A layer of windblown debris and aerosol that accumulates as dust on the surface of an ice sheet or glacier. The dust may contain nutrients and microbial cells, allowing biological processes to occur, and it may also contain small amounts of soot and other dark-coloured matter that lowers the albedo, causing the snow or ice beneath the dust to melt, forming holes called cryoconite holes. Cryoconite was first described in 1870 by the Finnish geologist and explorer Nils Adolf Erik Nordenskiöld (1832–1901) while travelling over the Greenland ice cap.