AUFC+2.1

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2.1 Earths Crust in Motion
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Vocabulary
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 * Earthquake**: shaking and trembling that results from the movement of rock beneath the Earth's surface
 * Stress**: a force that acts on a rock to change its shape or volume
 * Shearing**: stress that pushes a mass of rock in 2 opposite directions
 * Tension**: pulls on crust which stretches rock so that it becomes thinner in the middle
 * Compression**: squeezes rock until it folds or breaks
 * Deformation**: any change in the volume or shape of the Earth's crust
 * Strike-slip fault**: rocks on either side of fault slip past each other sideways with little up and down motions
 * Normal fault**: a fault that is at an angle so one part of the rock lies on top of the fault and the other part of the rock lies below the fault
 * Hanging wall**: the half of the fault lies above the footwall
 * Footwall**: the half of the fault that lies below the hanging wall
 * Reverse fault**: same structure as normal fault but the blocks go in the opposite direction
 * Fault-block mountain**: when normal faults uplift a block of rock a fault-black mountain forms
 * Folds**: bends in rock that forms when compression shortens and thickens the part of Earth's crust
 * Anticline**: a fold in rock that bends upward into an arch
 * Syncline**: a fold in rock that bends downward in the middle to form a bowl
 * Plateau**: a large area of flat land elevated high above sea level

Stress in the Crust

 * stress is what causes rock to change

Types of Stress

 * deformation
 * any change in the volume or shape of the earth's surface
 * shearing
 * can cause rock to break apart or to change shape
 * tension
 * stretches the rock so it's thinner in the middle
 * compression
 * pushes rock together until they compress

Kinds of Faults

 * strike-slip faults
 * the San Andreas fault
 * reverse faults
 * Mount Gould
 * started to form 60 million years ago
 * normal faults
 * the Sandia Mountains

Friction Along Faults

 * friction
 * the force that creates resistance when two things past each other
 * when the friction is high, the rocks won't budge
 * stress can overpower friction
 * when this happens small earthquakes occur

Mountain Building

 * Mountains formed by faulting
 * fault-block mountains form
 * Sierra Nevada, California

Mountains formed by folding

 * folds in the Earth's crust can form mountains
 * two plates collide together which folds the crust
 * Himalayas in Asia
 * Alps in Europe

Anticlines and Synclines

 * anticline
 * the Black Hills of South Dakota
 * syncline
 * the Illinois Basin

Plateaus

 * the Colorado Plateau

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