Economy of effort in Neolithic Portugal

Middle States Geographer, 1999, 32: 110- 124

A GEOMORPHOLOGY OF MEGALITHS: NEOLITHIC LANDSCAPES IN THE ALTO ALENTEJO, PORTUGAL

Gregory A. Pope and Vera C. Miranda

Many thanks to Greg Pope for drawing my attention to this influential paper from 25 years ago, which had escaped my attention.  It reports on a fascinating piece of work which demonstrates that in the Portuguese megalithic monuments in this area of grantic rocks, the rocks used were almost entirely local -- used more or less where found.  Schmidt Hammer investigations revealed that there were no major differences in weathering characteristics between "used" megaliths and slabs and corestones which were lying about in the landscape.  Used stones and naturally occurring stones near rock ourcrops showed similar weathering characteristics, lichen cover and "buried" and "exposed" surfaces.  There was no reason to believe that any of the "used" stones had been quarried or transported across great distances.

This is exactly the point I have been making for years regarding the stones at Craig Rhosyfelin, Carn Goedog and Waun Mawn -- and indeed at Stonehenge.  The stones do NOT show any signs of quarrying or long distance transport -- and indeed if they are examined (as I have done with the Newall Boulder and the infamous big slab at Rhosyfelin) we can see weathered and unweathered faces and signs of different exposure ages, related to orientation or positioning in or on the ground surface.  When cosmogenic exposure ages are worked out for all these rock and boulder faces (as they will be) this quarrying fantasy will be thrown out once and for all........

To their credit, Ixer, Bevins and Pearce have already started to make measurements on dolerite and other rock surfaces in order to assess what geochemical changes are down to weathering processes; this is really interesting work, and I look forward to seeing the results when they are all drawn together. As far as I can see, none of the work so far has allowed them to differentiate between a "quarried" monolith and a naturally occurring one transported by ice!

The other relevant point here is the claim by MPP and others that the stone transporting expeditions which they love so much were done not because they were easy, but because they were difficult.  I have argued (as have many others) that the builders of Stonehenge were sensible enough to preferentially use stones found locally, as did the builders of all the other megalithic structures in Britain.  To have carried 80 megaliths all the way from West Wales would have been stupid, I reckon.  No no, say MPP and his friends, it would have neen stupendous, and highly sophisticated.  Well, if Portugal is anything to go by, the old residents of Alto Alentejo knew a bit about cost-benefit analysis and economy of effort.....

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ABSTRACT: 

The Alentejo region of Portugal is known for a high concentration of Neolithic-aged megalithic monuments: tombs (dolmens or antas) and ceremonial features such as standing stones (menhirs) and stone circles (cromleques). Concentrations of these monuments tend to be found on or near weathered granite terrains.  Unloading slabs and remnant corestones appear to be the stones ofpreference for megalith makers in the Alentejo district of Portugal. Some of the stones may have been imported from distant sources, but most appear to be of local origin. In general, most stones do not appear to have been altered much from their original state as field stones. Weathering tests demonstrate that menhirs are essentially identical to native corestones.  Many menhirs still exhibit a soil line. The former subaerial side of the stone usually retains a thick growth of lichen, while the soil side remains oxidized. Newly exposed antas and menhirs now suffer from enhanced weathering and erosion from atmospheric and biological agents. This deterioration is often difficult to discern from the inherited decomposition of pre-megalithic time.

CONCLUSIONS

The granitic megalith stones of the Alto Alentejo are interesting for what they reveal about weathering rates. From this information, we can speculate about their origin and construction, and recommend practices for their conservation. The exposures results are summarized below. 

1) Naturally weathered outcrops provided material for these early megalith monuments, a practice possibly used in megalith construction across western Europe. Lack of damage to superficial weathering features suggests that megalith stones were not transported long distances, or alternately, were transported with great care.

2) Weathering processes active on the megaliths included biotic, mechanical, and microclimate-intluenced dissolution processes.  While there is evidence of some human alteration (in the form of engravings or dressing) that removes original surfaces, most megaliths in the Alentejo region have superficial weathering features similar to the local field stones. Schmidt hammer data on rock hardness corroborate these results. Except where altered, megalith stones are statistically identical in weathering-controlled rock hardness to natural field stones. Stone dressing and polishing remain relatively clear, and engravings, while muted, are visible after more than 5000 years of exposure.

