dirt cone

A cone of ice, as much as 2 m in height, covered with a thin layer of debris, found in the ablation zone of a glacier. It occurs wherever debris forms on a glacier surface, and comes about because the dirt protects the ice below from ablation. As the cone steepens, the debris will begin to slide off, and the core will decline.

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)