Glacis (geomorphology)

In geomorphology , a glacis [ɡlaˈsiːs] is a flat inclined plane that is in front of many mountain edges .

It is the gravel-covered part of the foot of the mountain and consists mainly of coarse loose sediments that become finer and finer with increasing distance from the edge of the mountain. If the glacis is cut by rivers ( fluvial erosion ) and / or lifted by tectonic processes, we speak of glacier terraces or glacier steps .

In the direction of the mountains, the glacis merges into a mountain base that is not covered by loose sediments. This part is called the pediment . Glacis and pediment are particularly common in dry climates ( arid and semi-arid ).