What are some other types of weathering apart from onion skin, freeze-thaw, chemical, and biological?
Onion skin and “freeze-thaw” are both forms of physical weathering – actual breaking of rocks into smaller bits. Chemical weathering is actually changing the composition of the rock due to chemical reactions (with water and acids mostly), making it fall apart. The two types of weathering interact – physical weathering breaks the rock up, so more surface area is exposed to chemical weathering. “Biological” weathering is actually a combination of physical and chemical – acids released by plants enhance chemical erosion, while roots and burrowing (some bivalves burrow straight into rocks!) are physical weathering processes.
