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.

UPDATE - I am now sure it is the middle of the stone as shown below - https://www.sarsen.org/2024/12/the-location-of-altar-stone-engravings.html

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 UPDATE  southeastern end south side of the middle of the Altar Stone, which has otherwise always been buried. 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:

Three drawings - click to enlarge - free to use with acknowledgement

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 embedded 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 UPDATE south side of the middle, probably, 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."