The white rings on this collection of salt-encrusted rocks from Wahweap wash are possibly related to the heating and cooling cycle of day and night. During the day, the water warms and evaporates creating a solution that is increasingly concentrated with salt. As the water cools at night, the super-saturated solution precipitates the salts at the water line on the rocks. Warming the next day keeps the salts in solution while evaporation continues. And then cooling the following night precipitates more salt but at a lowered water line. There are three or four "rings" on many of these stones, so this would represent a three- or four-day cycle.