For use in all LRRs.

A layer 15 cm (6 inches) or more thick with a depleted or gleyed matrix that has 60 percent or more chroma of 2 or less starting at a depth below 30 cm (12 inches) from the soil surface. The layer(s) above the depleted or gleyed matrix and starting at a depth of less than 15 cm (6 inches) from the soil surface must have value of 2.5 or less and chroma of 1 or less to a depth of 30 cm (12 inches) or more and a value of 3 or less and chroma of 1 or less in any remaining layers above the depleted or gleyed matrix. In any loamy fine sand and coarser material above the depleted or gleyed matrix, at least 70 percent of the particles must be masked with organic material when viewed through a 10x or 15x hand lens.

User Notes: The depleted matrix can occur in either sandy soil layers or loamy and clayey soil layers. This indicator applies to soils that have a very dark layer of 30 cm (12 inches) or more thick and then can get a little less dark in any remaining layers directly above a depleted or gleyed matrix (fig. 17). This indicator is most often associated with overthickened soils in concave landscape positions. A depleted matrix requires a value of 4 or more and chroma of 2 or less. Redox concentrations, including soft iron-manganese masses and/or pore linings, are required in soils with matrix colors of 4/1, 4/2, or 5/2. A, E, and calcic horizons may be mistaken for a depleted matrix because they may have low chromas and high values. These horizons are excluded from the concept of a depleted matrix unless they have at least 2 percent distinct or prominent concentrations occurring as soft masses or pore linings. In sandy textures observed without a hand lens, the masked sand particles appear to be closer to 100 percent masked with organic material when moist. Masked sand grains can disappear quickly if a soil has been drained or disturbed.