cryoconite
Dark silt accumulating mainly from airborne volcanic sediment or soot from artificial pollution, or detritus in water of ablation from ice sheets or glaciers. Cryoconite typically appears either as surface discoloration or in cryoconite holes.
countable, uncountable
In these environments the cryoconite, a wind-borne fine debris deposited on glacier surfaces, represents a potential sink for organic and inorganic pollutants because of its high content of organic matter.
Where it comes from
From cryo- + Ancient Greek κόνις (kónis, “dust”) + -ite.
Adapted from the Wiktionary entry cryoconite (CC BY-SA 4.0).