The Chalk Plaque Lozenges

In 1968 during the widening of the A303 road near Stonehenge. archaeologists uncovered what is now known as the Chalk Plaque Pit, which contained two extraordinary engraved chalk plaques. The plaques feature intricate geometric designs incised into their surfaces. Recent analysis using advanced imaging techniques has revealed previously unseen details, including what appears to be a representation of a twisted cord on one of the plaques. 

 Full details are in Davis, B., Harding, P. and Leivers, M. (2021) ‘Reflectance Transformation Imaging (RTI) Investigation of Engraved Chalk Plaques from the Stonehenge Region’, Proceedings of the Prehistoric Society, 87, pp. 133–160. doi:10.1017/ppr.2021.13. 

The plaques have what has been termed front and back sides, the fronts having the intricate series of lines we are used to seeing but a picture of the "back" of plaque one in the Salisbury museum collection - https://collections.salisburymuseum.org.uk/object/SBYWM:2009R.125.1869 - which is very clear, lead me to look again at the the lozenges depicted.

The reverse of Plaque one from Davis et al.

A familiar pattern that is overshadowed by the other side of the plaques.

And a couple of unrelated uses of symbolic lozenges I have noticed this last week.

The Norman font in Minster Church - St Merteriana's - near Boscastle and a Japanese Mayo bottle.

  

The characteristics of lines engraved by stone tools versus metal tools

 The characteristics of lines engraved by stone tools versus metal tools can differ in several key ways:

 

## Stone Tool Engravings

 

**Groove Morphology:**

- Stone tool engravings tend to have more irregular, V-shaped or U-shaped cross-sections[1][2].

- The grooves may be shallower and less uniform in depth compared to metal tool engravings[1].

 

**Surface Texture:**

- Lines engraved by stone tools often exhibit a rougher, more irregular surface texture within the grooves[1].

- Microscopic analysis may reveal parallel alignments of smoothing and linear striations consistent with repeated cutting strokes using a stone edge[1].

 

**Width and Depth:**

- Stone tool engravings are generally wider and shallower than those made by metal tools[2].

- The width and depth can vary more along the length of a single line due to the irregular nature of stone edges[1].

 

**Precision:**

- Stone tools typically produce less precise and controlled lines compared to metal tools[2].

- Parallel lines or grid patterns may show more irregularity in spacing and alignment[1].

 

## Metal Tool Engravings

 

**Groove Morphology:**

- Metal tools tend to produce more uniform V-shaped or U-shaped grooves with smoother walls[2].

- The cross-section of the grooves is often more consistent along the length of the line[2].

 

**Surface Texture:**

- Lines engraved by metal tools generally have a smoother internal surface texture[2].

- Under magnification, metal tool marks may show more regular and finer striations within the grooves[2].

 

**Width and Depth:**

- Metal tool engravings can achieve narrower and deeper lines compared to stone tools[2].

- The width and depth of the lines are typically more consistent throughout the engraving[2].

 

**Precision:**

- Metal tools allow for greater precision and control in creating fine details and complex patterns[2].

- Parallel lines or grid patterns made with metal tools tend to be more evenly spaced and aligned[2].

 

It's important to note that the characteristics of engravings can also be influenced by factors such as the skill of the engraver, the specific type of stone or metal used for the tool, and the properties of the material being engraved[1][2]. Advanced microscopic analysis and 3D scanning techniques are often employed by researchers to distinguish between stone and metal tool engravings in archaeological contexts[1][3].

 

Differences in the terminations of engraved lines made by stone tools compared to metal tools:

 

## Stone Tool Engravings

 

**Termination Characteristics:**

- Stone tool engravings often exhibit more irregular and varied terminations.

- The ends of lines may curve out or feather, creating a less defined edge.

- Feather terminations are common, where the fracture front remains balanced and cleanly exits the stone, creating a sharp but potentially curved edge[9].

 

**Cross-Section:**

- Stone tool engravings can feature both angular V-shaped and concave U-shaped cross-sections[1].

- The variation in cross-section shape may be due to differences in the degree of wear and slight variations in the shape of the tool edges used[1].

 

## Metal Tool Engravings

 

**Termination Characteristics:**

- Metal tools generally produce more controlled and sharper line terminations.

- The ends of lines engraved by metal tools tend to be more precise and defined.

 

**Tool-Specific Features:**

- Gravers and burins, common metal engraving tools, can create very fine and sharp line endings[10].

- Square or V-point gravers, typically used for cutting straight lines, have very small cutting points that allow for precise terminations[10].

 

**Precision and Control:**

- Metal tools allow for greater precision in creating fine details, including the ability to control line endings more accurately[2].

- The "sculptor's stroke" technique, using a metal point chisel at a shallow angle, can create controlled parallel lines with well-defined endings[2].

 

It's important to note that while these general differences exist, the specific characteristics of line terminations can vary depending on factors such as the engraver's skill, the exact type of tool used, and the properties of the material being engraved. Advanced microscopic analysis and imaging techniques are often necessary to definitively distinguish between stone and metal tool engravings in archaeological contexts.

