Frost weathering of rocks in the presence of salts‐a review

Abstract

AbstractIn many temperate and cold regions, rocks containing salt in solution are subject to frost action. Although the salts depress the freezing point of water, their most common effect at subzero temperatures is to increase the intensity of rock breakdown. Different mechanisms to explain why salts often accelerate frost weathering are outlined and their possible applicability to the weathering of different rocks undergoing different frost regimes is assessed. It is concluded that, because different salt solutions exhibit different crystallization behaviour at subzero temperatures, resulting in varied proportions of water, ice and salt crystals, more than one mechanism is likely to be responsible for rock breakdown. The importance of the different mechanisms will vary with the composition and strength of the salt solution, the temperature regime, the rock type and other factors.