On a medial moraine of Vadret Pers, 2780 m.a.s.l.: Since rocks protect the ice from solar radiation and, therefore, reduce ablation, medial moraines [1] are usually higher than the surrounding ice. Rock slabs or large boulders can lead to the formation of glacier tables [2] because they cast a shadow over the underlying ice.

From the left of Piz Trovat a rock glacier [3] flows towards us. Rock glaciers are phenomena of movement in permafrost. The are not, however, "real" glaciers. They contain mainly rock debris, but some ice in cavities. Their movement is much slower than that of glaciers, typically a few centimetres to a metre per year only.