1. 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 it’s original shape.
• In extreme stress, rock becomes so
deformed it may break.

2. 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.

3. 3 General Types of Folds
• Anticline:
Upcurve fold in which the oldest
layer is in the center of the of the
fold
ck
la ye r of ro
Oldest

4. 3 General Types of Folds
• Syncline:
is a down curved fold in which the youngest
layer is in the center
You
n ges
t lay
er o
f ro
ck

5. 3 General Types of Folds
• Monocline:
is a fold in which both limbs remain horizontal
or vertical.
Di
ffe
ren
tl
ay
er
s
re
m
ai
ni
ng
ve
rti
ca
l

6. 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

7. 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

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

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

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

11. 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.

12. 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.

13. Collision between Oceanic and
Oceanic Crust
• One plate usually submerges below the
other and may cause a volcano.
Mariana Island in the
North Pacific Ocean

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