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Tuesday, 8 December 2015

The "Antiquity" paper -- a critical assessment

The new paper:  Mike Parker Pearson, Richard Bevins, Rob Ixer, Joshua Pollard, Colin Richards, Kate Welham, Ben Chan, Kevan Edinborough, Derek Hamilton, Richard Macphail, Duncan Schlee, Jean-Luc Schwenninger, Ellen Simmons and Martin Smith (2015). Craig Rhos-y-felin: a Welsh bluestone megalith quarry for Stonehenge.   Antiquity, 89 (348) (Dec 2015), pp 1331-1352 doi:10.15184/aqy.2015.177


The long-distance transport of the bluestones from south Wales to Stonehenge is one of the most remarkable achievements of Neolithic societies in north-west Europe. Where precisely these stones were quarried, when they were extracted and how they were transported has long been a subject of speculation, experiment and controversy. The discovery of a megalithic bluestone quarry at Craig Rhos-y-felin in 2011 marked a turning point in this research. Subsequent excavations have provided details of the quarrying process along with direct dating evidence for the extraction of bluestone monoliths at this location, demonstrating both Neolithic and Early Bronze Age activity.


OK -- on the basis of the Abstract, we get the story!  However, here is a critical assessment for those who cannot get at the article itself:

In the Introduction -- about the geology -- there is a reasonable summary of published research, mercifully free of any speculation and dodgy assumptions.  There is mention of the 4 main groups of bluestones at Stonehenge.  Reference is made to the Ixer/Bevins research linking the N edge of the spur with the rhyolite debitage at Stonehenge.  Then there is a suggestion that stone 32d has come from a recess at Rhosyfelin -- partly because the dimensions 0.40m x 0.45m "correspond closely" with the famous recess at Rhosyfelin!!  Location 4 in Figure 2 is referred to as "the recess", and location 11, next to it, is the "close match". (I thought the original sample was taken from round the corner, at the old locality 8?)  From previous examination of the geological papers, I do not think it has ever been demonstrated that the match is as precise as this paper assumes, and the possibility remains that the rhyolite debris at Stonehenge has not come from here at all.

When the geology section is out of the way, the problems start.  After the petrography bit, on page 1335, there should have been a stratigraphy section -- but there is nothing.  The diggers have obviously plotted the stratigraphy fairly carefully (it's shown very colourfully in Fig 5 and Fig 8, but without any key), but at no stage do they describe the sequence of deposits.  Maybe they didn't think we'd be interested.  So we have no way of assessing the reliability of what follows.  The authors plunge straight into a description of the "archaeological deposits" without for a moment trying to assess what physical processes might have operated here --  the "glacial till" and the "colluvium" are referred to but not properly described.  There is no mention anywhere of the extensive rockfall accumulations which mask the lower part of the rock face, and no mention of the stratified slope deposits that were so prominent on the flanks of the dig site, when it was all open for viewing.  There is no mention of the fluvioglacial materials widely exposed in the dig site.  Without any presentation of sedimentary or other evidence, or discussion of what it means, the authors simply assume on page 1336 that this is all about prehistoric quarrying. 

Quote:  "Colluvium has buried and protected the remains of prehistoric quarrying from subsequent stone removal and disturbance in the medieval and modern era. The archaeological sequence lies on a bed of glacial till within a small tributary valley on the west side of the outcrop."   So presumably all of the scree and rockfall debris is assumed to be "the remains of prehistoric quarrying."  That illustrates to some degree the vast gulf in perceptions between archaeologists and geomorphologists.

