Are Stonehenge's Sarsens Really From West Woods?

A reanalysis of the sarsen fragments from Stonehenge argues that they point to many more sources than expected, some perhaps as far off as Sussex and Kent. The obvious question follows: does that unsettle the idea that the great standing stones came from West Woods?

When sarsen sourcing makes the news it is usually about the monoliths — the conclusion, from Nash and colleagues in 2020, that fifty of the fifty-two surviving standing sarsens share the chemistry of West Woods, on the Marlborough Downs about 25 km away. Less attention goes to the smaller stone fragments dug up across the site. When Ciborowski and colleagues analysed 54 of these in 2024 they called them debitage — a knapping term for the waste struck off while working stone — and found them more varied than the monoliths, drawn from at least three regions beyond West Woods.

A new paper in Archaeological and Anthropological Sciences — Michelaki, Barham, Gorton, Mahaney, Aufreiter and Hancock (2026) — reworks that same fragment dataset using raw element concentrations rather than the zirconium-normalised ratios of the original, and argues the picture is more varied still. I can’t judge the geochemistry, so what follows is what the paper claims.

The new paper makes a deliberate point of not calling this material debitage. It prefers the neutral “fragments,” on the grounds that “debitage” presumes human workmanship — waste from dressing stone — whereas some of these pieces may be natural detritus, weathered off bedrock and never worked by anyone. The distinction is not pedantry: as we shall see, it bears directly on what the fragments can and cannot tell us about the standing stones.

Fragments from all over

On the paper’s sorting, 33 of the 54 fragments can be tentatively tied to known sarsen sources, while the remaining 21 cannot be placed at all and appear to represent at least seven chemistries not documented anywhere yet. Some fragments are tentatively matched to sources well to the south-east — Hampshire, and possibly Sussex and Kent — though the authors are careful to say there are inadequate data to make any of these assignments firm.

They draw one striking implication from that. If some fragments really do derive from south-east England, which the last ice sheet never reached, then ice cannot have carried them, and intentional human transport over long distances is the only explanation left — a reading that fits the wider argument, made by Parker Pearson and colleagues, that Stonehenge deliberately gathered stone from across Britain. For once a critique from the Hancock group cuts against the glacial-transport idea rather than for it.

But the fragments are not the standing stones

Here is the distinction that matters, and that a quick headline will tend to blur. The fragments and the monoliths are not the same population of stone. They need not all come from dressing the great sarsens at all: some may be packing stones, hammerstones or pieces of broken-up earlier features, and — on the very point the paper’s terminology is at pains to keep open — some may be natural detritus that was never part of any worked stone. A varied bag of fragments is therefore perfectly compatible with a uniform set of standing stones. Indeed the original 2024 study already found the fragments more diverse than the monoliths; this paper widens that gap, but it does not invent it.

So finding more sources in the rubble does not, on its own, move the monoliths. The West Woods case for the standing stones rests on a different body of evidence — the analyses of the stones themselves, the Stone 58 core, the proximity of a large, dense silcrete field at the right distance, and the recent extension of the same chemistry to the outlying Cuckoo and Tor Stones. None of that is reanalysed here.

Where it does reach the monoliths

Two threads do connect back to the big stones, and they pull in the cautious direction.

The first is the method itself. If, as the paper argues, normalising every element to zirconium can mask real differences and manufacture apparent agreements — a hazard it says is acute when raw concentrations range over more than a factor of ten, as these do — then that charge applies wherever the technique was used, the monoliths included. The standing stones were placed at West Woods with the same normalised approach. The data behind that conclusion aren’t revisited here, but the tool used to reach it is exactly what the paper is questioning.

The second is more concrete, and I have checked it against the original data. Nash et al. published the full chemistry behind their conclusion, and only one Stonehenge monolith appears in it with the high-precision analyses that source-matching requires: the Phillips’ Core drilled from Stone 58 in the 1950s. The other fifty-odd standing stones were measured only by the coarser portable XRF, and were never individually tested against the sources this way — their West Woods attribution rests on resembling Stone 58, not on being matched to a source themselves. So “re-sourcing the monoliths” really comes down to re-sourcing Stone 58.

