The Gravel Bay Boulder Field, Freshwater West

Let's call it the "Gravel Bay Boulder Field".  It's located in area A on the above annotated satellite image, at the northern extremity of Freshwater West Bay.

This is a fringe benefit -- before visiting the site yesterday I did not know that this boulder field existed, let alone that it was rather important..........  Anyway, we are lucky to have some great photos from Jamie Crofts, and we thank him for permission to use them here:

The submerged boulder field (currently not submerged) with the setting sun beyond.  There is a lot of standing water here, suggesting that the deposit is quite thin, and that undulating bedrock is not far down.

There are large boulders here, and stones and cobbles of all shapes and sizes.  There are thousands of erratics, and many boulders of local Old Red Sandstone and other rocks from the neighbourhood.  This accumulation is nothing like a storm beach deposit, and is quite different from the rockfall accumulations we see beneath the sand in many Pembrokeshire bays.  These boulders and cobbles -- and finer gravels too -- can only have come from a deposit of glacial till. The fines have simply been washed away.  But when -- and how?

An exposure of bedrock projecting through the boulder field.  It appears to be an undulating and somewhat broken up rock platform made of Upper Silurian mudstones and sandstones. 

Another exposure of broken bedrock projecting through the boulder field.

I hoped that this would be here, but missed it because it was almost dark when I visited.  But Jamie and Ruth spotted it during their visit, and it confirms that there are a few remnants of coherent till still surviving in the boulder field.  Jamie says that the deposit is partly cemented.  Note the 

reddish colour -- reminiscent of the meltout tills deposits of West Dale, 

West Angle, Ballums Bay, Caldey, and various clifftop coastal sites along the South Pembrokeshire coast.  

In this photo, we see (I think!) a peat exposure beneath the water line.  That's interesting -- and it shows that the stratigraphy has been inverted in some places -- with washed out stones and boulders thrown on top of the peat beds.  More work needed.....

Click to enlarge all these photos from Jamie -- the definition is amazing.