Weathering and erosion also contribute to the formation of canyons. In winter, water seeps into cracks in the rock. This water freezes. As water freezes, it expands and turns into ice. Ice forces the cracks to become larger and larger, eroding bits of stone in the process. During brief, heavy rains, water rushes down the cracks, eroding even more rocks and stone. As more rocks crumble and fall, the canyon grows wider at the top than at the bottom.
