How did glaciers shape the valleys and peaks of the Alps?

During the Quaternary Period, Alpine glaciation fundamentally reshaped the mountains through intense erosion and deposition.1

Shaping Peaks and Ridges

Glaciers carved the mountaintops into distinct, rugged features:
* Cirques: These amphitheatre-like hollows were scoured into the mountainsides by ice.12
* Arêtes: As glaciers eroded parallel valleys, the bedrock divides between them were narrowed into sharp, knife-edge ridges.12
* Horns: When multiple cirques formed in a radial pattern around a mountain, they left behind sharp, towering peaks like the Matterhorn.12

Transforming Valleys

Glaciers drastically altered the landscape of the valleys:
* U-shaped Valleys: By removing debris and eroding the base and lower sidewalls of existing V-shaped river valleys, glaciers created characteristic parabolic or U-shaped profiles with steep, vertical walls.12
* Hanging Valleys: Tributary glaciers often carved shallower valleys that now sit high above the main valley floors, resulting in dramatic waterfalls.1
* Lakes and Deposits: Many deep, elongated lakes formed in ice-scoured basins, while melting glaciers left behind fertile morainic deposits and gravels that filled sections of the valley floors.1