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E&G Quaternary Sci. J., 73, 117–134, 2024
https://doi.org/10.5194/egqsj-73-117-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
A bluestone boulder at Stonehenge: implications for the glacial
transport theory
Brian Stephen Johna,b,
aformerly at: Department of Geography, University of Durham, Durham DH1 3LE, UK
bcurrent address: Trefelin, Cilgwyn, Newport SA42 0QN, Pembrokeshire, UK
retired
Correspondence: Brian Stephen John (brianjohn4@mac.com)
Relevant dates: Received: 30 April 2023 – Revised: 14 March 2024 – Accepted: 17 April 2024 –
Published: 5 June 2024
How to cite: John, B. S.: A bluestone boulder at Stonehenge: implications for the glacial transport theory, E&G
Quaternary Sci. J., 73, 117–134, https://doi.org/10.5194/egqsj-73-117-2024, 2024.
Abstract: There has been considerable dispute over the mode of transport of the Stonehenge bluestones from
their multiple sources in West Wales. For a century most archaeologists have accepted that the stones
were transported by humans, but a number of earth scientists have taken the view that they were
entrained and transported to Salisbury Plain by glacier ice. There is remarkably little evidence in
support of either theory, and for this reason any new description of a possible glacial clast found at or
near the stone monument is of potentially great importance. A small bullet-shaped boulder of welded
tuff was found in a Stonehenge excavation in 1924, and apart from a brief examination by geologists
from the Institute of Geological Sciences (IGS) around 1970, it has been stored out of sight and out
of mind. Its geological source is uncertain. Following a detailed examination of its shape and surface
characteristics it is now proposed that it has been subjected to glacial transport and that it has had
a long and complex history. It is also proposed that the abundant weathered and abraded bluestone
boulders and slabs at Stonehenge were also glacially transported, along with many of the cobbles and
stone fragments found in the sediments of the local landscape. The elaborate archaeological narrative
of bluestone quarrying and human transport to Stonehenge must now be re-examined.
Kurzfassung: Über die Frage wie die sogenannten “Bluestones” von Ihren zahlreichen Quellen im Westen von Wales
zu ihren heutigen Fundorten in und um Stonehenge transportiert wurden, gibt es ehebliche Differen-
zen. Seit einem Jahrhundert gehen die meisten Archäologen davon aus, dass die Steine von Menschen
transportiert wurden, allerdings sind viele Geowissenschaftler der Meinung, dass die Steine mittels
glazialen Transportes die “Salisbury-Plain” erreicht haben. Für beide Theorien gibt es bemerkenswert
wenige Beweise. Deshalb ist jede neue Beschreibung eines möglichen glazialen Geschiebes, das am
oder in der Nähe des Steinmonuments gefunden wurde, von potenziell großer Bedeutung. Ein kleiner,
geschossartig geformter Block aus verschweißtem Tuffstein wurde 1942 bei einer Ausgrabung in
Stonehenge gefunden und abgesehen von einer kurzen Untersuchung durch Geologen des UK Insti-
tute of Geological Sciences (IGS) um 1970, wurde er aus den Augen und aus dem Sinn eingelagert.
Seine geologische Herkunft ist ungewiss. Nach einer eingehenden Untersuchung seiner Form und
Oberflächenbeschaffenheit wird nun angenommen, dass er glazial transportiert wurde und eine lange
Published by Copernicus Publications on behalf of the Deutsche Quartärvereinigung (DEUQUA) e.V.
118 B. S. John: Stonehenge bluestone erratic
und komplexe Geschichte hinter sich hat. Es wird weiterhin vorgeschlagen, dass die zahlreichen ver-
witterten und abradierten “Bluestone”-Blöcke und -Platten, ebenso wie viele der Feldsteine und Ste-
infragmente, die in den Sedimenten der Landschaft um Stonehenge auftreten, ebenfalls glazial trans-
portiert wurden. Das ausgefeilte archäologische Narrativ des “Bluestone”-Abbaus und -Transports
durch den Menschen nach Stonehenge muss nun neu untersucht werden. (Abstract was translated by
Christopher Luethgens.)
1 Introduction
The Neolithic/Bronze Age megalithic monument of Stone-
henge, on Salisbury Plain in southern England, is the most
famous prehistoric structure in the British Isles. It is instantly
recognisable, and there is an insatiable appetite for research
“revelations” relating to its age, its purpose and the meth-
ods used in its construction. The small “bluestone” mono-
liths on the site (Fig. 1) have attracted attention ever since
it was realised that they are geologically distinct from the
larger sarsen stone monoliths which are found in the trilithon
setting (with large pillars supporting lintels) and in the outer
circle (Ramsey, 1858; Judd, 1903). They are however highly
varied, and the term “bluestone” has no geologically consis-
tent meaning. Studies of the petrography and geochemistry
of the 43 remaining bluestones and of thousands of fragments
in the “debitage” in the Stonehenge landscape have revealed
multiple sources, mostly in West Wales (Thorpe et al., 1991;
Ixer and Bevins, 2017; John, 2018a).
This lack of lithological conformity in the bluestone as-
semblage led Judd (1903) to conclude that they are probably
derived from ancient and degraded glacial deposits on Sal-
isbury Plain, and this interpretation was supported by Kell-
away (1971), Briggs (1977) and then Thorpe et al. (1991) in
the context of a detailed study by a team of geologists affil-
iated to the UK Open University. The present author (John,
2018a) pointed out that the bulk of the Stonehenge bluestone
monoliths are not elegant and carefully selected pillars but
highly abraded and weathered erratic boulders and slabs of
many different rock types, probably collected from within the
Stonehenge landscape (Field et al., 2015). He also supported
the view that the stone settings at Stonehenge (involving both
sarsen stones and bluestones) were frequently revised and
never finished. He supported Stone (1924) in proposing that
the stone monument was abandoned when the supply of ac-
cessible stones ran out.
This version of events is at odds with that proposed
initially by Thomas (1923). He discovered that many of
the sampled Stonehenge bluestones had close geological
matches in some of the intrusive and extrusive rocks of
the Fishguard Volcanic Group (FVG), which outcrops in
Mynydd Preseli, Pembrokeshire, West Wales (Fig. 2). He
postulated that they had come from a very limited geograph-
ical area. On the question of bluestone transport, he stated
that because glacier ice had never (in his view) extended
Figure 1. Six of the Stonehenge bluestones belonging to the blue-
stone circle, in the NE quadrant of the stone monument. They are
overlooked by the larger sarsens of the outer circle. For scale, stone
47 is 1.45 m tall. For the most part the bluestones are not elegant
pillars but heavily abraded and weathered erratic boulders and slabs
(photo: the author).
much further south than the South Pembrokeshire coast, this
“permanently disposes of the idea of glacial transport for the
foreign stones of Stonehenge”. He therefore proposed that
the bluestones were first gathered together in West Wales
and then transported over a distance in excess of 230km by
humans, and this version of events has subsequently been
repeated by many others (Atkinson, 1979; Parker Pearson,
2012; Pitts, 2022). The human transport theory has recently
been expanded to incorporate bluestone monolith quarrying
at two supposed Neolithic stone quarries, at Craig Rhosyfelin
and Carn Goedog, both on the northern flank of the Mynydd
Preseli upland ridge in North Pembrokeshire. This specula-
tion, which is the subject of intense debate, might explain
how some foliated rhyolite and spotted dolerite monoliths
were obtained, but it tells us nothing at all about how many
E&G Quaternary Sci. J., 73, 117–134, 2024 https://doi.org/10.5194/egqsj-73-117-2024
B. S. John: Stonehenge bluestone erratic 119
other rock types were incorporated into the Stonehenge blue-
stone assemblage (John, 2018a).
In the last century it has been established that the ice
of the Irish Sea Ice Stream (ISIS) has indeed affected the
coasts of Somerset, Devon and Cornwall and has extended
to the Celtic Sea shelf edge on at least one occasion (Clark
et al., 2022; Scourse et al., 2019). Numerical ice sheet mod-
elling has also demonstrated that the glacial transport of the
bluestones all the way to Stonehenge was “not impossible”
(Hubbard et al., 2009), since lateral spreading must have
filled the Bristol Channel, the Severn Estuary and the Som-
erset Lowlands with glacier ice (John, 2018b).
Opponents of the glacial transport theory have argued
that there is no bluestone erratic train between North Pem-
brokeshire (the entrainment area) and Salisbury Plain (the
emplacement area) and that there are no known bluestone
erratic boulders or glacial deposits on the Wiltshire chalk
downs (Scourse, 1997; Parker Pearson, 2012). Further, fol-
lowing research on the river terrace gravels of the river Avon
and its tributaries in the Salisbury area, Green (1973) re-
ported that after examining 50 000 pebbles from 28 sites, he
had not found a single pebble that could not have been de-
rived from the local bedrock sequence. He therefore argued
that there cannot have been a glacial incursion from the west
or any other direction.
In the light of these considerable disagreements about the
likelihood of glacial bluestone transport, it is clearly of some
importance that all “foreign” clasts that might have been de-
posited in the neighbourhood of the stone monument should
be carefully described and analysed.
It is frequently claimed that there are no known foreign
stones on Salisbury Plain, apart from those at Stonehenge.
This is not true. Fragments of many sizes and shapes have
been found since the 1700s in chalk rubble and in other su-
perficial deposits across Salisbury Plain (Thorpe et al., 1991;
Ixer and Bevins, 2010). The clasts are generally referred to as
“knock-offs” or debitage from the shaping of the Stonehenge
bluestone monoliths or from the manufacture of stone axes,
but some are discrete cobbles and larger clasts with abraded
edges. Cleal et al. (1995, p. 383), in a classic and com-
prehensive study, mentioned bluestone “lumps and blocks”
which “do not exhibit flaking characteristics”. They reported
that 90 % of the bluestone clasts and fragments found by
Col William Hawley in his Stonehenge excavations between
1919 and 1926 were thrown away on the grounds that they
were not recognisable as artefacts and were therefore worth-
less. It is not known what happened to them, but it seems
that some were thrown into Stonehenge “graves” along with
many cremated bone fragments. When Aubrey Hole 7 (one
of a series of holes outside the stone settings and near the
eastern edge of the monument) was re-opened in 2008, the
bones were deemed to be much more interesting than the
stones (Willis et al., 2016). Clast rejection on such a scale
has introduced an unconscious bias into all subsequent stud-
ies.
