I) Where Mountains FormA)Mountain Belts

1) Most Mountains are associated with convergent plate boundaries

2) Most mountains occur in long belts that follow convergent boundaries

3) Himalayas lie along a current convergent boundary

4) Appalachians are in the middle of a plate – but were formed by converging plates over a billion years ago.

B) Continental Margins (land and sea meet)

1) Active Margins

a) occur along plate boundaries

b) mountain building takes place

c) Himalayan Mountains

2) Passive Margins

a) stable areas away from plate

boundaries

b) Appalachian Mountains

c) Passive margins provide the materials or

sediments from which mountains form.

Active

Passive

IV) Mountain Building

A)Major mountain systems are related to plate tectonics. Most mountains form along convergent boundaries

Where else wouldyou find mountains?Divergent BoundariesHot Spots

V) Mountain Facts

A) Himalayan Mountains

1) The largest/highest mountain range

B) Mid-Atlantic Ridge

1) The longest mountain range

Factors that affect mountain Deformation

• Deformation – all changes that occur to a body of rock.

1. Temperature2. Pressure3. Rock Type4. Time exposed to pressure or heat

Tectonic Forces

Mountains are the result of rock that is permanently deformed by stress/forces

• Three types of forces cause three types of faults:

• Tension• Compression• Shear

1) Break in crustal rock with movement

Normal Faults(Dip-slip fault)

• Caused by TENSION forces• Occur along divergent plate boundaries• Rock ABOVE fault surface moves

DOWNWARD

Reverse Faults (Dip-slip fault)

• Caused by COMPRESSION forces• Occur along convergent plate boundaries• Hanging wall surface moves UPWARD

Strike-Slip Faults

• Caused by SHEAR forces• Occur along transform plate boundaries• Rocks on either side of fault line move

past each other with NO vertical movement.

Horsts & Grabens

• Large blocks of crust that rise due faulting on either side of the block.

Name this fault!

III) Types of Mountains

A)Mountains are classified according to their dominant featuresB) Four main categories

1) Volcanic mountains (Mt. Shasta)

Volcanic Mountains• Formed by lava and pyroclastic material that

build up.

2) Folded mountainsa) Largest mountains on Earthb) Urals, Himalayas, Appalachians

Folded Mountains

• Mountains that form from folding processes (compression)

A) Folds

1) Rock is bent into a series of waves2) Results from compressional force3) Two common types of folds

a) Anticline – upward fold of rockb) Syncline – downward fold of rock

Anticline

Synclines

Video syncline

3) Fault-block mountains a) Upliftedb) Sierra Nevada Mountains

Fault-block mountains

a) Tilted b) Teton Range, WY

• http://www.as.uky.edu/academics/departments_programs/EarthEnvironmentalSciences/EarthEnvironmentalSciences/Educational%20Materials/Documents/elearning/module10swf.swf

4) Dome Mountains

a) Individual, isolated structures that form in layers of sedimentary rock.

b) There are two types of dome mountains:

Plutonic Dome

• an igneous intrusion pushes up existing rock layers.

Tectonic Dome

Tectonic Dome:

Black Hills of South Dakota (Mt. Rushmore)

Yosemite National Park

• uplifting forces arch rock layers into a dome

Normal Reverse Strike-Slip

Type of Force

Name of Boundary

Type of Mountains

Direction it is moving