|glacier:type = rock|
|Mixtures of rock and ice that move slowly downhill when active|
|Used on these elements|
|Status: in use|
|Tools for this tag|
or are mixtures of rock and ice that move slowly downhill when active. The outer surface of a rock glacier is a layer of broken rock, scree or boulders, that insulates the underlying layers of rock, ice, and permafrost. Rock glaciers are not "true" ice glaciers, but distinct geological landforms. In contrast to glaciers, they do not form as a result of the accumulation of large amounts of snow, but mainly occur in areas with little snow.
Many rock glaciers have been mapped using natural=scree, which correctly identifies the broken rock surface of a rock glacier. Some mappers have used geological=rock_glacier as a secondary tag to distinguish rock glaciers from ordinary scree.
Using natural=glacier to map a rock glacier is controversial because rock glaciers are not "true" glaciers composed of ice and using this tag may mislead data consumers into making incorrect assumptions about the nature of the landform. Using glacier:type=rock as a secondary tag for rock glaciers is controversial for the same reasons.