What is the primary characteristic of skeletal soils?

Skeletal soils are primarily characterized by the presence of a significant amount of rock fragments within the soil matrix. When soil contains more than 35% rock fragments, it is classified as skeletal. This characteristic primarily influences the soil's physical properties, including its structure and texture, which can affect drainage, aeration, and the types of vegetation that can thrive in such soils.

The extensive quantity of rock fragments differentiates skeletal soils from other soil types that may have higher organic content or finer particles. High organic content is not specific to skeletal soils, and while water retention capacity is an essential function of many soils, skeletal soils typically exhibit lower water retention due to the larger gaps created by rock fragments. Lastly, the presence of fine fragments is not a defining feature; instead, skeletal soils often have a coarser texture compared to finer-textured soils. Thus, the definitive characteristic of skeletal soils is indeed their rock fragment content exceeding 35%.