Compression, shear, and tension are three types of stress that act on layers of rock. Explain the results that each type of stress can have on layers of rock. Include a
discussion of whether each result happens slowly or quickly.

:A deeply buried rock is pushed down by the weight of all the material above it. Since the rock cannot move, it cannot deform. This is called confining stress.

Compression squeezes rocks together, causing rocks to fold or fracture (break) (figure 1). Compression is the most common stress at convergent plate boundaries.

Rocks that are pulled apart are under tension. Rocks under tension lengthen or break apart. Tension is the major type of stress at divergent plate boundaries.

When forces are parallel but moving in opposite directions, the stress is called shear (figure 2). Shear stress is the most common stress at transform plate boundaries.