Ogof Golchfa striated bedrock

 

Surprisingly, given the history of glaciation in Pembrokeshire, there are very few examples of striated bedrock slabs.  But right now, at Ogof Golchfa, just to the west of Porthclais, sediment removal during exceptional storms has exposed some bedrock exposures that were previously buried.  The rocks are Middle Solva shales and mudstones (Cambrian) which are here very steeply dipping.  The striae are pretty chaotic, as you would expect on sloping surfaces -- but where striae are visible on surfaces that are more or less horizontal, the prevailing direction of ice movement is confirmed as NW towards SE.