/reader036/viewer/2022062511/551582b155034674578b55ff/html5/thumbnails/20.jpg)