Roots of plants growing into cracks may put pressure on the surrounding rock, eventually breaking rocks apart as the roots grow.Forest and range fires can cause rocks that are located along the surface of the ground to weather.Ice crystals can grow in cracks of rocks. Over time this weakens the rock, and it can break apart.Glacier movement can cause pressure release as it moves away from a surface of rock.Water flowing in a stream into a rock can eventually create a hole in the rock.