 

Citations:

[1] https://ro.uow.edu.au/cgi/viewcontent.cgi?article=8675&context=scipapers

[2] https://artofmaking.ac.uk/content/essays/2-stoneworking-tools-and-toolmarks-w-wootton-b-russell-p-rockwell/

[3] https://www.nature.com/articles/s41599-023-01742-7

[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5931501/

[5] https://www.britannica.com/topic/burin

[6] https://humanorigins.si.edu/evidence/behavior/stone-tools

[7] https://link.springer.com/article/10.1007/s10816-024-09658-5

[8] https://www.artslookup.com/prehistoric/rock-engravings.html

[9] https://stonetoolsmuseum.com/analysis/propagation-and-terminations/

[10] https://en.wikipedia.org/wiki/Engraving

[11] https://intarch.ac.uk/journal/issue40/8/4-1.html

[12] https://www.nature.com/articles/s41599-023-01742-7

[13] https://www.cambridge.org/core/books/stone-tools-in-the-paleolithic-and-neolithic-near-east/lithics-basics/487AB7381E1E3B42C4980448AF364C40

Was the Altar Stone ever a pillar?

 

The Altar Stone Outline based on Atkinson.

Richard Atkinson in the 1979 revision of his "Stonehenge" book addressed the question of whether the Altar Stone was erected or not:

 

"During the work of restoration in 1958 a small excavation was made round the Altar Stone in order to settle its exact shape, and thus to decide, if possible, whether it had ever formerly stood upright on one end.

The north-western end of the stone was found to have been heavily battered and defaced by former souvenir-hunters; but enough remained to suggest that in its original form it had been squared off at right-angles to the length of the stone.

The other end, however, was better preserved, and had clearly been dressed to an oblique bevelled outline, very much like the bases of some of the sarsens (e.g. stones 57 an d 58).

The purpose of these obliquely pointed bases seems to have been to facilitate the final adjustment of the stone after it had been raised to vertical position. The occurrence of the same form, deliberately worked, at one end of the Altar Stone suggests that it too was a pillar,"

Leaving aside that no stone hole at either end was found where it could have fallen from his logic seems to me to be very weak. And his squared off end doesn't appear to be so in his photo, below.

His belief is that an oblique end to a stone indicates it was a buried end, whereas I think that monoliths with a sloped top are more common than with a squared end. 

I don't think the angles of the ends of the Altar Stone tell us anything about whether it was ever vertical. The absence of evidence that was, however, give us a reason to believe it was placed prone deliberately in its present position. 

Are the engravings actually on the Altar Stone?

Over on X Mike Pitts makes a reasonable observation about the claims in https://www.sarsen.org/2024/10/prehistoric-engravings-discovered-on.html

 

2 The stone in the marked face does not look like the little we know of that end of the Altar Stone, which appears to be smoothly dressed (note other end is rough, suggests how it might have stood upright?)

3 Mark down the centre of the stone face looks like steel drilling

2/2 pic.twitter.com/S9JgXXvbHO

— Mike Pitts (@pittsmike) October 3, 2024

The bluestone with the scale in Mike's first post is 1958 Excavation, Unidentified Bluestone. https://historicengland.org.uk/images-books/photos/item/P51121. I have seen the two photos of it in the archive and it looks like Spotted Dolerite to me and it is labelled as being at Stonehenge, with what looks like a chalky pile behind it. But I must admit I can't see it in any other photos of the excavations. If it isn't Stonehenge though where would it be, where else would Atkinson have dug up such a stone? And that then got mislabeled? That the scale only appears in these couple of photographs isn't a worry, it also appears in two other Stonehenge photos https://historicengland.org.uk/images-books/photos/item/P51898 and https://historicengland.org.uk/images-books/photos/item/P51899 .We can also see that the archive numbering indicates that these photographs are in the series of Stonehenge ones.

The only other photo that shows the eastern end of the Altar stone is https://historicengland.org.uk/images-books/photos/item/P51908:  

 

 Richard Atkinson in the 1979 revision of his book Stonehenge described the ends of the Altar Stone: "The north-western end of the stone was found to have been heavily battered and defaced by former souvenir-hunters; but enough remained to suggest that in its original form it had been squared off at right-angles to the length of the stone. The other end, (The one we are discussing) however, was better preserved, and had clearly been dressed to an oblique bevelled outline, very much like the bases of some of the sarsens (e.g. stones 57 an d 58). The purpose of these obliquely pointed bases seems to have been to facilitate the final adjustment of the stone after it had been raised to vertical position. The occurrence of the same form, deliberately worked, at one end of the Altar Stone suggests that it too was a pillar, and one which, in view of its exceptional size among the bluestones, probably stood on the axial line.

My opinion is that the photo of the engraved stone matches both the description and the other photo of that end of the Altar Stone.

As to whether it is a quartz vein or a drill hole I am undecided and I don't think either indicate whether or not it is at Stonehenge.

The stone in the photograph is a sedimentary rock with its layers lying in the natural position with worked sides and a rougher top. It is about 50cm thick, according to the scale and lying in a dark chalky soil. All of this is also a description of the Altar Stone.  I can point out similar areas in it on other photos of the Altar Stone but I accept they are not definitive.

The other area that looks very similar is the middle section where it is exposed between 55b and 156 and the edges are worn down. And if the soil hadn't been removed under the overlying fallen stones the section would look similar to the photograph. The caption says it is taken from the North East but if it was taken towards the North East then it would be of the excavated southern side that we have no photographs of. 

So I am sure the engraving photographs were taken at Stonehenge, where else could they be of?

To suggest it is from an excavation anywhere else would need to be supported by photographs and documentation of the other site.

