Glaciated Landscapes Corrie Deep rounded hollows with a steep back wall. After the ice has melted a lake will be formed behind the rock lip , the lake is called a tarn Examples Mt Snowdon – N Wales Helvellyn – Red Tarn – Lake District
Corrie - Helvelyn - Red Tarn (Lake D) Steep back wall Tarn Rock lip
During ice age smaller tributary glaciers joined with larger ones in the main valley.
Glaciers in the main valley eroded more deeply
When ice melts smaller valleys left at a higher level.
Tributary streams descend to the main valley via a waterfall.
Mt Everest - Pyramidal Peak Corries either side When 3 or more corries cut into a mountain a pyramidal peak or horn develops. Arêtes separate the corries. Perhaps the most famous one is ?
The Matterhorn - Switzerland
U Shaped Valley's V shaped river valley – narrow floor, steep sided and winding U shaped, straight, wide flat floor with truncated spurs
How do they form ?
Glacier moves down an existing river valley
Through abrasion and plucking it widens, deepens and straightens the valley
It removes the ends of interlocking spurs forming cliff like truncated spurs
The V shaped valley turns into a U shape
Arete - Striding Edge (Lake D) When 2 or more corries are side by side / back to back. They erode towards each other so that the land between them gets narrower and narrower until a knife edge ridge forms, called an Arête . Back wall of corrie either side Arete
Ribbon Lake - Thirlmere (L District) A lake in the bottom of a glacial trough formed by lots of plucking or deposition of moraine. There are many examples in the lake District such as Windermere, Buttermere or Coniston water. Long narrow lake, water may be dammed up behind terminal moraine Bottom of lake could be softer rock Can form when tributary glacier joins to add to the amount of erosion