Running its core against all twenty source areas, the answer depends entirely on the method — and the dependence runs one way. The more the calculation leans on normalising to zirconium, the better West Woods looks; strip that step out and rank the sources on raw concentrations, as the critics prefer, and West Woods slides down the table.

Approach used on Stone 58’s core	Nearest source(s)	West Woods rank
Geometric mean of element/Zr ratios (Nash & Ciborowski’s own method)	West Woods	1st of 20
Element/Zr ratios, nearest-neighbour distance	Bramdean, Castle Rising	3rd
Raw concentrations, nearest-neighbour distance	Castle Rising, Piggledene	6th
Raw concentrations, ±50% agreement count	Castle Rising, Piggledene	8th

Under Nash and Ciborowski’s own geometric-mean method West Woods comes top, with a real margin — that is how they reached their result, and it is not a marginal call on their own terms. Without the normalising step, West Woods falls to sixth or eighth and the nearest neighbours become Castle Rising and Piggledene. So the assignment is real under one method and gone under another, and the thing doing the work is the zirconium step that both critique papers are arguing about.

Two caveats keep this honest, and both cut against over-reading it. The distant front-runner, Castle Rising in Norfolk, almost certainly owes its place to an accident of scale: Stone 58 is very low in zirconium, Castle Rising lower still, and a raw-concentration comparison simply rewards stones that are uniformly low — the very dilution effect that normalising to zirconium was meant to cancel. And the other near neighbour, Piggledene, lies about two kilometres from West Woods on the same stretch of the Marlborough Downs; on the geology they are all but the same place. So the non-normalised re-sort does not move Stone 58 off the Downs at all. It simply cannot separate West Woods from the source next door, while coughing up one spurious long-distance match. What it shows is not a different source, but that the headline precision — this stone, that hillside — is more fragile than it looks.

So what happens to West Woods?

On the strength of this paper, West Woods is not overturned as the source of the standing sarsens, and the authors do not claim it is. What erodes a little is the confidence attached to the headline figure. “Fifty of fifty-two from West Woods” is a tidy number; the picture from the fragments — many sources, much undocumented variability, signatures that overlap and won’t cleanly separate — and the behaviour of Stone 58 above, which can’t be told from its neighbouring valley once you change the sum, both point the same way: the silcrete chemistry of southern Britain may be too smeared-together for any single method to pin a stone to one hillside with great precision. That is a caution about resolution, not a new provenance.

It is also now the second such caution in a matter of weeks, after Pearce, Bevins, Ixer and Pirrie’s comment on the related arithmetic-similarity method. The two come from opposite ends of the field and agree on little else, but they converge on one unglamorous point: don’t let a processed number stand in for the raw data, and check every match against the plots and the petrography. The most likely upshot is not that West Woods is wrong, but that the next round of sourcing will have to lean less on a single clever statistic and more on the unglamorous business of looking hard at the rock.

Under Nash and Ciborowski’s own geometric-mean method, West Woods is the closest of all twenty sources, with a real margin — that is how they reached their result, and it is not a marginal call on their own terms. Read the same data without normalising, scoring each source by how many elements fall within ±50% of Stone 58, and West Woods drops into the bottom half. The table below shows every source on that non-normalised basis, closest first.