And that it is of the Altar Stone. I think it is very likely to be eastern end but it could be on the southern side. In the two pictures of the scratched stone I  notice the section edge showing on the right which is coming back towards the camera. That end of the stone hasn't been excavated. I can't square that with the other photos of his excavation, though of course it might be during the dig. However I think it does match with the middle section looking north east where the soil under 55b doesn't appear to have been excavated. And the top of the stone matches the curve. So this is an alternative part of the Altar Stone they might be on. Or even at the eastern end of the south side.

Which makes the indecipherable note with an arrow pointing at the South side on Atkinson's plan intriguing. I am trying to track down the original.

Click to enlarge.

Prehistoric Engravings Discovered on Stonehenge's Altar Stone

In the Historic England archive of Richard Atkinson's 1958 excavations at Stonehenge, I came across two photographs (link to full size copies)  that revealed an astonishing and unexpected feature of the Altar Stone. The photographs, labeled P50106 and P50107, partially show the excavated southeastern end of the Altar Stone, which has otherwise always been buried. (There is a possibility that they are on the south side of the stone instead) To my surprise, there appeared to be prehistoric engravings on it.

In his 1979 book on Stonehenge, Atkinson merely noted that the stone was deliberately worked. However, with the benefit of recent knowledge about prehistoric engravings on stones and ceramics from across the British Isles, the diagonal lines on the altar stone can now be clearly identified as part of that tradition. These lines are more than just functional stoneworking or accidental damage, they have a meaning.

This preliminary identification of the alternating diagonal lines, which indicate they were inscribed by stone tools, is just the beginning of a larger debate. Questions arise about their connection to the builders of Stonehenge, their meaning, and their origin. Given this significant discovery, it is crucial to reopen the previous excavation for a modern, detailed examination. This would ensure that any speculation is grounded in realism.

My sketch of the engravings:

The photos are on https://www.sarsen.org/2024/10/examining-physical-properties-of-altar.html and at https://historicengland.org.uk/images-books/photos/item/P50106 and https://historicengland.org.uk/images-books/photos/item/P50107 

I paid for them to be digitised and they are now available online, the embeded versions are below.

To confirm that this is the eastern end of the Altar Stone I compared different photos and matched up features. It isn't certain, the south side is also a possibility - https://www.sarsen.org/2024/10/are-engravings-actually-on-altar-stone.html

Examining the physical properties of the Altar Stone

The Historic England Archives in Swindon has a collection of unpublished photographs from Richard Atkinson's 1958 Stonehenge Excavations. Examining them recently, I came across several of the Altar Stone which provide new insights into this enigmatic stone.

Two in particular of the southeastern end of the stone are of particular interest, which I will investigate in a separate post.

P50106 - surface of altar stone from north-east

Click to enlarge. Photograph copyright and source Historic England Archive.

Not to be reproduced without written permission.

Used under Permission 10050_14608

Online version:

https://historicengland.org.uk/images-books/photos/item/P50106

P50107 - surface of altar stone from north-east

Click to enlarge. Photograph copyright and source Historic England Archive.

Not to be reproduced without written permission.

Used under Permission 10050_14608

Online version:

https://historicengland.org.uk/images-books/photos/item/P50107

The Barrow where the Lake House Meteorite was excavated from.

From Pillinger & Pillinger* we know that the Lake House Meteorite wasn't exposed to the weather on the steps for many years prior to its earliest photograph (1899) as the local chalk on its surface hadn't been washed off. This also indicates that its last subterranean home had been close by.

In 1899 the house had been recently bought by Lovibond the brewer and he doesn't seem to have had any connections to archaeology or geology so is unlikely to have been instrumental in its excavation.

However a previous owner Edward Duke had organised the excavation of numerous barrows on the estate and kept the finds in his private museum, the portable objects of which were sold at auction in 1895.

Duke recorded he found a large stone in the barrow he numbered 18. (p586, WANHS vol35:

In the absence of any other evidence or history of the meteorite this seem to be most obvious source of the meteorite. Duke's excavators found it in a barrow and he kept it at Lake House, probably in some outbuilding as a curio. Lovibond as the new owner turned out the barns put it on display. And this is the nub of the Pillinger & Pillinger article.  

But where is Barrow 18? 

The barrow expert and sleuth Simon Banton (check out his barrow map) stepped up to the challenge and reviewed all the evidence in great depth including more recent work on the Lake House Barrows. And whilst the identification isn't certain there is one barrow that fits the description and reported size and has not been identified as one of the other Duke barrows.

Wilsford 81

"A field visit by the OS in 1972 found the barrow to be a mound, 1.15m high, with a diameter of 13m, this is 0.4m higher than Grinsell reported.
The Bronze Age bowl barrow referred to above (1-8) was surveyed at a scale of 1:1000 in May 2009 as part of English Heritage's Stonehenge WHS Landscape Project. It was originally listed as Wilsford 81 by Goddard in 1913. The barrow has an overall diameter of 13.8m and comprises a mound, 1m high, with a slight berm on its northern and western sides plus possible traces of a ditch to the south-west, although this could be a plough line."

The question of where the bronze age barrow builders obtained it from is another question, it is unlikely to have fallen in southern England, so it would be worth investigating Wilsford 81 further, there may be fragments and clues that Duke's diggers missed. And if there still is a large stone there then it can be ruled out as the source.

That it is likely to be yet another example of the large stones manuported to Ancient Wessex from afar seems certain.

