The Newall Boulder: a multi-faceted glacial clast with post-emplacement prehistoric and recent human damage. (Courtesy Salisbury Museum)
Newall’s Glacial Erratic Boulder
Notes following a preliminary examination of the boulder recently "rediscovered" in Salisbury Museum
Observations
1. It is a coherent small boulder which hasn’t been knocked off a bluestone monolith either here or anywhere else. Shape — an elongated, tapering and flattened small boulder, c 22 cms x 15 cms x 10 cms. Approximately the same shape and size as a human face. Weight - not measured but estimated at over 5 kg.
2. The lithology appears to be quite unlike anything else previously recorded for a boulder at Stonehenge —it is a dense and heavy welded tuff, dark blue-black in colour. It is nothing like the Preseli spotted and unspotted dolerites, the foliated rhyolites or Lower Palaeozoic sandstones. Grain size is very small. There are many intersecting small fractures and veins marked by whitish crystal concentrations — and some lumps of what appear to be quartz crystals. Petrologist RK Harrison of the IGS said: “This large, dark blue-grey, hard, flinty (? partly worked artifact) shows a white weathered crust up to 5 mm thick. The thin section shows a complex structure of very finely banded welded tuff (compressed foliated shards cemented by fine silica) with composite quartz grains and strings of dusty leucoxene, separated by patches of much finer grained, finely fluxioned glassy lava with patches of granular quartz. This specimen appears to represent a complex of originally viscous glassy lava and welded vitric tuff, all presumably of rhyolitic composition.” In correspondence, there was agreement in 1971-2 among IGS geologists that this rock has probably come from North Wales, possibly from the Capel Curig area, although I think there is a chance that it has come from the Strumble Head - Fishguard area. Work is under way by geologists Ixer and Bevins, with a view to an accurate description of the petrology and a suggested provenance. It does not much matter where the stone has come from, but nonetheless we look forward to seeing the eventual report and to discovering whether this boulder might be related to one or more of the bluestones 38, 40, 46 and 48 in the bluestone circle at Stonehenge -- all classified as "dacitic ash-flow tuffs" or as rhyolite / ignimbrite. The dacites have recently been studied -- but they seem different too.
3. There are 5 main natural facets or faces, possibly influenced by the veins that run through the boulder. One of the facets has quartz (?) remnants sticking to it, which seem to be streamlined or slickensided. There is one quite prominent yellowish nodule about one cm thick. There is some iron-staining also, including a patina on some of the Neolithic (?) fracture scars which have been determined by vein positions. This is another typical feature of glacial erratics.
5. In essence this is a small boulder modified and shaped in subglacial transport. This is the consensus — from the photographic evidence, 11 out of 12 senior geomorphologists agree (see Appendix 1). The other expert suggests a glaciofluvial origin; I disagree with that. There are too many fresh micro surface features that would have been removed if there has been any water transport or modification. The surface characteristics also preclude an origin as a “quarried block” deliberately taken from a favoured rock outcrop.
7. I would also agree that it is a rejected “artefact” in the sense that somebody has tried at some stage (Neolithic?) to use the boulder either as a maul or (more likely) as the raw material for a large stone axe. This attempt at "dressing" was not successful — the rock does not fracture conchoidally, and when several chunks had been knocked off both the lee (downglacier) end and the stoss (upglacier) end the attempt was abandoned and the stone was thrown away. It has also been damaged in several different places by the geologists who examined it in 1970 -1972 and in 1978 — there are traces of cutting and grinding and there are several new percussion scars in a row near the stoss end of the clast.
9. The tip of the bullet-shape (at the stoss end) has been knocked off or cut off. This looks suspicious — was this done by the geologists when attempting to take samples? There is a flat, smooth face which looks as if it has been ground down in the collection of a rock powder sample.
10. We can identify a “top surface” and a “bottom surface” of the boulder. The curving and irregular top surface — including the place from which the sample RSN18 was taken — has a whitish surface colouring and a distinct weathering crust up to 5 mm thick. The “bottom surface” is flatter, and has a patina but no weathering crust. This is a crucial piece of evidence relating to the history of the boulder. We can interpret a “ground surface” position as revealed on the boulder itself; the top was clearly exposed to surface weathering over a very long period, while the rest was buried and protected.
11. In several places beneath “ground level” there is a crusty tufa deposit up to c 4 mm thick. This suggests burial in a calcium-rich environment — probaby on Salisbury Plain. Some white crusty deposits of tufa occur on ALL faces (including Neolithic (?) percussion fractures— this suggests further slight precipitation of calcium carbonate following the rejection by the axe maker and burial in chalk rubble.
