1. The Results of Stress...
Mr. Silva
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2. Objective
• Students will be able to identify and describe
two types of rock deformation and explain
the difference between them.
• Students will be able to demonstrate three
types of faults by acting them out using their
backpack.

3. The Results of Stress
• High pressure and temperatures caused by
stress in the crust generally deform rocks.
• When stress is applied slowly, the deformed
rock will return to its original shape.
• In extreme stress, rock becomes so
deformed it may bend, tilt or break.

4. Folding
• When rocks respond to stress by becoming
permanently deformed without breaking it is
called folding.
– Folds vary in size
– There are 3 general types of folds.

5. 3 General Types of Folds
• Anticline:
Upfolding or arching in which the
oldest layer is in the center of the of
the fold
k
yer of roc
Oldest la

6. Anticline
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7. 3 General Types of Folds
• Syncline:
is a linear downfold in which the youngest layer is
in the center
You
n ges
t laye
r of
rock

8. Syncline
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9. 3 General Types of Folds
• Monocline:
is a step-like fold in which both limbs remain
horizontal or vertical.
Di
ffe
re
nt
la
y er
s
re
m
ai
ni
ng
ve
r tic
a l

10. Monocline
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11. Faulting
• When rocks break due to stress instead of
fold.
– Joint: no movement in the rocks along either
side of a break.
– Fault: when rocks do move
– Fault plane: surface of a fault where any motion
occurs
– Hanging wall: rock above the fault plane of a
nonvertical fault
– Footwall: rock below the fault plane of a
nonvertical fault

12. 3 Types of faults
• Normal fault: hanging wall moves down
relative to the footwall along divergent
boundary
• Reverse fault: compression causes the
hanging wall to move up relative to the
footwall
• Thrust fault: fault plane is a low angle or
nearly horizontal & hanging wall is pushed
up over rock
• Strike-slip fault: rock on either side of the
fault plane slides horizontally at transform
boundaries

13. Mountain Formation
• Mountain Range: a group of adjacent
mountains with the same general shape and
structure.
Mount Everest
Himalaya Mountains

14. Mountain Formation
• Mountain System: a group of adjacent
mountain ranges.
Great Smoky Mountains
Green Mountains
Appalachian Mountains

15. Mountain Formation
• Mountain Belts: the largest mountain system
are part of two still larger systems.
Circum-Pacific
mountain belt
Eurasian- Melanesian
mountain belt

16. Plate Tectonics and Mountains
• Both circum-Pacific mountain belt and the
Eurasian- Melanesian mountain belt are
located along convergent plate boundaries.
• Evidence that most mountains are
formed from plate collisions.
• Ding Ding: Convergent
Plate
Boundaries build mountains!!!

17. Collision between Continental and
Oceanic Crust
• What do we know happens when continental
and oceanic crust collide?
• What do we know happens when crust
overlap each other? What can happen?
• This will cause
large scale deformation.
Continental
Volcanic Arcs!!!

18. Collision between Continental and
Oceanic Crust

19. Collision between Oceanic and Oceanic
Crust
• One plate usually submerges below the
other and will cause a volcanic island arc.
Mariana Island in the
North Pacific Ocean

20. Collision between Oceanic and Oceanic
Crust

21. Collisions Between Continents
• Mountains can also form when two
continents collide.

22. Collisions Between Continents

23. Review
• What is folding? What type of deformation?
Rock deformed without breaking...Ductile
• Name three folds...
Anticline, Syncline, Monocline
• What is faulting? What type of deformation?
Rock deformed by breaking...Brittle
• Name four faults...
Normal, Reverse, thrust, and Strike-Slip
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24. Review
• What boundary are most mountains formed?
Convergent Plate Boundaries
• What boundary do strike-slip faults occur?
Transform Fault Boundaries
• What convergent plate boundary are the
tallest mountains formed?
Continental-Continental
Convergent Plate Boundaries
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