Tuesday, 10 January 2023

The Avebury Papers

The Avebury Papers is a four-year Arts and Humanities Research Council funded project to develop, explore, and digitise the multimedia archive of Avebury’s Neolithic origins and its subsequent life-history. 

Photo - Wiltshire Museum -  close up view of ditch section during excavation of stone circle, Avebury, Wiltshire, 1911, an image from the Wiltshire Life Society collection


Currently dated to the first half of the 3rd millennium BCE, the megalithic monuments at Avebury, North Wiltshire, form part of the UNESCO Stonehenge and Avebury World Heritage Site. Avebury includes the world’s largest stone circle at almost 350 metres across, with avenues of paired standing stones that extend for 3.5 kilometres. 

 The only large-scale archaeological excavations to take place at Avebury were carried out just before the outbreak of WWII. Materials and objects collected and made at this time were left under-analysed for decades. As a result, we have – until now – only had a partial understanding of Avebury’s past and present. 

We will add to the archaeological work that ended so abruptly due to the war, bringing together findings from 1939 and subsequent excavations. The archive also includes creative work inspired by Avebury, and these stories are just as important as the stones for understanding Avebury today. Importantly, the entire archive will be made available online on an ‘open access’ basis for anyone to use for research, enjoyment, and artistic projects. xx By providing a fuller understanding of the history and modern significance of this World Heritage Site, this research and the creation of the multi-media digital archive will enable more effective heritage management, education, and tourism programmes. We look forward to visitors, enthusiasts and students of prehistory, artists, and heritage organisations, exploring the many stories of the origins and re-use of Avebury across over 5,000 years. 

The Avebury Papers is a collaboration between Bournemouth University, the University of York, the National Trust, and the Archaeology Data Service, with support from Historic England and English Heritage.

Sunday, 1 January 2023

6th January evidence a "Smoking Gun" or a damp squib?


"A STONEHENGE mystery has been solved, according to an expert, after a "smoking gun" discovery was made to provide the "missing piece" of the puzzle.

A giant bluestone erratic just discovered near Mumbles, on the south Gower coast, has been hailed as one of the most important glacial discoveries of the last century since it proves beyond doubt that the Irish Sea Glacier was capable of carrying large monoliths of dolerite rock from Pembrokeshire up the Bristol Channel towards Stonehenge."


First discovered and  photographed by Phil Holden on 5th January 2022, I believe the next day Dr Brian John was informed. Photos:




The photos' descriptions by Phil Holden state:"Hailed by (Dr) Brian (John) as the 'greatest glacial discovery this century'"

In an email of 2nd January 2023 Dr John writes: ""Hailed by Dr Brian John as the 'greatest glacial discovery this century'..." I have never made that ridiculous claim. Kindly withdraw that remark."   

I am happy to make clear I believe him that he never made that claim, I am merely reporting what others have written. A hint: words reported in quotation marks are attributed to the source not to the reporter. There are resources aimed at Lower Key Stage 2, Year 3, for those struggling with the concept.

And on his blog he writes "I have never claimed this as "the greatest glacial discovery of the century". I may be enthusiastic, but I am not that stupid,"

The Press Release on Dr John's blog: STONEHENGE: GIANT GLACIAL ERRATIC HAILED AS "MISSING PIECE” OF BLUESTONE PUZZLE  now has:  "hailed as one of the most important "chance discoveries" of recent times." 

But as reported in the press it originally said: (https://web.archive.org/web/20220127081903/https://brian-mountainman.blogspot.com/ "A giant bluestone erratic just discovered near Mumbles, on the south Gower coast, has been hailed as one of the most important glacial discoveries of the last century since it proves beyond doubt that the Irish Sea Glacier was capable of carrying large monoliths of dolerite rock from Pembrokeshire up the Bristol Channel towards Stonehenge."

It seems he has forgotten what was originally written, which seems close enough to the offending quote though to be fair it said "one of" rather than "the", and "important" rather than "greatest", and then it was later altered. If Dr John is not stupid enough to make that claim who wrote the Press Release? And why did he publicise it?

 After all that hailing, or not hailing, we might echo a sage and say:

"A year is a long time in academic geology. Looking back on it, it's actually quite intriguing to see how this piece of academic intrigue was instigated by somebody with an unshakeable belief that one theory (relating to human transport) was dead and buried, and that the only other theory in town (namely the bluestone glacial transport theory) must therefore be correct. He believed that all he had to do was find the evidence."

