I was looking the other day at Christopher Chippindale's 1983 book called "Stonehenge Complete" and noticed that he has a section on Boles Barrow (around p 186).
There are two things of particular interest:
1. He is pretty familiar with the correspondence relating to the Boles Barrow excavation of 1801, when William Cunnington and Wyndham dug down ten feet and found a "floor of flints" with many human remains. The stones making up the bulk of the long barrow ridge were for the most part sarsens, but much smaller than those used for the trilithons, pillars and lintels at Stonehenge. Ten of the "best stones" were taken to Heytesbury and set into a circle around a weeping ash tree in Cunnington'e garden. He noticed that one was not a sarsen, but was of the same rock type as some of the upright stones in the inner circle at Stonehenge. Later on his grandson BH Cunnington noticed this reference in the old papers and latched on to its significance. He tracked it down and discovered that it had been moved across the road into the grounds of Heytesbury House. It was a piece of spotted dolerite weighing "about 750 lb". Its importance was thus well known, but it could not be scheduled because it was a "loose stone". But when Siegfried Sassoon bought the house in 1934 he presented the stone to Salisbury Museum, where it remains. (It looks like a broken stone -- so there is still a possibility that a bit of the original might still be found somewhere else......) It's interesting that Chippindale -- like Mike Parker Pearson -- has no doubts at all about the authenticity of this lump of spotted dolerite as having come from the Neolithic burial mound of Boles Barrow, and no doubt about it having been present on the chalk downs long before Stonehenge was dreamed of, let alone constructed.
2. Chippindale draws attention to the "quarry ditches" which have been smashed up by Army vehicles around the flanks of the "seemingly unimpressive earth mound." The ditches and scars left by the people who built long barrows are not often remarked upon, but they had to get their raw materials from somewhere, and naturally enough they would not have carried soil, rubble and stones from far away if there was plenty close at hand. We see the same thing on Carningli Common, where the burial cairn called Carn Briw is surrounded by little pits from which boulders and stones have been taken.
Economy of effort was clearly the basic rule, and Chippindale accepts that sarsens, bluestone (or bluestones) and chalk rubble and soil were all counted as "building materials" and dug up in the immediate vicinity of the burial site. Indeed, as I have speculated before, it may be that the abundant availability of these materials may well have been a key locational factor. Forget about solar solstices, planetary and lunar alignments, ley lines, sighting lines, hilltop prominences and magnificent views............ we are talking about a construction team seeking to get a job done as efficiently as possible.
As I have said often before, if 80 bluestones were quarried and then carried all the way from Preseli to Stonehenge by our Neolithic ancestors, it would have been an aberration of truly spectacular proportions, since there is no history either before or afterwards of any long-distance carriage of monoliths. Such a project would have defied all the rules of prehistoric engineering.