How does a salt-free playa differ from a saline playa?

The primary distinction between a saline playa and a salt-free playa lies in the composition of the surface deposits that accumulate within these flat-bottomed desert depressions.1

• Saline Playas: These are characterized by the concentration of salts and evaporite minerals. When water evaporates in these basins, it leaves behind crusts of minerals such as halite, gypsum, and other evaporites. These surfaces can range from rugged, thick salt crusts to smooth, flat expanses depending on flooding and dissolution patterns. They are often referred to by local names such as salt flats, salt pans, or salinas.123

• Salt-Free Playas: These depressions are dominated by fine-grained sediments like clay, silt, and sand rather than significant salt accumulations. They are commonly termed clay pans, hardpans, or dry lake beds. While they may still experience desiccation and the formation of features like desiccation polygons due to the shrinking of clay minerals, they lack the thick, crystalline evaporite crusts found in saline environments.13