2 Discovery of the Newall Boulder (RSN18)
In 1924 an erratic rhyolitic boulder made of welded tuff or
ignimbrite and measuring ca. 22 ×15 ×10 cm was found at
Stonehenge in the course of one of the early excavations by
Col William Hawley (Hawley, 1926). It is much smaller than
any of the standing or fallen stones, and it has been referred to
subsequently as “the Newall Boulder” (Fig. 3). Its find con-
text is secure; it was one of four bluestone clasts found in
the same dig, in the south-east quadrant of the stone mon-
ument. The “find zone” is now designated as C13, not far
from Sarsen Stone 8, bluestone 34, and stumps 33f and 33e
(Fig. 4). Two of the other discovered clasts were made of
rhyolite and one of diorite. The archaeologists did not differ-
entiate between clasts found in primary and secondary posi-
tions, and because the Newall Boulder appeared to have been
worked or dressed, it was assumed to have been discovered
in prehistoric times in one place, dumped in another, and then
buried in the debitage and accumulating surface sediments.
The ignimbrite boulder was “rescued” by Robert Newall
(who was a part of Hawley’s team between 1919 and 1926),
taken home and stored in his attic, along with other clasts
and bluestone samples. There it stayed for 46 years. In 1970,
when Geoffrey Kellaway of the Institute of Geological Sci-
ences (IGS) was preparing his article called “Glaciation and
the stones of Stonehenge” (Kellaway, 1971), he discovered
a reference to the boulder in one of Hawley’s interim exca-
vation reports and tracked it down to Newall’s attic. Newall
passed it over to him, and it was then subjected to intensive
scientific scrutiny (and damage) by a team of petrologists in-
cluding R.K. Harrison, R. Sanderson and B.R. Young. Some
of their findings were later reported by Kellaway (1991), and
some are in unpublished reports (Bevins et al., 2023). The
boulder then went back into Newall’s attic, but in 1976, two
years before he died, it was passed for safe keeping to the
curator of the Salisbury Museum, where it remained for a
further 46 years.
It was deemed to have been lost, as mentioned by Thorpe
et al. (1991), Scourse (1997) and John (2018a), but follow-
ing the digitisation of Hawley’s interim reports in the spring
of 2022, blogger Tim Daw drew attention to the report of
the 1924 dig, and following a speculative request to Adrian
Green, the Director of Salisbury Museum, by the present au-
thor, the boulder was rediscovered. Following brief examina-
tion in June 2022, there is no doubt about its identity; it is the
same boulder as that photographed by the IGS in 1972, and a
cut rock sample numbered RNS18-ENQ2305 has also been
retained (along with three others from the same boulder) in
the extensive Salisbury collection of Stonehenge clasts and
samples (Ixer et al., 2022; Bevins et al., 2023). The prove-
nance is confirmed in correspondence between Kellaway,
Newall and IGS geologists, which is now held in the Kell-
away Archive of Bath University.
https://doi.org/10.5194/egqsj-73-117-2024 E&G Quaternary Sci. J., 73, 117–134, 2024
120 B. S. John: Stonehenge bluestone erratic
Figure 2. Map of basic Pembrokeshire geology, showing the outcrops of the Fishguard Volcanic Group extrusive rocks and the strips of
Ordovician intrusive rocks in the Mynydd Preseli area. Also marked are the two disputed “Neolithic quarrying” sites (source: modified from
a Pembrokeshire Coast National Park base map).
3 Description of the boulder
As reported by Kellaway (1991), geologist R.K. Harrison de-
scribed the lithology of the boulder as follows:
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 (com-
pressed 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 rep-
resent a complex of originally viscous glassy lava
and welded vitric tuff, all presumably of rhyolitic
composition.
It is a coherent small boulder (Fig. 5) which is elongated,
narrower at one end and with a wedge shaped cross section
with dimensions ca. 22 ×15 ×10cm. It was found at a depth
of about 64 cm. It is approximately the same shape and size
as an adult human face, and it is crudely bullet-shaped. Its
original weight is estimated at ca. 5 kg. There are five major
natural facets and several smaller ones, with further surface
damage associated with fracture scars and geological sam-
pling. One surface is undulating, one other is flat and another
is curved. Some of the smaller facets appear to have been
modified by abrasion, and others have a slight discoloura-
tion. The boulder has highly variable surface characteristics
and patina. Grain size in the dark blue matrix is very small.
There are many intersecting small fractures and veins marked
by whitish crystal concentrations, as well as some lumps and
patches of quartz crystals. There is one prominent yellow-
ish nodule about 10 mm thick. One of the facets has a quartz
crystal slickenside veneer, with remnants which seem to be
streamlined and fractured (Bevins et al., 2023). There is also
some iron staining on fresher fracture scars.
There are many slight scratches on the boulder sur-
face. There is one distinct patch of crossing scratches, ca.
5 cm ×5 cm on the flat facet. On another surface there are
E&G Quaternary Sci. J., 73, 117–134, 2024 https://doi.org/10.5194/egqsj-73-117-2024
B. S. John: Stonehenge bluestone erratic 121
Figure 3. A much-discussed photograph of the Newall Boulder,
annotated by the author. The shape and surface features are widely
interpreted as indicators of sub-glacial transport, in spite of heavy
damage by humans (courtesy of the Institute of Geological Sci-
ences/British Geological Survey).
deeper non-parallel striations that have been damaged by
weathering processes; these may be based on foliations
or other lithological features within the rock (Bevins et
al., 2023). Other marks are very shallow and do not appear
to be geologically controlled.
A striking feature of the boulder is the contrast between the
faceted and discoloured surfaces and the dark blue fracture
scars particularly at its blunt end. Here the rock surface is
very fresh, and edges are sharp. Some scars seem to have
been present before the most recent phase of surface damage
linked to geological sample collection. The two main fracture
scars on the flanks of the boulder also seem to be older and
are slightly stained. Some of the fresh fracture scars have
been determined by vein positions.
The “top surface” of the clast is slightly convex, undu-
lating and irregular. This surface, including the place from
which the sample RSN18/ENQ2305 was taken, has a whitish
colouring and a distinct weathering crust up to 5 mm thick
(Fig. 6). The “flank facet” of the boulder is flatter and has
a patina and quartz crystal veneer but no marked weather-
ing crust. This is a crucial piece of evidence relating to the
history of the boulder.
In several parts of the boulder where there is no weathering
crust, there is a tufa or sinter layer (calcium carbonate) up to
ca. 4 mm thick (Kellaway, 1991). Some white crusty deposits
of tufa occur on all faces and fracture scars, including the
relatively fresh percussion fractures. But on these fractures
there are simply a few small nodules.
The surface of the boulder has been extensively damaged
by geologists. As demonstrated by Bevins et al. (2023), four
substantial rock samples have been knocked or cut off the
blunt end of the boulder by Geological Survey and Open
University research teams, and the three samples that are
Figure 4. Above extract from Fig. 120 (east sector plan) in Cleal
et al. (1995), with annotations added. Below, plan of bluestone
and sarsen locations at Stonehenge, courtesy of Anthony Johnson
(2008). The Newall Boulder was found somewhere within the area
outlined in yellow.
still held in the collections can be fitted together with confi-
dence. Another chunk from the blunt end was taken and pul-
verised for geochemical analysis. Yet another sample (num-
bered 36/1978) has been taken from the flank. Further dam-
age can be seen on two fresh facets near the pointed end of
the boulder. The clean and unweathered surfaces of these
facets are either quite recent or else indicative of burial in
a “protective” environment.
4 Interpretation: boulder provenance
The dark blue flinty rock (Fig. 6) looks very different from
the dolerites (spotted and unspotted), foliated rhyolites and
https://doi.org/10.5194/egqsj-73-117-2024 E&G Quaternary Sci. J., 73, 117–134, 2024
122 B. S. John: Stonehenge bluestone erratic
Figure 5. The suggested original shape of the boulder, together with
the natural facets, as they might have appeared prior to the infliction
of damage by human beings (courtesy of Salisbury Museum).
Figure 6. Fresh “flinty” welded tuff exposed near the blunt end of
the boulder. The damage has most likely arisen because of multiple
blows with a hammer stone or other percussion tool (courtesy of
Salisbury Museum)
ashes that make up the bulk of the Stonehenge bluestones,
but it has similarities with some of the rhyolitic lavas and
welded tuffs found in the Fishguard Volcanic Group in North
Pembrokeshire. As suggested by Thomas (1923) and more
recently by Ixer et al. (2022) and Bevins et al. (2023), the
provenancing of the bulk of Stonehenge bluestone monoliths
and debitage is now reasonably secure (Ixer et al., 2020),
with the great majority of the examined clasts derived from
Mynydd Preseli and the surrounding countryside. No exact
provenances have yet been demonstrated satisfactorily, in
spite of claims to the contrary. At the latest count, there are
around 46 different lithologies represented in the “bluestone
assemblage” at Stonehenge, almost all of them derived from
the west (John, 2018a). Several attempts have been made
to group these into a small number of rock type categories,
but each attempt at simplification is followed by an admis-
sion of outliers and exceptions. Some Stonehenge monoliths
and clasts (including the sandstone Altar Stone) have still not
been subjected to modern physical sampling and are thus not
securely provenanced.
Gowland (1903) reported “chippings of a hard compact
rock” unlike any of the known bluestone monoliths. Was this
a reference to detritus related to the Newall Boulder? Harri-
son and his colleagues suggested that the boulder had most
likely come from near Capel Curig in North Wales, but that
may be because they were more familiar with North Wales
intrusions and volcanics than with similar rocks in Pem-
brokeshire. Peter Kokelaar of Liverpool University suggests
(personal communication, 2022) that the boulder might have
come from Ramsey Island or one of the minor rhyolite sheets
near the North Pembrokeshire coast.
