When one or more salt layers are present during extensional tectonics, a characteristic set of structures is formed. Extensional faults propagate up from the middle part of the crust until they encounter the salt layer. The weakness of the salt prevents the fault from propagating through. However, continuing displacement on the fault offsets the base of the salt and causes bending of the overburden layer. Eventually the stresses caused by this bending will be sufficient to fault the overburden. The types of structures developed depend on the initial salt thickness. In the case of a very thick salt layer there is no direct spatial relationship between the faulting beneath the salt and that in the overburden, such a system is said to be unlinked. For intermediate salt thicknesses, the overburden faults are spatially related to the deeper faults, but offset from them, normally into the footwall; these are known as soft-linked systems. When the salt layer becomes thin enough, the fault that develops in the overburden is closely aligned with that beneath the salt, and forms a continuous fault surface after only a relatively small displacement, forming a hard-linked fault.
In areas of thrust tectonics salt layers act as preferred detachment planes. In the Zagros fold and thrust belt, variations in the thickness and therefore effectiveness of the late Neoproterozoic to Early Cambrian Hormuz salt are thought to have had a fundamental control on the overall topography.