Lower Town, Fishguard -- moulded bedrock exposure

The exit of the Cwm Gwaun meltwater channel, at the end of the quaysde in Lower Town harbour.  The town of Fishguard is on the left.

 

Close to the end of the quay there is an extensive exposure of lavas and other volcanic rocks from the Fishguard Volcanic Group:  Rhyolitic and dacitic lavas, tuffs and agglomerates, locally with interbedded sediments and debris flows.  There are fractures and visible transitions from one rock type to another.  But bedding or layering is difficult to discern, and the undulating rock surface exposed near the John Cleal statue appears to be unrelated to anything structural  in the rock sequence. 

There are obvious traces of smoothing or moulding on the sloping rock surface, and while I think some of this may be down to abrasion by overriding ice, I am more inclined to think that we are looking at "P forms" associated with large volumes of meltwater heavily charged with debris.

How old are these features?  Possibly Late Devensian, possibly older.  

We can see that the Lower Town harbour occupies the lower flooded part of the Cwm Gwaun meltwater Channel, and this site in particular projects out into the centre of the meltwater route.  It is not surprising, in precisely this location, to find traces of concentrated meltwater erosion on solid bedrock.