The available samples from the boulder have been exam-
ined by Bevins et al. (2023), with a view to provenancing.
They state the following: “We have recently reunited and ex-
amined the joint block and all its offcuts and associated thin
sections, and the rhyolitic tuff shows all the key character-
istics needed to assign it to Rhyolite Group C from Craig
Rhos-y-Felin.” This is a crag (Fig. 2) in a deep valley near the
village of Brynberian. They provide no evidence in support
of this claim, and indeed Harrison’s description (see above)
suggests substantial physical differences between this dark
blue boulder and the light blue and fine-grained rock expo-
sures at the named outcrop.
Ixer et al. (2022) refer to the Newall Boulder as a “broken
joint block”. They assert the following:
analysis by pXRF on all pieces of the joint block
plus two other visually similar rhyolitic tuffs from
the same Newall collection (RSN9/ENQ 2295 and
RSN10/ENQ 2296) clearly show that these frag-
ments are compositionally Rhyolite Group C, con-
firming the petrographic identifications.
The geochemical plots of ppm of selected minerals (Ba,
Zr, Nb and Rb) on A and B axes, for a large number of
“Craig Rhos-y-felin” analyses compared with analyses for
three Newall samples numbered RSN18, RSN9 and RSN10,
are cited in support of this assertion. However, it is not clear
whether the Rhos-y-felin X-ray analyses were all conducted
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B. S. John: Stonehenge bluestone erratic 123
Figure 7. Some of the features of bullet-shaped clasts thought to
have been fashioned in a subglacial environment. There are mul-
tiple variations on these themes, with intersecting fractures, rough
scars which turn into polished facets, gouges in more or less random
positions, and crossing striations. There will also be modifications
related to the lithology and internal structure of the clast, foliations,
ancient fractures, presence of quartz veins etc. (based on clasts and
photos in the author’s field collection).
on rock faces at Rhos-y-felin or whether some (or even most)
of the analyses were conducted on samples found at Stone-
henge but deemed to have come from Rhos-y-felin. The
“field” covered by the Rhos-y-felin samples is very large,
and plots from many other rhyolites and dolerites from di-
verse sources would fall within it if they were to be added.
The bivariate plot of Ca ppm against K ppm shows virtu-
ally no coincidence or overlap between RSN18 samples and
Craig Rhos-y-felin samples (Bevins et al., 2023). The fact
that the petrography and geochemistry of the RSN18 samples
are “consistent” with rocks classified as “Rhyolite Group C”
does not mean that the boulder must have come from Craig
Rhos-y-felin. Thus their Fig. 7 tells us nothing about the pre-
cise source of the Newall Boulder.
A highly magnified image published by Ixer et al. (2022)
as their Fig. 5 shows the mineral stilpnomelane, labelled as
follows: “This image highlights the pale brown wispy stilp-
nomelane, which is a defining characteristic of rhyolites from
Craig Rhos-y-felin.” However, no provenance is attached to
the image, so its significance is difficult to assess. Stilpnome-
lane also occurs elsewhere in the Fishguard Volcanic Group
outcrops and in other areas of low-grade metamorphism, and
it cannot therefore be used as a precise provenance indicator
(Howells, 2007). The best that can be said about provenance
is that the boulder has possibly come from one of the FVG
outcrops in the Brynberian–Pont Saeson area of North Pem-
brokeshire.
Bevins et al. (2023) suggest that the boulder is the broken-
off top of a foliated rhyolite standing stone, and they compare
its shape with the tips of bedrock pillars at Craig Rhos-y-
felin (Parker Pearson et al., 2015). However, if it is indeed
the broken-off tip of an elongated monolith, the latter must
have been so tall and slim that it could not possibly have
been extracted intact from a quarry face or transported in-
tact from West Wales to Stonehenge. The “parent monolith”
would have had b-axis and c-axis dimensions of ca. 10 and
ca. 15 cm – making it far more fragile than any of the 43
known bluestones at Stonehenge. In any case, the breakage
of the top of a monolith (whether by natural processes or
human agency) would have left one clean fracture scar, prob-
ably iron-stained. Instead, there are at least three intersecting
fresh fracture scars on the blunt end of the boulder, two near
the pointed tip, and another three on the flanks (Fig. 5). As
appreciated by both Newall and Kellaway, damage on this
scale is a sure sign of human activity, probably in the prehis-
toric period.
Further, there are no known monoliths of this rock type
in the stone settings. It is speculated by Bevins et al. (2023)
that the stump of stone 32d (less than 10 m from the find
location) might be all that is left of a destroyed foliated rhy-
olite monolith, but no sound evidence for that claim has ever
been published. The stump was excavated by Richard John
Copland Atkinson in 1954, and in photographs it looks like
a fractured and flaky rhyolite, but it is recorded confidently
by Cleal et al. (1995, p. 246) as a “spotted dolerite”. So any
link between the Newall Boulder and stump 32d is at present
entirely speculative.
The rhyolite exposed in the rock face at Craig Rhos-y-felin
is so fractured and brittle that during the Neolithic and the
Bronze Age it was never valued in West Wales as a raw ma-
terial for megalithic structures (John et al., 2015a). It is there-
fore highly unlikely that there would have been any motiva-
tion for the removal of “rubbish” monoliths for use in either
local or distant stone settings (Thorpe et al., 1991).
5 Interpretation: shape and surface characteristics
In seeking to understand how the Newall Boulder might have
been transported from its original place of origin, a number
of key features need to be explained:
1. a crude bullet shape, with a pointed nose and a blunt
back end
2. at least five major facets and several smaller ones
3. abraded surfaces and edges
4. fracture scars on the flanks and especially at the lee or
blunt end
5. apparent streamlining prominent on one facet
6. faint crossing scratches on one facet and weathered par-
allel scratches on another
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124 B. S. John: Stonehenge bluestone erratic
7. minor crescentic gouges and microfeatures (chip marks
or chatter marks) attributed to pressure exerted at par-
ticular points.
On the basis of its shape the Newall Boulder is classi-
fied on the Powers six-category scale as sub-angular (Pow-
ers, 1953). In general, clasts in periglacial slope deposits
and rockfall fragments tend to be sharp-edged or angular,
simply because they have not travelled far. This boulder is
clearly not simply a broken piece of rockfall debris. In anal-
yses of glacially transported clasts the majority fall in the
sub-angular and sub-rounded categories. Glaciofluvial sands
and gravels contain more rounded and sub-rounded stones
and fewer sub-angular ones (Lukas et al., 2013; Evans, 2018;
Benn and Lukas, 2021). Fluvially transported clasts contain
more rounded clasts, and clasts on wave-washed beaches
tend to be well rounded. The boulder is therefore unlikely to
have come from river gravels or from a wave-washed shore-
line.
The simplest explanation of the bullet shape is that the
boulder has been shaped while taking a position of least re-
sistance in a flowing medium, with erosive forces concen-
trated on the pointed (upstream) end and reduced at the blunt
(downstream) end. When shown a simple photograph of the
boulder (Fig. 3), without any contextual information, 11 out
of 12 senior geomorphologists agreed that the boulder has
probably been transported sub-glacially. The other colleague
suggested a glaciofluvial origin. However, close examination
reveals that there are many fresh microsurface features which
would have been removed if there had been prolonged water
transport or modification.
Clasts occupy a wide range of positions in mobile sub-
glacial till (Evans et al., 2016, 2018). They are subject to
complex transport histories that involve variable amounts of
dragging, rolling and lodging, during which they are sub-
ject to surface modification through inter-clast collisions and
contacts. Any single clast may be reworked numerous times
during successive glaciations. Because clasts will tend to take
the line of least resistance to the flow of the surrounding de-
forming till matrix, facetted and bullet or wedge shapes are
developed. Whenever a clast is disrupted from its lodged po-
sition, it can be subject to fresh fracturing, gradually chang-
ing its overall shape to one of a block (Boulton, 1978; Benn
and Evans, 1996; Evans, 2018). Although not all glacially
transported clasts display such bullet or flat-iron shapes, such
an appearance is diagnostic of significant subglacial transport
(Evans, 2018; Evans et al., 2006) (Fig. 7).
The characteristics of the Newall Boulder suggest a sub-
glacial transport history. For example, the top of the boulder
is abraded and yet rough, with a number of surface projec-
tions and grooves related to lithology. Another large facet is
convex or curved, dominated by sheets and strips of micro-
crystalline quartz with slickenside alignments roughly par-
allel with the boulder’s long axis. One small facet near the
boulder tip is concave. Two small meeting facets near the
Figure 8. Faulted surface displaying slickenside features. These
include sheets and slabs of microcrystalline quartz and prominent
lineations. The marked quartz nodule appears to have formed on
a smaller intersecting faulted surface (courtesy of Salisbury Mu-
seum).
boulder tip are remarkably clean, with a “polished” appear-
ance, and another near the tip has a protruding quartz mass
that has somehow survived abrasion. On the edge of a facet
near the blunt end of the boulder, there are two pronounced
concave fracture scars. Overall, the surface characteristics of
this boulder suggest that it is a discrete erratic that has been
transported for much if not all of the time in a subglacial po-
sition (Benn and Ballantyne, 1994; Lukas et al., 2013; Benn
and Lukas, 2021).
The apparent streamlining on a patchy crystalline quartz
deposit on one large curved facet is not thought to be evi-
dence of glacial transport. This is also pointed out by Ixer
et al. (2022) and Bevins et al. (2023). Instead, it is inter-
preted as the result of slickensiding on a fault plane (Fig. 8).
Peter Kokelaar suggests (personal communication, 2022)
that there are several diagnostic features, including quartz-
mineral ribbon/fibre growths, growth increments, and rib-
bons with stepped ends showing where missing counterparts
have broken away. The protruding yellowish quartz mass
near the boulder tip appears to be associated with a second,
smaller fault plane. The presence of two intersecting faulted
surfaces in the original rock outcrop could have facilitated
either breakage under a periglacial climatic regime or glacial
entrainment of the boulder at a time of thick ice cover.
