Effects of sulfate hydration transitions on salt crust dynamics in dry lakes

Investigate how temperature-driven hydration–dehydration transitions of salts (e.g., the thenardite–mirabilite transition of sodium sulfate) influence the growth, morphology, and mechanics of salt crusts and polygonal ridge patterns in evaporite pans.

Background

Dry salt lakes (evaporite pans) develop polygonal crusts through evaporation-driven salt accumulation and density-driven groundwater convection. While thermal buoyancy is minor compared to salinity contrasts, temperature changes can affect the hydration state of some salts and induce large volume changes (e.g., sodium sulfate swelling on hydration).

The review notes that the potential impact of such hydration transitions on salt crust formation and dynamics has not yet been explored, defining a specific gap in current understanding.

References

This phase transition occurs at temperatures and relative humidities routinely experienced in dry lake environments, but its effects on the salt crusts have not yet been explored.

— Self-Organized Pattern Formation in Geological Soft Matter  (2412.18999 - Cartwright et al., 2024) in Subsection Dry salt lakes and convection

Another interesting parameter that requires further research is whether these hygroscopic salt minerals are capable of shrinking as a result of drying.

— Current water trapping micro-habitats on the surface of Mars  (2609.01156 - Bognar et al., 1 Sep 2026) in Section 5, Suggestions for future research