Source: Salisbury Museum.
Assessing the authenticity of a sample taken from the Altar Stone at Stonehenge in 1844 using portable XRF and automated SEM-EDS. 2023.
Richard E. Bevins, Nick J.G. Pearce,Duncan Pirrie, Rob A. Ixer, Stephen Hillier, Peter Turner, Matthew Power. Journal of Archaeological Science: Reports, Vol 49, Elsevier, June 2023, 013973
I'm interested that the authors of this article refer to the bluestones as "a diverse range of lithologies exotic to the Wiltshire Landscape." Well, there are 46 of them at the last count, in the full assemblage of standing stones, stumps and other rock debris at or near Stonehenge. So is common sense breaking out at last? That would be nice.....
Sadly, the article is stuck behind a paywall, so it is accessible to only a privileged few.......
Megalithic Stone 80 at Stonehenge, the so-called Altar Stone, is traditionally considered to be part of the bluestone assemblage, a diverse range of lithologies exotic to the Wiltshire Landscape. However, the Altar Stone, a grey-green micaceous sandstone, is anomalous when compared with the other (predominantly igneous) bluestones, in terms of its lithology, size and weight, and certainly in terms of its provenance. Recent investigations into the character of the Altar Stone have focussed on excavated fragments now attributed to be derived from the Altar Stone, as well as non-destructive portable XRF (pXRF) analysis on the Altar Stone itself (re-analysed as part of this investigation). In this study we have investigated a sample from the collections of Salisbury Museum, 2010K 240 (also referred to as Wilts 277), which bears a label recording that it was collected from the underside of the Altar Stone in 1844. We examined the sample petrographically and also by using pXRF and automated SEM-EDS techniques. Like the excavated fragments, this sample from the Altar Stone shows a distinctive mineralogy characterised by the presence of baryte and kaolinite along with abundant calcite cement. The presence of baryte leads to relatively high Ba being recorded during pXRF analysis (0.13 wt%). Combined, these results validate the history recorded on the specimen label and, as far as we know, makes this the only specimen taken purposely from that megalith. As such sample 2010K 240 provides a ‘go-to’ proxy for future studies of the Altar Stone as well as validating those samples recently assigned to the Altar Stone. In addition, this study demonstrates the vital importance of historic collection specimens and their preservation, conservation and documentation, as well as the role pXRF can play in the analysis of sensitive cultural artefacts and monuments that cannot be analysed using invasive or destructive techniques.
I have received a copy of the article, for which many thanks. It's a good and careful study, and the main points are covered in my post. But we are still none the wiser as to where the Altar Stone came from -- and MPP suggests England may now be the favoured country of origin......
ReplyDeleteHi Brian.
ReplyDeleteMay I respectfully remind you that I am one of the biggest exponents of the man made transport theory of bluestones from Preselis to Stonehenge and may soon be one of the most vociferous of the sea transport theorists. You may be interested to know that my current mission is to get people to believe that the Orcadians gifted Stone 80 to the project. That would involve a sea journey four times further than stones taken from Fishguard area.
Regards Tom Bennett
Hi Tom. Hope all is well. As ever, let's see the colour of the evidence.......
ReplyDeleteWell.....I've reinforced the message to the Wiltshire Museum
ReplyDelete( Devizes) Facebook site with my Post stating there are "OVER 40" geological varieties of bluestone" at or very adjacent to Stonehenge.
I wonder whether something very akin to this article about the Altar Stone is about to re - appear, this time in the WANHS Magazine for 2023, although. that may not arrive through my letterbox for for quite a while.....
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteIn all probability. It's one of their favourite outlets, and at least it has the benefit (as I recall) of real open access. One gets fed up of all these paywalls in the bigger journals..........
ReplyDeleteWANHS at Devizes Museum likes to always place the Bevins - Ixer articles on their Stonehenge - related rock topics at the very FRONT of the annual magazine. Much hubris results.....
ReplyDeleteMost readers, of course, don't see the paper copies, but read articles online. Maybe the Editor just likes the first article in each issue to be full of complicated diagrams and graphs which nobody actually understands........
ReplyDelete