Mountain building ppt nc 13Presentation Transcript
Mrs. Z’s Mountain Building notes ONLY!
Rock Deformation AKA – Mountain
• Deformation - the bending, breaking, and
tilting of the earth’s crust.
• Three types of Stress:
FOLDING - flat layers of rock are
under severe compression and are
squeezed from the sides. The
layers moved into folded positions
without breaking (although some
cracks may appear).
Three types of Folds:
1. Anticlines - upward folds
2. Synclines – downward
3. Monoclines – gently
dipping bends in
horizontal rock layershttp://www.cr.nps.gov/history/online_books/geology/publications/bul/1508/images/fig27.jpg
Features formed by tectonic activity
1. Faults - A break in the
rock layers along
which there is no
movement is called a
occurs, the fracture is
known as a fault.
Three Main Types of
2. Reverse Fault
• occurs along convergent boundaries (compression force)
• The hanging wall moves up above the foot wall
o reverse fault where the hanging wall is pushed at
such a low angle (not steep) that it moves UP AND
OVER the foot wall
3. Strike-Slip Fault
• occurs at transform boundaries
• The rocks along either side of the fault
Ex. San Andreas Fault
North Carolina Fault System
Four Types of Mountains
1. Folded Mountains - Found where continents have
collided. Ex. Appalachian Mts., Himalayan Mts.
• Plateaus - areas of flat-topped land high above
sea level. Ex. Colorado Plateau (Grand Canyon)
2. Fault-Block Mountains - Formed by faults, where
part of the earth’s crust have been broken into large
blocks and then were lifted above the surrounding
crust. Ex. Grand Teton, MT
3. Volcanic Mountains - Form when molten rock erupts
onto earth’s surface.
Ex. Cascade Mts. in Pacific NW and
the mid-Ocean ridges
4. Dome Mountains - An unusual type that is formed when
molten rock rises but does not break through the surface.
Ex. Adirondacks, NY