Brian John has a book to sell and explains on his blog the reasoning why he believes a glacier extracted the bluestones from Wales and placed them on Salisbury Plain. That there is no evidence for such a glacier and no glacial erratics in Wiltshire doesn't deter him. He has published a handy list of his top ten reasons, which I reproduce below with my off the cuff thoughts.
Ten fundamental problems with the human quarrying & transport thesis
1. There is no sound evidence from anywhere in the British Neolithic / Bronze Age record of large stones being hauled over long distances (more than 5 km or so) for incorporation in a megalithic monument. The builders of Neolithic monuments across the UK simply used whatever large stones were at hand.
There’s an old joke where a man walks up to a woman in a bar and says, “Will you sleep with me for a million dollars?” She thinks for a second and then says, “Sure.” The man smiles and says, “Will you sleep with me for one dollar?” The woman tosses her drink in the man’s face and says, “What kind of girl do you think I am?” “We already know the answer to that,” replies the man. “Now we’re just haggling over the price.”
Once you accept that neolithic man can haul stones 5 km, then you must accept that they can haul them 50 or 500. The earthen monuments, such as Silbury Hill show that unimaginable amounts of work were performed by neolithic man to raise their monuments. Stonehenge is a unique monument in its design so it is not unexpected that its construction also was unique.
2. If ancestor or tribute stones were being transported to Stonehenge, why have all of the known bluestones come from the west, and not from any other points of the compass? Were belief systems and "local politics" quite different to the north, east and south?
Why are all the imperial monuments of the Raj in India designed by people from the places far to the west of that country? Why should the local politics of the time involve people from the north, east or south?
3. There is no evidence either from West Wales or from anywhere else of bluestones (or spotted dolerite or Rhosyfelin rhyolite in particular) being used preferentially in megalithic monuments, or revered in any way. The builders always used whatever was available to them in the vicinity, and it can be argued that stone availability was a prime locational determinant for stone settings.
Professors Tim Darvill and Geoffrey Wainwright certainly believe that there were special properties to the stones that were revered in the past. But we simply do not know what the builders of Stonehenge believed and there is no evidence that local availability of stone is or is not of importance.
4. If long-distance stone haulage was "the great thing" for the builders of Stonehenge, why is there no evidence of the development of the appropriate haulage technology leading up to the late Neolithic, and a decline afterwards? It is a complete technological aberration.
But there is evidence for the haulage technology, thousands of stones were moved around in the neolithic and there was then a complete change of culture and, it seems, change of population based on the emerging DNA evidence. There is no aberration at all.
5. The evidence for Neolithic quarrying activity in key locations is questionable. No physical evidence has ever been found of ropes, rollers, trackways, sledges, abandoned stones, quarrymen's camps, or anything else that might bolster the hypothesis. The so-called “engineering features” are entirely natural.
The transport and quarrying are separate arguments. Even if there was no quarrying and the rocks were just lying on the surface (not that I'm doubting MPP's evidence but it hasn't been fully presented yet), it is how the rocks got from Wales to Wiltshire that is the question here.
6. The sheer variety of bluestone types (near 30 when one includes packing stones and debris) argues against selection and human transport. There cannot possibly have been ten or more "bluestone quarries" scattered across West Wales.
Ever been to a crystal shop? Many reasons why it is possible, first example off the top of my head, what if 30 different families all wanted to bring a bit of their land along?
7. Bits and pieces of experimental archaeology on stone haulage techniques (normally in "ideal" conditions) have done nothing to show that our ancestors could cope with the sheer physical difficulty of stone haulage across the heavily-wooded Neolithic terrain of West Wales (characterised by bogs, cataracts, steep slopes and very few clearings) or around the rocky coast. The one reasonably "authentic" project (the moving of the "Millennium Stone" in the year 2000) was a shambles and a disaster.
The Millenium Dome Experience was a shambles and a disaster but that doesn't show that the Romans couldn't build them.
8. Neither has it been shown that the Stonehenge builders had the geographical awareness and navigational ability to undertake long and highly complex journeys with very heavy loads.
The Durrington Walls cattle teeth analysis suggests otherwise.
9. And if there was a "proto-Stonehenge" somewhere, built of assorted local stones and then dismantled and taken off to Stonehenge, where was it? The mooted "Preselite" axe factory has never been found, and neither has the mythical Stonehenge precursor.
I still haven't found the spare set of car keys I put down in the kitchen last month, but that doesn't mean they didn't exist.
10. Analyses of bluestone monolith stone shapes does not suggest that elongated “pillars” were preferred. Slabs, stumps and boulders of all shapes and sizes are highly suggestive of a glacial erratic assemblage.
To quote a couple of examples: "Stone 35a is particularly spectacular, ... We can see several other fractures within the rock, so it is in a dodgy state, and presumably always has been." A fragile rock then, doesn't sound like it would have survived glacial transport. "like a pillar is SH61" Some people see phalli when they look at the stones, Brian sees stumps, but I see pillars..