12. We can be certain that this is not the only striated small boulder found at Stonehenge, as confirmed by Hawley, Newall, Engleheart and Dale. Some appear to have been found in 1920. They were all treated as rubbish and thrown away because they were not “worked”— and only worked stones and monolith remnants were of interest to Hawley. They are probably in the trenches used for waste from the excavations. Hawley and Newall were clearly heavily influenced by the forceful views of HH Thomas — and there may well have been something of a “conspiracy” after 1923 to bury (quite literally) anything that was inconvenient and likely to upset the human transport hypothesis.
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Suggested history of the boulder:
1. Following entrainment the boulder was reduced in size and heavily modified during glacial transport, for much of the time on the bed of a glacier.
2. It was eventually dumped on the chalklands of Salisbury Plain, probably at or near Stonehenge.
3. The top of the boulder projected above the ground surface, and was subjected to subaerial weathering over a protracted period. In this calcium-rich environment a crust of tufa was deposited on some of the buried surfaces of the boulder.
One of the igneous boulders exposed during the digs at Waun Mawn. The weathered top was previously exposed above the turf layer, and the old ground level can be traced -- as on Newalls' Boulder.
4. It was dug up and collected by an axe-maker on the basis that it was the right shape and size for a hand axe. He tried to shape it by percussion, particularly on the lee end, taking advantage of existing fracture scars acquired during glacial transport. Some attempts were also made to shape the pointed or stoss end. The enterprise failed because the stone did not fracture conchoidally or predictably.
5. The stone was thrown away into a pile of accumulating chalk rubble in connection with the Neolithic erection of standing stones at Stonehenge.
6. It was gradually buried to a depth of 64 cms and over time further nodules and crusts of tufa were formed on all surfaces, including the “fresh” man-made surfaces.
7. Following its discovery (probably in 1924) by Hawley and his co-workers, Hawley treated it as “rubbish” and wanted to throw it out— but Newall took it home together with other foreign stones and they remained in his attic for the next 46 years.
8. When geologist Geoffrey Kellaway was preparing his 1971 “Nature” article he found the mention in Hawley’s interim report published in 1926, and contacted Newall about the whereabouts of the boulder. Newall passed the boulder (and other rock fragments) over to Kellaway and the IGS, and Kellaway arranged for it to be sampled and examined by some of his specialist colleagues including Harrison. In 1971-72 they did considerable damage it because they too presumably treated it as a “rubbish stone”. They had no knowledge of the processes involved in the shaping of glacial clasts — but they did know about the potential significance of striations. Newall handed the boulder (together with other bluestone fragments) to Salisbury Museum on 24 November 1976, when it was put into storage. There it remained without anybody being aware of its significance for another 46 years.
9. This is where it gets confusing! In 1989 the OU team (including Olwen Williams-Thorpe and Rob Ixer) examined as many bluestone fragments as they could find, including one that they referred to as RSN18 - ENQ2305. They renamed it OU2 and the analysis showed it to be a typical blue-grey rhyolite from the north slopes of Mynydd Preseli. However, they list the sampled rock fragment as having dimensions 10 cm x 7 cm x 3.4 cm and a weight of 244 g. The Newall erratic boulder with which we are concerned does not have those dimensions and it is certainly not a blue-grey rhyolite. The boulder dimensions are c 22 cm x 15 cms x 10m cms, and I guess its weight as being around 5 kg. The OU team did not examine the cut IGS boulder sample either, since that has dimensions c 8 cms x 4 cms x 6 cms — ie considerably smaller. We know that the IGS staff examined many samples / thin sections from the Newall collection, since there are notes in the Kellaway Archive about acid welded tuff samples S50, S51, S52, S65, S66 and S67. Malcolm Howells and Mike Nutt were among the specialists consulted. We also know that the record keeping was somewhat chaotic, and in one letter to Kellaway Newall referred to his notes and labels being eaten by mice while the samples were stored in his attic…….. But then the mystery gets even deeper, since there is a mark on the flank of the boulder that says "36/1978" and signs of another slice of rock being cut off. This slice was about the same size as ENQ-2305. However, Museum Director Adrian Green confirms that the number is simply the acquisition number, now expressed as "1978.36". If there was another sample taken from this position, it must have been taken earlier, by the IGS geologists.
10. It seems that the geological samples of ignimbrites and "acid vitric welded tuffs" were retained by the IGS (to become the BGS). Some of them might have been examined by the OU team in 1989 and by geologists Rob Ixer and Richard Bevins in 2015 when they were analysing Volcanic Group B samples. Confirmation is needed on this. Information gratefully received!
11. Following a blog post in May 2022 by Tim Daw, citing material from newly accessible interim excavation reports, I followed with blog posts of my own, and the boulder was “rediscovered” by Director Adrian Green in the Salisbury Museum collection. I was given permission to examine it in the company of Tony Hinchliffe on 14th June 2022.
