Abstract: | Semicircular and crescent-shaped accumulations of salt crystals developed on salt crusts were measured on three Tunisian playas in September 1990. These features have been termed salt ramps. Their morphology and chemistry suggest that they are formed in the late stages of shallow ephemeral lake desiccation in playa basins. They form by salt precipitation from shallow brine lakes that are blown across salt-encrusted playa surfaces by the wind. Moreover, they appear to be short-lived features and their degradation is related to the flooding of playas with less saline water, and possibly rainfall and deflation. |