Cryoconite

Adam LeWinter on the rim of Birthday Canyon on the Greenland Ice Sheet. The black deposit in the bottom of channel is cryoconite. Birthday Canyon is approximately 150 feet deep.

The photo comes from a small gallery at The Guardian depicting scenes of glacial melting in the Arctic.  Second gallery.

Blogged for the stark beauty, but it also prompted me to look up what "cryoconite" is.

Cryoconite is powdery windblown dust which is deposited and builds up on snow, glaciers, or icecaps. It contains small amounts of soot which absorbs solar radiation melting the snow or ice beneath the deposit sometimes creating a cryoconite hole. 

Cryoconite holes have been suggested to play important roles in the glacier ecosystems because many kinds of living organisms have been reported from this structure on the glaciers, for example, algae, rotifer, tardigrada, insects and ice worm.

Details about cryoconite granules.