Erosion and Deposition

1. Erosion and Deposition • Glaciers

2. Glaciers • Glacier - a large mass of ice that moves over land • Alpine glaciers – occur in mountain and are erosional • Continental glaciers – occur on flatter land and are mostly depositional.

3. Glaciers • Glaciers occur in a cold region where more snow falls than melts each year. • In alpine glaciers the weight of the heavy mass of ice causes it to flow downward slowly. • A continental glacier spreads out under its own weight.

4. Alpine Glaciers • Cirque – a bowl-shaped erosion near the top of a mountain caused by a glacier through ice wedging. • Horn – a sharp peak where 3 or 4 cirques come together. • Arete – a ridge that forms where 2 cirques come together. • Alpine glaciers create U-shaped valleys.

9. Moraines • Till – different sized sediments deposited by a glaciers. • Moraine – a deposit left behind by a retreating glacier. • End moraine – left at the end or toe of a glacier. • Lateral moraine – left at the sides of a glacier. • Medial moraine – left in the middle, where two glaciers come together.

14. Glaciers • Kettle – occurs when a large chunk of ice becomes buried in the soil. When the glacier retreats, the ice melts forming a lake. • Esker – a sinuous ridge of sorted till that forms as sediment is laid in a river that forms on or under a glacier. • Kame – a mound of sort till that forms in a lake that form on a glacier.