Bevins et al. (2023) argue that because slickenside features
are present on the Newall Boulder and also on foliated rhyo-
lite surfaces at Craig Rhos-y-felin, this suggests a source for
the boulder. However, slickenside features including slicken-
crysts are common across West Wales, in all faulted litholo-
gies and of all ages. None of the surface features of this boul-
der demonstrates a link with Craig Rhos-y-felin.
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B. S. John: Stonehenge bluestone erratic 125
Figure 9. Possible traces of glacial erosion on the rough and weath-
ered face of the boulder (courtesy of Salisbury Museum).
The presence of genuine glacial striations on the surface
of the boulder is a matter of dispute. It is appreciated that
the smaller striations on the boulder surface are so faint that
some will doubt their significance as glacial diagnostic fea-
tures. However, both Engleheart and Dale said in 1921 that
they had seen striated glacial erratics at Stonehenge (Hawley,
1921). Bevins et al. (2023) suggest that Kellaway thought the
streamlined/slickensided features were glacial striations, but
in the view of the present author he must have been recording
some very subtle but still discernible features that are unre-
lated either to the internal structure of the rock or to slicken-
siding (Fig. 9).
When discussing the possible impacts of glacial processes
on the Newall Boulder, Bevins et al. (2023) claim that striae
typically cover abraded surfaces. However, the great major-
ity of glacially transported clasts do not carry any striae at
all. Striae are not typically dense or continuous over a large
proportion of a facet surface. In short, most striated clasts are
not particularly spectacular (cf. Sharp, 1982; Kruger, 1984;
Benn and Evans, 2010; Evans et al., 2016, 2018).
The weathering crust on the top of the boulder, ca. 5mm
thick, is of considerable importance (Fig. 10). Kellaway
(1991) suggested that it might have been created prior to
glacial transport. This is unlikely; although it is known that
some glacial erratics carry inherited cosmogenic exposure
ages for example, it would be 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
transport. This dilemma can be resolved by cosmogenic dat-
ing. Bevins et al. (2023) have conducted valuable work on the
Figure 10. Features associated with different phases in the boul-
der’s history. The crescentic gouges are suggestive of subglacial
transport. The weathering crust and larger tufa nodules suggest
long-continued exposure in a calcium-rich environment. The fresh
rock surfaces suggest fracturing as a result of repeated percussion
in prehistoric (?) time. The smaller tufa nodules suggest renewed
precipitation of calcium carbonate following Neolithic/Bronze Age
reburial at Stonehenge (courtesy of Salisbury Museum).
weathered surface of the Newall Boulder and on other rock
surfaces, using pXRF technology, but only with a view to es-
tablishing geological relationships and provenancing. They
have not commented on the “exposure ages” of the surfaces
investigated. The fact that the weathering crust only exists
on part of the boulder argues for the operation of weathering
processes on an exposed surface after its emplacement, while
the rest of the boulder was buried and thus protected.
An old “ground surface” position is revealed by a change
in surface colouration; the whitish boulder top was clearly
exposed to weathering/cosmic bombardment over a long pe-
riod, while the rest (coloured dark blue or black) was buried.
There may also have been effects associated with a vegeta-
tion cover and humic acid penetration. In several places be-
neath “ground level” there are crusty tufa or sinter deposits
up to ca. 4 mm thick (Fig. 9). This suggests a calcium-rich en-
vironment, probably on Salisbury Plain. Some white crusty
deposits of tufa occur on all faces and on some percussion
fracture scars of probable human origin, and this suggests
a second phase of tufa precipitation while the boulder was
completely buried.
The interpretation of the boulder is made more intriguing
because of the substantial prehistoric human damage that it
has suffered (Fig. 11). This damage has been recognised ever
since it was found in 1924. Detailed investigation suggests
the following narrative. It is a rejected “artefact” in the sense
that somebody has tried at some stage (Neolithic?) to use it
either as a maul (hammering tool) or as the raw material for
a large stone axe (Fig. 5). The axe-making attempt was not
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126 B. S. John: Stonehenge bluestone erratic
Figure 11. Likely human damage to the top and the flanks of the
boulder. Areas 1 and 8 (and possibly 6) have also been affected
by geological sampling since Kellaway initiated research investiga-
tions (courtesy of Salisbury Museum).
successful, probably because the rock does not fracture con-
choidally, and when several chunks had been knocked off
the pointed end, the blunt end and the edges, the attempt
was abandoned and the stone was thrown away and buried
under accumulating debris associated with the Stonehenge
stone settings. It has also been damaged within the last 60
years in several different places by the geologists who have
examined it; as mentioned above, there are traces of cutting
and grinding in perhaps four different places, and there are
several new percussion scars in a row near the pointed end
of the clast (Fig. 12). There is one flat, smooth face which
looks as if it has been ground down in the collection of a
rock powder sample. The fact that tufa nodules are found on
some percussion fractures suggests further slight precipita-
tion of calcium carbonate following the rejection by the Ne-
olithic (?) axe maker and subsequent burial in chalk rubble.
The boulder remained in this position until it was uncovered
by Hawley’s team in 1924.
Is there a possibility that this stone could have been trans-
ported to Stonehenge from far away by the people who built
the monument or by visiting traders? This was the response
of Kellaway (1991) in answer to that question:
When found, the weathered boulder had been
thrown away with chippings and other waste ma-
Figure 12. A row of small percussion (?) scars near the damaged
pointed tip of the boulder (courtesy of Salisbury Museum).
terial. An attempt had been made to dress one end
of the boulder but this, in Mr Newall’s opinion,
had failed because of the sheared condition of the
rock. It would appear that this small boulder, al-
ready deeply weathered, would never have been of
any practical value. To suggest it had been carried
from North Wales to Wiltshire only to be tested
and thrown away as worthless would imply an as-
tounding lack of common sense and understanding
of the properties of rocks on the part of the men
who built Stonehenge. If, however, the bluestones
were recovered locally from material scattered on
the surface of the Chalk or were present in solu-
tion cavities, then the presence of inferior mate-
rial is comprehensible. Having gathered up all the
available bluestones, both from natural sources and
from abandoned Neolithic structures, the Bronze
Age builders of Stonehenge used the large ones
for constructional purposes and tested the smaller
boulders for the manufacture of implements. Those
which were unsuitable were thrown away.
Kellaway’s comments appear to be well founded, and this
author concurs with most of them. The boulder’s irregular
faceted shape and varied surface features must have ren-
dered it almost impossible from the outset to fashion into
an axe, and this suggests strongly that it was found locally.
The attempted dressing of the stone was crude and appar-
ently somewhat half-hearted, and this indicates that it never
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B. S. John: Stonehenge bluestone erratic 127
was a particularly desirable or special object. It happened to
be there, so it was used.
The tufa deposits, together with the above characteristics,
indicate that this boulder was not freshly quarried at Rhos-y-
felin and carried by humans to Stonehenge. As initially ob-
served by Kellaway, it is unclear why anybody would gather
up a small stone of this size and carry it all the way to Stone-
henge only to knock a few bits off and then discard it.
In summary, this boulder has undergone a complex trans-
port history of several distinct phases:
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. It was eventually
dumped at some location on, or relatively close to, Sal-
isbury Plain.
2. The top of the boulder projected above the ground sur-
face 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 sur-
faces of the boulder.
3. It was dug up and collected by an axe-maker on the ba-
sis that it was roughly the right shape and size for a large
hand axe. He tried to shape it by percussion, particularly
on the blunt end, possibly 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 frac-
ture conchoidally or predictably.
4. The stone was thrown away into a pile of accumulating
chalk rubble in connection with the Neolithic erection of
standing stones at Stonehenge. It was gradually buried
to a depth of 64 cm, and over time further nodules and
crusts of tufa were formed on all surfaces, including the
“fresh” human-made surfaces.
5. Following its discovery (in 1924) by Hawley and his co-
workers, Hawley treated it as “rubbish” and wanted to
discard it, but Newall took it home together with other
foreign stones and put them in his attic.
6 The evidence for glaciation on Salisbury Plain
“Although it still has vocal supporters, emi-
nent geologists and glaciologists have dismissed
the glacial theory” (Bowen, 2005; Green, 1997;
Scourse, 1997) and concur with Thomas’s origi-
nal suggestion that the stones “were transported by
human agency, in all probability by an overland
route” (Thomas, 1923).
This statement from Darvill and Wainwright (2016) is mir-
rored in scores of other publications and is too easily ac-
cepted as confirmation that a consensus exists. However, it
is notable that many specialists in the field of glacial ge-
omorphology have pointed to conditions suitable for the
long-distance transport of monoliths and other glacial debris
from west to east, on at least one occasion (Gilbertson and
Hawkins, 1978; Thorpe et al., 1991; Green, 1992; Bowen,
2005; Hubbard et al., 2009; Patton et al., 2017; Gibbard et
al., 2017). If there is a specialist consensus in the earth sci-
ences field, it is in favour of the glacial transport hypothesis.
As noted above, in spite of the wide belief that erratic
clasts are entirely absent from the chalk downs and Salis-
bury Plain, there is abundant evidence of finds in the liter-
ature (Thorpe et al., 1991; John, 2018a). It is true that no
coherent glacial deposits or morainic landforms have been
described, but most of the land surface on Salisbury Plain
has never been investigated, and research within the military
training area is not encouraged. It is also true that no erratic
train has ever been traced between Pembrokeshire and Salis-
bury Plain, but those who repeatedly highlight this fact forget
that a large percentage of the route that might have been fol-
lowed by the ice is now submerged beneath the waters of the
Bristol Channel and the thick organic sediments of the Som-
erset Levels (Gibbard et al., 2017).
