Water and salts are a package deal. If you have a planet with one, you’re going to have all the others as well, because they all come from an exploding star.
When a star goes supernova, it creates oxygen, which can later combine with hydrogen to make water. That very same supernova also makes sodium, potassium, magnesium, chlorine, sulfur etc. so you end up with all the elements for making a bunch of different salts. Ask physicists why supernova does this sort of packaging.
But what if there’s some sort of nuclear/zombie/robot/alien-apocalypse which results in tremendous data loss. Maybe a thousand years from now a future archeologist wonders why there are so many cursed pictures from a particular era. That might be a deeply unsettling mystery until someone finds an ancient research document about image generating AI. However, if nobody finds that document, the archeologists might just go with the traditional “ritual purposes” explanation.