3) Visually, megalith stones still retain former subaerial and buried sides, despite their current placement. Lichens grow on surfaces formerly situated on the subaerial side of the stone, while oxidation staining prevails on the former buried side of the stone. Areas with lichen are more weathered, with softer rock. Lichen colonization is an obvious concern for conservators, but eradication can be a problem if doing so damages the stone surface and any engravings. Where lichens are not present, there is no difference in weathering (as detected through rock hardness) between former subaerial and former buried sides, counter to what might be expected (and what appears on recently unearthed non-megalith field stones).

4) Post-emplacement exposure may be a factor in the degree of weathering. There is a preference for softer rock in a quadrant from southwest to northwest, independent of the presence of lichens or former subaerial or buried characteristics. This exposure factor cannot have existed prior to megalith construction, and suggests that post-megalith weathering overrides characteristics inherited over a much longer premegalith weathering interval. Conservators can anticipate areas of concern on certain exposures, particularly after ruined monuments have been excavated and reconstructed.

As "the first public monuments of humankind" (M. Gomes, 1997a), megaliths provide unique opportunities to extend geomorphic theory and conservation practice. Both geomorphic and built, megaliths exist at an age that promotes translation between studies of more recent building stone and more ancient natural landscapes. Further investigations in different climates (e.g. Brittany and Cornwall or Malta) and with different types of stone (sandstone, slate, etc.) can expand on the results presented in this initial investigation.

My three 2024 published papers

These are the three papers published so far in 2024. All of them have been received very well by the specialist group of researchers whose opionions I respect.........

Refs:

1. John, B.S. 2024. The Stonehenge bluestones did not come from Waun Mawn in West Wales. The Holocene, 20 March 2024 (published online), 13 pp.

https://www.researchgate.net/publication/379121966_The_Stonehenge_bluestones_did_not_come_from_Waun_Mawn_in_West_Wales

2. John, B. S. 2024. A bluestone boulder at Stonehenge: implications for the glacial transport theory. E&G Quaternary Sci. Journal 73, 5 June 2024, pp 117–134,

https://www.researchgate.net/publication/381205542_A_bluestone_boulder_at_Stonehenge_implications_for_the_glacial_transport_theory

3. John, B.S. 2024. An Igneous Erratic at Limeslade, Gower & the Glaciation of the Bristol Channel. Quaternary Newsletter 162, 28 June 2024, pp 4 - 14.

https://www.researchgate.net/publication/381775577_Quaternary_Newsletter_Article_AN_IGNEOUS_ERRATIC_AT_LIMESLADE_GOWER_AND_THE_GLACIATION_OF_THE_BRISTOL_CHANNEL

These three articles, published in quality peer-reviewed publications for an international readership, have had good media coverage and abundant hits, especially on Researchgate. The Waun Mawn article, which was published in March, has had more than 2,800 hits already, in addition to the 7,000 hits on the pre-publication version. The members of the "archaeology establishment" are undoubtedly reading my articles published over the last decade, even though those who are responsible for the promotion of the human transport myth refuse to cite anything written by me, since my ideas are far too disruptive. That's rather sad, and also rather pathetic, involving a betrayal of the ancient academic tradition that you must cite and deal with your opponents. So I am portrayed (behind the scenes) as a maverick and an incompetent old fool, drawing conclusions which are unworthy of consideration by those who like to think of themselves as "experts". It's a strange old world......

Alongside the thunderous silence of the Bluestone transport gang, we have the thunderous blogging of one Timothy Daw, who presumably thinks of himself as an expert because he shared the authorship of a "learned article" some months ago with Messrs Ixer, Bevins, Pearce and Scourse. Tim posts a stream of articles in which he seeks to rubbish my ideas and quesstion my competence, while demonstrating over and again that he knows nothing of glaciology or glacial geomorphology and has no particular wish to learn. Of course, he refuses to allow comments on his blog, so all of his preposterous claims about bluestones and earth surface processes, and about my hard evidence, go completely unchallenged. It's a strange old world..........

