For use in LRRs W, X, and Y.

A mineral layer with more than 50 percent gleyed matrix. The layer starts at a depth of 30 cm (12 inches) or less from the mineral surface and is underlain at a depth 1.5 m (60 inches) or less from the soil surface by soil material with hue of 5Y or redder in the same type of parent material.

User Notes: The indicator has two requirements (fig. 18). First, one or more of the specified gley colors occurs at 30 cm (12 inches) or less from the soil surface. These must be the colors on the pages of the “Munsell Soil Color Book” (X-Rite, 2009) that show gley colors, not simply gray colors. Second, below these gley colors, the color of similar soil material is 5Y or redder (2.5Y, 10YR, 7.5YR, etc.). The presence of the truly gley colors indicates that the soil has undergone reduction.

The requirement for 5Y or redder colors lower in the profile ensures that the gley colors are not simply the basic color of the parent material. Some tidal sediments, lacustrine sediments, loess, and glacial tills have base colors that appear as gley. This indicator proves that the near-surface gley colors are the result of anaerobic conditions. When comparing the near-surface and underlying colors, make sure that both are the same type of soil material. Many soils in Alaska consist of two or more types of material (e.g., silty loess overlying gravelly glacial till or sand and gravel river deposits).