Further description Vertisols owe their specific properties to the presence of swelling clay minerals, mainly montmorillonite. As a result of wetting and drying, expansion and contraction of the clay minerals take place.
Contraction leads to the formation of the wide and deep cracks.
The cracks close after rain when the clay minerals swell. During expansion of the clay minerals high pressures are developed within these soils, causing a characteristic soil structure with wedge-shaped aggregates in the surface soil and planar soil blocks in the subsoil. General environment Vertisols occur principally in the soils of hot environments with marked alternating wet and dry seasons. Vertisols are generally found on sedimentary plains, both on level land and in depressions. Smaller areas of Vertisols are found on hill slopes and piedmont plains.