Morainic ridges at Gelli-fawr and Gernos-fawr?

I have been looking again at the satellite imagery of the Preseli foothills, and am intrigued by a series of alignments showing up in the vicinity of Gelli-fawr and Gernos-fawr.  I have remarked on these before, in a number of posts.  The features -- seen in very subtle changes of tone in grassy fields -- have a surface relief maybe no greater than a metre, but there is a consistent pattern, and I need to check it out.

I'm keeping an open mind here -- the features may be structural, showing bedrock outcrops beneath a thin superficial layer.  Intriguing, nonetheless.  On the illustrations below I show the undoctored versions and the annotated versions, so that you can see what I am up to......

It's conceivable that these features are ice-marginal channel remnants, cut by meltwater flowing along a lowering ice edge, but they look a bit too irregular for that, and if they really are ridges then they must be marginal or terminal moraines created on an ice front.

Interestingly enough, these features do not show up very well on the phenomenal new satellite imagery (dated 2020) from Bing Maps -- maybe the above images are courtesy a low sun and diffuse light......