Forces in earth's crust

how does stress change earth’s crust?

tension, compression, and shearing

stress

a force that acts on rock to change its shape or volume

tension

the stress force that pulls on the crust and thins rock in the middle

compression

the stress force that squeezes until it folds or breaks

shearing

stress that pushes rock in two opposite directions

how do faults form?

when enough stress builds up in rock, the rock breaks, creating a fault

normal fault

the fault cuts through rock at an angle, so one block of rock sits over the fault, while the other block lies under the fault

hanging wall

the block of rock that sits over the fault

footwall

the rock that lies under the fault

reverse fault

has the same structure as a normal fault, but the blocks move in the reverse direction

strike-slip fault

the rocks on either side of the fault slip past each other sideways, with little up or down motion

how does plate movement create new landforms?

over millions of years, the forces of plate movement can change a flat plain into features such as anticlines and synclines, folded mountains, fault-block mountains, and plateaus

anticline

a fold in rock that bends upward into an arch

syncline

a fold in rock that bends downward to form a V shape

plateau