[[  In academic publishing the protocol is always as follows:  introduction >> presentation of field evidence >> analysis and interpretation of the evidence >> discussion >> conclusions and suggestions for future research. In this paper, this protocol has been completely ignored, and the whole paper seems to be an extended exercise in the confirmation of a ruling hypothesis.  I find it extraordinary that all of the authors must have signed up for this strategy, and even more extraordinary that the paper in its present form made its way through a refereeing process, and past an experienced editor, and actually made it into print..............  I hope there are some people within the archaeological academic establishment who are as concerned about this as I am.  ]]

Then we jump straight into an analysis of the radiocarbon and OSL dating evidence.  This occupies the bulk of the paper.  There are no less than 50 dates itemised in Table 1.  This is extremely interesting, but the analysis is spoiled because the significance of the dates is never properly discussed.  Instead, everything is interpreted, without further ado, as evidence concerning the dating of "prehistoric quarrying activity."   This heavy bias screws up everything, and it does not seem to have occurred to the authors that they might simply be looking at evidence of intermittent occupation of this site by Mesolithic and later hunting parties.  That is the most parsimonious explanation of the dates and features described, but it is ignored in the mad pursuit of "evidence" that will confirm the quarrying hypothesis. 

The dates deserve much greater consideration from the authors.  The lowest Mesolithic material in the sequence is dated to c 10,400 BP (carbonized shells and roundwood in a hearth in a pit).  Above that, the buried soil numbered 098 is dated to around 9,000 BP (it contains charcoal).  Quote: "There was no evidence of any Mesolithic quarrying or working of rhyolite from the outcrop."

On the topic of "Neolithic activity" a  hearth is identified but not described near the tip of the spur.  The relevant radiocarbon dates are around 5,400 BP.  The Neolithic horizon is described as  "dark brown, charcoal-rich sediment (059 = 159)"...... there is a hearth in a shallow pit which was used many times.

Quote:  "Within this stratigraphic horizon are three features associated with the quarrying of megaliths. Two of these are stone orthostats set in pits that contained carbonised wood or nutshell fragments dating to the late ninth to early eighth millennium BC; these fragments are probably thus residual from the Early Mesolithic layers into which the pits were cut (as detailed below)."  No evidence is presented  in support of any of this.  How big are the orthostats?  Where were they? Could they not simply have been fire pit lining stones?

A Bronze Age deposit is described above the Neolithic horizon -- presumably this extends to the surface?  Dates c 3717 BP - 3076 BP have been obtained from roundwood and hazel nuts.  A yellow colluvium (035) is above that -- it is dated (from bits of charcoal) to c 2800 BP.  This layer extends across the dig site.  Quote: "This deposit is contemporary with the uppermost fill of a palaeochannel of the Brynberian stream that flowed past the northern tip of the outcrop. Charcoal of Corylus and Tilia from the basal fill of this palaeochannel dates to  c 6833 BP and  c 6543 BP."

Quote:  ".....a prone monolith rests on a level artificial terrace that contains charcoal of Mesolithic and Early Bronze Age date. The monolith probably dates to the Early or Middle Bronze Age (see below) as the terrace is stratigraphically below Late Bronze Age and Iron Age deposits."  The level artificial terrace is never described in a comprehensible fashion, and one has to assume that it is simply a fantasy, seen only by archaeologists.........

Next, to the Iron Age:  Quote:  "The Late Bronze Age colluvial deposit did not reach the north-western face of the outcrop, where the prehistoric buried soil (098) was covered by a layer (081) with a wide range of dates from the Late Bronze Age onwards. Layer 81 was covered by a sequence of Iron Age layers (041 and 020) and localised deposits (e.g. pit 047). The Iron Age activity consisted of a sequence of two cultural layers with cut features, an iron artefact, worked flints and sherds of pottery. Dates of c 4400 BP and c 4074 BP fall within the Neolithic but come from hazelnut shell fragments in the fill of an Iron Age pit (047). Thus, their context cannot be considered to relate to the Neolithic horizon."  There are no descriptions of the characteristics of these layers or their relationships.

The next section of the article is called "Megalith-quarrying features".
Quote (p 1342):  "Six megalith-quarrying features have been discovered at Craig Rhos-y-felin, three of them dating to the Bronze Age. From south-west to north-east, they consist of a prone monolith sitting on an artificial platform, a threshold slab embedded in the north end of this platform, two stone orthostats set in pits, a recess from which a pillar has been removed and a lower artificial platform revetted with a drystone wall above the bank of the palaeochannel."