The debate continues about the significance of the spot-
ted dolerite boulder found in a Neolithic context in Boles
Barrow, near Heytesbury, the lumps of rotten granite found
near West Kennet and the dolerite debris found near the vil-
lage of Lake. There is also speculation about an abraded
rhyolite cobble found near Durrington (Fig. 13) and about
bluestone clasts found in the long barrow numbered Ames-
bury 39. Bluestone clasts have been found near the summit of
Silbury Hill, and finds from the Cursus and Fargo Wood have
been identified as “acid volcanics and tuffs” and also spotted
dolerite. Some finds were identified as calcareous ashes. In
2008 a further “bluestone” from the fill of a Cursus pit was
identified as identical to one of the sandstone stumps in the
Stonehenge bluestone circle. At least 20 “bluestones” have
been listed by the Wessex Archaeological Trust in the Stone-
henge environs but outside the monument itself. According
to Thorpe et al. (1991),
Bluestone fragments are frequently reported on
and near Salisbury Plain in archaeological litera-
ture, and include a wide range of rock types from
monuments of widely differing types and dates,
and pieces not directly associated with archaeolog-
ical structures
In much of the current literature these finds are dismissed
as fragments of destroyed Stonehenge bluestones that have
found their way into other contexts. But this fails to explain
why some finds seem to have been in position prior to the
assumed “bluestone arrival date” of ca. 5000 years BP (Cleal
et al., 1995).
As Thorpe et al. (1991) pointed out,
The monoliths at Stonehenge include some struc-
turally poor rock types, now completely eroded
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128 B. S. John: Stonehenge bluestone erratic
Figure 13. The Durrington rhyolite cobble, minus a sample taken
by the geologists. It has a weathered and abraded surface and bears
signs of subglacial pressure fractures. It is highly unlikely to be a
“knock-off” from a destroyed Stonehenge bluestone monolith or a
cultural “object” (reproduced with permission, © Wessex Archaeol-
ogy).
above ground. We conclude that the builders of
the bluestone structures at Stonehenge utilized a
heterogeneous deposit of glacial boulders readily
available on Salisbury Plain.
It should be noted that most of the 43 bluestone “mono-
liths” at Stonehenge are not elongated elegant pillars (as
portrayed in most reconstructions) but heavily abraded un-
remarkable boulders and elongated slabs. There are clearly
defined facets, some of which are rough and others smooth.
There are few sharp edges. The stones would not be out of
place in the morainic accumulations around any glacier snout
in the world (Benn and Evans, 2010, and references therein).
They look like glacial erratics, and they are heavily weath-
ered as a result of prolonged exposure (Fig. 14). On some
weathered surfaces segments of the crust have peeled away
and have been lost. It is probable that Stonehenge was built
where the stones were found, as suggested by Judd (1903)
and Field et al. (2015), and this is supported here by the pre-
liminary analysis of the Newall Boulder.
On the matter of clast morphology in the debitage, Ixer
and Bevins (2010, 2011a, b, 2013) have consistently failed
to differentiate between sharp-edged fragments, cobbles and
larger clasts and have concentrated on material that might
be related to existing or destroyed bluestone monoliths.
So-called hammer stones, mauls and packing stones have
not received adequate attention, although some of them are
made of igneous rock and look like glacial clasts (Cleal et
al., 1995).
Green’s evidence relating to Salisbury Plain river gravels
is at odds with that presented above. He claims that there is
a “complete lack of glacially derived material in the Pleis-
tocene river gravels of the Wylye, Nadder and Avon” (Green,
1973, p. 216). He did find “far travelled pebbles” in the river
gravels but expresses the view that they came from post-
Cretaceous rocks which once capped the chalk and which
have subsequently been removed by erosion. He appears
to have used vein quartz pebbles as a proxy for “far trav-
elled material”. In examining ca. 50 000 pebbles he classi-
fies the great majority of them (in excess of 95 %) as “flint
and greensand”. While it is accepted that the river gravels
of the Thames Valley contain much more abundant glacially
transported erratics, Green does not adequately demonstrate
a “complete lack” of glacial detritus on the chalk downs of
Salisbury Plain. Upper greensand pebbles might themselves
have been glacially transported from Upper Greensand out-
crops to the west.
The multiple arguments assembled by Scourse (1997)
against glacial impacts in the Stonehenge landscape are even
more problematical, although most have been overtaken by
events. In the last sentence of his chapter, James Scourse
claims to have “eliminated the impossible” from the debate
about bluestone transport, thereby demonstrating that the hu-
man transport of the stones – however improbable – actually
happened. It is unusual for a scientist to use the word “impos-
sible”. James Scourse claims that if Salisbury Plain had been
glaciated, there should be glacial sediment sequences and
“depositional landforms”. This claim cannot be sustained,
since “unglaciated” or “drift-free” terrain in all glaciated ar-
eas has been shown, over and again, after detailed investiga-
tions, to have been affected by ice (Clapperton and Sugden,
1975; Håkansson et al., 2009; Evans, 2016; John, 2023). He
claims that if the chalk scarp had been overridden by ice from
the west, there would be “glacio-tectonic structures”. Such
glacitectonic disturbance is indeed common in glaciated soft
bedrock terrains (e.g. Vaughan et al., 2011) but is dictated
by optimum localised conditions and may only be detected
if suitably large exposures are available. Such conditions
were satisfied in some of the chalk areas of eastern Eng-
land. He claims that glaciological theory makes it impossible
for glacier ice to have carried erratics from Preseli to Stone-
henge. That is disproved simply by reference to the large far-
travelled erratics found in Somerset, Devon and Cornwall,
some of which are in excess of 80 m above sea level (Mad-
gett and Inglis, 1987). Spectacular igneous erratics are still
being found on Bristol Channel coasts; indeed a large do-
lerite boulder was found on the shoreline in Limeslade Bay
(Gower Peninsula) as recently as 2022. James Scourse says
there is an inconsistency between “observational and theoret-
ical data... and the regional geological data”. That is a matter
of opinion, and as noted above glacier modelling has repeat-
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B. S. John: Stonehenge bluestone erratic 129
Figure 14. Some of the Stonehenge boulders found in the Bluestone Circle. All have rounded edges and facets, some rough and some
smooth. These features in combination are suggestive of ice transport. These are mostly made of dolerite, which seldom supports striations.
Note also the weathering crusts, which in places have peeled off. For the locations of these monoliths, please refer to Fig. 4 (courtesy of
Simon Banton and the Stones of Stonehenge website: http://www.stonesofstonehenge.org.uk/, last access: 27 May 2024).
edly shown that Salisbury Plain could well have been located
within the “glacial footprint” during some Quaternary glacial
episodes (Patton et al., 2017, 2022) (Fig. 15).
It is widely accepted that at some stage during the Quater-
nary glacier ice travelling from the west affected the coastal
zone near Bristol, the Mendips and Bathampton Down near
Bath (Hunt, 1998; Gilbertson and Hawkins, 1978). This
means that the ice surface must have been at least 250m
above present sea level. It follows that in accordance with
the laws of ice physics and the tendency of flowing ice
to spread laterally into depressions, the extensive Somerset
Lowlands must have been glaciated. Indeed, glacial deposits
are recorded at Greylake (south-east of Bridgwater) beneath
approximately 7 m of interglacial deposits, and at nearby We-
stonzoyland there was a giant erratic (now destroyed) known
as the Devil’s Upping Stock.
With regard to the timing of the glacial episode responsi-
ble for the transport of the Stonehenge bluestones, the rel-
ative scarcity of field evidence suggests that a prolonged
period of landform degradation and sediment redistribution
has occurred since the last glacial ice on or near Salisbury
Plain melted away. The glaciation is unlikely therefore to
have been that of the Last Glacial Maximum (LGM), which
culminated around 25 000 years ago. The depositional fea-
tures, till and related deposits from that episode are still rel-
atively fresh, and the extent of that glaciation in the Celtic
Sea arena and in SW England is now relatively well under-
stood (Scourse et al., 2022). The LGM Irish Sea Ice Stream is
thought to have pushed into the Bristol Channel and to have
affected the coasts of Devon and Cornwall, but it is unlikely
to have reached Somerset or Wiltshire. Very little is known
about the MIS10–16 glacial episode in the western part of
the British Isles, so the most likely candidate for bluestone
transport is the Irish Sea Ice Stream of the Anglian glacial
episode (MIS12), around 450 000 years ago (Fig. 16).
The Anglian Glaciation (ca. 0.43 Ma; MIS 12)
marks the biggest Quaternary expansion of the
BIS and had a marked effect on the landscape
of Britain. It radically altered drainage and relief,
and initiated the formation of the Straits of Dover
which led Britain to be isolated from mainland Eu-
rope during various high sea-level stands during
the Middle and Late Pleistocene. The chronology
of Middle Pleistocene expansions of the BIS is still
contentious, with conflicts existing between differ-
ent types of evidence, and in some cases, differ-
ent interpretations of the same evidence (Lee et
al., 2011).
In the view of the present author there are cemented till de-
posits probably dating from the Anglian Glaciation in a num-
ber of West Wales localities, and elsewhere concentrations
of sub-rounded and weathered erratic boulders appear to be
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130 B. S. John: Stonehenge bluestone erratic
Figure 15. Three “extreme” models in which attempts are made to define the extent and other characteristics of the LGM British–Irish
Ice Sheet. (a) Hubbard et al. (2009), an outlier model run showing the percentage of time during which the land surface was ice covered.
(b) Patton et al. (2016), showing potential LGM erosion. (c) Patton et al. (2022), showing rates of erosion during the Late Devensian glacial
episode. These models are all constrained by unreliable information about ice extent in the Celtic Sea arena. If the ice edge is pushed south-
westwards to the shelf edge in line with “ground truthing”, then it must also be pushed south-eastwards in southern England. The new limit
would incorporate local ice caps over the uplands of SW England.
