Some pics from our Christmas Day walk on Traeth Mawr, Newport. There was a very low spring tide, so access to the northern end of the beach was easy -- and the splendid wave-cut platforms were clear of overlying sediments (sometimes large parts are covered by the sand).
As we can see, the platforms are cut across the mudstone, shale and sandstone strata (the cliffs here reveal very convoluted folding and faulting structures) and there is a very sharp break at the foot of the cliffs. The pebble beach is not very well developed here -- but the pebbles in these beaches are clearly the tools use by the waves in the fashioning of the platform. Surface relief on the platform is generally around 50 cms -- but in places it is more than 1 m. Distinct gullies have been formed by the backwash of the waves. All of the platform remnants are below HWMST.
The bottom photo shows a clear break in the platform near mid-tide mark, not far from the Boat Club and car park. There is a clear step about 1 m high, between an extraordinary flat platform cut across black mudstones, and a more irregular platform above. I can see no geological explanation for this feature. Elsewhere beneath these cliffs there re other slight steps as well -- and I am convinced that we are looking at multiple platform remnants here, of different ages. Are some of them Ipswichian in age (around 100,000 years old)/ And could some remnants be even older -- ie from earlier interglacials?
We like to think that the Ipswichian raised beach platform is well above HWST (as at Poppit, Porth Clais and Broad Haven South) -- but things are clearly not that simple......