sabkha

A flat, salt-encrusted coastal or inland plain in an arid region, formed where a shallow water table lies close enough to the surface for groundwater to evaporate and deposit its dissolved minerals as a crust. Sabkhas are treacherous — the surface appears firm but may collapse into soft, saline mush beneath. Coastal sabkhas are common along the Persian Gulf and the Red Sea; inland sabkhas form in closed basins throughout the Sahara and the Arabian Peninsula.