You can't get blood from a stone... or can you?

Two years ago I visited Canyonlands in Utah and I  thought even the most hardened rock-hater could be moved to geologise over the spectacle. However, after recently seeing new images of Blood Falls in Antarctica I think I've found a new contender for my top Geological Wonder of the World, the one place where it seems you CAN get blood from stone.

Blood Falls, Antarctica

With such an unexpected and gory appearance, especially against the bleak icy landscape of Antarctica, I can't understand why Taylor Glacier is not mentioned more often. Especially when the striped red sands of Arizona's 'The Wave' (especially with the recent 127 Hours film just released) and the Grand Canyon are so well known, and the processes which formed them are considered general knowledge.   

The Wave in Arizona

Although it seems as if a miracle, and the Earth literally appears to be bleeding, the processes which formed Blood Falls are in fact well known.  It was originally thought that algae lived on the surface of the ice and caused the colouration but last year something more spectacular was discovered.

The glacier is actually underlain by a dank and salty lake with no oxygen, light or food source. The lake formed 2 million years ago when Snowball Earth events caused part of the Antarctic Ocean to become trapped and the brine concentrated to be three times as salty as normal seawater. Despite less-than-savoury conditions, there are still microbes living there (seventeen different types to be exact), which have been there since the lake formed and have learnt to 'eat' sulphates and to 'poop' out iron. It's as this waste iron rises 400m to the surface and reacts with oxygen to form the red rust colour that it stains the ice to look like blood.

Diagram by Zina Deretsky, ref: Science doi:10.1126/science.1167350

These microbes exist in such unfavourable conditions that they are one of the best and most easily accessible (scientists don't even need to drill through the ice to reach them) extremophiles for NASA and other astrobiology organisations to use in research to discovere how  places like Mars and Europa could support life.