Figure 16. Suggested ice flow patterns for the southern parts of the Irish Sea Ice Stream and the Welsh Ice Cap during the “Greatest British
Glaciation” (?Anglian). Approximate ice surface altitudes are added. The ice edge maximum position for this episode is still to be delineated.
older than the raised beach deposits attributed to the Last In-
terglacial (Ipswichian). The glacial deposits of Somerset are
also likely to be of Anglian age (Green, 1992), as are some of
the tills and terrace gravels of the Upper Thames basin. The
correlation of deposits in the South Midlands (including the
Upper Thames drainage basin) presents a formidable chal-
lenge (Gibson et al., 2022; Gibbard et al., 2022), and it now
appears that the Wolstonian Glaciation might, in some sec-
tors, have been more extensive than the Anglian. Much work
remains to be done on the timing, extent and characteristics
of the British–Irish Ice Sheet and its associated ice streams
prior to the last (Ipswichian) interglacial (Lee et al., 2004).
With regard to ancient glacial episodes, the Newall Boul-
der has an intriguing association with the “Ardleigh Boul-
der” found in river gravels near Colchester in Essex in 2009
(Rose et al., 2010). The two boulders have clear morpho-
logical similarities. They are approximately the same size;
both are roughly bullet-shaped, both are made of rhyolite,
and both appear to have come from Wales. Both are faceted
and have abraded edges, and both have one facet that ap-
pears to support striations. Rose et al. (2010) have suggested
that the Ardleigh Boulder, more than 200km from its proba-
ble source, was transported fluvially in or on floe ice. And it
was also suggested that the Ardleigh Boulder came originally
from ancient glacial deposits, possibly in the Welsh Borders.
The difference between the two boulders is that the Ardleigh
Boulder was entirely naturally emplaced, whereas the human
damage to the Newall Boulder, following its initial discovery,
is all too obvious.
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B. S. John: Stonehenge bluestone erratic 131
7 Shortcomings of the human transport hypothesis
In emphasising the possibility that the Stonehenge bluestone
monoliths and other fragments in the debitage were trans-
ported by Anglian ice, and in accepting that firm evidence
on the ground is hard to come by, as pointed out by Scourse
(1997), it should be emphasised that evidence in support of
the alternative theory – of human transport – is even more
difficult to assemble.
1. There is no sound evidence from anywhere in the
British Neolithic/Bronze Age record of large stones be-
ing hauled over long distances for incorporation in a me-
galithic monument (Thorpe et al., 1991).
2. Field observations show, consistently, that the builders
of Neolithic monuments across the UK simply used
whatever large stones were at hand (Burrow, 2006).
3. If special or sacred stones were being transported to
Stonehenge, it is vanishingly unlikely that they would
all have been collected in the west, to the exclusion of
all other points of the compass (John, 2018a).
4. There is no evidence either from West Wales or from
anywhere else of bluestones (for example foliated rhyo-
lite or spotted dolerite) being used preferentially in me-
galithic monuments or revered in any way (Darvill and
Wainwright, 2016).
5. If long-distance stone haulage was an “organised activ-
ity” for the builders of Stonehenge, it is noteworthy that
there is no evidence of the development of an appropri-
ate haulage technology leading up to the Late Neolithic
and a decline afterwards. In other words, there is no sign
of any diffusion of innovation (Rogers, 2003).
6. The evidence for quarrying activity in key Preseli loca-
tions is questionable (John et al., 2015b). No archaeo-
logical or cultural links have been established between
Stonehenge and the proposed “quarries” at Craig Rhos-
y-felin and Carn Goedog.
7. The sheer variety of bluestone types argues against hu-
man selection and transport. There cannot possibly have
been multiple “bluestone monolith quarries” scattered
across West Wales (Thorpe et al., 1991).
8. No physical evidence has ever been found of ropes,
rollers, trackways, sledges, abandoned stones, quarry
worker camps or anything else that might bolster the
hypothesis (Kellaway, 1971).
9. Experimental archaeology on stone haulage techniques
(normally in “ideal” conditions) has done nothing to
show that our ancestors could cope with the sheer physi-
cal difficulty of stone haulage across the heavily wooded
Neolithic terrain of West Wales (characterised by bogs,
cataracts, steep slopes and very few clearings) or around
the rocky coast. Burl (2007) made this point forcefully,
and it remains forceful today.
10. No convincing evidence has ever been found of a
“proto-Stonehenge” in West Wales, built of assorted lo-
cal stones that were dismantled and taken off to Stone-
henge. Mike Parker Pearson’s claim that a “giant stone
circle” at Waun Mawn in Mynydd Preseli was the
source and the inspiration for Stonehenge has been crit-
icised by Darvill (2022) and others and has now been
abandoned (Bevins et al., 2022).
8 Conclusions
This is the first well-documented small glacial clast to have
been described in a Stonehenge context. It is noteworthy that
its finders, Hawley and Newall, did not recognise its signifi-
cance. However, in 1924 they were clearly heavily influenced
by the forceful views of Herbert H. Thomas, who had de-
clared that “the geological evidence is such that the idea of
a glacial origin for the foreign stones will not bear investi-
gation” (Thomas, 1923). He had also declared that his own
evidence “permanently disposes of the idea of glacial trans-
port”. This view was not seriously challenged in 1923, and it
has prevailed in archaeological circles for almost a century,
in spite of the fact that the “human transport hypothesis” has
remained unproven.
With regard to the exact origins of the boulder, it may have
come from one of the rhyolitic tuff exposures in the Mynydd
Preseli area, but the geological work done thus far does not
support provenancing to the Rhos-y-felin–Pont Saeson area
(Bevins et al., 2023).
This preliminary investigation, which must be followed
and corrected by more detailed research by experts in a num-
ber of fields, strongly suggests that glacially deposited ma-
terials and far-travelled erratics unrelated to the bluestone
monoliths do exist at Stonehenge. This is what has been
suspected for many years and proposed by Kellaway (1971,
1991), Thorpe et al. (1991) and John (2018a). The inter-
pretations made by Thomas (1923) and repeated by many
other Stonehenge researchers and commentators have not
been verified by recent research. This also brings into ques-
tion the views of geologists Robert Ixer and Richard Bevins:
(1) that the bluestone fragments and small boulders at Stone-
henge must have been quarried and then transported by hu-
mans from Pembrokeshire, (2) that the debris must be re-
lated to the known (and unknown) bluestone monoliths in
the stone settings, and (3) that there was an identifiable Late
Neolithic “arrival date” for the bluestones at the site of the
monument.
The complex narrative concerning the Stonehenge blue-
stones, involving large-scale bluestone quarries at Craig
Rhos-y-felin and Carn Goedog and a “lost stone circle” at
Waun Mawn (Parker Pearson et al., 2015; Bevins et al., 2013;
https://doi.org/10.5194/egqsj-73-117-2024 E&G Quaternary Sci. J., 73, 117–134, 2024
132 B. S. John: Stonehenge bluestone erratic
Ixer and Bevins, 2011a, 2013; Parker Pearson et al., 2021),
appears to this author as a classic example of interpretative
inflation (Barclay and Brophy, 2020). It must therefore be re-
examined. There are no demonstrable cultural links between
the three Pembrokeshire sites or with Stonehenge (Darvill,
2022; Bevins et al., 2022).
The simplest explanation of the presence of the bluestones
at Stonehenge is that they are glacial erratics from the west,
emplaced by ice at some site still to be discovered, on or near
Salisbury Plain, where they were later collected up and used
by the builders of the stone monument.
Data availability. No data sets were used in this article.
Competing interests. The author has declared that there are no
competing interests.
Disclaimer. Publisher’s note: Copernicus Publications remains
neutral with regard to jurisdictional claims made in the text, pub-
lished maps, institutional affiliations, or any other geographical rep-
resentation in this paper. While Copernicus Publications makes ev-
ery effort to include appropriate place names, the final responsibility
lies with the authors.
Acknowledgements. I am grateful to Adrian Green, Director of
Salisbury Museum, for permission to examine and photograph the
Newall Boulder and to publish this article. I also thank Lizzie Rich-
mond for information from the Kellaway Collection in the Library
of Bath University, which was invaluable for confirming the history
of the boulder since its initial discovery in 1924. David Evans and
an anonymous referee are thanked for their constructive comments
which have led to significant improvements since the first drafting
of this paper.
Review statement. This paper was edited by Christopher Lüth-
gens and reviewed by David Evans and one anonymous referee.
References
Atkinson, R. J. C.: Stonehenge, Hamilton, London, 224 pp.,
ISBN 014 02 0450 4, 1979.
Barclay, G. J. and Brophy, K.: ’A Veritable Chauvinism of
Prehistory’: Nationalist Prehistories and the ’British’ Late
Neolithic Mythos, Archaeological Journal, 178, 330–360,
https://doi.org/10.1080/00665983.2020.1769399, 2020.
Benn, D. I. and Ballantyne, C. K.: Reconstructing the transport his-
tory of glacigenic sediments: a new approach based on the co-
variance of clast shape indices, Sediment. Geol., 91, 215–227,
https://doi.org/10.1016/0037-0738(94)90130-9, 1994.
Benn, D. I. and Evans, D. J. A.: The interpretation and classifica-
tion of subglacially-deformed materials, Quaternary Sci. Rev.,
15, 23–52, 1996.
Benn, D. I. and Evans, D. J. A.: Glaciers and Glaciation, Hodder,
London, 802 pp., 2010.
Benn, D. I. and Lukas, S.: Clast morphology, in: A Practical Guide
to the Study of Glacial Sediments, edited by: Evans, D. J. A.
and Benn, D. I., QRA, London, 107–124, ISBN 9780203783481,
2021.
Bevins, R. E., Ixer, R. A., and Pearce, N. G.: Carn Goedog is
the likely major source of Stonehenge doleritic bluestones: ev-
idence based on compatible element geochemistry and prin-
cipal components analysis, J. Archaeol. Sci., 42, 179–193,
https://doi.org/10.1016/j.jas.2013.11.009, 2013.
Bevins, R. E., Pearce, N. J. G., Parker Pearson, M., and
Ixer, R. A.: Identification of the source of dolerites used at
the Waun Mawn stone circle in the Mynydd Preseli, west
Wales and implications for the proposed link with Stone-
henge, Journal of Archaeological Science: Reports, 45, 103556,
https://doi.org/10.1016/j.jasrep.2022.103556, 2022.
