Press Release

26 May 2014 - Plymouth, England

The SHIPS Project Jennycliff Wall Excavation

This week the SHIPS Project team will be investigating a large wall feature on the bottom of Jennycliff Bay in Plymouth Sound, to see if it is man made.  The origins of the 570m long boulder wall are unknown, but investigations by SHIPS Project divers suggest that it has a structure similar to a dry stone wall so it may not be a natural feature.  Initial ideas were that the wall was part of an ancient harbour or a large fish trap but it is now thought to be a sea wall to protect the shore against rising sea levels.  Thousands of years ago the sea level in the English Channel was much lower than it is today, Plymouth Sound would have been dry land and the river Tamar would cut across the valley and out to sea.  When sea levels rose the Sound would have been slowly flooded so the wall may have been built to protect what was dry land in Jennycliff Bay.

 The wall runs north to south across the bay in 9m of water, it is 1.5 metres tall with the seabed shallower on the eastern side.  Geophysical surveys in the area conducted with Plymouth University have given clues about the shape of the buried part of the wall, so divers will now dig trenches in the seabed to get more detailed information.

The SHIPS Project team of volunteer divers will be working from the local dive boat Maid Maggie which will be anchored over the site.  The wall is partly buried on the deeper side because the Sound has partly silted up since the wall would have been built, so the divers will excavate down this side of the wall to confirm that it does continue under the sand.  On the shallow side the seabed has filled in up to the top of the wall so trenches will be dug to find out the wall’s shape on this side.  Samples of the sediment from the trenches will be taken at different depths and will be taken back to Plymouth University for analysis that may provide a date when the structure was built.

More information and photographs about the Jennycliff Wall see:

Contact: Peter Holt, Project Manager, the SHIPS Project
Mob: +44 (0) 7813 018588
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