Source area (mean of 3)	Zr	Ba	Sr	TiO2	Hf	Nb	Y	Pass
Castle Rising	25	6.47	1.63	0.04	0.63	0.9	1.33	7/7
Piggledene	62	10.37	1.7	0.05	1.57	0.87	1.33	5/7
Lewes Road	56.67	64.7	11.23	0.05	1.17	1.03	1.17	4/7
Bramdean	60.67	30.83	5.17	0.05	1.27	1.33	1.13	4/7
Stoney Wish	77.67	35.83	4.5	0.06	1.8	1.27	1.2	3/7
Clatford Bottom	98	10.23	1.77	0.11	2.47	2.07	2.63	2/7
Standean	83.33	56.63	11.17	0.05	1.8	1.33	1.83	2/7
Sudbury	49.67	23.3	22.2	0.09	1.3	1.6	3.57	2/7
West Woods	96.33	32.43	1.83	0.12	2.27	2.4	2.2	1/7
Lockeridge Dene	133.33	17.67	2.47	0.13	3.33	2.3	2.53	1/7
Monkton Down	225	33.9	5.6	0.21	5.17	4.53	4	0/7
Totterdown Wood	188	19.6	4.13	0.09	4.67	2	2.13	0/7
Blue Bell Hill	201.67	91.83	10.43	0.15	4.67	3.8	1.83	0/7
Gestingthorpe 1	106.33	48.43	11.97	0.11	2.53	1.83	2.2	0/7
Mutter's Moor 1	415.67	140.83	13.3	1.75	10.2	32.8	7.17	0/7
Mutter's Moor 2	471.33	245	14.27	1.42	11.33	25.97	6.77	0/7
Valley of the Stones 1	436.67	88.8	8.2	0.56	10.47	10.67	5	0/7
Valley of the Stones 2	415.33	83.6	6.9	0.47	9.63	8.97	4.53	0/7
Lenham Quarry	433.33	58.73	10.73	0.28	9.73	6.17	3.13	0/7
Gestingthorpe 2	115.33	83.07	163.83	0.11	2.8	2.23	9.77	0/7
Stone 58 (reference)	37.67	12.1	1.27	0.06	1	1	1.13	–

within ±50% of the Stone 58 mean    outside ±50% (below 0.5× or above 1.5×). ICP-MS/AES data, Nash et al. (2020); ppm except TiO₂ (%).

On the fuller 12-element mean comparison West Woods passes 4 of 12, Castle Rising 11 of 12 and Piggledene 9–10 of 12 — but Piggledene fails on zirconium itself, the primary sorting element. The table shows where Stone 58 is not (West Woods) more reliably than where it is: the green for Castle Rising and Piggledene arises largely because all three are uniformly low in every trace element, so a ±50% test is easily met — the dilution effect that normalising to zirconium is meant to cancel. Piggledene also lies ~2 km from West Woods on the same downs. The table therefore shows non-resolution, not a Norfolk or Piggledene source for Stone 58.

References

Michelaki, K., Barham, D., Gorton, M. P., Mahaney, W. C., Aufreiter, S., and Hancock, R. G. V. 2026. “Geochemical Data Treatment and Interpretive Uncertainty: A Reanalysis of Stonehenge Stone Fragments (‘Debitage’).” Archaeological and Anthropological Sciences 18: 162. doi:10.1007/s12520-026-02518-1.

Ciborowski, T. J. R., Nash, D. J., Darvill, T., Chan, B., Parker Pearson, M., Pullen, R., Richards, C., and Anderson-Whymark, H. 2024. “Local and Exotic Sources of Sarsen Debitage at Stonehenge Revealed by Geochemical Provenancing.” Journal of Archaeological Science: Reports 53: 104406. doi:10.1016/j.jasrep.2024.104406.

Harding, P., Nash, D. J., Ciborowski, T. J. R., Maniatis, G., and Colman, K. 2024. “Earliest Movement of Sarsen Into the Stonehenge Landscape: New Insights from Geochemical and Visibility Analysis of the Cuckoo Stone and Tor Stone.” Proceedings of the Prehistoric Society 90: 229–251 (published online January 2025). doi:10.1017/ppr.2024.13.

Nash, D. J., Ciborowski, T. J. R., Ullyott, J. S., Parker Pearson, M., Darvill, T., Greaney, S., Maniatis, G., and Whitaker, K. A. 2020. “Origins of the Sarsen Megaliths at Stonehenge.” Science Advances 6(31): eabc0133. doi:10.1126/sciadv.abc0133.

Parker Pearson, M., Bevins, R., Bradley, R., Ixer, R., Pearce, N., and Richards, C. 2024. “Stonehenge and Its Altar Stone: The Significance of Distant Stone Sources.” Archaeology International 27(1): 113–137. doi:10.14324/AI.27.1.13.

Pearce, N. J. G., Bevins, R. E., Ixer, R. A., and Pirrie, D. 2026. “Arithmetic Approaches Alone Are Inadequate in Defining Similarity.” Journal of Archaeological Science: Reports: 105874. doi:10.1016/j.jasrep.2026.105874.