Bevins, R. E., Ixer, R. A., Pearce, N. G., Scourse, J., and Daw,
T.: 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 de-
bate of the monument’s bluestone megaliths, Geoarchaeology,
38, 771–785, https://doi.org/10.1002/gea.21971, 2023.
Boulton, G. S.: Boulder shapes and grain-size distributions of debris
as indicators of transport paths through a glacier and till genesis,
Sedimentology, 25, 773–779, 1978.
Bowen, D. Q.: South Wales, in: The Glaciations of Wales and Ad-
jacent Areas, edited by: Lewis, C. and Richards, A. E., Logaston
Press, 145–164, ISBN 1 904396 36 4, 2005.
Briggs, C. S.: Stone axe “trade” or glacial erratics?, Current Archae-
ology, 57, p. 303, 1977.
Burl, A.: A Brief History of Stonehenge, Robinson, 368 pp.,
ISBN 9781845295912, 2007.
Burrow, S.: The Tomb Builders, National Museum Wales, 150 pp.,
ISBN 0 7200 0568 X, 2006.
Clapperton, C. M. and Sugden, D. E.: The glaciation of Buchan – a
reappraisal, in: Quaternary studies in North East Scotland, edited
by: Gemmell, A. M. D., Department of Geography, University of
Aberdeen, 19–22, 1975.
Cleal, R., Walker, K. E., and Montague, R.: Stonehenge in its
landscape: 20th century excavations, English Heritage, 618 pp.,
ISBN 1 85074 605 2, 1995.
Clark, C. D., Ely, J. C., Hindmarsh, R. C. A., Bradley, S., Ignéczi,
A., Fabel, D., Ó Cofaigh, C., Chiverrell, R. C., Scourse, J.,
Benetti, S., Bradwell, T., Evans, D. J. A., Roberts, D. H., Burke,
M., Callard, S. L., Medialdea, A., Saher, M., Small, D., Smed-
ley, R. K., Gasson, E., Gregoire, L., Gandy, N., Hughes, A. L. C.,
Ballantyne, C., Bateman, M. D., Bigg, G. R., Doole, J., Dove,
D., Duller, G. A. T., Jenkins, G. T. H., Livingstone, S. L., Mc-
Carron, S., Moreton, S., Pollard, D., Praeg, D., Sejrup, H. P.,
Van Landeghem, K. J. J., and Wilson, P.: Growth and retreat
of the last British–Irish Ice Sheet, 31 000 to 15 000 years ago:
the BRITICE-CHRONO reconstruction, Boreas, 51, 699–758,
https://doi.org/10.1111/bor.12594, 2022.
Darvill, T.: Mythical rings? Waun Mawn and Stonehenge Stage 1,
Antiquity, 96, 1515–1529, https://doi.org/10.15184/aqy.2022.82,
2022.
Darvill, T. and Wainwright, G.: Neolithic and Bronze Age
Pembrokeshire, Chap. 2, in: Pembrokeshire County His-
E&G Quaternary Sci. J., 73, 117–134, 2024 https://doi.org/10.5194/egqsj-73-117-2024
B. S. John: Stonehenge bluestone erratic 133
tory, Vol. 1, Pembrokeshire County History Trust, 55–222,
ISBN 0 903771 16 0, 2016.
Evans, D. J. A.: Landscapes at the Periphery of Glacierization
– Retrospect and Prospect, Scot. Geogr. J., 132, 140–163,
https://doi.org/10.1080/14702541.2016.1156732, 2016.
Evans, D. J. A.: Till – A Glacial Process Sedimentology, Wiley-
Blackwell, Chichester, ISBN9781118652596, 2018.
Evans, D. J. A., Phillips, E., Hiemstra, J. F., and Au-
ton, C. A.: Subglacial till: Formation, sedimentary char-
acteristics and classification, Earth-Sci. Rev., 78, 115–176,
https://doi.org/10.1016/j.earscirev.2006.04.001, 2006.
Evans, D. J. A., Roberts, D. H., and Evans, S. C.: Multi-
ple subglacial till deposition: a modern exemplar for Qua-
ternary palaeoglaciology, Quaternary Sci. Rev., 145, 183–203,
https://doi.org/10.1016/j.quascirev.2016.05.029, 2016.
Evans, D. J. A., Roberts, D. H., Hiemstra, J. F., Nye, K. M.,
Wright, H., and Steer, A.: Submarginal debris transport and
till formation in active temperate glacier systems: the south-
east Iceland type locality, Quaternary Sci. Rev., 195, 72–108,
https://doi.org/10.1016/j.quascirev.2018.07.002, 2018.
Field, D., Anderson-Whymark, H., Linford, N., Barber, M., Bow-
den, M., Linford, P., Topping, P., Abbott, M., Bryan, P., Cun-
liffe, D., Hardie, C., Martin, L., Payne, A., Pearson, T., Small,
F., Smith, N., Soutar, S., and Winton, H.: Analytical Surveys of
Stonehenge and its Environs, 2009–2013: Part 2 – the Stones,
P. Prehist. Soc., 81, 125–148, https://doi.org/10.1017/ppr.2015.2,
2015.
Gibson, S. M., Bateman, M. D., Murton, J. B., Barrows, T., Fi-
field, L. K., and Gibbard, P. L.: Timing and dynamics of Late
Wolstonian Substage ’Moreton Stadial’ (MIS 6) glaciation in the
English West Midlands, UK, Roy. Soc. Open Sci., 9, 220312,
https://doi.org/10.1098/rsos.220312, 2022.
Gibbard, P. L., Hughes, P. D., and Rolfe, C. J.: New insights into the
Quaternary evolution of the Bristol Channel, UK, J. Quaternary
Sci., 32, 15 pp., https://doi.org/10.1002/jqs.2951, 2017.
Gibbard, P. L., Hughes, P. D., Clark, C. D., Glasser, N. F.,
and Tomkins, M. D.: Chapter 34 – Britain and Ireland:
glacial landforms prior to the Last Glacial Maximum, European
Glacial Landscapes, Maximum Extent of Glaciations, 245–253,
https://doi.org/10.1016/B978-0-12-823498-3.00050-9, 2022.
Gilbertson, D. S. and Hawkins, A. B.: The Pleistocene Succession
at Kenn, Somerset, Bulletin of the Geological Survey of Great
Britain, 66, 41 pp., 1978.
Gowland, W.: Recent excavations at Stonehenge, Wiltshire Maga-
zine, June 1903, 1–46, 1903.
Green, C. P.: Pleistocene river gravels and the Stonehenge problem,
Nature, 243, 214–216, 1973.
Green, C. P.: The provenance of rocks used in the construction of
Stonehenge, in: Science and Stonehenge, edited by: Cunliffe, B.
and Renfrew, C., P. Brit. Acad., 92, 257–270, 1997.
Green, G. W.: British regional geology: Bristol and Gloucester re-
gion, 3rd edn., HMSO for the British Geological Survey, London,
ISBN 978 0118844826, 1992.
Håkansson, L., Alexandersson, H., Hjort, C., Mölle, P., Briner, J.
P., Aldahan, A., and Possnert, G.: Late Pleistocene glacial his-
tory of Jameson Land, central East Greenland, derived from cos-
mogenic 10Be and 26Al exposure dating, Boreas, 38, 244–260,
https://doi.org/10.1111/j.1502-3885.2008.00064.x, 2009.
Hawley, W.: The Excavations at Stonehenge: Interim Report on the
exploration, Antiq. J., 1, 9–41, 1921.
Hawley, W.: Report on the excavations at Stonehenge during the
season 1924, Antiq. J., 6, 1–25, 1926.
Howells, M. F.: Wales: British Regional Geology, BGS, 230 pp.,
ISBN 0 85272 584 9, 2007.
Hubbard, A., Bradwell, T., Golledge, N., Hall, A., Patton, H., Sug-
den, D., Cooper, R., and Stoker, M.: Dynamic cycles, ice streams
and their impact on the extent, chronology and deglaciation of
the British–Irish ice sheet, Quaternary Sci. Rev., 28, 759–777,
https://doi.org/10.1016/j.quascirev.2008.12.026, 2009.
Hunt, C. O.: Quaternary of South-West England, in: Geological
Conservation Review Series, edited by: Campbell, S., Hunt, C.
O., Scourse, J. D., Keen, D. H., and Stephens, N., Joint Nature
Conservation Committee, Springer Science, 287–363, 1998.
Ixer, R. A. and Bevins, R. E.: The petrography, affinity and prove-
nance of lithics from the Cursus Field, Stonehenge, Wiltshire Ar-
chaeological and Natural History Magazine, 103, 1–15, 2010.
Ixer, R. A. and Bevins, R. E.: Craig Rhos-y-Felin, Pont Saeson is
the dominant source of the Stonehange rhyolitic ’debitage’, Ar-
chaeology in Wales, 50, 21–31, 2011a.
Ixer, R. A. and Bevins, R. E.: The detailed petrography of six or-
thostats from the bluestone circle, Stonehenge, Wiltshire Archae-
ological and Natural History Magazine, 104, 1–14, 2011b.
Ixer, R. A. and Bevins, R. E.: Chips off the old block: the Stone-
henge debitage dilemma, Archaeology in Wales, 52, 11–22,
2013.
Ixer, R. A. and Bevins, R. E.: The bluestones of Stonehenge,
Geology Today, 33, 180–184, https://doi.org/10.1111/gto.12198,
2017.
Ixer, R. A., Bevins, R., and Pirrie, D.: Provenancing the
stones: mapping the Stonehenge bluestones using mineral-
ogy, Current Archaeology, 366, 34–41, https://archaeology.
co.uk/articles/features/provenancing-the-stones.htm (last access:
28 May 2024), 2020.
Ixer, R. A., Bevins, R., Pearce, N., and Dawson, D.: Victorian
gifts: new insights into the Stonehenge bluestones, Current
Archaeology, 29 August 2022, https://the-past.com/feature/
victorian-gifts-new-insights-into-the-stonehenge-bluestones/
(last access: 28 May 2024), 2022.