Quote relating to the large stone variously referred to by others as a "proto-othostat" or a "picnic table":  "A 4m-long prone megalith sits on a bed of horizontally laid stones, the largest of which are two rail-like pillars to its rear (south-west) end (Figure 9). This bed of stones lies on a level artificial terrace 6m long and at least 4m wide, built on the sloping ground beside the outcrop. This platform was formed from at least 8 tons of 0.3–0.4m-diameter dumps of sediment and stones (layer 115), to reach a depth of 0.5m at its north end. Three determinations on Corylus charcoal from this platform fill date to c 3665 BP, c 3700 BP and c 5367 BP."  It is obvious that these dates must have decided MPP et al that the proto-orthostat could not have been quarried earlier than  3665 BP -- and that it therefore had nothing to do with the Neolithic.  So the article settles on a Bronze Age quarrying phase, with no supporting evidence whatsoever.  And what are we to make of the 8 tonnes of sediment and stone dumps, the artificial terrace and the platform fill?  No attempt is made to describe these "installations" or to convince the humble reader that they are anything other than figments of a fertile imagination.

The descriptions of the so-called quarrying features are all entirely unconvincing, and even fanciful, from beginning to end.......

On page 1344 we come to a section called "Dating the quarrying activity."
With respect to the supposed earlier phase of quarrying:  Quote:  "The most probable dates associated with the removal of the rhyolite pillar from its recess are c 4590 BP and c 4667 BP, provided by carbonised hazelnut shells from the small occupation layer just 1.5m away from it."  There is no logic in that, and nothing to link any stone removal with any phase of occupation.

The authors seem to like the idea that there was an Early Bronze Age phase of quarrying in Pembrokeshire, around 4,000 BP, at Carn Goedog, Carn Meini and Rhosyfelin.  This ties in with the ideas published by Darvill / Wainwright from their work at Carn Meini.......

How were the bluestones extracted and when were they dressed?  Quote:  "There is relatively little debris within the quarry to indicate the methods used for detaching monoliths from the rock face. Nor is there any evidence of fire-setting to split the monoliths from the rock...."    This is a truly extraordinary statement, given that there are hundreds of tonnes of rockfall debris and shattered rock against the rock face..........  The message is that it was easy to extract stones with aid of wedges, and that therefore that was what happened.  Quote:  "In the case of the recess from which the ‘rhyolite with fabric’ monolith was extracted, a 0.07m-wide indentation on its north edge appears to be a hollowed-out wedgehole."  There is no end to the fantasy..........

Most bluestones at Stonehenge, say the authors,  are undressed -- those that are dressed were probably shaped at Stonehenge quite long after their arrival.

There follows a rather indecisive and vague discussion of likely transport routes and methods (with a map of the routes) -- it is concluded that the stones (mostly only about 2 tonnes in weight) were carried and slid along the A40 route much beloved of Prof Parker Pearson........

Then there is a consideration of the Boles Barrow "bluestone dilemma"  -- it's all rather inconclusive, although the authors seem to accept that the bluestone genuinely DID come from a Neolithic long barrow context at Boles Barrow, as claimed by Cunnington.  Quote:  "Were bluestones brought en masse to Salisbury Plain at this early date (ie before 5,500 yrs BP), perhaps to form kerbs and fac ̧ades for Wessex long barrows in the same manner as documented for sarsen orthostats at Millbarrow near Avebury (as recorded by William Stukeley; Whittle 1994), Arn Hill, Warminster, and possibly King Barrow, Bishopstrow (Eagles & Field 2004: 59)? Or were they brought at many different dates, ultimately to be rounded up and installed at Stonehenge within its Aubrey Holes during Stage 1?"   These questions are not answered.

