Which of the following is NOT a defining characteristic of skeletal soils?

Skeletal soils are characterized by having a significant amount of rock fragments, which influences several of their properties. These soils tend to have a high rock fragment content, which directly contributes to their classification. Additionally, this composition leads to low soil moisture retention since the presence of larger particles and voids does not hold water effectively. Gravel is also a common component in skeletal soils, further categorizing them by the size and type of materials present.

In contrast, very fine particle size is not a characteristic of skeletal soils. Rather, these soils are defined by their larger rock fragments, which include gravel and stone. The presence of fine particles would suggest a different soil type that is more cohesive and retains moisture better, differing fundamentally from skeletal soils. Therefore, recognizing that skeletal soils primarily consist of larger rock fragments explains why very fine particle size is not applicable to them.