*"Pillinger, CT and Pillinger, JM. 2024 Grandfather's stone: the Lake House Meteorite, Britain's largest and earliest extraterrestrial sample. Wilts Arch & Nat Hist Magazine 117, pp 181-196."

1899 Photo of the Lake House Meteorite

In the latest WANHS, the Lake House Meteorite is discussed at length in "Pillinger, CT and Pillinger, JM. 2024 Grandfather's stone: the Lake House Meteorite, Britain's largest and earliest extraterrestrial sample. Wilts Arch & Nat Hist Magazine 117, pp 181-196."

In tracing the history of it the authors struggle to explain its appearance in a 1908 photo and say: "Other dated contemporary photographs would be of considerable help"

UPDATE - 1899 photograph found https://collections.salisburymuseum.org.uk/object/SBYWM:1947.39.9

Which clears Detmar Blow and refutes the theory it came from Stonehenge.

Previous Post:

Salisbury Museum can provide that help:

A photograph dated 1903 of Lake House shows it.

https://collections.salisburymuseum.org.uk/object/SBYWM:1947.39.8

As does an October 1905 one by Miss Clarice Hules

https://collections.salisburymuseum.org.uk/object/SBYWM:1947.39.43

Its sudden appearance on the steps in the early 1900s supports Andrew  Ziminski's Theory that it was removed from Stonehenge in 1901.

See  https://www.sarsen.org/2022/07/detmar-blow-and-meteorite-andrew.html

Did Cunnington find any bluestone in Boles Barrow?

The notion that the Boles Barrow Bluestone came from Boles Barrow is based on an undated footnote William Cunnington added to his copy of a letter he had sent to H P Wyndham in 1801. In which he had described the large stones in the barrow he found when excavating it that year as "are of the same species of stone as the very large Stones at Stonehenge". In other words he was saying they were sarsens. Further on in the letter he notes he has brought ten such stones to his house, not explicitly saying they were or were not from the barrow. His later footnote to himself is ":Since writing the above I discover amongst them (presumably the stones in his garden) the Blue Hard Stone also, ye same to some of the upright stones in ye inner circle at Stonehenge". (Mike Pitts Hengeworld 2000 p 199-200)

So the linking of any bluestone to the barrow is not clear, even without the disparity between the weights of the Boles Barrow bluestone (611kg) and the weights of stones Cunnington records (13-90kg)

So at some time looking at his rockery he realises he has inadvertently got a bluestone in there, and as some of the rockery may, and only may, have come from Boles Barrow it is assumed that is where it came from. Even though he didn't notice it at the time.

In Colt Hoare's description of the excavation of Boles Barrow - see the bottom of this post - there is no note of the discovery of a bluestone.at all.

But he did record finding "a large piece" of one of the Stonehenge Bluestones in a tumulus in the Stonehenge triangle,  Amesbury G4, for details search for it on  Simon Banton's Barrow Map and here it is recorded in Colt Hoare's book:

 Click to enlarge

 https://historicengland.org.uk/listing/the-list/list-entry/1012387

Sir Richard Colt Hoare The History of Ancient Wiltshire 1812 Volume 1. Boles Barrow Excavation

In this ride I shall ascend the hills at the back of Sir William A'Court's demesne, and proceed over Nanny Down towards Bowls Barrow. At the upper end of Heytesbury field and near the summit of the hill, is a flat barrow ploughed over, which Mr. Cunnington opened in 1800, and found about a foot under the surface, a layer of flints that extended nearly over the whole tumulus, intermixed with fragments of thick and coarse pottery; and was much surprized in finding ten small brass Roman coins of the Emperors Constantine, Valentine I. and II. and Arcadius, together with some pieces of the fine red Samian pottery. From the discovery of these articles, viz. first, the rude pottery, and afterwards the fine Samian ware, and coins, we may conceive this to have been occupied both by the Celtic and Romanized Britons.

On the summit of the hill we meet the great track-way, and crossing it come to a large tumulus named BOWLS BARROW; its length is one hundred and fifty feet at the base; its width ninety-four feet, and its elevation ten feet and a half, though it appears to the eye much higher; the broad end points towards the east. This large barrow was opened by Mr. Cunnington in 1801, and attended with much labour. He began by making a section of considerable width and length across the barrow near the east end, and at the depth of two feet nine inches found a human skeleton lying south-west and north-east, and with it a brass buckle, and two thin pieces of the same metal. Towards the centre of the barrow, were two other skeletons interred, with their heads towards the south, and one of them lying on its side. The interior parts of the barrow were composed entirely of white marl stone to the depth of four feet and a half: this was succeeded by a ridge of large stones and flints, which extended wider as the men worked downwards. At the depth of ten feet and a half, which was the base of the barrow, was a floor of flints regularly laid, and on it the remains of several human bodies deposited in no regular order. It appeared therefore, that they had been thrown together promiscuously, and a great pile of stones raised length-ways along the centre of the barrow over them. This pile (in form like the ridge of a house), was afterwards covered with marl excavated from the north and south sides of the barrow, the two ends being level with the plain. Although four men were employed for three days, they could not explore more than the space of about six feet by ten; yet in this small portion they found fourteen skulls, one of which appeared to have been cut in two by a sword. It is rather singular, that no fragments whatever of pottery, charred wood, or animal bones, were found in the course of the above operations.

At a subsequent period Mr. Cunnington made a second attempt on this tumulus, by opening more ground both at the east as well as west end; at the former he found the heads and horns of seven or more oxen; also a large cist close to the skeletons; but owing to the great height of the barrow, and the large stones continually rolling down upon the labourers, he was obliged to stop his operations.

