1. Topographic sequence of soils, of the same age and usually on the same parent material, that is repeated across larger landscape transects. Individual soil-profile types are related to site conditions and to position on a slope. The term was introduced in E. Africa in the 1930s, and is mainly applicable in certain non-glaciated landscapes, particularly those with small, hilly relief, e.g. loess areas.
2. A chain of craters on the surface of an extraterrestrial body.