Full size photo - https://photos.app.goo.gl/fgJgkqLgdkMhzvyj9
Thought experiment: What if the Altar Stone is a later, say, Roman addition to the monument? Is there anything that proves it isn't? If it was what would we expect it to be like? How could we tell? Where might they have brought it from?
An important paper on the Stonehenge Altar Stone has just been released:
It probably didn't come from South Wales and surrounding areas.
Its petrographic fingerprint which includes a diagnostic high Barium (Ba) content mostly doesn't match the Old Red Sandstones (ORS) of the area, and the ORS rocks there that also have a high Ba don't match other characteristics.
The hunt for the source is on. Suitable areas that also have neolithic sites are the top suspects.
The Stonehenge Altar Stone was probably not sourced from the Old Red Sandstone of the Anglo-Welsh Basin: Time to broaden our geographic and stratigraphic horizons?,
AbstractStone 80, the recumbent Altar Stone, is the largest of the Stonehenge foreign “bluestones”, mainly igneous rocks forming the inner Stonehenge circle. The Altar Stone’s anomalous lithology, a sandstone of continental origin, led to the previous suggestion of a provenance from the Old Red Sandstone (ORS) of west Wales, close to where the majority of the bluestones have been sourced (viz. the Mynydd Preseli area in west Wales) some 225 km west of Stonehenge. Building upon earlier investigations we have examined new samples from the Old Red Sandstone (ORS) within the Anglo-Welsh Basin (covering south Wales, the Welsh Borderland, the West Midlands and Somerset) using traditional optical petrography but additionally portable XRF, automated SEM-EDS and Raman Spectroscopic techniques. One of the key characteristics of the Altar Stone is its unusually high Ba content (all except one of 106 analyses have Ba > 1025 ppm), reflecting high modal baryte. Of the 58 ORS samples analysed to date from the Anglo-Welsh Basin, only four show analyses where Ba exceeds 1000 ppm, similar to the lower range of the Altar Stone composition. However, because of their contrasting mineralogies, combined with data collected from new automated SEM-EDS and Raman Spectroscopic analyses these four samples must be discounted as being from the source of the Altar Stone. It now seems ever more likely that the Altar Stone was not derived from the ORS of the Anglo-Welsh Basin, and therefore it is time to broaden our horizons, both geographically and stratigraphically into northern Britain and also to consider continental sandstones of a younger age. There is no doubt that considering the Altar Stone as a ‘bluestone’ has influenced thinking regarding the long-held view to a source in Wales. We therefore propose that the Altar Stone should be ‘de-classified’ as a bluestone, breaking a link to the essentially Mynydd Preseli-derived bluestones.
Richard E. Bevins, Nick J.G. Pearce, Rob A. Ixer, Duncan Pirrie, Sergio Andò, Stephen Hillier, Peter Turner, Matthew Power,
Journal of Archaeological Science: Reports, Volume 51, 2023, 104215,ISSN 2352-409X,
https://doi.org/10.1016/j.jasrep.2023.104215
(https://www.sciencedirect.com/science/article/pii/S2352409X23003905)
Photos of quarry from, and more information available at :
Craig Rhos-y-felin: a Welsh bluestone megalith quarry for Stonehenge
Published online by Cambridge University Press: 07 December 2015
Mike Parker Pearson , Richard Bevins , Rob Ixer , Joshua Pollard , Colin Richards , Kate Welham , Ben Chan , Kevan Edinborough , Derek Hamilton , Richard Macphail , Duncan Schlee , Jean-Luc Schwenninger , Ellen Simmons and Martin Smith
Click any photo to embiggen A few photos from my periodic visits - the vegetation recovery from 2014, the excavation years to 2023 is great to see. The bottom photo looking down on it is from 2016 - Please feel free to copy and use the photos if they are useful
Kenny Brophy - "...recently visited Stonehenge, curious to see how this icon of Britishness is presented to visitors and tourists. ...It is very clear that the Stonehenge experience – the real Stonehenge – is a long way removed from the idealised Stonehenge we keep getting told about. If this monument is a jewel in the crown, it’s a fake.
The reality is sadly many miles removed from the glossy airport adverts – make no mistake, visiting Stonehenge in the summer these days is a tawdry, tacky experience...
Over the course of the seventeenth century, two representations of Stonehenge—one published in William Camden’s Britannia (1600) and the other in Inigo Jones’s Stone-heng Restored (1655)—were invoked repeatedly in an intensifying debate over the monument’s origins. This debate engaged both the virtuosi community of the Royal Society and members of the closely related, fledgling world of English architectural discourse, and the two representations became the common ground for both conversation and contestation. This paper traces the entangled afterlives of these two images, and argues that their reproduction and reinterpretation by members of natural history, antiquarian, and architectural communities created both discord and new, collective knowledge. Drawing on recent work exploring how images produced for divergent purposes and audiences were integrated into natural philosophical study, I explore how, through their reproduction, alteration, and recontextualization, these images functioned as tools of both division and mediation, and created space for debate and new investigation.
Kaemmer, H. (2023). Description or Design: Debating Visual Truth at Stonehenge in the Seventeenth Century. Nuncius, 38(2), 278-310. https://doi.org/10.1163/18253911-bja10064
Just a reminder that any Glacial erratic found on the edge of a body of water is probably a boulder that hitched a ride on an iceberg rather than evidence of actual glaciers.
