A soil type characteristic of chalk or limestone subsoils; any of a group of dark grayish brown intrazonal soils developed in grasslands on soft calcareous marl, soft limestone, or chalk. Rendzinas are one of a group of soils known as primitive soils. Unlike mature soils, which have three or more horizons in their profile, rendzinas have only a mixed mineral/humus horizon which rests directly on the weathered parent material. They represent an early stage in soil development. This fertile lime-rich soil is characterized by a dark friable humus-rich surface layer above a softer pale calcareous layer.