Glaciation and O.S maps

1
Glaciation and O.S maps
2
Remember!
Corrie
Arete
Contour lines are very close together showing
very steep land. The contour lines are curved
showing a bowl-shape Sometimes a tarn is evident
U-Shaped Valley
Where two corries form back to back. The arete
(ridge) is shown as a black rugged line
Contour lines are very close together showing
very steep land. There is a long strip of white
in the middle showing flat land.
3

• Using the O.S map of Snowdon and your
  lithosphere notes, answer the following
  questions
• Describe the evidence which shows that Snowdon
  was once affected by glaciation.
• 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
4
Glaciation and O.S maps

• When looking for evidence of glaciation look
  specifically at the
• contour lines.
• Contour lines that are very close together,
• shows steep land (which is particularly important
  in glaciation, as
• most 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 a
• corrie loch.
• 2 Corries back to back show an arete
• 3 corries back to back show a pyramidal peak
• Two areas of steep land, with an area of flat
  land (shown by the
• white of the map) in between is a U-shaped valley.