20.2 - Orogeny

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20.2 - Orogeny

• These notes are not used to replace the book.
  For more detail, go to chapter 20.2 in your book.

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Orogeny

• All processes that form mountain ranges
• oro- mountain
• -geny production

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Orogenic Belts

• Linear regions of deformation that we know as
  mountain ranges
• Occur at convergent boundaries
• Figure 20.7, page 567

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Compressive Forces

• Squeezing force that can cause intense deformation

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Oceanic-Oceanic Convergence

• When 2 oceanic plates collide it creates a
  subduction zone
• One plate is forced under the other and it melts,
  causing magma to rise, forming series of volanic
  peaks
• Ex Aleutian Islands
• Figure 20.8, page 568

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Aleutian Islands
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Oceanic-Continental Convergence

• Creates subduction zones and trenches
• Produces mountain belts that are bigger and more
  complicated
• Descending oceanic plate forces continental plate
  upward
• Continental crust gets thicker to form higher
  mountains
• Figure 20.9
• Page 569

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Continental-Continental Convergence

• Neither plate is subducted
• Plates fold, fault, and thicken
• Doubles thickness of crust
• Figure 20.10
• Page 570

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Appalachian Mountains

• Check out figure 20.13
• Page 572