The repairs to Thornborough

The Northern Henge is now open to visit 

As part of the landscaping of Thornborough Henges now it has control of them English Heritage are repairing the banks of the Central Henge where livestock, the wild burrowing and the farmed grazers have damaged them. They will look a lot better.

Some photos of my recent visit when English Heritage were showing off their work compared to a previous visit a couple of years ago.

I am very pleased to see the previously blocked southern entrance to the Northern Henge has been reopened to view the the other henges, opening up the ancient route to the eyes only sadly.

The public entrance to the North Henge is through the northern entrance - details at https://www.english-heritage.org.uk/visit/places/thornborough-henges/  

Led by local pagans visiting Thornborough Henges at English Heritage celebration of reuniting all three and bringing them into the national collection of historic sites and monuments pic.twitter.com/9aT2yvDKQu

— Duncan Wilson (@HE_ChiefExec) September 17, 2024

The Mystery of the Dagger Carvings on Stone 11

In the 1950s  Richard Atkinson during his excavations at Stonehenge, when the axe and dagger carvings on the stones were first being recognised, photographed Stone 11 and noted and highlighted  five axe carvings on it. The photograph is generically dated 1 Jan 1958 and is in the Historic England Archive:

Close-Up Of Dagger Carvings On Stone 11 Part of the Series: ATK01/01 R J Atkinson photographs. Reference: P50839  It is not available online, only in the archive.

My sketch of the dagger carvings on the South Side of Stone 11 based on the photo:

He doesn't mention them in his book about the excavations, and the 2012 Laser Scan of the Stones did not spot them, and whilst it looked at and judged other possible carvings it seems not to have looked for these.

So a mystery. Are they real? One to look for on a visit to the stones.

Investigation of Engraved Chalk Plaques from the Stonehenge Region

Davis, B., Harding, P. and Leivers, M. (2021) ‘Reflectance Transformation Imaging (RTI) Investigation of Engraved Chalk Plaques from the Stonehenge Region’, Proceedings of the Prehistoric Society, 87, pp. 133–160. doi:10.1017/ppr.2021.13 is available as a pdf from: https://www.cambridge.org as an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.

Fascinating study which I didn't realise was available for free. 

Lot Long's Location

The iconic photo of The Wiltshire Thatcher discovered by Brian Edwards has just finished being on exhibition at The Wiltshire Museum.

Detective work by Brian identified the Thatcher was most likely to be Lot Long from Mere.

Looking carefully at the embiggened scan of the photo at the Museum I realised the hedge was quite distinctive. The hedge isn’t straight and the difference in focus of the trees emphasises it. From the left it comes out towards the camera and then curves round to go away at about 90 degrees.

Whitsun 1892 – June 5-6th – is the date in the album and so we can assume the photograph was taken around this time. The trees and hedge are in full leaf which would be expected. The Thatcher’s shadows show the sun is quite high and in front of him, to the right of the photo. The sun is lower than it would be at noon so probably early afternoon. The photo is taken facing in an easterly direction.

The Ordnance Survey map of  1890 shows such a hedge with trees visible to the east from the Shaftesbury Road on which Lot Long lived and the photographer, who was based in Shaftesbury, probably travelled. 

The field and hedge are still unaltered and Google Earth shows the view from the gate into the field and the direction of the sun in the early afternoon.

No other similar view of a hedge was found in a search of the areas covered by the photographic album.

From the Public Right of Way I was able to take my own photographs and superimpose the Thatcher photograph.

That such a matching location is exactly where Lot Long would be expected to be photographed adds considerable weight to his plausible identification as the thatcher.

(Click pictures to enlarge them)

 

Boles Barrow Excavation 2024 - The finds.

Oh and no bluestone!

— Richard Osgood (@richardhosgood) September 5, 2024

Stonehenge origins search heats up as Orkney ruled out

Scientists’ search for the source of Stonehenge’s iconic Altar Stone has intensified, with a new paper ruling out Orkney as where it came from.- Video from Daily Motion 

And: Stonehenge tale gets ‘weirder’ as Orkney is ruled out as altar stone origin - The Guardian

The long flight of the Devil's Arrows

"The Devil's Arrows, a trio of towering prehistoric standing stones near Boroughbridge in North Yorkshire, have long captured the imagination of visitors with their sheer size and enigmatic history.

But where exactly did these massive monoliths come from? 

 According to archaeological evidence, the stones were likely quarried from Plumpton Rocks, a natural millstone grit formation located about 9 miles (14 km) south of their current location[1][3]. Millstone grit is a coarse-grained sandstone that is quite distinct from the finer-grained local building stone in the area[2]."

[1] Devil's Arrows — Storied Traveling https://www.storiedtraveling.com/blog/devilsarrows 

[2] The Devil's Arrows - The Smell of Water https://teessidepsychogeography.wordpress.com/2017/11/15/the-devils-arrows-3/ 

[3] Devil's Arrows Standing Stones, Boroughbridge, Yorkshire https://www.britainexpress.com/counties/yorkshire/ancient/devils-arrows.htm

Timeline of the Altar Stone Papers

With the release of a brace of papers about the Altar Stone in short order there is some confusion about who said what when.

