What is the typical permeability characteristic of organic deposits?

The characteristic of organic deposits being very slow in terms of permeability is linked to their high water retention capabilities and dense structure. Organic soils, often rich in decomposed plant and animal materials, can hold large amounts of moisture due to their composition. This moisture retention is a result of the soil's ability to form a gel-like substance when saturated, which significantly reduces the rate at which water can flow through the soil.

In addition, organic layers can become compacted, further inhibiting water movement. This slow permeability can lead to surface water pooling, reduced infiltration rates, and can affect drainage in construction and agricultural practices. Understanding this characteristic is crucial for soil evaluation, especially in terms of land use decisions and environmental management, as it influences water availability and the aeration of the soil, impacting plant growth and the ecosystem.

Other options indicating faster or more variable permeability do not accurately reflect the inherent properties of organic deposits, emphasizing the distinct nature of organic materials in comparison to mineral soils.