But there is no point in getting too upset about all this palaver, and I continue to be reassured by messages such as the following:

    
Quotes:

I have been sent a link to your paper. Thank you. It is a wonderful deconstruction of much of the hyperbole that surrounds SH.

........so good to see these arguments in print Brian!

Enjoyed the paper, but to be honest found it a bit ridiculous that it had to be written. There is clearly a problem in archaeology at the moment, it should not be possible to publish these nonsense papers.

Thank you so much for sending me your article. Such impressive scholarship and a cracking good read. Really questions the current narrative in a persuasive way. 

...........good media cover. extremely welcome!

.......very many thanks for the article. Congratulations once more -- great stuff.

..........thanks! it was great to see your previous article get a lot of attention in the media online, look forward to reading the new one

Well done, Brian. Good to get this published. Pity that a 100% provenance match was not yet possible.. Nevertheless, an important record. Enjoyed reading it.

Interesting article indeed and I think the gentle tone provides a convincing case for a discovery that bolsters your overall case....

Amazing what a lot of information can be derived from a piece of rock!

I believe you, for what that is worth! A wonderfully researched and presented paper. Congratulations!

Interesting read!

Thanks for this Brian. You are very restrained on the antics of the MPP myth factory.

Brilliant Brian.

Thanks Brian, great paper.

Good stuff - many thanks for the pdf. You are on roll!

I felt privileged to have an early sight of your latest 'offering'. I can see that you have put a lot of effort into producing it. Keep up the good work!

Excellent! I am a firm believer in the glacial theory of course. Seems obvious to me, and supported by evidence........

Your paper provides a compelling and thorough presentation.

Limeslade Erratic article published

My new article on the Limeslade erratic is published today in the journal Quaternary Newsletter.

Details:

Brian John, 2024.  An Igneous Erratic at Limeslade, Gower & the Glaciation of the Bristol Channel.  Quaternary Newsletter 162, June 2024.  pp 4 - 14.

The article is freely accessible, and can be downloaded here:

https://www.qra.org.uk/quaternary-newsletter/quaternary-newsletter-current/

It is also on Researchgate, and can be accessed here:

https://www.researchgate.net/publication/381775577_Quaternary_Newsletter_Article_AN_IGNEOUS_ERRATIC_AT_LIMESLADE_GOWER_AND_THE_GLACIATION_OF_THE_BRISTOL_CHANNEL

Thanks are due to Phil Morgan, Prof Tim Darvill and Dr Steve Parry for their help on the technical front, and to Prof Peter Kokelaar and Dr Katie Preece for their notes on the petrology and surface characteristics of the boulder. The biggest thanks of all go to Phil Holden, who found the boulder while scrambling about on Limeslade beach!  Other very helpful comments came from Prof John Hiemstra, Prof Danny McCarroll, Olwen Williams-Thorpe, my late friend Dr Dyfed Elis-Gruffydd, editor Dr Ed Garrett and the anonymous referees.

ABSTRACT

A large unspotted dolerite erratic boulder was discovered in 2022 on the rocky foreshore in Limeslade Bay near the SE tip of the Gower Peninsula. It is about 2.2m long, weighs about 5 tonnes and rests in a gully where it is subjected to wave action at every rise and fall of the tide. Its surface is heavily abraded and it may have been substantially reduced in size since its original emplacement. It has a greenish colour and is described as a metamorphosed coarse dolerite or ophitic microgabbro. Thin section analysis and pXRF analysis suggest that it is not related to the spotted and unspotted dolerites of Mynydd Preseli, and that it is most likely to have come from one of the Ordovician igneous outcrops near the north Pembrokeshire coast between St Davids and Fishguard. It is not known whether the rock type is precisely matched in any of the bluestones (monoliths or rock fragments) in the Stonehenge landscape. It is unlikely that this erratic was transported by floating ice, since near the peak of a glacial episode sea-level must have been at least 80m lower than it is today. Further, of the scores of known glacial erratics on the shores of the Bristol Channel, many are found at altitudes in excess of 100m, indicating that during at least one glacial episode the ice of the Irish Sea Ice Stream was thick enough and dynamic enough to press inland across the coasts of Devon and Cornwall. It is therefore probable that glacier ice also reached Salisbury Plain, and that the bluestone boulders and smaller fragments at Stonehenge — from more than 30 different sources — were glacially transported.