The bombshell paper: Clarke, A.J.I., Kirkland, C.L., Bevins, R.E. et al. A Scottish provenance for the Altar Stone of Stonehenge. Nature 632, 570–575 (2024). https://doi.org/10.1038/s41586-024-07652-1 was submitted on 16 December 2023 

As this suggested an Orcadian Basin (not Orkney) source for the stone the it is only to be expected that the basin should be searched for the best match. For the reasons expressed in the paper the Orkney Mainland was the prime suspect so that is where the first search was performed. This search was promptly reported by a large team of experienced experts:  Richard E. Bevins, Nick J.G. Pearce, Stephen Hillier, Duncan Pirrie, Rob A. Ixer, Sergio Andò, Marta Barbarano, Matthew Power, Peter Turner, Was the Stonehenge Altar Stone from Orkney? Investigating the mineralogy and geochemistry of Orcadian Old Red sandstones and Neolithic circle monuments The paper was fully peer reviewed but only the tiniest of revisions were needed so prompt electronic publication was possible.  

Surprisingly they drew a blank, which is in itself an illuminating result. The paper was over six months later to the original paper as it was submitted on 23 July 2024.

So all good scientific work as the investigators narrow their search down. No conspiracy theories needed here.

The Altar Stone wasn't from Orkney

Fascinating update on the hunt for the source of the Stonehenge Altar Stone, and great insights into the sources of the monoliths on Orkney.

Richard E. Bevins, Nick J.G. Pearce, Stephen Hillier, Duncan Pirrie, Rob A. Ixer, Sergio Andò, Marta Barbarano, Matthew Power, Peter Turner,

Was the Stonehenge Altar Stone from Orkney? Investigating the mineralogy and geochemistry of Orcadian Old Red sandstones and Neolithic circle monuments,

Journal of Archaeological Science: Reports, Volume 58, 2024, 104738,

ISSN 2352-409X,

https://doi.org/10.1016/j.jasrep.2024.104738

(https://www.sciencedirect.com/science/article/pii/S2352409X24003663)

Abstract: Recent petrological, mineralogical and geochemical investigations of the Stonehenge Altar Stone have negated its source in the Old Red Sandstone (ORS) Anglo-Welsh Basin. Further, it has been suggested that it is time to look wider, across northern Britain and Scotland, especially in areas where geological and geochemical evidence concur, and there is evidence of Neolithic communities and their monuments. In this context the islands of Orkney, with its rich Neolithic archaeology, are an obvious area worthy of investigation. The same techniques applied to investigations of the Altar Stone and ORS sequences in southern Britain have been applied to two major Neolithic monuments on Mainland Orkney, namely the Stones of Stenness and the Ring of Brodgar. In addition, field samples of ORS lithologies from the main stratigraphic horizons on Mainland Orkney have been investigated. Portable XRF analyses of the five exposed stones at the Stones of Stenness and seven of the exposed stones at the Ring of Brodgar show a wide range of compositions, having similar compositions to field samples analysed from both the Lower and Upper Stromness Flagstone formations, with the stones at Stenness appearing to have been sourced from the Upper Stromness Flagstone Formation while the Ring of Brodgar stones possibly being sourced from both formations. Examination of the mineralogy of ORS field samples and the Stonehenge Altar Stone, using a combination of X-ray diffraction, microscopy, Raman spectroscopy and automated SEM-EDS shows there to be no match between the Orkney samples and the Altar Stone. Only two samples from Orkney showed the presence of baryte, a characteristic mineral of the Altar Stone. Another key discriminant is the presence of abundant detrital K-feldspar in all of the Orkney field samples, a mineral which has only very low abundance in the Altar Stone. In addition, the regularly interstratified dioctahedral/dioctahedral smectite mineral tosudite is present in the clay mineral assemblage of the Altar Stone, but not detected in the Orkney samples. It is concluded that the Altar Stone was not sourced from Mainland Orkney, despite considerable evidence for long-distance communications between Orkney and Stonehenge around 3000/2900 BCE.

Keywords: Altar Stone; Stonehenge; Orkney; Old Red Sandstone; Sandstone; Provenancing

Middens and Nettles

Living at All Cannings Cross with midden material scattered in the fields around me and having been involved in several excavations of the local middens I was fascinated by this discussion of growing nettles on them.

When I have been asked about the Pewsey Vale middens this is the best explanation that I can think of for them. I thought the enriched soil and the stone tools as well as the value of long nettle fibres supported it.

My theory has usually just been humoured but not taken seriously so imagine my surprise at this:

 

From: Ben Chan,

Settling the argument: The contribution of use-wear studies to understanding artefact scatters in Neolithic Britain,

Journal of Archaeological Science: Reports,  Volume 57, 2024, 104686,

ISSN 2352-409X,

https://doi.org/10.1016/j.jasrep.2024.104686.

(https://www.sciencedirect.com/science/article/pii/S2352409X24003146)

Early science and colossal stone engineering in Menga, a Neolithic dolmen (Antequera, Spain)

Abstract 

Megaliths represent the earliest form of monumental stone architecture. The earliest megalithic chambers in Europe appeared in France in the fifth millennium BCE. Menga is the oldest of the great dolmens in Iberia (approximately 3800 to 3600 BCE). Menga’s capstone #5 weighing 150 tons is the largest stone ever moved in Iberia as part of the megalithic phenomenon and one of the largest in Europe. The research presented here proposes a completely innovative interpretation of how this colossal monument was built.

https://www.science.org/doi/10.1126/sciadv.adp1295

José Antonio Lozano Rodríguez et al. ,Early science and colossal stone engineering in Menga, a Neolithic dolmen (Antequera, Spain).Sci. Adv.10,eadp1295(2024).DOI:10.1126/sciadv.adp1295

Original Position of the Altar Stone

In the recent discussions of the Altar Stone at Stonehenge variations of the equivocation that is unknown if it was originally vertical or if it was placed in its present horizontal position keep reoccurring.

