Deforming the Earth’s Crust

Deformation• Deformation: process by which a rock changes

shape due to _______stress

Stress

• causes ________ and _________1. Compression: type of stress that occurs when

an object is _______________– Occurs at ____________ plate boundaries

2. ________: type of stress that occurs when rock is stretched/pulled– Occurs at __________ plate boundaries

folding faulting

squeezed/pushedconvergent

Tension

divergent

Stress

3. Shear: type of stress that occurs when objects slide past each other (rubbing)–Occurs at ___________ plate boundariestransform

Folding

• Folding: the ________of rock layers due to stress

1. __________: upward arching fold2. Syncline: __________ trough like fold3. Monocline: both ends of fold are __________

bending

Anticline

downward

horizontal

1. ______________________ 2. _____________________

3. _______________________

1. Syncline 2. Anticline

3. Monocline

Faulting

• Fault: a ________in a body of rock along which one _____slides relative to the other

• _____________ are common along fault lines• In non-vertical faults, the fault is at an ______,

which creates a _____________and ________

breakblock

Earthquakes

anglehanging wall footwall

1. Normal Fault: the hanging wall moves _______compared to the footwall– _________stress occurs

2. __________ Fault: the hanging wall moves up compared to the footwall– _______________stress occurs

down

Tension

Reverse

Compression

Normal and Reverse Faults

A. ____________________________ B.___________________________

Normal and Reverse Faults

A. Normal Fault B. Reverse Fault

3. Strike-Slip Fault: the break in the rock is _______, but the rocks move __________– Example: ______________Fault in California– Shear stress– NOTE: This type of fault does NOT create a footwall or

hanging wall because the break in the rock is not at an angle

vertical horizontal

San Andreas

Birds-Eye View

San Andreas Fault

Picture Type of Fault Type of Stress Type of Boundary

Picture Type of Fault Type of Stress Type of Boundary

Reverse Fault

Strike Slip Fault

Normal Fault

Compression

Shear

Tension

Convergent

Transform

Divergent

Mountain Building

1. Folded Mountains: Formed at convergent plate boundaries

– Highest, Smooth – Ex: Appalachian, Andes, Alps, Himalayas

ALPS

APPALACHIAN MOUNTAINS

ANDES MOUNTAINS

HIMALAYAN MOUNTAINS

2. Fault-Block Mountains: Formed at divergent boundaries– Sharp, jagged peaks– At a fault, block of rocks drops down– Ex: Grand Tetons, Sierra Nevada

SIERRA NEVADA MOUNTAINS

GRAND TETON MOUNTAINS

3. Volcanic Mountains: Formed at convergent boundaries– Eruption and cooling of magma– Creates islands– Ex: Mt. Kea, Mt. Loa, Mt. St. Helens, Mt. Pinatubo

MT. MAUNA KEA

MT. MAUNA LOA

MT. PINATUBO

MT. ST. HELEN