The weathered upper surface of the boulder is also convincing evidence that it was only partly buried in the ground; and the patchy tufa crust on the lowert part suggests that the erratic spent many thousands of years embedded in the ground in a calcium-rich environment such as the chalklands of Salisbury Plain. RK Harrison, in his report to Kellaway (1991), suggested that the boulder had spent time in an area of acidic groundwater, but I do not think that argument is well supported, and the geologists did not notice that the weathering crust is only present on the “top” of the boulder. I therefore think that the weathering was a result of prolonged exposure to atmospheric processes and maybe humic acid derived from the vegetation cover.
It's interesting that in 1903 Gowland noted that many "chippings" of an unknown hard and compact rock were found in his excavation at Stonehenge, with many "cemented together" by "incrustation".
In his discussion of the weathering crust on the Newall boulder, Kellaway (1991) suggests that it might have been created prior to glacial transport. I do not agree with that; although it is known that some glacial erratics carry ”inherited cosmogenic exposure ages” it would be exceedingly rare for a heavily abraded and faceted erratic boulder to display “pre-glacial” weathering traces, since those would be the first to be removed during a long and stressful journey. This dilemma can of course be resolved by cosmogenic dating. The fact that the weathering crust only exists on part of the boulder argues for the operation of weathering processes post-deposition.
It should be pointed out (yet again) that most of the 43 bluestone "monoliths" at Stonehenge are not elongated elegant pillars but heavily abraded boulders and elongated slabs. They would not be out of place in the morainic accumulations around any glacier snout in the world. They look like glacial erratics, but they are heavily weathered and therefore ancient.
Conclusion
This preliminary investigation (which must be followed and corrected by more detailed research by experts in a number of fields) strongly suggests that glacially deposited materials and far-travelled erratics unrelated to the bluestone monoliths do exist at Stonehenge. This is what has been suspected for many years since the days of Gowland and Judd, and proposed more recently by Kellaway (1971, 1991), Thorpe et al (1991) and by this author in a number of publications. In turn, this means that the assertions made by HH Thomas in 1923 and repeated ad infinitum by scores of other Stonehenge experts and commentators about the “impossibility” of bluestone monolith transport by ice are shown to be incorrect.
Finally, the elaborate narrative concerning the Stonehenge bluestones, involving bluestone quarries at Craig Rhosyfelin and Carn Goedog and a "lost stone circle" at Waun Mawn, is brought into question. This narrative, developed by Parker Pearson and his team over the last decade, has never been underpinned by evidence that withstands scrutiny, and must now be replaced with another, no less appealing story in which natural processes are accorded a modicum of respect.
Appendix 1
Comments from 12 senior glacial geomorphologists who have examined the photos featured in the article by Kellaway in 1991. I told them nothing about the boulder and simply asked them for their opinions on how it might have been shaped and what its mode of transport might have been.
1. If I had been doing a Reichelt shape classification I would have classed this as sub angular and typical of igneous clasts that have been dragged along the glacier bed.
2. I would say it has been glacially transported. That could account for the relatively smooth (abraded) surface and the other sub-angular surface and edges. There could even be some grooves on the abraded surface (upper image).
3. I would not be surprised if it is glacially transported. It looks to be the result of physical processes rather than chemkcal weathering. The light parts look hard and fresh and one side is flat. Corners and edges are neither sharp nor rounded. I could have picked it from a till in Bergen.
4. I am a bit less convinced. Looking at the right side of the first image the facets might be where cooling joints meet. That end is almost hexagonal. It is quite bullet-shaped though.
5. I would agree with my esteemed colleagues and say that there is certainly evidence for a possible faceted surface but difficult to say much more based on the photos.
6. In addition to the facets and chip marks that jumped out at first glance, the lower image to me has a slight bullet shape to it. Nothing definite from photos alone, and perhaps especially not from these two angles, but my very careful guess would agree with a subglacial transport path. Striae rarely preserve well (and on many lithologies don’t even form). Having said that, the clasts seem pretty weathered and battered.
7. Although quite hard to get a complete picture from just these two images, I’d say they seem to show a subrounded cobble/small boulder that is faceted, and has a shape that some people might say approaches a bullet-shape. I can also see some – what look like - chipmarks on some of its edges, the arrangement of which could indicate a responsible force from a single direction. From behind my wall of disclaimers and from within my cloud of speculation, I would probably guess that this boulder was subglacially transported. Striations on the faces would perhaps clinch it for me, but I could not see those in the images.
8. It's not possible to be definitive on the basis of these pictures alone. However, the presence of planar facets is consistent with subglacial transport. It would help if there were additional characters that might corroborate this, such as a stops-lee or double stoss-lee form. I guess there are no striations, or you would have mentioned them. Also rhyolite doesn't tend to striate.
