What does silt consist of?

Silt primarily consists of fine particles that are larger than clay but smaller than sand, typically made up of weathered rock material. This fine texture allows silt to retain moisture and nutrients better than sand and gravel, making it beneficial for soil fertility. When considering the description, it describes silt as having components similar to rich soil, which indicates the presence of organic matter, along with tiny particles resulting from the breakdown of larger rocks. This composition enables silt to support plant growth effectively.

The other options do not accurately characterize silt. Heavy clay consists of much finer particles, while sand and gravel are larger and don't fit the definition of silt. Lastly, while water and organic matter are essential components of soil health, they do not specifically describe the physical composition of silt itself. Thus, the correct understanding of silt is a combination of the qualities attributed to rich soil and its fine particulate nature, aligning with the chosen answer.