On the QRA web site the article does not have a URL of its own, but I will also place it on Researchgate where it will attract an additional readership.

These are early days in the analysis of the boulder, and I look forward to seeing further research which might enable a more accurate provenancing of the boulder.  That, I think, is of less importance than the key point made in this paper -- namely that if the Irish Sea Ice Stream responsible for the carriage and dumping of the boulder was strong enough to impinge upon the Gower coast, it was also strong enough to reach Somerset and even Wiltshire.

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This is my third article about the glaciation of the Bristol Channel and the Celtic Sea to be published in Quaternary Newsletter, and it should be read in conjunction with the other two:

https://www.researchgate.net/publication/ 328413421_Evidence_for_extensive_ice_cover_on_the_Isles_of_Scilly/figures?lo=1

Brian John, 2018. EVIDENCE FOR EXTENSIVE ICE COVER ON THE ISLES OF SCILLY. Quaternary Newsletter Vol. 146, October 2018, pp 3-27.

ABSTRACT

Previous studies of the Quaternary sediments on the Isles of Scilly have suggested that the ice of the Late Devensian Irish Sea Glacier impinged upon the north coasts of the islands but that it did not extend much further south. There is also disagreement in the literature about whether any earlier glacial episode affected the islands, although a number of researchers have noted the presence of erratic cobbles in pre-Devensian raised beaches. The new field research, based in part upon examinations of exposures that might not have been available to earlier researchers, shows that erratic cobbles and pebbles are common in raised beaches and in early and middle Devensian brecciated slope deposits around all of the island coasts. The most parsimonious explanation is that they have come from disaggregated glacial deposits dating from at least one glacial episode (Anglian?) during which the islands were completely inundated by ice. Furthermore, coherent diamictons similar to those found on the north coasts of the islands, and in western and southern Pembrokeshire, are also found on the coasts of St Mary’s and St Agnes islands, indicating that the Devensian ice cover was more extensive than previously suggested. It appears that ice from the Celtic Sea pressed into the archipelago from the north-west and west, with lobes fingering into sounds and straits which are currently below sea-level. The diamictons, rich in striated and faceted erratic cobbles and pebbles from many different lithologies, do not appear to be primary tills; they are suggestive of an ice-margin environment in which disaggregation and redistribution of glacial and glaciofluvial sediments has occurred. The new interpretation of Late Glacial Maximum ice extent is consistent with other recent work which places the limit of the Irish Sea / Celtic Sea ice lobe around 250 km south-west of the Isles of Scilly, near the Celtic Sea shelf edge.

https://www.qra.org.uk/mp-files/qn158_1_late-devensian-ice-free-corridor-in-pembrokshire.pdf/

Citation:
John, B.S. 2023. Was there a Late Devensian ice-free corridor in Pembrokeshire? Quaternary Newsletter 158, pp 5-16.

ABSTRACT

An ice-free enclave or corridor covering most of Pembrokeshire has featured in many of the recent reconstructions of glacial activity in western Britain during the LGM. This appears to be a hangover from the days when the terms "Older Drift" and "Newer Drift" were frequently used in the literature. However, the supposed ice-free corridor is not well supported in published studies, and it causes difficulty for those involved in ice-sheet modelling. With the aid of new field observations from scores of sites across West Wales, it is suggested that there is no convincing evidence in support of the ice-free hypothesis. The regional Quaternary stratigraphy in Central and South Pembrokeshire matches that of North Pembrokeshire and the St Brides Bay coast, and it is suggested that the whole of the peninsula was inundated by the ice of the Irish Sea Ice Stream travelling broadly NW to SE at the time of peak glaciation, around 26,000 years ago. 

