Re: ...but -- that's not a song, Marcia . . . ;^)
The rings are left by gradual, perhaps seasonal, dissipation of a lighter, erosive substance, likely a liquid, but not necessarily.
Dan
Space/Science » in reply to ...left bathtub ring/s(?!) Well, it happened in Salt Lake City, Utah! ;)
The rings are left by gradual, perhaps seasonal, dissipation of a lighter, erosive substance, likely a liquid, but not necessarily.
Dan