What is a horn and how is it formed?
A glacial horn is the peak that forms from three arêtes.
A glacial horn is a feature created by glaciers and what exactly this term means is intricately linked with how it formed. A horn is a peak that forms from three arêtes. It is also known as a pyramidal peak.
An arête is the edge that forms in the land from cirque erosion, or when two cirque glaciers form up against each other, creating that sharp edge. When more than two arêtes meet, this is a horn.
Good example of a cirque :