Quaternary Newsletter Vol. 158 February 2023. pp 5-16

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PS.  First press coverage, in Heritage Daily:

https://www.heritagedaily.com/2024/06/new-study-upends-prevailing-theory-on-transportation-of-stonehenge-bluestones/152473#google_vignette

More Millennium Stone photos

 

Photos: courtesy Martin Cavaney

In conjunction with their report on my recent QSJ article, the Pembrokeshire Herald has published two more splendid photos by Martin Cavaney -- featuring episodes from the Millennium Stone pull in the year 2000.  The top photo was taken on Day One of the pull, showing the pushing harnesses which were preferred to pulling harnesses on the grounds that they were less likely to result in injuries.  Notice the low-friction netting.  In the background is the Waldo Williams Memorial Stone.

The lower photo shows the "deck" that was built across the two curraghs to support the stone on its sea voyage.  This was tried out at Blackpool Mill and rapidly abandoned because the connected vessels behaved very unpredictably.  The intrepid boatmen decided that a sling holding the stone beneath the water line would be a better bet -- but that was a complete disaster, and the stone ended up on the bed of Milford Haven............

Just another local folk tale...........

 

It's nice to see a journalist who has a sense of humour.  In one of the local papers here in Pembrokeshire, the coverage of my latest article in QSJ was straightforward enough, but when the editor hunted through the archive for a suitable photo of me, he chose this one, taken many years ago by Martin Cavaney.  It was first published in connection with my "Pembrokeshire Folk Tales" trilogy, which resulted in four hardcover books containing, in all, around 500 stories.  

Anyway, one of the tales told in Volume 2 of the four-volume trilogy was the heroic tale of the "bluestone expeditions"as narrated by HH Thomas and many others since then..........

I included the story because it is an archetypal myth, invented by somebody with a fertile mind to explain something strange and spectacular (like Stonehenge) which science, at the time, could not cope with.  That is what myths are -- stories used to express respect or admiration for wondrous things -- night and day, the sun, the moon, the seasons, storms, tides, epidemics or plagues, birth and death. And so forth.  This is one definition:

Myth, a story of the gods, a religious account of the beginning of the world, the creation, fundamental events, the exemplary deeds of the gods as a result of which the world, nature and culture were created together with all parts thereof and given their order, which still obtains. A myth expresses and confirms society's religious values and norms, it provides a pattern of behavior to be imitated, testifies to the efficacy of ritual with its practical ends and establishes the sanctity of cult.

You don't have to have gods in myths, but it helps.  And mythology does not have to be associated with religious beliefs or rituals.  But heroes and heroic deeds commonly feature, and indeed the heroic deeds of our Neolithic ancestors are central to the bluestone myth.  HH Thomas was fully aware of that, and artists like Alan Sorrell quite deliberately flagged up the "heroic" element just to hammer home how extraordinary and wonderful the transport of the bluestones really was.  Really?  In other words, truthfully, as a matter of fact?   Yes -- and this is where the danger lies, because the bluestone myth is now quite cynically sold to the nation and the world as if it is a matter of fact --  regardless of the fact that mythology is ALWAYS overtaken by events, as the most enquiring of minds in  any society make observations, make deductions and assemble hard evidence to show that the sun was not created by a giant and that nighttime does not occur because a great god is covering the sun with a blanket.

But certain archaeologists and geologists -- and the top brass of English Heritage -- persist in trying to convince the world that the myth is TRUE.  There is certainly a cult that insists on it, and there is a never-ending flood of pseudo-science devoted to demonstrating that there were bluestone quarries, that stones were parked up in a "giant lost circle", and that Neolithic tribesmen had the technical and geographical knowledge required to move 80 bluestones from West Wales to Stonehenge.  They also of course believe in the parallel myth of sarsen transport, over somewhat shorted distances.  And they all get furious when people like me gently point out that there is a vast data deficit -- and that science has moved on very considerably from the time when HH Thomas started the myth off in 1923, demonstrating in the process a very inadequate understanding of the British Quaternary.

There is something rather pathetic about people like MPP, Ixer and Bevins trying at every turn to demonstrate the truth of the bluestone transport myth,  and dreaming up brand new mythological components every time the facts get in the way of one or another of the elements of their narrative.  They might just as well try to prove that the universe really is held up in the branches of a giant ash tree called Yggdrasil, or that there is an "otherworld" called Annwn, or that somewhere underground in Wales a red dragon fights against a white one, or that the sun is really a great god called Ra, riding across the sky..........

