Deposition features on an OS map
Name evidence
A good way to find depositional features is to look for name evidence - the term ‘sands’ appears at Slapton Sands, 833443 (Map 1) and Beesands, 821406 (Map 3).
In Scotland, the term ‘links’ often indicates a sandy area along a coastline.
Shape
The shape of the coast in a map is also a good indicator. In all three maps, the smoothness of the coastline shown indicates a depositional coastline.
Longshore drift
Longshore drift in this area has been responsible for the formation of sand bars across the mouths of several streams which would previously have drained into Start Bay, such as those in squares 8244 (Map 1) and 8345 (Map 2).
When sand spits appear on an O.S. map the direction of the longshore drift can be determined as it will be moving towards where the end of the spit is being formed.
Here, however, the direction cannot be determined from the map as the spits have formed sand bars right across the river mouths.
Lagoons
Bars have trapped water which form lagoons at Slapton Ley and Lower Ley in 8243 (Map 1) and the lake at 818411 (Map 3).
These lagoons are likely to remain, fed by the streams that flow into them. If the streams increased in flow, they might breach the sand bar and once again flow into Start Bay.
Longshore drift
When sand spits appear on an OS map the direction of the longshore drift can be determined as it will be moving towards the point where the end of the spit is being formed. Here, however, the direction cannot be determined from the map as the spits have formed sand barA linear landform extending into the sea and across a bay. right across the river mouths.
Sand spits
Sand spits are fairly easy to identify on an OS map. The fact that they extend out into the water is a good way of spotting them and if you look closely you can see the curved hookThe end of a sand spit is often shaped in this way by a change in wind direction which makes it curve into a hook. at the end.