John, B. S.: The Stonehenge Bluestones, Greencroft Books, 256 pp.,
ISBN 978 0905559 94 0, 2018a.
John, B. S.: Evidence for extensive ice cover on the
Isles of Scilly, Quaternary Newsletter, 146, 3–27,
https://www.researchgate.net/publication/328413421_Evidence_
for_extensive_ice_cover_on_the_Isles_of_Scilly (last access:
28 May 2024), 2018b.
John, B. S.: Was there a Late Devensian ice-free corridor
in Pembrokeshire?, Quaternary Newsletter, 158, 5–16,
https://www.qra.org.uk/mp-files/qn158_1_late-devensian-ice-
free-corridor-in-pembrokshire.pdf/ (last access: 28 May 2024),
2023.
John, B. S., Elis-Gruffydd, D., and Downes, J.: Observations
on the supposed “Neolithic Bluestone Quarry” at Craig
Rhosyfelin, Pembrokeshire, Archaeology in Wales, 54, 139–
148, https://www.researchgate.net/publication/286775899_
OBSERVATIONS_ON_THE_SUPPOSED_NEOLITHIC_
BLUESTONE_QUARRY_AT_CRAIG_RHOSYFELIN_
PEMBROKESHIRE (last access: 28 May 2024), 2015a.
https://doi.org/10.5194/egqsj-73-117-2024 E&G Quaternary Sci. J., 73, 117–134, 2024
134 B. S. John: Stonehenge bluestone erratic
John, B. S., Elis-Gruffydd, D., and Downes, J.: Quaternary Events
at Craig Rhosyfelin, Pembrokeshire, Quaternary Newsletter, 137,
16–32, https://www.researchgate.net/publication/283643851_
QUATERNARY_EVENTS_AT_CRAIG_RHOSYFELIN_
PEMBROKESHIRE (last access: 28 May 2024), 2015b.
Johnson, A.: Solving Stonehenge, Thames & Hudson, 288 pp.,
ISBN 978 0 500 05155 9, 2008.
Judd, W.: Note on the nature and origin of the rock fragments found
in the excavations made at Stonehenge by Mr Gowland in 1901,
Wiltshire Magazine, 47–61, 1903.
Kellaway, G. A.: Glaciation and the stones of Stonehenge, Nature,
233, 30–35, https://doi.org/10.1038/233030a0, 1971.
Kellaway, G. A.: The older Plio-Pleistocene glaciations of the re-
gion around Bath, in: Hot Springs of Bath, edited by: Kellaway,
G. A., Bath CC, 243–241, 1991.
Krüger, J.: Clasts with stoss-lee forms in lodgement tills: a discus-
sion, J. Glaciol., 30, 241–243, 1984.
Lee, J. R., Rose, J., Hamblin, R. J. O., and Moorlock,
B. S. P.: Dating the earliest lowland glaciation of east-
ern England: A pre-MIS 12 early Middle Pleistocene Hap-
pisburgh glaciation, Quaternary Sci. Rev., 23, 1551–1566,
https://doi.org/10.1016/j.quascirev.2004.02.002, 2004.
Lee, J. R., Rose, J., Hamblin, R. J., Moorlock, B. S., Riding,
J. B., Phillips, E., Barendregt, R. W., and Candy, I.: The
Glacial History of the British Isles during the Early and Mid-
dle Pleistocene: Implications for the long-term development of
the British Ice Sheet, edited by: Ehlers, J., Gibbard, P. L., and
Hughes, P. D., Developments in Quaternary Sciences, 15, 59–74,
https://doi.org/10.1016/B978-0-444-53447-7.00006-4, 2011.
Lukas, S., Benn, D. I., Boston, C. M., Brook, M. S., Coray,
S., Evans, D. J. A., Graf, A., Kellerer-Pirklbauer-Eulenstein,
A., Kirkbride, M. P., Krabbendam, M., Lovell, H., Machiedo,
M., Mills, S. C., Nye, K., Reinardy, B. T. I., Ross, F.
H., and Signer, M.: Clast shape analysis and clast trans-
port paths in glacial environments: A critical review of meth-
ods and the role of lithology, Earth-Sci. Rev., 121, 96–116,
https://doi.org/10.1016/j.earscirev.2013.02.005, 2013.
Madgett, P. A. and Inglis, E. A.: A Re-Appraisal of the Erratic Suite
of the Saunton and Croyde Areas, North Devon, Rep. Transac-
tions of the Devon Association for the Advancement of Science,
119, 135–144, 1987.
Parker Pearson, M.: Stonehenge: exploring the greatest Stone Age
mystery, Simon and Schuster, 406 pp., ISBN 978 0 85720 730 2,
2012.
Parker Pearson, M., Bevins, R. E., Ixer, R. A., Pollard, J.,
Richards, C., Welham, K., Chan, B. K., Edinborough, K., Hamil-
ton, D., McPhail, R., Schlee, D., Schweenninger, J.-L., Sim-
mons, E., and Smith, M.: Craig Rhos-y-felin: a Welsh blue-
stone megalith quarry for Stonehenge, Antiquity, 89, 1331–1352,
https://doi.org/10.15184/aqy.2015.177, 2015.
Parker Pearson, M., Pollard, J., Richards, C., Welham, K.,
Kinnaird, T., Shaw, D., Simmons, E., Stanford, A., Bevins,
R. E., Ixer, R. A., Ruggles, C., Rylatt, J., and Edinbor-
ough, K.: The original Stonehenge? A dismantled stone cir-
cle in the Preseli Hills of west Wales, Antiquity, 95, 85–103,
https://doi.org/10.15184/aqy.2020.239, 2021.
Patton, H., Hubbard, A., Andreassen, K., Winsborrow, M., and
Stroeven, A. P.: The build-up, configuration, and dynamical sen-
sitivity of the Eurasian ice-sheet complex to Late Weichselian
climatic and oceanic forcing, Quaternary Sci. Rev., 153, 97–121,
2016.
Patton, H., Hubbard, A., Andreassen, K., Auriac, A., White-
house, P. L., Stroeven, A. P., Shackleton, C., Winsborrow,
M., Heymane, J., and Hall, A. M.: Deglaciation of the
Eurasian ice sheet complex, Quaternary Sci. Rev., 169, 148–172,
https://doi.org/10.1016/j.quascirev.2017.05.019, 2017.
Patton, H., Hubbard, A., Heyman, J., Alexandropoulou, N.,
Lasabuda, A. P. E., Stroeven, A. P., Hall, A. M., Winsborrow,
M., Sugden, D. E., Kleman, J., and Andreassen, K.: The extreme
yet transient nature of glacial erosion, Nat. Commun., 13, 7377,
https://doi.org/10.1038/s41467-022-35072-0, 2022.
Pitts, M.: How to build Stonehenge, Thames and Hudson, 249 pp.,
ISBN 978 0 500 02419 5, 2022.
Powers, M. C.: New roundness scale for sedimentary parti-
cles, J. Sediment. Res., 23, 117–119, https://doi.org/10.1306/
D4269567-2B26-11D7-8648000102C1865D, 1953.
Ramsey, A. C.: Geology of Parts of Wiltshire and Gloucestershire
(Sheet 34), HMSO, London, 1858.
Rogers, E.: Diffusion of Innovations, 5th edn, Simon and Schuster,
576 pp., ISBN 978074322209 9, 2003.
Rose, J., Carney, J. N., Silva, B. N., and Booth, S. J.: A striated,
far travelled clast of rhyolitic tuff from Thames river deposits at
Ardleigh, Essex, England: evide.nce for early Middle Pleistocene
glaciation in the Thames catchment, Neth. J. Geosci., 89, 137–
146, 2010.
Scourse, J. D.: Transport of the Stonehenge Bluestones: Test-
ing the Glacial Hypothesis, in: Science and Stonehenge, edited
by: Cunliffe, B. and Renfrew, C., British Academy, 271–314,
ISBN 0 19 726174 4, 1997.
Scourse, J. D., Saher, M., Van Landeghem, K. J. J., Lockhart, E.,
Purcell, C., Callard, L., Roseby, Z., Allinson, B., Pie´
nkowski, A.
J., O’Cofaigh, C., Praeg, D., Ward, S., Chiverrell, R., Moreton,
S., Fabel, D., Clark, C. D.: Advance and retreat of the marine-
terminating Irish Sea Ice Stream into the Celtic Sea during the
Last Glacial: Timing and maximum extent, Mar. Geol., 412, 53–
68, https://doi.org/10.1016/j.margeo.2019.03.003, 2019.
Sharp, M. J.: Modification of clasts in lodgement tills by glacial
erosion, J. Glaciol., 28, 475–481, 1982.
Stone, E. H.: The Stones of Stonehenge, Robert Scott, London,
ISBN: 9781169296169, 1924.
Thomas, H. H.: The source of the stones of Stonehenge, The Anti-
quaries Journal, 3, 239–260, 1923.
Thorpe, R. S., Williams-Thorpe, O., Jenkins, D. G., and Watson, J.
S. (with contributions by Ixer, R. A. and Thomas, R. G.): The
Geological Sources and Transport of the Bluestones of Stone-
henge, Wiltshire, UK, Proceedings of the Prehistoric Society, 57,
103–157, 1991.
Vaughan, D., Phillips, E., Lee, J. R., and Hart, J. K.: Glacitectonic
rafting of chalk bedrock: Overstrand, in: Glacitectonics – Field
Guide, edited by: Phillips, E., Lee, J. R., and Evans, H., Quater-
nary Research Association, ISBN 9780907780830, 2011.
Willis, C., Marshall, P., McKinley, J., Pitts, M., Pollard, J., Richards,
C., Richards, J., Thomas, J., Waldron, C., Welham, K., and
Parker Pearson, M.: The dead of Stonehenge, Antiquity, 90, 337–
356, https://doi.org/10.15184/aqy.2016.26, 2016.
E&G Quaternary Sci. J., 73, 117–134, 2024 https://doi.org/10.5194/egqsj-73-117-2024
