3D Laser Scan Survey of Stonehenge, Wiltshire. By Andrew J Dodson & Cory D Hope. 2012
https://www.greenhatch-group.co.uk/plugins/downloads/files/Stonehenge_micro_site.pdf
See also:
Abbott, M. et al 2012. Stonehenge Laser Scan -- archaeological analysis report. EH Report Series 32-2012 (EH Project 6457), 71 pp
(Authors include Parker Pearson, Ixer and Colin Richards)
StonehengeLaserScan_ArchaeologicalAnalysis.pdf
Unfortunately there is a copying lock on this file, which means it is much less useful than it might be........
See also:
Extract:
Bluestone Circle
The Bluestone Circle is located between the Sarsen Circle and the Sarsen Horseshoe.
Thirty stones survive, but originally there would have been many more; Paul Ashbee
(1998) favoured a total of 56 stones, while Mike Pitts indicates that there may have been
up to sixty or seventy (Pitts 2001, 137). Of the surviving stones, 8 are standing, Il are
fallen, 2 are displaced and 9 survive as buried stumps.
The overall structure of the circle is unclear but, in general, the stones increase in size
towards the NE and the two most substantial stones (Stones 31 and 49) are placed with a
wide gap straddling the main NE-SW axis of the monument. The stones in the Bluestone
Circle include spotted dolerite, unspotted dolerite, rhyolite, rhyolitic and dacitic tuffs (Ixer and
Bevins 201 |a, Bevins et al., 2012), altered volcanic ash, sandstone with mica and calcareous
ash (Atkinson 1956; Thorpe et al. 1991. However, the three latter stone types only survive
as buried stumps, along with one stone of spotted dolerite and another of rhyolite.
The stones in this circle are largely unworked, with the exception of two spotted dolerite
lintels (36 and 150), reused from an earlier structure that included bluestone trilithons.
Stone 45 exhibits coarse pick dressing on its interior (now upper) face and very fine
pecking on both sides. Stone 45 is therefore comparable to the uprights re-used in
the Bluestone Horseshoe and one may speculate that the buried face is finely dressed;
as has been observed on the stones of the Horseshoe. It may be significant that the
roughest dressed face was orientated towards the centre of the monument when this
stone was erected in the circle of largely undressed stones. The reused lintels, which
were both originally erected in the Bluestone Horseshoe with their mortises facing the
exterior of the circle, have fallen and are now largely buried. Richard Atkinson excavated
both of these stones in 1954, lifting Stone 36 for the purpose of recording it, but both
were re-buried in their original positions. Atkinson recorded transverse fine tooling on
the outer end of lintel 150, but noted that the other surfaces had been worked smooth
'probably by fine overall pecking with light hammers' (Atkinson 1956, 137).
Above is an interesting table showing bluestone weights of the above ground portions of the monoliths. Elsewhere there are reports of 30% to 35% of the standing stones being beneath the ground surface, so using an average of maybe 33% the stone weights can be adjusted approximately.
There are a number of comments about the relatively light weathering of the bluestone surfaces, and especially on dolerite surfaces. It is assumed that some other rock types (including rhyolites and volcanic ashes) have broken up as a result of weathering -- but this is a large assumption, and it cannot be adequately demonstrated that all of the stumps were originally tall pillar-shaped monoliths -- because the debitage in general does not seem to be made up of debris coming from nearby stones. The idea that the majority of bluestones in the bluestone circle are "regular, natural joint blocks" is wide of the mark. Wishful thinking, methinks. They are best described as heavily abraded boulders and slabs (and some blocky pillars) with distinct facets and rough areas resulting from fracturing during transport.
From this report and from other material coming out of the laser project, it appears that there are laser generated images of all of the Stonehenge bluestones -- but I am not aware that these have been published anywhere.
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