Plate Tectonics

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Plate Tectonics
Court Monroe Chapter 17, pages 443 - 463
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Alfred Wegener, father of continental drift
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Wegener thought that the continents were once
connected. Continents fit into each
other Landforms, like mountains Fossils of
continents meshed in key areas People did not go
along with theory, because they could not figure
out what force would be strong enough to move a
continent. Continents would crack if pushed
through ocean Gravity would not make them go
downhill Spin of the Earth was not fast
enough Wegener died on expedition to
Greenland Probably died by falling into a
crevice When digging in Greenland, when you are
are deep as you are going to go, one yells
Ive found Wegener. Theory widely accepted in
early 1960s
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www.vulkaner.no/v/vulkinfo/ tomtech/etomtech.html
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http//pubs.usgs.gov/publications/graphics/Fig2-5g
lobes.gif
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www.astro.umn.edu/john/ Ast1001/earth/Earth.html
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oak.cats.ohiou.edu/.../ Diversification.htm
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www.ucmp.berkeley.edu/ tectonics/quakecenters.htm
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http//www.classzone.com/books/earth_science/terc/
content/visualizations/es0806/es0806page01.cfm?cha
pter_novisualization
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• When plates converge, one of three things can
  happen.
• A continental plate (granite) can collide with
  oceanic plate (basalt), and the more dense goes
  under (subducts).
• Fig 4.32

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• When plates converge, one of three things can
  happen.
• A continental plate (granite) can collide with
  continental plate (granite), and it crumples
  (mountains)
• Fig 4.33

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• When plates converge, one of three things can
  happen.
• An oceanic plate (basalt) can collide with an
  oceanic plate (basalt), and it make an island arc
  (Japan)
• Fig 4.28

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1. The ocean comes apart at ridges. Most of these
   are in the middle of oceans.
2. Fig 4.12

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1. We know that the plates come apart here (called
   Sea Floor Spreading), because of magnetic
   anomalies.
2. Fig. 4.14
3. Fig 4.16
4. Fig 4.18

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Plates can also slide past each other (transform).
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Break it down (Old School Style) Plates come
together at PLATE BOUNDARIES CONVERGENT (Where
they come together) a. Continent to continent
(mountains like Himalayas) b. Ocean to Ocean
(Island arcs like Japan, with TRENCH) c. Contine
nt to Ocean (Rockies and Andes, with TRENCH and
MOUNTAINS) DIVERGENT (Where they come
apart) a. RIDGE (small hump where lava comes
up) b. RIFT (where the canyon is between
plates) c. SEA FLOOR SPREADING (where Ridges
and Rifts are) d. NEWEST (land is born
here) TRANSVERSE (Where they slide past each
other) a. L.A. and San Francisco b. Crooked
sidewalks All of this is energy
driven a. Convection currents b. Heat from
birth of Earth, gravitational pressure,
radioactive decay
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What kind of plate boundary is this a
representation of?
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What kind of fault is THIS a representation of?
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Convergent zones can be Continent to continent
(mountains) Continent to Ocean (ocean trench, and
mountains) Ocean to Ocean (island arc Japan)
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This is oceanic vs. continental crust. Name a
place where this is happening.
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www.tki.org.nz/.../ what_on_earth/bumps2_e.php
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www.calstatela.edu/ faculty/acolvil/plates.html
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Excellent animations, on another
website. http//highered.mcgraw-hill.com/sites/00
72826967/student_view0/chapter4/animations_and_mov
ies.html
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