"An iceberg carries a rock though Jökulsárlón, Iceland's glacial lagoon." https://pin.it/3xNpM9M
The archaeological park which integrates the necropolis also contains several educational spaces intended to evoke the construction of megaliths , through the experiments carried out between 1979 and 1998 in Exoudun-Bougon, and the large Neolithic collective habitat of the Fief Baudouin discovered in Airvault .
- The text and photos are translated from the French version of Wikipedia entry for the site and used under under CC BY-SA 4.0 -
These experiments were directed by Jean-Pierre Mohen. For details see Jean-Pierre Mohen and Chris Scarre (with the participation of F. Bouin, E. Cariou, P. Chambon), The tumulus of Bougon (Deux-Sèvres): Megalithic complex from the 5th to the 3rd millennium , Paris, Errance 2002 (ISBN 2-87772-240-6 and 978-2-87772-240-7 )
The first experiment concerned the extraction of a large megalithic slab of 3 m by 2.50m from a rocky outcrop located on the Chaumes plateau in Exoudun . The block was surrounded on three sides by large cracks. The fourth side was hollowed out by three people with chalk hammers . Wider notches were dug with these same hammers and antler picks, in the faults to drive wooden wedges into them. The wooden corners were wetted to make them swell in volume and the slab came off after an hour of work. It was then lifted with wooden levers to be able to slide wooden rolls of about 10 cm in diameter intended to move it .
The second experiment aimed to test a transport system for a monumental slab of the type found in tumulus F2. Faced with the impossibility of having a natural slab of this type, a concrete copy of the slab of tumulus F2 was made (identical weight and volume - a single slab 6 m long by 3.50 m wide and 1.30 m high whose weight is estimated at 32 tons). A removable transport path was built with unbarked wooden rollers 40 cm in diameter. The ropes were made from viburnum and ivy fibers by a craftsman according to a tradition still in force on local farms at the beginning of the 20th century . The block, covered with a braided rope net, rested on the wooden rollers arranged perpendicular to the two rails of the raceway. On July 28, 1979, 230 people pulling on ropes and 20 others pushing the block managed to move it 40 m away. Raising the block to 0.50m in height with three levers was then successfully tested.
Liberliger, CC BY-SA 4.0, via Wikimedia Commons - Click to enlarge
In 1997, F. Collin and B. Poisonnier experimented on site with a new “proto-wheel” type traction system with the 32-tonne test block. In this system, the principle of the removable path is retained but each roller is transformed into a hub after having fitted four recesses at each end. These recesses are intended to receive levers arranged radially to drive the movement of the roller. The experiment made it possible to move the block with only about thirty people while saving most of the ropes and the pullers. However, no mechanism of this kind is attested in the Neolithic period.
In 1998, B. Poisonnier and R. Joussaume experimented with the construction of a trilith at a height of 1.50 m using levers and wooden wedges.
ABSTRACT
This thesis is an inter-disciplinary study of human engagement with the silcrete called sarsen stone, found dispersed across parts of south-central and south-eastern England and used prolifically since prehistory...
https://centaur.reading.ac.uk/112469/
Nearly 800 pages of Sarsen goodness - It is a big download but worth it.
It might be thought unkind to remind people of the erroneous opinions that have been published on Newall's Boulder now the full scientific analysis is available and any suggestion it is a glacial erratic dismissed. But I think a sample of them should be archived. We should see them as the grit in the oyster, worthless irritants except when they help pearls to be produced.
To cut a long story to its appropriate length:
"A rhyolite boulder collected by R. S. Newall in 1924 from an excavation at Stonehenge has been pivotal to arguments concerning glacial versus human transport of the bluestones to Stonehenge. Initial studies suggested that the boulder came from north Wales, and hence was a probable glacial erratic. New petrographic and geochemical analyses however support it being from Craig Rhos‐y‐Felin in west Wales, the source of much debitage recovered from Stonehenge. Examination of the form and surface features of the boulder provides no evidence for it being erratic. Instead, it is considered to be one more piece of debitage probably derived from a broken‐up monolith."
The full paper is available here:
Lithological description and provenancing of a collection of bluestones from excavations at Stonehenge by William Hawley in 1924 with implications for the human versus ice transport debate of the monument's bluestone megaliths: DOI:10.1002/gea.21971
Richard Bevins Rob Ixer Nick Pearce James Scourse Tim Daw
https://onlinelibrary.wiley.com/share/author/YUUAUVRWBNTZTPSQVBGM?target=10.1002/gea.21971
The more excitable section of the Glacial Transport true believers thought it showed signs of glacial striations where it had been dragged under the ice from Wales but the marks are just a slickensided surface. The paper: "We note that identical slickensides characterise the bedrock outcrop at Craig Rhos‐y‐Felin where we can see clear evidence of lateral movement between adjacent blocks in the outcrop".
The bullet like shape was even cited as evidence of it being ice transported but luckily Dr Brian John provides a photograph showing an identical boulder still happily lying at the Craig.
To illustrate the point further I have superimposed the "Newall Boulder" from Salisbury Museum on to Dr John's photo:
Do read the complete paper, but the simple message is: the boulder and the samples taken from it show no signs of being glacially transported, it is simply "one more piece of debitage probably derived from a broken‐up monolith".
