In geology, a fracture is any kind of separation or break in a rock formation. Examples are joints or faults. These divides the rock into two or more pieces. A fracture can sometimes form a deep, wide crack in the rock. They are usually caused when the rock is not strong enough to hold up under too much stress. This makes the rock crack along its weakest point. Fractures can provide access for fluids, like water or hydrocarbons, to move into the rock.