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).

An ordnance survey map of Slapton Sands.Map 1 - Ordnance Survey Coastal Features © Crown copyright and database rights 2013 Ordnance Survey

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.

An ordnance survey map of Strete Gate.Map 2 - Ordnance Survey Coastal Features © Crown copyright and database rights 2013 Ordnance Survey

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).

An ordnance survey map of Torcross.Map 3 - Ordnance Survey Coastal Features © Crown copyright and database rights 2013 Ordnance Survey

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.

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.

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