I went for a flight to catalina island and did one lap around the island at 500 feet. Flew home, parked, thought nothing of it. The next day I do a prelight and notice a crust on the leading edges of my blades. It was pretty substantial, chunks the size of salt shaker salt. the color was off white to yellowish, but it was on a wooden blade and I thought the blade color was influencing it. It tasted like salt. Is this common? Most of my leading edges were also salty. I would not have expected this condition at 500 feet altitude. I was close to the mountain walls of the island, so maybe it was mist carried by the updraft? It did not seem misty out other than standard atmospheric conditions. I'm perplexed.