What phenomenon causes the decomposition of rock through the pressure of crystallizing salts?

The correct answer is salt crystallisation, a process where salts dissolved in water can seep into the cracks and pore spaces of rock. As the water evaporates, the salts crystallize, expanding in volume and exerting pressure on the surrounding rock material. This pressure from the growing crystals leads to the physical breakdown of the rock structure, making salt crystallisation an important mechanism of weathering in arid environments where evaporation rates are high.

Understanding the mechanisms of weathering is crucial in geology as it informs us about how landscapes evolve over time due to natural processes. Salts typically involved in this process include sodium chloride and other soluble salts. They can accumulate in rock formations, especially in coastal and dry regions, where their effects are pronounced. Recognizing the role of salt crystallisation helps comprehend not only the weathering of rocks but also the potential impacts on built structures in areas susceptible to such phenomena.