Final section:  why were the bluestones moved to Stonehenge? 
The Darvill / Wainwright "healing stones" thesis is dismissed, on the grounds that the bluestones are now thought to have been in the Stonehenge vicinity far too early.  So the hypothesis is that the stones were "brought to Stonehenge" around 5,000 yrs BP.  So the date of Neolithic quarrying at Rhosyfelin is stated to be around or shortly after 5,300 yrs BP.  There is a brief discussion of conflict and unification etc -- there is nothing new here, for those who have heard MPP speak or who have read his books.  Quote:  "Alternatively, the bluestones were brought by communities migrating eastwards and settling on Salisbury Plain."  Quote:  ".........the motivation for moving the bluestones such a distance was probably related to their significance as symbols of identity. This supports the hypothesis that their identity was ancestral, with stones representing the deceased ancestors, because the earliest contexts in which bluestones were placed—Boles Barrow and the Aubrey Holes—were monuments with ancestral and funerary associations."

Final para:  "It is possible that the bluestone monoliths were taken directly from their quarries to Salisbury Plain. An alternative explanation postulates ‘the removal of a venerated stone circle from Preseli to Salisbury Plain’ (Thomas 1923: 258). Might the bluestones have formed one or more monuments within Wales that were dismantled and moved in order to be incorporated, eventually, into Stonehenge? Such an act could have served to merge two sacred centres into one, to unify two politically separate regions, or to legitimise the ancestral identity of migrants moving from one region to another. Future research into Neolithic monuments within north Pembrokeshire may shed light on these possibilities."

That is all in the realm of fantasy, providing justification for all those purple prose press releases and providing the rationale for further grant applications and digs that could extend far into the future............  a nice little earner......... 

So hold onto your hats -- the search for the North Pembrokeshire proto-Stonehenge starts NOW!!!! (Actually, it has already started.  But you ain't seen nothin' yet........)


In summary, I am mystified that this paper has found its way into print in a prestigious journal, since it comprehensively ignores all the protocols of scientific publishing and since it is simply an exercise in ruling hypothesis confirmation.  That's a great pity, because the authors obviously do have at their disposal a detailed stratigraphic record from this site which they could -- and should -- have placed into the public domain.  It is also a pity because the dating information is inherently fascinating and could have been useful if it had been presented straight, instead of being used  as an exercise in the dating of supposed quarrying activity.  This paper does nothing to enhance the quarrying hypothesis or to diminish the strength of the glacial entrainment hypothesis. The authors would have done themselves a service if they had stayed well clear of their discussion of monolith transport mechanisms.  Those mechanisms -- whether glacial or human -- deserve a separate paper, with the evidence analysed dispassionately.  This paper should have been restricted to a presentation and analysis of what can be seen at Rhosyfelin.  Sadly, it is apparent right from the beginning of this paper that the authors have deemed the glacial transport hypothesis to have been "impossible" and that there is no need to convince anybody that Rhosyfelin was a Neolithic monolith quarry site.  So the article has a powerful bias built into it from the start, and I for one am profoundly disappointed by its lack of rigour.



Jerry Guern said...

I've read a lot about the rock/soil layers around Stonehenge, but I've never seen anything about what the liths were set in by the original builders to hold them in place. Were they just stuck in the chalk? Was gravel poured into the gap between the lith and the hole? Could they have mixed some very primitive cement out of chalk? Thank you for any info you can offer.

BRIAN JOHN said...

This is something I'm not very well informed about, Jerry. Others may have more to contribute. My understanding is that pits were dug into the chalk to take the stones, and that once they were in position packing stones and rubble were thrown in and packed down hard, to stop the stones from moving. I have never heard of "cement" being used.......

Myris of Alexandria said...

Would be interesting to know if there were any Roman cement around.
But all the info is in the 1900s excavation reports see Gowland and with drawings in feet and inches.
Those were the days.
The primary literature is there or even Cleal (still that is more than the $30 whinge threshold).
The British Archaeology festive issue is out showing the quarries to great advantage.
Buy buy buy far less than $30 closer to 3 and less than a packet of Capstan Full Strength.

BRIAN JOHN said...

I have been taken to task by a regular reader of this blog for using the terms "academic" and "scholarly" interchangeably. Fair point. He argues that much academic publishing cannot now be considered to be scholarly, because "quantity' (I almost said "weight") and "impact" are the things that matter most -- and not quality and accuracy. So yes, let us mourn the fact that in the latest "Antiquity" article the normal protocols of SCHOLARLY PUBLISHING have been rather dramatically abandoned.......