Slaggyford Stones 1
Image by StoneGloves

Littlestone wrote:
The fact that Silbury is man made is incredibly important what it looks like is secondary and we wouldn't consider comparing it with a natural hill or lump . Similarly if someone claims that that a natural lump is another man made hill we should ensure that it really is as they are precious .
I beg to differ Mr t. True, the fact that Silbury is manmade is of immense importance but I disagree that what it looks like is of secondary importance. Indeed, what it looks like may indeed be of primary importance, that is why it was made to look like it is, and it may even have been modelled on, or inspired by, a natural formation. Again, as stated above, I think it’s a mistake to lay too much emphasis on the purely manmade when we can easily list several natural mounds, hills, rocks and mountains which, because of the cultural importance they have been endowed with, are of anthropological if not of purely archaeological importance.
There is no way that Silbury could have looked much different due to soil mechanics . From our perspective no matter how impressive , it's the fact that it was man made that is most important . We can only guess at the builders priorities visual versus collective effort if indeed there were any . I have only been talking about man made rock art as opposed to non rock art and pointed out an example a combination of both which appears to be intentional . Natural features like outcrops ,hilltops , streams were and are imporatnt to people but it's a slightly different subject from the simple case of whether something is a prehistoric artefact or not .

There is no way that Silbury could have looked much different due to soil mechanics . From our perspective no matter how impressive , it's the fact that it was man made that is most important .
That is not quite true – it could have looked very different but, as you rightly point out, soil mechanics (perhaps more accurately geotechnical mechanics here as Silbury is not strictly made of soil) would have dictated the shape (if it were indeed just a mound of heaped up material). But Silbury is not a mound of heaped up material - it is, actually, a very sophisticated structure, and could have looked like anything the builders wanted it to look like. It would certainly have had a tiered aspect when the final stage was first completed.

But sorry, that’s all beside the point; the point being that art (rockart or otherwise) is a construct of the human mind not the human hand – simply taking hammer and chisel to a material is not the only way to elevate something to the status of art.

Aren't you both right? i.e. they knew exactly what it would look like and were well aware of the soil mechanics that would be involved. It wasn't the whim of a long haired disorganised artist but a planned project that started from a blueprint (or slateprint...) and involved their equivalents of surveyors, quantity surveyors, civil engineers etc etc.

As for what if anything it's meant to represent, that's unlikely to be figured out although if you Google Silbury and Womb you get 87,000 hits - which is testament only to how the internet can spread utter cobblers worldwide IMHO.