9. My guess would be glacial. Not overly far travelled I’d say, but there does appear to be edge rounding and also chipping, with potential flat-iron faces. Looks like a lot of igneous clasts in tills in the north of Ireland.
10. I agree that this could be interpreted as subglacially transported boulder. Some rounding of the corners, but the facetted surface is not the best I have seen…if it has striations I would of course be 100% convinced.
11. Looks like a fluvioglacial clast. Definitely been in a fluvial system but only for short time as the degree of rounding is limited. The pic maybe misleading but I can see parallel lines -? Striations.
12. It looks partially faceted, edge rounded and abraded. The surfaces even appear to have some crude chattermarks/flip-outs. I cannot see any definitive striations but the lower image has an interesting set of linear marks that warrant a better image, though they may well be structural. I would say definitely glacially transported.
Experts consulted, in no particular order: Prof Neil Glasser, Prof Peter Worsley, Prof David Sugen, Prof Doug Benn, Prof Dave Evans, Prof Dave Roberts, Prof Jim Rose, Prof John Hiemstra, Prof Danny McCarroll, Prof Sven Lukas, Prof Jan Mangerud, Prof Steve McCarron. Some have indicated a willingness to be involved in future research on the boulder.
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1. It is a coherent small boulder which hasn’t been knocked off a bluestone monolith either here or anywhere else. Shape — an elongated, tapering and flattened small boulder, c 22 cms x 15 cms x 10 cms. Approximately the same shape and size as a human face. Weight - not measured but estimated at over 5 kg.
2. The lithology appears to be quite unlike anything else previously recorded for a boulder at Stonehenge —it is a dense and heavy welded tuff, dark blue-black in colour. It is nothing like the Preseli spotted and unspotted dolerites, the foliated rhyolites or Lower Palaeozoic sandstones. Grain size is very small. There are many intersecting small fractures and veins marked by whitish crystal concentrations — and some lumps of what appear to be quartz crystals. Petrologist RK Harrison of the IGS said: “This large, dark blue-grey, hard, flinty (? partly worked artifact) shows a white weathered crust up to 5 mm thick. The thin section shows a complex structure of very finely banded welded tuff (compressed foliated shards cemented by fine silica) with composite quartz grains and strings of dusty leucoxene, separated by patches of much finer grained, finely fluxioned glassy lava with patches of granular quartz. This specimen appears to represent a complex of originally viscous glassy lava and welded vitric tuff, all presumably of rhyolitic composition.” In correspondence, there was agreement in 1971-2 among IGS geologists that this rock has probably come from North Wales, possibly from the Capel Curig area, although I think there is a chance that it has come from the Strumble Head - Fishguard area. Work is under way by geologists Ixer and Bevins, with a view to an accurate description of the petrology and a suggested provenance. It does not much matter where the stone has come from, but nonetheless we look forward to seeing the eventual report and to discovering whether this boulder might be related to one or more of the bluestones 38, 40, 46 and 48 in the bluestone circle at Stonehenge -- all classified as "dacitic ash-flow tuffs" or as rhyolite / ignimbrite. The dacites have recently been studied -- but they seem different too.
Fresh damage reveals a dark blue flinty welded tuff / lava with multiple veins of white minerals. It is completely different from the rhyolites and dolerites exposed on Mynydd Preseli, but might be related to a group of samples of "ignimbrites" and ash-flow tuffs. Source currently unknown.(Courtesy Salisbury Museum)
3. There are 5 main natural facets or faces, possibly influenced by the veins that run through the boulder. One of the facets has quartz (?) remnants sticking to it, which seem to be streamlined or slickensided. There is one quite prominent yellowish nodule about one cm thick. There is some iron-staining also, including a patina on some of the Neolithic (?) fracture scars which have been determined by vein positions. This is another typical feature of glacial erratics.
4. Clast morphology: it is crudely bullet-shaped, with multiple facets and fracture scars and highly variable surface characteristics and patina. There are micro-features suggestive of ice-related damage. These features have not been modified in a glaciofluvial environment. The boulder clearly has has a complicated life, through several distinct phases.
5. In essence this is a small boulder modified and shaped in subglacial transport. This is the consensus — from the photographic evidence, 11 out of 12 senior geomorphologists agree (see Appendix 1). The other expert suggests a glaciofluvial origin; I disagree with that. There are too many fresh micro surface features that would have been removed if there has been any water transport or modification. The surface characteristics also preclude an origin as a “quarried block” deliberately taken from a favoured rock outcrop.
https://www.blogger.com/blog/post/edit/1228690739485734684/2700580815420234125
6. After close examination of slight scratches on the boulder surface — in several places — I am convinced that they are crossing glacial striae. There is one distinct patch of scratches, c 5 cm x 5 cm. They are very shallow, and I am prepared for others to take a different view of their origin — but they do NOT seem to tie in with foliations or other features related to the lithology or internal structure of the rock. On another face there are traces of parallel scratches, again unrelated to visible veins in the rock. We should remember that Engleheart and Dale both said in 1921 that they had seen striated glacial erratics at Stonehenge, and according to Hawley four more small erratics (including the Newall boulder) were discovered in the 1924 dig.
