The process that breaks rocks and minerals down at Earth’s surface without transporting them is weathering.
Weathering happens in place through physical, chemical, and biological mechanisms. Physical weathering can split rock through ice wedging, thermal expansion, abrasion, or pressure release. Chemical weathering changes minerals through reactions with water, oxygen, carbon dioxide, or acids. Plant roots, lichens, and burrowing organisms can also weaken exposed rock.
Weathering is different from erosion. Erosion includes the movement of loosened material by water, wind, ice, or gravity, while weathering describes the breakdown itself. Deposition is the later settling of transported sediment. These processes commonly occur together in landscapes, but they are not interchangeable terms.
Weathering helps create soil and supplies sediment to rivers, beaches, and sedimentary basins. Its speed depends on climate, rock composition, surface area, and exposure. For example, warm, wet conditions generally accelerate many chemical reactions, while repeated freezing and thawing strongly promotes physical fragmentation.