Saltweathering

Saltweathering is a geomorphological process that causes the physical disintegration of rocks and minerals due to the crystallization of soluble salts within their pores. This occurs when saline water, often from groundwater, sea spray, or atmospheric deposition, penetrates the rock. As the water evaporates, dissolved salts are left behind. These salts can then crystallize, and the pressure exerted by the growing crystals, especially during changes in temperature and humidity, can fracture and weaken the rock over time.

The process is most prevalent in arid and semi-arid environments where evaporation rates are high, but it can also affect coastal areas and regions with salinized soils. Different types of salts can contribute to weathering, with sodium chloride (common salt) and gypsum being particularly effective due to their relatively low hydration energies and significant volume changes upon crystallization or hydration. The physical breakdown can manifest in various forms, including the formation of pits, cavities, and granular disintegration, leading to the erosion of rock surfaces and structures. This weathering mechanism is a significant factor in the degradation of building materials, historical monuments, and natural rock formations.