Types of Stress

Stress

A stress is a force that acts on rocks to change its shape or volume

The force adds energy to the rock until it breaks or changes shape

Causes

Unequal heating and cooling in the Earth’s mantle

Results in Earthquakes

Shearing

Stress that pushes rock mass in two opposite directions.

Crust slides side by side

Evidence of this?

Tension

Pulls on the crust Stretching the rock so it is thinner in the middleCrust pulls apart

Compression

Squeezes rock until it folds or breaks

Crust pushes together

Rock has two options when these stresses are present

1. Rock Folds2. Rock breaks