The age of the Vertisol is estimated as less than 10,000 years, and this Vertisol is fertile because a balance between soil erosion and soil creation is maintained. Excessive erosion removes the topsoil, causing desertification; but, where soil erosion is much less than soil creation, over the long term it eluviates and dissipates soil nutrients, forming aged soils (Oxisols). Under the rainfall categorization, it is primarily part of Region IV (annual aridity index of 20 or more and summer aridity index of 5 or more), and has made the development of North European-type agriculture possible.