KYTL+2.1

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Vocabulary

 * Earthquake**-the shaking of the Earth's crust
 * Stress**-force that changes a rock's shape or volume
 * 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 until it folds or breaks
 * Deformation**-a change in volume or shape of Earth's crust
 * Fault**-a break in Earth's crust where slabs of rocks slip past each other
 * Strike-slip fault**-a type of fault where rocks either side move past each other sideways with little up-or-down motion
 * Normal fault**-a type of fault where the hanging wall slides downward
 * Reverse fault**-type of fault where the hanging wall slides upward
 * Hanging** **wall**- block of rock that forms the upper half of a fault
 * Footwall**-block of rock that forms the lower half of the fault
 * Fault-block** **mountain**-mountain that forms where a normal fault uplifts a block of rock
 * Fold**-bend in rock that forms when Earth's crust is compressed
 * Anticline**-an upward fold in rock
 * Syncline**-a downward fold in rock
 * Plateau**-a land form that has a more or less level surface and is elevated high above sea level

Stress in the Crust

 * stress adds energy to rocks
 * movements of Earth's plates creates powerful forces that squeezes or pulls the rock in the crust
 * energy is stored in the rock until the rock either breaks or changes its shape

Types of Stress

 * three types
 * shearing
 * cause rock to break and slip apart or to change its shape
 * tension
 * effect on rock is like pulling apart a piece of warm bubble-gum
 * compression
 * squeezes rock until it folds or breaks
 * most changes in the crust occur so slowly that they cannot be observed directly

Kinds of Faults

 * faults usually occur along plate boundaries, where the forces of plate motion compress, pull or shear the crust so much that the crust breaks
 * strike-flip faults
 * created by shearing
 * forms transform boundaries between two plates
 * example-San Andreas Fault, California
 * normal faults
 * caused by tension
 * forms at an angle
 * half of the fault that lies above is the hanging wall
 * half of the fault that lies below is the footwall
 * when movement occurs, hanging wall slips downward
 * example: Rio Grande Rift Valley, New Mexico
 * reverse faults
 * caused by compression forces
 * hanging wall slides up and over the footwall
 * example: Appalachian Mountains

Friction along Faults

 * force that opposes the motion of one surface as it moves across another surface is referred to as Friction
 * how rocks move along a fault depends on how much friction there is between the opposite sides of the fault

Mountain Building

 * over millions of years fault movement can change a flat plain into a towering mountain range.
 * mountains formed by faulting
 * when normal faults uplifts a block of rock, fault-block mountain is created
 * Example of Fault block mountain range-Sierra Nevada
 * mountains formed by folding
 * the collisions of two plates can cause compression and folding of the crust
 * largest mountain range-Himalayas (Asia) and The Alps (Europe)
 * folding rocks can fracture and produce faults
 * anticlines and Synclines
 * example of anticline: Black Hills of South Dakota
 * example of Syncline: Illinois Basin
 * plateaus
 * force that raise mountains can also raise plateaus
 * example: Colorado Plateau
 * consists of many different flat layers
 * wider than it's height

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