Meltwater moulding of rock surfaces

I thought this was worth sharing -- an amazing image of the moulded bedrock floor of a subglacial meltwater channel -- near the snout of Bruarjokull in Iceland.

These "moulding" features are not often seen, but they do occur at Rhosyfelin, and I am still not sure whether they are very old (ie associated with the cutting of the meltwater channels, probably in the Anglian Glaciation) or relatively young (ie associated with the Late Devensian meltwater flowing in the vicinity at the time of the deposition of those torrential meltwater deposits near the tip of the rocky spur).