Weathering
Science

The breaking of rocks without any chemical change, like by plant roots
Mechanical weathering
The breaking of rocks without any chemical change, like by plant roots, is called mechanical weathering. Mechanical weathering is when rocks are broken down into smaller pieces by physical forces, such as wind, water, or plant roots, without changing their chemical structure.

A soil layer different from the layers above and below it, in particle size or pH
Soil horizon
A soil layer different from the layers above and below it, in particle size or pH. Soil horizon. A soil horizon is a distinct layer within the soil that has unique characteristics like texture or acidity, compared to the layers above and below it.