Because Stone 55 fell and broke it there is assumed to be ambiguity over this. In the words of an engineering expert who has looked at the plans, the excavation records and scenarios of the collapse of the Trilithon onto it, the idea that it was a vertical stone is "knuckle-dragging, mouth-breathing stupidity that isn't worth a pitcher of warm spit". I wouldn't go so far myself just that the idea that has no logic or evidence behind it. 

It was placed as a horizontal stone. Which means that its 81 degree angle to the main Solstical Alignment is also deliberate.

As I argued in my "The Twisted Trilithon of Stonehenge" it is just one of the group of stones at the apse end of the inner horseshoe so aligned. They indicate the sunrise and sunset of the Solstical days that the main alignment indicates the other end of the day of. So the 81 Degree angle aligns to the sunrise of the Winter Solstice Sun which at the end of the day sets in line with the middle of the horseshoe. As well as the Altar stone (Stone 80), and the tallest Trilithon, there were a pair of Bluestone pillars 66 and 68 (68 has been pushed over but its original position is known from Gowland's excavation records), marked by blue circles in the plan below. There was also a pair of wooden posts to the north of the Altar Stone 3364 and 3362.

Plan based on Cleal et al

Intriguingly the layout is reminiscent of the Aberdeen recumbent stone circles -

   

Easter Aquhorthies stone circle (cropped view) by stu smith from Hampton Wick / Aberdeen, uk, CC BY-SA 2.0, via Wikimedia Commons

Dr John Hill goes even further "The Scottish Stonehenge Architect and His Aberdeenshire Stone Circles".  

The Stonehenge Palisade - a video by Paul Whitewick

Altar Stone Analyses, A Simplified Overview.

Cumulative probability density function plot of comparative Old Red Sandstone detrital zircon U–Pb datasets (concordant ages) versus the Altar Stone. Proximity between cumulative density probability lines implies similar detrital zircon age populations.

Re: A Scottish provenance for the Altar Stone of Stonehenge [2]

## Analytical Techniques

- Automated mineralogy: A TESCAN Integrated Mineral Analyser was used to study the stone's texture and mineralogy[2].

- Scanning electron microscopy (SEM): A CLARA field emission SEM provided high-resolution imaging of individual minerals like zircon, apatite, and rutile using back-scatter electron and cathodoluminescence techniques[2].

- Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS): This method was used for detailed chemical analysis of the stone[2].

## Geochronology

- U-Pb dating: This technique was applied to date zircon, apatite, and rutile mineral grains within the Altar Stone[2][4].

## Key Findings

The analysis revealed:

- The mineral grains in the Altar Stone have two distinctive date peaks at just over 1 billion years old and 458-470 million years old [5]

- The chemical composition matches rocks from the Orcadian Basin in northeastern Scotland[5][6]

- This indicates the stone originated about 435 miles (700 km) from Stonehenge[5]

The Samples

## Altar Stone Samples

- A sample labeled 2010K 240, collected from the underside of the Altar Stone in 1844[8].

- A sample labeled MS3, from an excavation near stone 1 by Colonel Hawley [7]

## Verification Methods

The researchers verified the samples through several means:

- Visual identification: Debitage fragments were initially identified based on lithological similarity to the Altar Stone[S1].

- Portable X-ray fluorescence (pXRF) analysis: This non-destructive technique was used to analyze the chemical composition of the Altar Stone's surface directly at the site[1].

- Conventional optical microscopy: Researchers examined thin sections of the stone using transmitted and reflected light microscopy[2].

- Geochemical comparison: pXRF analysis was used to compare the elemental composition of the fragments to the in situ Altar Stone[S1].

- Mineralogical analysis: Automated SEM-EDS was used to quantify the mineralogy of the Altar Stone and debitage fragments[S1].

- Petrographic analysis: Supported the identification of the debitage fragments as being derived from the Altar Stone. They also verified the authenticity of the historical sample (2010K 240) through comparison with other Altar Stone samples[8].

- The provenance of  the historical sample (2010K 240) was confirmed [22]

##  Comparative Samples of the Orcadian Basin

   - Samples were professionally collected from the Old Red Sandstone (ORS) of the Orcadian Basin in northeastern Scotland - specifically, samples came from Spittal Quarry, Caithness (sample AQ1) and Cruaday Quarry, Orkney (sample CQ1)[2].

##  Analysis Methods:

   - The samples underwent apatite U-Pb dating[2].

   - In situ thin-section analysis was used, which can help mitigate against potential contamination[2].

##  Results:

   - Apatite U-Pb age components from these Orcadian Basin samples matched those from the Altar Stone[2].

   - Group 1 apatite from Cruaday (CQ1) yielded an age of 473 ± 25 Ma.

   - Group 1 apatite from Spittal (AQ1) yielded an age of 466 ± 6 Ma.

   - Group 2 apatite from Spittal (AQ1) yielded an age of 1,013 ± 35 Ma.

   - Apatite U-Pb dating of MS3 (Altar Stone Sample) yielded 117 analyses.

