An order of mineral soils in the US soil taxonomy that are identified by a deep mollic surface soil horizon (well-decomposed and finely distributed organic matter) and base-rich mineral soil below.
Geography
In US soil classification, soils with a rich humus content, developed under grassland. Rendzinas and chestnut soils fall into this category. Kravchenko et al. (2011) Chin. Geogra. Sci. 21, 3, 257 provide a clear and useful account.