kivimite ja mineraalide lagunemine ning koostise muutumine keemiliste protsesside (peamiselt lahustumise, hüdrolüüsi, hapendumise, hüdrateerumise) toimel, the process of weathering by which chemical reactions (hydrolysis, hydration, oxidation, carbonation, ion exchange, and solution) transform rocks and minerals into new chemical combinations that are stable under conditions prevailing at or near the Earth's surface