What is regolith?

Regolith refers to a layer of loose and fragmented material, which can include soil, rock particles, and organic matter, that lies over bedrock. This material forms as a result of weathering processes that break down solid rock into smaller particles without completely transforming them into soil. Regolith serves as an important substrate for plant growth and is crucial in understanding various geological and ecological processes.

The other options can cause confusion because they gloss over the specific definition of regolith. For instance, while fertile soil is formed from the weathered material, regolith itself isn’t necessarily fertile or organic; rather, it can be composed of a variety of materials at different stages of weathering. A type of mineral found in rocks does not accurately describe regolith, as regolith encompasses a broader collection of materials rather than a specific mineral. Finally, a soil-enhancing substance might improve soil quality, but regolith itself is not defined in this way; it is more related to geological context than soil enhancement. Thus, identifying regolith as a layer of loose rocky material covering bedrock provides a precise understanding of its geological significance.