If you're talking about a natural process, I think it's decomposition. Breaking down exposed rock into smaller fragments could also be done by physical crushing.
Weathering.
WEATHERING
Intrusive.
Weathering breakdown of rocks into smaller pieces sediments results in the formation sedimentary rocks.
Clastic
hydrolisis is the chemical breakdown of rocks as they react with water where as hydration is the breakdown of rocks as they absorb water.
Clastic rocks are made from fragments of pre-existing rocks.
Texture
The literary term that describes when a character is experiencing a mental breakdown or moment of intense emotional distress is called a "nervous breakdown" or "mental collapse."
physical, chemical or biological breakdown of rocks and minerals into smaller sized particles.
Intrusive.
yes
The breakdown of rocks results in the formation of soil over many thousands of years.
diagenesis
nonconformity
Weathering breakdown of rocks into smaller pieces sediments results in the formation sedimentary rocks.
Clastic
yes;)
Erosion can sure help in the breakdown of rocks, but technically, erosion is the movement of material from one place to another place. Weathering is the term used to describe the breaking down of rocks.