Download - Plate Tectonics
![Page 1: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/1.jpg)
Plate TectonicsLiz LaRosa for use with my 5th Grade Science Class
http://www.middleschoolscience.com 2009
![Page 2: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/2.jpg)
Earth’s LayersThe Earth's rocky outer crust solidified billions of years ago, soon after the Earth formed.
This crust is not a solid shell; it is broken up into huge, thick plates that drift atop the soft, underlying mantle.
![Page 3: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/3.jpg)
The Crust
• Outermost layer• 5 – 100 km thick• Made of Oxygen, Silicon, Aluminum
![Page 4: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/4.jpg)
The Mantle• Layer of Earth between
the crust and the core• Contains most of the
Earth’s mass• Has more magnesium
and less aluminum and silicon than the crust
• Is denser than the crust
![Page 5: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/5.jpg)
The Core• Below the mantle
and to the center of the Earth
• Believed to be mostly Iron, smaller amounts of Nickel, almost no Oxygen, Silicon, Aluminum, or Magnesium
earth's layers
![Page 6: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/6.jpg)
Tectonic Plates
![Page 7: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/7.jpg)
Plate Tectonics
• Greek – “tektonikos” of a builder• Pieces of the lithosphere that move around• Each plate has a name• Fit together like jigsaw puzzles• Float on top of mantle similar to ice cubes
in a bowl of water
plate tectonics
![Page 8: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/8.jpg)
Continental Drift
http://members.enchantedlearning.com/subjects/astronomy/planets/earth/Continents.shtml
Alfred Wegener 1900’sContinents were once a single land mass that drifted apart.
Fossils of the same plants and animals are found on different continents
Called this supercontinent Pangea, Greek for “all Earth”
245 Million years ago
Split again – Laurasia & Gondwana 180 million years ago
continental drift
![Page 9: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/9.jpg)
Evidence of Pangea
![Page 10: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/10.jpg)
Sea Floor Spreading
![Page 11: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/11.jpg)
Sea Floor Spreading
• Mid Ocean Ridges – underwater mountain chains that run through the Earth’s Basins
• Magma rises to the surface and solidifies and new crust forms
• Older Crust is pushedfarther away from the ridge
sea floor spreading
![Page 12: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/12.jpg)
How Plates Move
http://pubs.usgs.gov/gip/dynamic/unanswered.html
![Page 13: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/13.jpg)
Different Types of Boundaries
http://pubs.usgs.gov/gip/dynamic/understanding.html
plate boundaries
![Page 14: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/14.jpg)
Divergent Boundary
• Plates move apart• Constructive plate boundaries – where new
oceanic lithosphere is created• Forms oceanic ridges in oceans• Forms rift vallies in continents
![Page 15: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/15.jpg)
Divergent Boundary – Arabian and African Plates
Arabian Plate
African PlateRed Sea
![Page 16: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/16.jpg)
Divergent Boundary – Iceland
http://pubs.usgs.gov/gip/dynamic/understanding.html
![Page 19: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/19.jpg)
Convergent boundary
• Destructive plate margins• Leading edge of one plate is bend downward
and slides beneath the other• subduction zones are where one oceanic plate
slides beneath a second plate
![Page 20: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/20.jpg)
Convergent Boundary – Indian and Eurasian Plates
Indian Plate
Eurasian Plate
![Page 21: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/21.jpg)
Convergent Boundary – Oceanic & Continental
http://pubs.usgs.gov/gip/dynamic/understanding.html & http://www.geology.com
Oceanic plate is more dense and sinks below the continental plate which is less dense and floats on top.
Denser oceanic plate sinks to asthenosphere and begins to melt.
Magma is less dense than surrounding rock and rises, sometimes causing volcanic eruptions.
![Page 22: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/22.jpg)
Convergent Boundaries - Continental
http://pubs.usgs.gov/gip/dynamic/understanding.html & http://www.geology.com
Continental lithosphere is buoyant and doesn’t sink to great depth.
Complex mountain ranges are formed.
Appalachian, Alps, Himalayas, and other mountain ranges were formed this way.
![Page 23: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/23.jpg)
Convergent plates - oceanic
• One plate sinks beneath the other causing volcanic activity similar to oceanic – continental plate margins
• Volcanic island arcs are newly formed land masses forming arc shaped volcanic islands.
![Page 24: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/24.jpg)
Transform boundary
• Plates grind past each other without destroying the lithosphere
• Most are located within ocean basins.• A few, like the San Andres Fault, cut through
continental crust
![Page 26: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/26.jpg)
Slab Pull• Slab pull- old oceanic crust, which is cool and
dense, has sunk under another plate into the asthenosphere which pulls the trailing lithosphere along.
![Page 27: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/27.jpg)
Ridge Push
• Ridge push- results from elevated oceanic ridge system and causes oceanic lithosphere to slide down the sides of oceanic ridge.
![Page 28: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/28.jpg)
Convection• Hot plumes of rock are flowing upward in
mantle convection.• Hot plumes sometimes show themselves on
earth’s surface as hot spots and volcanoes.
![Page 29: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/29.jpg)
Review
• Name the 3 main layers of the Earth• What is a tectonic plate?• What was Pangea?• What is Sea-Floor spreading?• Name the three different types of plate
boundaries and one location on Earth for each one
![Page 30: Plate Tectonics](https://reader035.vdocuments.us/reader035/viewer/2022081604/5681654d550346895dd7c73a/html5/thumbnails/30.jpg)
Resources
• This powerpoint was adopted from middleschoolscience.com by Ms. Glass on 9/07/12
• Video clips were found on youtube and incorporated