6. After close examination of slight scratches on the boulder surface — in several places — I am convinced that they are crossing glacial striae. There is one distinct patch of scratches, c 5 cm x 5 cm. They are very shallow, and I am prepared for others to take a different view of their origin — but they do NOT seem to tie in with foliations or other features related to the lithology or internal structure of the rock. On another face there are traces of parallel scratches, again unrelated to visible veins in the rock. We should remember that Engleheart and Dale both said in 1921 that they had seen striated glacial erratics at Stonehenge, and according to Hawley four more small erratics (including the Newall boulder) were discovered in the 1924 dig.
Faint crossing scratches (glacial striations?) on the flat face of the boulder. (Courtesy Salisbury Museum)
Other faint parallel scratches on the weathered face of the boulder. These do not appear to be related to its internal structure. (Courtesy Salisbury Museum)
7. I would also agree that it is a rejected “artefact” in the sense that somebody has tried at some stage (Neolithic?) to use the boulder either as a maul or (more likely) as the raw material for a large stone axe. This attempt at "dressing" was not successful — the rock does not fracture conchoidally, and when several chunks had been knocked off both the lee (downglacier) end and the stoss (upglacier) end the attempt was abandoned and the stone was thrown away. It has also been damaged in several different places by the geologists who examined it in 1970 -1972 and in 1978 — there are traces of cutting and grinding and there are several new percussion scars in a row near the stoss end of the clast.
Six percussion scars on the edge of a fresh (?) facet near the tip (stoss end) of the boulder. Has a powder sample also been taken from here by mechanical grinding? (Courtesy Salisbury Museum)
Unweathered facet with remnants of a quartz (?) vein which has influenced the alignment and form of the fracture. Note the apparent streamlining parallel with the long axis. This might be slickensiding on a faulted rock surface. (Courtesy Salisbury Museum)
Quartz (?) nodule near the pointed end of the bullet-shaped boulder, on the edge of a "fresh" facet. Note also the encrustations identified as tufa by IGS geologists -- consistent with the boulder being embedded in a calcium-rich environment.(Courtesy Salisbury Museum)
8. There are abundant rough fracture scars, especially on the lee end. In these scars, the rock surface is very fresh, and edges are sharp ansd unabraded. Some scars seem to have been present before the axe-maker got to work on it. The two fracture scars on the flanks of the boulder also seem to be older and are slightly stained. These may be natural or partly so.
9. The tip of the bullet-shape (at the stoss end) has been knocked off or cut off. This looks suspicious — was this done by the geologists when attempting to take samples? There is a flat, smooth face which looks as if it has been ground down in the collection of a rock powder sample.
10. We can identify a “top surface” and a “bottom surface” of the boulder. The curving and irregular top surface — including the place from which the sample RSN18 was taken — has a whitish surface colouring and a distinct weathering crust up to 5 mm thick. The “bottom surface” is flatter, and has a patina but no weathering crust. This is a crucial piece of evidence relating to the history of the boulder. We can interpret a “ground surface” position as revealed on the boulder itself; the top was clearly exposed to surface weathering over a very long period, while the rest was buried and protected.
IGS photo showing two apparent crescentic gouges / fracture scars on the edge of the weathered facet.
IGS photo showing the weathered ("top") facet and the bullet shape of the clast. Note the location of the cut sample numbered RSN18.
My photo of the "top" of the boulder, with the sample positioned at the edge from which it was originally cut. (Courtesy Salisbury Museum)
11. In several places beneath “ground level” there is a crusty tufa deposit up to c 4 mm thick. This suggests burial in a calcium-rich environment — probaby on Salisbury Plain. Some white crusty deposits of tufa occur on ALL faces (including Neolithic (?) percussion fractures— this suggests further slight precipitation of calcium carbonate following the rejection by the axe maker and burial in chalk rubble.
12. We can be certain that this is not the only striated small boulder found at Stonehenge, as confirmed by Hawley, Newall, Engleheart and Dale. Some appear to have been found in 1920. They were all treated as rubbish and thrown away because they were not “worked”— and only worked stones and monolith remnants were of interest to Hawley. They are probably in the trenches used for waste from the excavations. Hawley and Newall were clearly heavily influenced by the forceful views of HH Thomas — and there may well have been something of a “conspiracy” after 1923 to bury (quite literally) anything that was inconvenient and likely to upset the human transport hypothesis.
