In Antarctica from Taylor glacier sometimes leaves a bloody waterfall. The water contains ferrous iron, which, combining with atmospheric air, oxidizes and forms rust. It gives the waterfall of blood-red color.
However, ferrous iron in water occurs for a reason — it is produced by the bacteria that live in isolation from the outside world body of water deep under the ice. These bacteria were able to organize the life cycle in the absence of sunlight and oxygen. They recycle organic residues, and “breathe” ferric iron from the surrounding rocks.