Plate Tectonics Learning Goal: Comprehend plate tectonics and apply in lab.

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Plate TectonicsLearning GoalComprehend plate
tectonics and apply in lab.
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Convection currents
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• Continental drift idea that continents have
  moved slowly to their current positions due to
  convection currents in the mantle.
• Pangea the idea that the all land masses on
  earth were once a single large land mass.

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• Ocean floor spreading theory that hot less
  dense material below Earths crust rises toward
  the surface at the mid-ocean ridges. Then, it
  flows sideways, carrying the seafloor away from
  the ridge in both directions. http//geology.com/n
  sta/divergent-boundary-oceanic.gif
• Convection current unequal distribution of heat
  in the mantel causes a net movement in a circular
  motion.

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• The Earths CRUST is the outer most part of the
  Earths surface.
• Average 32 km thick (19.84 miles)
• Thickest point 70 km (in mountains)
• Thinnest point 8 km (under ocean)

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• Plate tectonic theory that Earths crust and
  part of the upper mantle are broken into sections
  called plates.
• Lithosphere all of the earths crust and part
  of the upper mantle.
• http//www.allaboutspace.com/subjects/astronomy/pl
  anets/earth/Inside.shtml
• Asthenosphere plastic like layer below the
  lithosphere. The ridged plates of the lithosphere
  float on the more plastic layer called the
  asthenosphere.

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• l

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• Deformation The breaking, tilting, and folding
  of crustal rock due to crustal movement. (three
  types of forces)
• Compression squeezing of earths crust that
  compacts the rock. Convergent boundary
• 2. Tension is the pulling apart of the earths
  crust. Divergent boundary.
• 3. Shearing pushes rocks side by side in
  opposite directions. Transform boundary.

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Convergent boundary
Divergent boundary
Transformation boundary
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Rift valley
subduction
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• FAULTS
• Normal Fault (Divergent Boundary) fault caused
  by tension stress that moves the hanging wall
  down relative to the foot wall.

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• Fault block mountain is a mountain created by
  blocks of rock uplifted by normal faults.

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Divergent boundary in Iceland
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• Reverse Fault (Convergent Boundary) fault
  caused by compression forces where the hanging
  wall will move up relative to the foot wall.

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In Lateral (strike-slip) faulting (Transform
Boundary), the two blocks move either to the left
or to the right relative to one another.
Strike-slip faults are associated with crustal
shear.
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San Andreas Fault, CA
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• Facts about folds/faults.
• increased temp. s fold
• decreased temp s fault
• increased pressure s fold
• decreased pressure s fault
• rock type brittle s fault
• rock type ductile s fold
• time greater the time s fold
• time less time s fault

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• Earthquakes
• Earthquake is the shaking and trembling that
  results from the sudden movement of part of the
  Earths crust.
• Tsunamis A giant sea wave produced by an
  earthquake.

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• Seismic Waves
• Focus The point beneath the Earths surface
  where the rocks break and move, the underground
  origin of the earthquake.
• Epicenter The point directly above the focus,
  on the earths surface where the origin of an
  earthquake is above ground.

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Faults- Once the elastic limit of rocks is
passed, they break and move along surfaces.

• 3 types of faults are
• Normal Fault- These form at divergent boundaries.
• Reverse Fault- These form at convergent
  boundaries.
• Strike-Slip Fault- These form at transform
  boundaries.

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• Seismic waves earthquake waves. Three types.
• 1. Primary waves (P-waves) - arrive at a given
  point before any other type of seismic wave. Will
  pass through solid, liquid and gas.(fastest of
  the three)
• 2. Secondary Waves (S-waves) arrive at a
  given point after the P wave. (second fastest)
  Will only travel thru solids. Will NOT pass
  through liquids and gases thus creating a shadow
  zone.

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• 3. Surface waves (L-waves) slowest
  moving seismic waves. Arrives last.

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• Volcanoes
• Volcano A mountain that forms when layers of
  lava and volcanic ash erupt and build up.
• Magma rock that exists as a hot liquid deep
  within the earth.
• Lava is magma that reaches the Earths surface.

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• Composite Volcanoes Violent eruptions due to
  high amount of silica (D.A.N, quartz, mica,
  feldspar) which is light in color and is
  explosive because of large amounts of gas, ash
  and lava.

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• Domes is the uprising area caused by magma

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• Shield volcano Volcanoes composed of quiet lava
  flows. The lava has a low amount of silicia
  (D.A.N, quartz, mica feldspar) and is dark in
  color. These volcanoes are nice with gently
  sloping sides with very wide base.