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Suggested history of the boulder:
1. Following entrainment the boulder was reduced in size and heavily modified during glacial transport, for much of the time on the bed of a glacier.
2. It was eventually dumped on the chalklands of Salisbury Plain, probably at or near Stonehenge.
3. The top of the boulder projected above the ground surface, and was subjected to subaerial weathering over a protracted period. In this calcium-rich environment a crust of tufa was deposited on some of the buried surfaces of the boulder.
Dolerite erratics embedded in turf near Crosswel, Pembs. It is suggested that the Newall boulder was similarly embedded in the turf, with its "top" exposed, when it was found by one of our Neolithic ancestors.
One of the igneous boulders exposed during the digs at Waun Mawn. The weathered top was previously exposed above the turf layer, and the old ground level can be traced -- as on Newalls' Boulder.
4. It was dug up and collected by an axe-maker on the basis that it was the right shape and size for a hand axe. He tried to shape it by percussion, particularly on the lee end, taking advantage of existing fracture scars acquired during glacial transport. Some attempts were also made to shape the pointed or stoss end. The enterprise failed because the stone did not fracture conchoidally or predictably.
5. The stone was thrown away into a pile of accumulating chalk rubble in connection with the Neolithic erection of standing stones at Stonehenge.
6. It was gradually buried to a depth of 64 cms and over time further nodules and crusts of tufa were formed on all surfaces, including the “fresh” man-made surfaces.
7. Following its discovery (probably in 1924) by Hawley and his co-workers, Hawley treated it as “rubbish” and wanted to throw it out— but Newall took it home together with other foreign stones and they remained in his attic for the next 46 years.
8. When geologist Geoffrey Kellaway was preparing his 1971 “Nature” article he found the mention in Hawley’s interim report published in 1926, and contacted Newall about the whereabouts of the boulder. Newall passed the boulder (and other rock fragments) over to Kellaway and the IGS, and Kellaway arranged for it to be sampled and examined by some of his specialist colleagues including Harrison. In 1971-72 they did considerable damage it because they too presumably treated it as a “rubbish stone”. They had no knowledge of the processes involved in the shaping of glacial clasts — but they did know about the potential significance of striations. Newall handed the boulder (together with other bluestone fragments) to Salisbury Museum on 24 November 1976, when it was put into storage. There it remained without anybody being aware of its significance for another 46 years.
Geoffrey Kellaway, who was instrumental in "recovering" the boulder from Newall's attic and in the geological investigation of the boulder by IGS geologists.
9. This is where it gets confusing! In 1989 the OU team (including Olwen Williams-Thorpe and Rob Ixer) examined as many bluestone fragments as they could find, including one that they referred to as RSN18 - ENQ2305. They renamed it OU2 and the analysis showed it to be a typical blue-grey rhyolite from the north slopes of Mynydd Preseli. However, they list the sampled rock fragment as having dimensions 10 cm x 7 cm x 3.4 cm and a weight of 244 g. The Newall erratic boulder with which we are concerned does not have those dimensions and it is certainly not a blue-grey rhyolite. The boulder dimensions are c 22 cm x 15 cms x 10m cms, and I guess its weight as being around 5 kg. The OU team did not examine the cut IGS boulder sample either, since that has dimensions c 8 cms x 4 cms x 6 cms — ie considerably smaller. We know that the IGS staff examined many samples / thin sections from the Newall collection, since there are notes in the Kellaway Archive about acid welded tuff samples S50, S51, S52, S65, S66 and S67. Malcolm Howells and Mike Nutt were among the specialists consulted. We also know that the record keeping was somewhat chaotic, and in one letter to Kellaway Newall referred to his notes and labels being eaten by mice while the samples were stored in his attic…….. But then the mystery gets even deeper, since there is a mark on the flank of the boulder that says "36/1978" and signs of another slice of rock being cut off. This slice was about the same size as ENQ-2305. However, Museum Director Adrian Green confirms that the number is simply the acquisition number, now expressed as "1978.36". If there was another sample taken from this position, it must have been taken earlier, by the IGS geologists.
10. It seems that the geological samples of ignimbrites and "acid vitric welded tuffs" were retained by the IGS (to become the BGS). Some of them might have been examined by the OU team in 1989 and by geologists Rob Ixer and Richard Bevins in 2015 when they were analysing Volcanic Group B samples. Confirmation is needed on this. Information gratefully received!
11. Following a blog post in May 2022 by Tim Daw, citing material from newly accessible interim excavation reports, I followed with blog posts of my own, and the boulder was “rediscovered” by Director Adrian Green in the Salisbury Museum collection. I was given permission to examine it in the company of Tony Hinchliffe on 14th June 2022.
