A3. Black Histic

For use in all LRRs.

A layer of peat, mucky peat, or muck 20 cm (8 inches) or more thick that starts at a depth of ≤15 cm (6 inches) from the soil surface; has hue of 10YR or yellower, value of 3 or less, and chroma of 1 or less; and is underlain by mineral soil material with chroma of 2 or less.

User Notes: Unlike indicator A2, this indicator does not require proof of aquic conditions or artificial drainage.