The existence of the erratic was announced in a press release 
This note was added later: 
"Phil's close-up photo of the sample taken from the erratic can be seen here: https://www.alamy.com/two-rock-samples-of-green-dolerite-with-thin-section-on-right-from-summit-of-foel-eryr-preseli-and-left-from-the-erratic-gower-boulder-eg-2hferaj-image455859195.html"

The photo is dated 6th January 2022

On 8th February 2022 Dr John wrote: "We have two samples from the boulder. We have been fortunate enough to receive sufficient financial support to pay for professional laboratory analyses, and the work is in hand. The results of the tests will be reported in a peer-reviewed journal in due course." (In the comments https://www.megalithic.co.uk/article.php?sid=56283 ) and a preliminary paper written:
https://www.researchgate.net/publication/358426131_A_newly_discovered_giant_erratic_at_Limeslade_Gower_Peninsula_Interim_Report
 
And since then silence.

Dr John kindly informs me:
I have no interest at all in withholding info about this boulder, and I don't actually care where it came from. The truth is perfectly simple -- we sent the Limeslade samples off for analysis to a geologist who -- for a variety of work and personal reasons -- has still not reported back to us, after almost 12 months. So in spite of many pleas, we still have no data. Rest assured that as soon as we get the info through, it WILL be published.

Is the "smoking gun" a damp squib?


Wednesday, 28 December 2022

Is this year’s tumultuous weather set to become the new ‘norm’ ?

 

The National Trust has warned that this year’s tumultuous weather is set to become the new ‘norm’ https://www.nationaltrust.org.uk/services/media/weather-and-wildlife-2022  The Stonehenge and Avebury WHS are thought to be at risk from climate change, so it is of interest here - http://www.stonehengeandaveburywhs.org/assets/Climate-Change-RA-for-web.pdf

We hear a lot about climate breakdown, that our climate is getting more unpredictable and tumultuous. We can survive and thrive in nearly any climate if we can plan and prepare for it from the arctic to the equator, from deserts to rainforests. But instability and uncertainty is dangerous. So is it getting more disorderly?

To check if any increasing instability was evident in England  I thought a simple, quick and dirty way would be to compare the annual, and each season’s, temperature and rainfall using the long running Hadley Centre Central England Temperature (HadCET) dataset and  HadUKP,  the UK regional precipitation series  available from https://www.metoffice.gov.uk/hadobs/index.html

My method was to compare the differences between years.

For instance the mean spring temperature in 2020 was 9.9°C, in 2021 8°C, and 2022 10.1° so the differences are  -1.9°C and 2.1°C.   I charted out the differences from 1963.

Wow, the swings are getting larger. English spring temperatures are getting less predictable.

So, I looked at more of the data.

Here’s the mean spring temperatures from 1904 – 1963:

 


Huh? That looks the same as the 1963 – 2022 chart.  Let’s overlay them to see:

 

So, spring temperature got more unpredictable from 1904 to 1963 and then the pattern repeated from 1964 to now.

What is going on? I don’t know but whatever it is it isn’t unprecedented.

 Just eyeballing the rest of the data graphs for the other seasons, years and annually I couldn’t spot any other repeating patterns either for temperature or rainfall. But torturing it with statistical analysis may reveal more. I hope someone with the skills does so.




  Another surprise to me from the series is how related the Min and Max series are. It appears that the temperature band is narrow, is it self-regulating?  A plot of spring temperatures shows: 



 A simple plot of Maximum temperature minus Minimum shows this over the whole period:


Sometimes very simple analysis is all that is needed to answer a question.

Friday, 23 December 2022

Mesolithic Machans

Yesterday the Mesolithic tree-throw and post holes were showing up well with grass mown and it reminded me to record my belief that there may have had been a practical purpose. 

If you are ever to try a spot of big game hunting, I haven't myself, I am assured that the Cape Buffalo is the most dangerous beast to hunt. I imagine Aurochsen were similar. They don't take kindly to being wounded and a couple of tonnes of beef behind some horns travelling at speed intent on revenge is best avoided. Using only spears and arrows kills would not have been quick and easy. 

Deer hunters in our local woods still use high seats, not so much to avoid the danger, as to be out of sight and smell of the prey and have a better view and platform to operate from. 

In India and south Asian countries, such platforms, in trees and where trees were absent on poles, are called "Machans". Thankfully they now more often used to photograph big game from than for shooting.

David Saunders* in his excellent studies on prehistoric cattle movements touches on the roles the posts may have played but doesn't, I think, suggest them as machans. So combining a sketch from E P Stepping's Diary of a Sportsman Naturalist in India and a photo of the post holes let me supply a suggestion of how the posts alongside a natural funnel for the beast may have been used.
*Saunders, David. The Cursus Enigma: Prehistoric Cattle and Cursus Alignments. Austria: NIELSEN BOOKDATA, 2021.

Wednesday, 21 December 2022

How many original entrances did Durrington Walls have?

 It seems surprising that the number of entrances that Durrington Walls originally had is uncertain.

1, 2, 4 and even 3 have been suggested.