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Discussion
This boulder is a discrete erratic that has been transported for a considerable distance by glacier ice, for much if not all of the time in a subglacial position. Its characteristics all point in the same direction, and although the presence of striations on the boulder surface might be open to debate, that is the least significant of the “glacial” diagnostic features used by glacial geomorphologists.
Discussion
This boulder is a discrete erratic that has been transported for a considerable distance by glacier ice, for much if not all of the time in a subglacial position. Its characteristics all point in the same direction, and although the presence of striations on the boulder surface might be open to debate, that is the least significant of the “glacial” diagnostic features used by glacial geomorphologists.
In summary, the diagnostic features are these:
** a crude bullet shape
** at least five major facets and several smaller ones
** abraded surfaces and edges
** fracture scars on the flanks and especially at the lee end
** apparent streamlining prominent on one facet
** faint crossing striae on one facet and other parallel striae on another
** minor crescentic gouges and micro features (chip marks) attributed to pressure from glacial "tools"
These features are all independent of the substantial damage done by a Neolithic axe maker and by geologists who have taken samples from at least three different sites on the boulder surface.
The boulder seems to have been deposited “fresh” — ie without any subsequent modification by glaciofluvial or other processes. There is no reason to assume that the boulder was deposited anywhere other than on Salisbury Plain, at or very near Stonehenge. Following on from the comments of Judd in 1903, Engleheart and Dale in 1921, Kellaway (1991) argued convincingly that no Neolithic or Bronze Age tribesman or axe maker would carry a stone of this size all the way to Stonehenge just to try and make an axe out of it, and then to reject it when he discovered that its characteristics were unsuitable. This also argues for the stone not having any sacred or ritual significance.
The weathered upper surface of the boulder is also convincing evidence that it was only partly buried in the ground; and the patchy tufa crust on the lowert part suggests that the erratic spent many thousands of years embedded in the ground in a calcium-rich environment such as the chalklands of Salisbury Plain. RK Harrison, in his report to Kellaway (1991), suggested that the boulder had spent time in an area of acidic groundwater, but I do not think that argument is well supported, and the geologists did not notice that the weathering crust is only present on the “top” of the boulder. I therefore think that the weathering was a result of prolonged exposure to atmospheric processes and maybe humic acid derived from the vegetation cover.
It's interesting that in 1903 Gowland noted that many "chippings" of an unknown hard and compact rock were found in his excavation at Stonehenge, with many "cemented together" by "incrustation".
In his discussion of the weathering crust on the Newall boulder, Kellaway (1991) suggests that it might have been created prior to glacial transport. I do not agree with that; although it is known that some glacial erratics carry ”inherited cosmogenic exposure ages” it would be exceedingly rare for a heavily abraded and faceted erratic boulder to display “pre-glacial” weathering traces, since those would be the first to be removed during a long and stressful journey. This dilemma can of course be resolved by cosmogenic dating. The fact that the weathering crust only exists on part of the boulder argues for the operation of weathering processes post-deposition.
It should be pointed out (yet again) that most of the 43 bluestone "monoliths" at Stonehenge are not elongated elegant pillars but heavily abraded boulders and elongated slabs. They would not be out of place in the morainic accumulations around any glacier snout in the world. They look like glacial erratics, but they are heavily weathered and therefore ancient.
The present author has argued many times that Stonehenge was probably built where the stones were found; and this suggestion is now supported by the preliminary analysis of the Newall Boulder. This, after all, was what William Judd said in 1903.
Conclusion
This preliminary investigation (which must be followed and corrected by more detailed research by experts in a number of fields) strongly suggests that glacially deposited materials and far-travelled erratics unrelated to the bluestone monoliths do exist at Stonehenge. This is what has been suspected for many years since the days of Gowland and Judd, and proposed more recently by Kellaway (1971, 1991), Thorpe et al (1991) and by this author in a number of publications. In turn, this means that the assertions made by HH Thomas in 1923 and repeated ad infinitum by scores of other Stonehenge experts and commentators about the “impossibility” of bluestone monolith transport by ice are shown to be incorrect.
We must also now question the assumptions that have underpinned the multiple geological studies of Ixer and Bevins, namely that the bluestone fragments and small clasts at Stonehenge must have been transported by human beings from Pembrokeshire and that they must be related to the known (and unknown) bluestone monoliths in the stone settings.
Thanks
Thanks to Adrian Green for permission to examine the boulder in Salisbury Museum. I’m grateful to Lizzie Richmond of the Bath University Archive for unearthing a number of important items from the Kellaway Collection. Thanks also to Tony Hinchliffe for taking notes during our examination of the boulder on 14th June 2022.
