One is organic soils, or peat. These are both called hydric soils. Organic soils develop in depressions and consist of plant remains that do not decompose because soil is saturated. Organic soils can range in thickness from 2 to 30 feet. Mineral soils that are saturated much of the time become dull-colored or gleyed.
Gleyed soils are neutral gray and occasionally greenish or bluish gray.
Mineral soils saturated for short periods develop spots or blotches of different colors. These spots are called mottles and can be an indication of hydric or wetland soils. Wetland Hydrology Hydrology is the third criterion used in describing a wetland. Hydrology refers to the presence or flow of water through the site. Often, aerial photographs, personal interviews with neighbors, and visual evidence are used to determine wetland hydrology.