Stonehenge 181
Image by baza
Stonehenge

Stone Shifting 2

Not sure where it came from but I was under the impression it was a socket (dug into the bedrock I suppose), tightly packed with chalk rubble, sarsen chips, mauls etc. Whether all of the packing was all done after the stone was in, I don't know. i.e. not sure if the stuff under the stone was pre-planned rubble (seems like an ideal impact bed) or if some of it was the result of the sarsen smashing into the bedrock and cracking it up. Knowing which, in itself, would give a clue to how the stone went in, but it would need quite a technical eye to analyse it I would think.

I would imagine that side packing would be rammed in afterwards to make the stone stand exactly plumb and also perhaps to align the tops to the correct position for the lintel. As to packing underneath the stone, It might have been easier for them to dig the holes a little deeper than needed (labourer) and then pack them back up to the correct depth for the particular stone they were erecting (surveyor). I can just imaging the conversation between them:

Surveyor: Just dig all these holes I've marked on the plan 9 foot deep and I'll adjust them to the correct depth later.

Labourer: Right y'ar, guv. (then under his breath) effin' bosses, thur ahl the effin' same. We do ahl the effin' graft an they ger ahl thu effin' credit.