Proposed by pedologist Henry Erhart in 1951, the theory defines two climatic phases: biostasy and rhexistasy.
During rhexistasy (from rhexein, to break) the protective vegetative cover is reduced or eliminated as a result of a drier climate.
The drier climate slows pedogenesis and soils no longer contribute the limestone building mineral components that characterize biostasy.
Unprotected by thick vegetation or deep soils, wind acts to expose subsoil to erosion and rock to physical weathering.
The intensity of punctuating rainfall events during rhexistasy results in erosion, and the accumulation of sand and silt as sedimentary layers.