What type of glacier forms in a mountain cirque?

A cirque glacier is the type of glacier that forms in a mountain cirque. A cirque is a steep-sided, bowl-shaped hollow carved into a mountainside, often near the head of a former or existing glacial valley.

Snow accumulates in the depression because the surrounding rock walls shelter it from wind and direct sunlight. Avalanches from higher slopes can add more snow. Over many seasons, pressure compacts the snow into dense glacial ice, which may slowly move within the cirque.

Cirque glaciers are generally smaller than valley glaciers because their ice remains confined to the mountain hollow. If a cirque glacier grows and advances through an outlet, it can develop into a valley glacier. Conversely, a retreating valley glacier may eventually shrink back into the cirque where it began.

The terms corrie glacier and niche glacier are also used in some regions for closely related landforms. These glaciers are not ice caps, which spread over broad upland areas, nor piedmont glaciers, which spread outward when valley ice reaches flatter land. Lower Curtis Glacier in Washington is a well-known example.