What does the term "regolith" refer to?

The term "regolith" refers specifically to the layer of loose, unconsolidated rock and mineral fragments that lie above the bedrock. This layer is produced through the weathering processes that break down solid rock into smaller particles. Regolith can consist of a variety of materials, including sand, silt, clay, and other mineral fragments resulting from physical and chemical weathering. It serves as an important component of soil formation and is essential for supporting plant life.

While the other definitions present some concepts related to geology and soil, they do not accurately capture the specific meaning of regolith. For example, soil developed on bedrock would be referred to as developed soil but does not define regolith itself, which includes a broader range of weathered materials. A combination of mineral and organic matter describes soil, which is distinct from regolith that does not necessarily include the organic component. Lastly, the description of weathering that creates rounded edges relates to the texture and shape of weathered rocks and minerals but does not define regolith. Therefore, the choice that accurately describes regolith is about the weathered layer of rock and mineral fragments.