Solid rock slowly disintegrates under the influence of weather and organisms. Weathering is the in-place breakdown of rocks and minerals by physical, chemical, and biological processes. Unlike erosion, weathering does not involve transport of the material.

Physical weathering includes frost wedging and abrasion. Chemical weathering involves dissolution, oxidation, and hydrolysis that alter the mineral composition. Plant roots and microbes contribute biological weathering. Climate controls the relative importance of each process—cold climates favor physical breakdown, warm wet climates favor chemical alteration.

Weathering produces the regolith and soil that support plant life. It also prepares material for later erosion and contributes dissolved ions to rivers and the ocean. The rate of weathering influences landscape evolution and the long-term carbon cycle through silicate mineral reactions.

• In-place breakdown of rock
• Physical, chemical, and biological processes
• Produces soil and prepares sediment
• Rate depends strongly on climate