Transcript Mountain Building Forces and Faults

SC Indicator 8-3.7
Illustrate the creation and changing
of landforms that have occurred
through geologic processes (including
volcanic eruptions and mountainbuilding forces).
Mountain Building Forces and
Faults
Building Mountains
• Forces (stresses)
that cause rocks to
break or move are:
– Tension
– Compression
– Shearing
– These forces cause
the lithosphere to
bend and stretch
These stresses can be strong enough to
cause rocks to break
• This creates faults: a
fracture in Earth’s
lithosphere
• Blocks of rock move
past each other along
faults
• Earthquakes occur
along faults when these
rocks move
South Carolina Faults
Tension forces
• Tension: forces that
pull rocks apart
• Occurs at divergent
boundaries
• Tension stretches
rock
• Creates a normal fault
• If a normal fault
uplifts a large block of
rock, a fault-block
mountain forms
Normal Fault
Normal Faults
Fault-block mountains
Normal fault in
Death Valley, CA
Compression Forces
• Compression: forces
that push or squeeze
rocks together
• Occurs along
continental convergent
boundaries
• Rock folds or breaks
• Creates reverse faults
Compression can produce
mountain ranges
If pressure
is applied
slowly,
folded
mountains
form
Appalachian Mtns.
Himalayan Mtns.
Rocky
Mtns. Of
Wyoming
Shearing Forces
• Shearing: forces that
cause rocks on either
side of faults to push
in opposite directions
• Causes rock to break
and split apart
• Creates strike-slip
faults
Plate Boundaries
Movements form
Movements form
Movements form
Do Now: Tuesday 3/23
Read pgs. 221-225 in
textbook and answer the
following questions (copy
down the questions):
1. What is a fault?
2. Where are most faults
located?
3. Explain how earthquakes
occur.
4. Where do most
earthquakes occur?
5. What are the three types
of faults?
6. What type of stress
produces a reverse fault?
Do Now Thursday 2/19
On light-blue side of PACT workbook:
Read pgs. 73-74 and answer the following questions:
1.
2.
3.
4.
5.
6.
What type of stress will create a normal fault?
How do normal faults form?
What three landform features are formed due
to tension forces?
What type of stress can create mountains,
reverse faults, and volcanoes?
What happens in order for volcanoes and
mountains to form along a coastline?
Why are there so many earthquakes along the
San Andreas Fault?
Do Now Thursday March 25
1. Where converging continental plates meet, earthquakes
often occur. What type of stress is placed on the rocks
along converging continental plate boundaries?
A. Normal
B. Compression
C. Tension
D. Shearing
2. The primary cause of continental drift, earthquakes,
and volcanic eruptions is
A. convection currents beneath Earth's crust.
B. the rotation of Earth on its axis.
C. the gradual sinking of Earth's crust.
D. heat form the Sun warming Earth.
Do Now – Friday Feb 20
In PACT workbook
(dark blue side)
Complete pg. 83
#48-51
Do Now – Monday March 29
In PACT workbook
(dark blue side)
Complete pg. 45
#1-4
Diagram the Faults
• Draw a diagram for
each of the three
types of faults.
Include:
– Arrows showing block
movement
– Label the type of plate
boundary, stress, and
fault
• Use the diagrams on
pgs. 224-225 to help
you create your own
illustrations