In short, it's high time that the Bluestone Transport Myth is recognised for what it is, and for those involved in the worship of the bluestone cult to accept that science has moved on rather impressively since 1923.  Can we, in the circumstances, expect a statement from English Heritage on the matter?

Credit where credit is due

In the midst of all the fun and games relating to my latest published article, it's worth reminding ourselves that almost all of the points which I make have been made before by assorted geologists and geomorphologists, and -- strange to relate -- by certain respectable archaeologists.  One of the key articles, heavily cited, is Geoffrey Kellaway's article in "Nature" journal in 1971, and the other is the big article published by Richard Thorpe et al in 1991 in the Proceedings of the Prehistoric Society.  The latter is hugely detailed, and over 50 pages long.  Unfortunately, it is still behind a paywall, so it is not as widely read aa it should be.  Kellaway's article is also behind a paywall, and that too tends to distort the perceptions of the people who enjoy reading things about Stonehenge........... very few of them will have actually read it.

But here is another immensely valuable article by Olwen Williams-Thorpe and Richard Thorpe -- sadly, Richard died in 1991 before the article was published in 1992.  This one is NOT behind a paywall, and I hope it will be widely read by a new generation, perhaps stimulated by my own modest contributions to the debate........

https://www.thebritishacademy.ac.uk/documents/4040/77p133.pdf

Nothing new under the sun......

Courtesy David Field and English Heritage.  Too many stones?  Who knows?

I have had a number of recent comments from people who are greatly exercised by the ideas that (a) Stonehenge might have been built where it is because that is where the stones were; and (b) that Stonehenge was never completed, and went through lots or rebuilding and rearranging phases because the builders had simply run out of stones.

These ideas have been around for well over a hundred years, as others have pointed out with detailed citations.  They have been articulated most clearly by David Field and Trevor Pearson in 2010 -- as mentioned several times on this blog, in previous posts.

http://services.english-heritage.org.uk/ResearchReportsPdfs/109_2010WEB.pdf
http://heritageaction.wordpress.com

RESEARCH DEPARTMENT REPORT SERIES no. 109-2010
ISSN 1749-8775
STONEHENGE WORLD HERITAGE SITE LANDSCAPE PROJECT STONEHENGE, AMESBURY, WILTSHIRE ARCHAEOLOGICAL SURVEY REPORT 

by David Field and Trevor Pearson

If you have not read it, please do.   The following things stand out from the pages:

1. An admission that the sarsen stones might well have come from the immediate locality of Stonehenge, and that the idea of sarsen-collecting expeditions to the Marlborough Downs is dubious and probably unnecessary.

2. An acceptance that the bluestones MIGHT be glacial erratics (although the authors don't want to stray too far from the party line on this.....)

3. An acceptance of the idea that the Stonehenge stone monument was probably unfinished, and that the builders went through many changes of plans.

 4.  The builders of Stonehenge, who must have had great aspirations,  probably ran out of stones before their vision could be turned into reality.

It is often claimed by Stonehenge experts that there is a consensus on the broad outlines of the Stonehenge narrative -- and they have tried, especially in recent years, to reinforce this narrative while trying to discredit others. The "immaculate Stonehenge" as portrayed by Anthony Johnson, figures prominently.   But there is no consensus, and there never was.

By the way, back in 2012 David had a very interesting conversation with Edward Pegler, as reported here:

http://armchairprehistory.com/2012/05/22/the-sarsens-of-salisbury-plain-a-conversation-with-david-field/

He talks of the attempts to portray a sarsen litter in the Stonehenge area, and was concerned that the artist involved had perhaps been over-generous with the stoniness of the landscape! He was also concerned that the bluestones were missing from the artists impression -- suggesting to me that he thought it possible that the bluestones were also in the landscape before anybody started collecting stones and building a monument.........

This is an interesting comment from David: "Today the Imber to Chittern valley has many small boulders and cobbles on the slopes and in the stream and presumably many more were once visible when the area was cultivated."  

Was he talking just about sarsens, or about stones of all types?