mechanical weathering The in situ breakdown of rocks and minerals by a set of disintegration processes that do not involve any chemical alteration. The chief mechanisms are: crystal growth, including gelifraction and salt weathering; hydration shattering; insolation weathering (thermoclastis); and pressure release.

mechanical weathering The in situ breakdown of rocks and minerals by a set of disintegration processes that do not involve chemical alteration. The chief mechanisms are: crystal growth, including frost wedging and salt weathering; hydration shattering; insolation weathering (thermoclastis); and pressure release.