LEQ: How do stress forces in Earth

1
LEQ How do stress forces in Earths crust form
mountains and what kinds of mountains are formed
from the stress?

• Key Terms
• fault block mountain,
• upwarped mountain,
• folds, folded mountain,
• anticline,
• syncline

2
Mountain Building

• Please turn to page 106 in your textbook.
• Stress forces produced by plate movement can
  build up mountains on Earths surface.
• The process occurs over millions of years
• The types of mountains formed from stress forces
  are
• Fault Block Mountains
• Upwarped Mountains
• Folded Mountains

3
Mountains formed by Faulting

• When movement along faults moves blocks of rock
  up or down.
• Caused by dip slip faults.
• Uplift occurs over millions of years
• Types of mountains formed
• Fault block mountains.
• Upwarped mountains.

4
Fault Block Mountains

• When normal faults uplift a block of rock.
• Caused by the stress force of tension.
• View some images of fault block mountains at this
  link.

5
Upwarped Mountains

• When reverse or thrust faults uplift a block of
  rock.
• Caused by the stress force of compression.
• View some images of upwarped mountains at this
  link.

6
Mountains formed from folding

• Under certain conditions, the stress force built
  up by plate movement does not break the rock, but
  causes the crust to fold.
• Caused by compression.
• Folds
• A bend in the rock that forms where part of
  Earths crust is compressed.
• Folds vary in size from a few centimeters across
  to hundreds of kilometers wide.

7
Types of Folds

• Observe figure 4 on page 107 and the sketch on
  the side board.
• Two types of folds
• Anticline
• An upward fold in the rock layers
• Syncline
• A downward fold in the rock layers.
• View some images of folded mountains at this
  link.

8
How are mountains formed?

• Open the link below and view the teacher tube
  video on How Mountains are Formed.
• How are Mountains Formed?

9
Mountains formed by Stress Graphic Organizer
10
Mountain Building

• Mountain Building Streaming Video
• After reviewing this power point, complete you
  Folding and Faulting notes Sheet (including the
  back).