Faults
When sedimentary rock is squeezed from the sides, it can form into slabs that move up and over each other like shingles on a roof.This process is called thrust faulting. When tectonic forces stretch the Earth's crust, fault blocks tilt or slide down. The older rock may end up on top of the younger rock and these huge amounts of rock can form fault block mountains.Rock movement along a fault can be vertical or horizontal. The amount of movement along a fault may be traced by matching rock on opposite sides.