   - Two distinct groups of apatite were identified:

     Group 1:

     - 108 analyses

     - Lower intercept age: 462 ± 4 Ma (MSWD = 2.4)

     - Upper intercept 207Pb/206Pb: 0.8603 ± 0.0033

     Group 2:

     - 9 analyses

     - Lower intercept age: 1,018 ± 24 Ma (MSWD = 1.4)

     - Upper intercept 207Pb/206Pb: 0.8910 ± 0.0251

 - Apatite Lu–Hf data for the Altar Stone. A) Apatite Lu–Hf isotopic data and ages for thin-section 2010K.240. B) Apatite Lu–Hf data for secondary references. See Spreadsheet in Citation [20]

-   - The Early Palaeozoic apatite components from Caithness and Orkney (473 ± 25 Ma and 466 ± 6 Ma) are identical, within uncertainty, to the Altar Stone Group 1 apatite (462 ± 4 Ma)[2].

-Zircon age data was collated with with the U–Pb analyses1 of "FN593" (another fragment of the Altar Stone) . (This should be FN573 [23] - SH08 Context 16 FN573 (previously erroneously labelled as FN593). From a Roman context at Stonehenge. Described in Ixer and Bevins (2013) under FN593.[24])

The result was at >95% certainty, no distinction in provenance can be made between the Altar Stone zircon age dataset (n = 56) and those from the Orcadian Basin (n = 212), Svalbard ORS (n = 619) and the Laurentian basement.

- Rutile U–Pb Results: From Altar Stone sample MS3 two groups were obtained. "Group 1 which constitutes 83 U–Pb rutile analyses, forming a well-defined mixing array on a Tera-Wasserburg plot between common and radiogenic Pb components. This array yields an upper intercept of 207 Pb/ 206 Pb i = 0.8563 ± 0.0014. The lower intercept implies an age of 451 ± 8 Ma implies an age of 451 ± 8 Ma

Group 2 comprises 9 grains, with 207 Pb corrected 238 U/206 Pb ages ranging from 591–1,724 Ma. Three grains from Group 2 define an age peak 68 at 1,607 Ma. Given the spread in U–Pb ages, we interpret these Proterozoic grains to represent detrital rutile derived from various sources."

##  Significance:

   - These matches support a provenance from the Orcadian Basin for the Altar Stone[2].

##Citations:

[1] https://pure.aber.ac.uk/ws/portalfiles/portal/50647128/linking_derived_debitage_to_the_stonehenge_altar_stone_using_portable_x_ray_fluorescence_analysis.pdf

[2] https://www.nature.com/articles/s41586-024-07652-1

[3] https://www.sciencealert.com/stonehenge-mystery-scientists-reveal-how-they-traced-the-altar-stone

[4] https://www.cnn.com/2024/08/14/science/stonehenge-altar-stone-scotland/index.html

[5] https://www.somersetlive.co.uk/news/history/stonehenge-altar-stone-stunning-twist-9485735

[6] https://www.cbsnews.com/news/stonehenge-altar-stone-came-from-scotland-not-wales-research/

[7] https://www.cambridge.org/core/journals/mineralogical-magazine/article/linking-derived-debitage-to-the-stonehenge-altar-stone-using-portable-xray-fluorescence-analysis/23E9A00C0C2B9FAC0BC74AC11AAE5B2D

[8] https://pure.aber.ac.uk/ws/portalfiles/portal/65608443/Assessing_the_authenticity_of_a_sample_taken_from_the_Altar_Stone_accepted_version_v2_Archaeologican_Science.pdf

[9] https://www.sciencedirect.com/science/article/abs/pii/S2352409X23001487

[10] https://phys.org/news/2024-08-stonehenge-giant-altar-stone-northeast.html

[11] https://www.cnn.com/2024/08/14/science/stonehenge-altar-stone-scotland/index.html

[12] https://www.academia.edu/81723766/Handheld_X_Ray_Fluorescence_Analysis_HH_XRF_a_non_destructive_tool_for_distinguishing_sandstones_in_historic_structures?uc-sb-sw=19875163

[13] https://www.snexplores.org/article/stonehenge-altar-stone-origin-chemistry-minerals

[14] https://www.nature.com/articles/s41586-024-07652-1

[15] https://data.jncc.gov.uk/data/d156c160-558d-4855-9927-6066e183045e/gcr-v31-old-red-sandstone-c2.pdf

[16] https://en.wikipedia.org/wiki/Orcadian_Basin

[17] https://nora.nerc.ac.uk/id/eprint/516767/1/CR16017.pdf

[18] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9230696/

[19] https://www.sciencedirect.com/science/article/pii/S0191814123001396

[20] https://pure.aber.ac.uk/ws/portalfiles/portal/65608443/Assessing_the_authenticity_of_a_sample_taken_from_the_Altar_Stone_accepted_version_v2_Archaeologican_Science.pdf

[21] https://static-content.springer.com/esm/art%3A10.1038%2Fs41586-024-07652-1/MediaObjects/41586_2024_7652_MOESM4_ESM.xlsx

[22] https://www.sarsen.org/2022/09/the-altar-stone-sample-provenance.html

[23] https://research.aber.ac.uk/files/38490241/Altar_Stone_Final_submitted_v6_4_June_1_1_.pdf

[24] https://www.academia.edu/5464937/Chips_off_the_old_block_The_debitage_Dilemma

(Lightly edited from originals kindly supplied - extra citations retained for further research)