Model from Gaffney V, Neubauer W, Garwood P et al (2018) Durrington Walls and the Stonehenge Hidden Landscape Project 2010-2016. Archaeological Prospection. 25(3): 255-269. http://hdl.handle.net/10454/16081


"Durrington Walls is a large oval henge, classified as a type 2 henge (Piggott 1939), with an internal irregular ditch and external bank, and with two entrances known, to the east and to the west (Wainwright and Longworth 1971, 1), although Parker Pearson et al. (2007) suggest four entrances."
Higham, R., & Carey, C. The Durrington Walls Sarsen Burial relocated and reconsidered. The Wiltshire Archaeological and Natural History Society Magazine, 112, 74-84.

 
"It was not possible to determine the presence or absence of the assumed north-west entrance in the bank/ditch as there is significant metallic noise at the surface here. Similarly, it is not possible to establish the nature of the apparent breaks on the north and east sides due to the presence of the old and new main roads cutting through the earthworks at these points."
"There appears, for example, to be no certain evidence for a north-west entrance. The air photograph used by Crawford (1929, 54-6, pl.III) might indicate such an entrance, but this also seems to show a gap in the ditch on the east side of the enclosure which certainly does not exist. The land surface in the area of the supposed entrance is steep and very uneven, apparently heavily-disturbed, suggesting relatively recent modification of the scarp slope possibly to create an entrance ramp into the field within the enclosure area, which might account for the ‘gap’ observed by Crawford. The geophysical survey data (GPR and FDEM) are ambiguous, but there is certainly a suggestion that the ditch is continuous (see fig. 15). It is possible, therefore, that the Durrington Walls henge enclosure only had a single south-east entrance." Gaffney et al 

So the South -East entrance is certain, it seems to be ceremonial and aligned to the Solstice.

The North West one opposite seems to be becoming less certain, the area was used as a rubbish dump so it is hard to survey but there doesn't seem to be any evidence it was there.

 "the vexed issue of the north-western entrance to Durrington Walls henge becomes significant. Initially postulated by Crawford (1929, 54–56, plate III), the entrance is complicated by the presence of a large scarp that lies between the bank and ditch, and which must pre-date the enclosure (Gaffney et al2018, 10). The area associated with the postulated entrance is very steep, uneven and heavily disturbed and the geophysical survey data from the henge is ambiguous regarding whether an entrance actually exists at this point."   Gaffney, V. et al. 2020 A Massive, Late Neolithic Pit Structure associated with Durrington Walls Henge, Internet Archaeology 55. https://doi.org/10.11141/ia.55.4

The North and South entrances are hard to interpret as the old road went through them. Talking to archaeologists the feeling is that the north one probably is the least certain and is probably more a modern agricultural access to the interior. The South entrance has more features such as a curve to the ditch which hint it may be original. 

To answer the question, I think 1 is certain and 2 probable, but not the traditional two. I think as at Stonehenge there was a ceremonial entrance and maybe a more functional one to the south. 


Saturday, 3 December 2022

The Stonehenge Sarsens didn't float down the Avon

The route that the great sarsens were brought from the Marlborough Downs to Stonehenge is still debated. This blog was started to investigate it and it is still of interest.


I am using 40 tonnes as the maximum weight of an untrimmed sarsen that was moved. The raft or sledge it was moved on then adds to this weight.

The idea that they were brought down the River Avon from Upavon to Amesbury is still popular despite the impossibility of it.

The River Avon we see now isn't the same as it was in Neolithic times, the main difference is that it has historically been dredged, over-widened and impounded in many places due to past river management.

It would have been a multichannel meandering stream in a marshy valley bottom with trees and bushes growing over and in it.

1) They weren't slid on the frozen river. 

The River Avon is largely fed from ground water along its route, water that is referred to as warm during the winter as it stays at near constant temperature all year round. The river doesn't freeze solid and according to Gold's Formula the ice would need to be over 500mm thick 


The River at Amesbury has a normal maximum depth of 700mm and is usually half  of that, and at Upavon it is a lot less.


Photo from Pennsylvania Lumber Museum 

2) They weren't loaded onto rafts and floated down.

To float 40 tonnes of stone  40 cubic metres of water must be displaced. If we had a weightless box to load the stone on it would need to be 4 metres wide, 20 metres long and 500mm deep, the depth of the river being a limiting factor here.

A wooden raft made of logs would need to be much larger. Wood has a specific gravity of 500 - 800 kg per m3 . The photo shows how only half of a  log raft is out of the water. At the lightest end the raft would need to weigh another forty tonnes to displace enough water, at a more realistic weight for hardwoods of 750kg/m3 it nearly 100 tonnes. A forty five meter by five meter wide raft at 500 mm deep. The river is not big enough.

Only by using hollowed logs or canoes could the weight and size of the raft be reduced but would they be strong enough for the massive stones?

Dragging heavy stones through an overgrown bog didn't happen, they went overland away from the river.