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**Vocabulary**

 * Earthquake** : A shaking that results in the movement of Earth's surface.
 * Shearing** : Stress that pushes a mass of rock in opposite directions.
 * Tension** :Stress that stretches rock so that it becomes thinner in the middle.
 * Compression** :Stress that squeezes rock together until it folds or breaks.
 * Deformation** :A change in the volume or shape of Earth's crust.
 * Fault** : A break in Earth's crust where slabs of rock slip past each other.
 * Strike-slip fault** : A fault where rocks on either side move past each other sideways with little up or down motion.
 * Normal fault** : A type of fault where the hanging wall slides down; caused by tension in the crust.
 * Hanging wall** : The slab of rock that forms the upper half of a fault.
 * Footwall** : The slab of rock that forms the lower half of a fault.
 * Reverse fault** : A fault where the hanging wall slides upward.
 * Fault-block mountain** : A mountain that forms where a normal fault uplifts a slab of rock.
 * Anticline** : An upward fold in rock formed by compression of Earth's crust.
 * Syncline** : A downward fold in rock formed by compression in Earth's crust.
 * Plateau** :A landform that has more or less level surface and is elevated high above sea level.
 * Folds** : A bend in rock that forms where part of Earth's crust is compressed.

Stress in the crust

 * The movement of Earth's plates are powerful forces that changes the rocks in the crust.
 * These forces are examples of stress.
 * Stress is a force, so it adds energy to the rock.
 * Energy is stored in the rock until it either breaks or changes shape.

Types of Stress

 * There are three kinds of stress: Shearing, tension, and compression
 * Shearing
 * Shearing can cause rock to become very brittle, and eventually snap.
 * Tension
 * Tension pulls on the crust, so it gets much thinner in the middle of the crust/rock.
 * Tension occurs when two plates are moving apart.
 * Compression
 * Compression squeezes rock until it folds or breaks.
 * Any change in the volume or the shape of the Earth's crust is called:Deformation..
 * Most changes occur very slowly.
 * They cannot be observed directly.
 * The slow shift of Earth's plates causes deformation.

Kinds of faults

 * There are three types of faults: Strike-Slip faults, Normal faults, and reverse faults
 * Strike-Slip Fault
 * Shearing creates strike-slip faults.
 * An example of a strike slip fault is a transform boundary.
 * Normal Fault
 * Tension forces causes normal faults.
 * The fault is at an angle, so one piece of rock lies above the other.
 * The half of the fault that lies above is called the hanging wall.
 * The half of the fault that lies below is called the footwall.
 * Reverse Fault
 * A reverse fault has the same structure as a normal fault, but the blocks move in opposite directions.
 * The hanging wall lies below
 * The footwall lies above.

Friction Along Faults

 * Friction is the force that opposes the motion of one surface as it moves across another surface.
 * Friction exists because surfaces are not perfectly smooth

Mountain Building

 * Mountains Formed by Faulting
 * When a normal fault uplifts a block of rock, a fault-block mountain forms.
 * The Sierra Nevada of California is a fault-block mountain.
 * Mountains formed by folding
 * Under certain conditions, plate movement causes the crust to fold and bend.
 * Folds are bends in rock that form when compression shortens and thickens part of earth's crust.


 * Anticlines and Synclines
 * Geologists use the terms anticlines and synclines to describe upward and downward folds in rock.
 * A fold in rock that bends upwards into an arch is called an anticline.
 * A fold in rock that bends downwards into an arch is called an syncline.
 * Plateaus
 * A plateau is a large area if flat land elevated high above sea level.
 * Sometimes plateaus form when vertical faults push up a large,flat block of rock.



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