Raised beach sands at Hedderwick

Hedderwick deer hoofprints

9000 year old deer hoof prints from the estuarine muds exposed below the tsunami layer

Tsunami deposits near Dunbar

David Smith and others have described the southernmost example of deposits of the Storegga tsunami at ~7300 BP from amongst the raised beach deposits at Hedderwick. The raised shoreline deposits are almost uniformly horizontally-bedded and well sorted sands that grade into muds further into the estuary. One or two prominent gravel layers occur, however, with rip-up clasts of mud and broken shells. In the sheltered wave environment of the Tyne estuary these coarse deposits must relate to either major storms or tsunami. As sea level 7300 years ago was 5-8 m above the present the deposits are unlikely to be products of storm waves. Aside from the tsunami deposit, the excellent exposures in the raised beaches around Hedderwick await further study.

shetland tsunami deposits