Glaciation and O.S maps

Remember!Contour lines are very close together showing very steep land.

The contour lines are curved showing a bowl-shape

Sometimes a tarn is evident

Contour lines are very close together showing very steep land. There is a long strip of white in the middle showing flat land.

Corrie

U-Shaped Valley

Arete

Where two corries form back to back.

The arete (ridge) is shown as a black rugged line

Using the O.S map of Snowdon and your lithosphere notes, answer the following questions;

1) Describe the evidence which shows that Snowdon was once affected by glaciation.

2) Explain with the aid of a diagram, the formation of two features that you have identified on the O.S map extract.

4 marks

5 marks

Glaciation and O.S mapsWhen looking for evidence of glaciation look specifically at thecontour lines.

Contour lines that are very close together,shows steep land (which is particularly important in glaciation, asmost features have steep sides)

Curved contour lines show corries, also shown on O.S maps(sometimes) as Coire or Cwm. Often with blue inside showing acorrie loch.

2 Corries back to back show an arete3 corries back to back show a pyramidal peak

Two areas of steep land, with an area of flat land (shown by thewhite of the map) in between is a U-shaped valley.