Thanks to Adrian Green for permission to examine the boulder in Salisbury Museum. I’m grateful to Lizzie Richmond of the Bath University Archive for unearthing a number of important items from the Kellaway Collection. Thanks also to Tony Hinchliffe for taking notes during our examination of the boulder on 14th June 2022.
(Courtesy Salisbury Museum)
Appendix 1
Comments from 12 senior glacial geomorphologists who have examined the photos featured in the article by Kellaway in 1991. I told them nothing about the boulder and simply asked them for their opinions on how it might have been shaped and what its mode of transport might have been.
1. If I had been doing a Reichelt shape classification I would have classed this as sub angular and typical of igneous clasts that have been dragged along the glacier bed.
2. I would say it has been glacially transported. That could account for the relatively smooth (abraded) surface and the other sub-angular surface and edges. There could even be some grooves on the abraded surface (upper image).
3. I would not be surprised if it is glacially transported. It looks to be the result of physical processes rather than chemkcal weathering. The light parts look hard and fresh and one side is flat. Corners and edges are neither sharp nor rounded. I could have picked it from a till in Bergen.
4. I am a bit less convinced. Looking at the right side of the first image the facets might be where cooling joints meet. That end is almost hexagonal. It is quite bullet-shaped though.
5. I would agree with my esteemed colleagues and say that there is certainly evidence for a possible faceted surface but difficult to say much more based on the photos.
6. In addition to the facets and chip marks that jumped out at first glance, the lower image to me has a slight bullet shape to it. Nothing definite from photos alone, and perhaps especially not from these two angles, but my very careful guess would agree with a subglacial transport path. Striae rarely preserve well (and on many lithologies don’t even form). Having said that, the clasts seem pretty weathered and battered.
7. Although quite hard to get a complete picture from just these two images, I’d say they seem to show a subrounded cobble/small boulder that is faceted, and has a shape that some people might say approaches a bullet-shape. I can also see some – what look like - chipmarks on some of its edges, the arrangement of which could indicate a responsible force from a single direction. From behind my wall of disclaimers and from within my cloud of speculation, I would probably guess that this boulder was subglacially transported. Striations on the faces would perhaps clinch it for me, but I could not see those in the images.
8. It's not possible to be definitive on the basis of these pictures alone. However, the presence of planar facets is consistent with subglacial transport. It would help if there were additional characters that might corroborate this, such as a stops-lee or double stoss-lee form. I guess there are no striations, or you would have mentioned them. Also rhyolite doesn't tend to striate.
9. My guess would be glacial. Not overly far travelled I’d say, but there does appear to be edge rounding and also chipping, with potential flat-iron faces. Looks like a lot of igneous clasts in tills in the north of Ireland.
10. I agree that this could be interpreted as subglacially transported boulder. Some rounding of the corners, but the facetted surface is not the best I have seen…if it has striations I would of course be 100% convinced.
11. Looks like a fluvioglacial clast. Definitely been in a fluvial system but only for short time as the degree of rounding is limited. The pic maybe misleading but I can see parallel lines -? Striations.
12. It looks partially faceted, edge rounded and abraded. The surfaces even appear to have some crude chattermarks/flip-outs. I cannot see any definitive striations but the lower image has an interesting set of linear marks that warrant a better image, though they may well be structural. I would say definitely glacially transported.
Experts consulted, in no particular order: Prof Neil Glasser, Prof Peter Worsley, Prof David Sugen, Prof Doug Benn, Prof Dave Evans, Prof Dave Roberts, Prof Jim Rose, Prof John Hiemstra, Prof Danny McCarroll, Prof Sven Lukas, Prof Jan Mangerud, Prof Steve McCarron. Some have indicated a willingness to be involved in future research on the boulder.
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5 comments:
Congratulations. A sacred cow should be feeling rather uneasy about its future.
Thanks Steve. No credit to me -- but we should thank Newall and Kellaway for realising that this stone should be given some respect, while others simply wanted to chuck it away...... How many other important stones WERE chucked away, I wonder, simply because there were no geomorphologists around who could examine them competently?
Just to add that I think the Museum Assistant's name was Ann Chumbley or similar. That is, she was the person who remained near Brian & myself after Salisbury Museum Director Adrian Green left us inspecting and photographing the boulder.
Perhaps I am slightly ahead of the curve before the necessary additional scientific research, but maybe there is now ONE Bob Dylan song which sums up the situation regarding how the Stonehenge bluestones arrived from Pembrokeshire:-
"It's All Over Now, Baby Blue"
All together now..........
Just found out that the aforementioned ANN CHUMBLEY is Salisbury Museum's Collection Officer. One of her responsibilities is to oversee the ADOPT AN OBJECT scheme there.
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