THE BOOK
Some of the ideas discussed in this blog are published in my new book called "The Stonehenge Bluestones" -- available by post and through good bookshops everywhere. Bad bookshops might not have it....
To order, click
HERE

Monday, 27 June 2022

The Preseli Roman Road -- a hypothesis in search of some evidence


This is a strange article -- thanks to Dave for sending it to me.  Some weeks ago we covered the advance press release, which as also very strange........

The Golden Road: Fact, Fable, Flemish, or ‘Flavian’?
Mark Merrony, Antiqvvs, Summer 2022, pp 25-34


Anyway, in this piece Mark Merrony discusses the documentary and "folk memory" aspects of the ancient trackwasy along the Preseli ridge, variously describes as the Golden Road, the Flemings Way, a Roman Road a a few more things besides.  It's a strange article, which could well have been cut in half -- since most of it consists of a somewhat self-indulgent description of springtime ramblings with a mountain bike across the landscape, with the author searching for depressions, sunken lanes, trackways, and anything that might indicate the presence of a Roman Road.  There are some nice photos and there are indeed many short sections of old rutted trackways, some of which I know well.  But nowhere does the author show that these are anything other than segments of ancient  routeways including bits of the old drovers' routes and also forestry tracks created at the times of forestry planting, maintenance and harvesting.  Heavy military vehicles used this area for training during WW2.  Some "sunken" sections have been deeepened by serving as streambeds during periods of heavy rain. No evidence is presented to show that the trackway was a single continuous route; no evidence is presented to show that it was paved or properly engineered; and no evidence is presented of a Roman connection.

Much speculation, made worse by gratuitous mentions of bluestones and bluestone haulage, again on the basis of no evidence whatsoever.  

Perhaps Mark will come back to us again when he actually has some evidence?


Glacial Erratics and Flights of Fancy


 Some of the erratics in Flimston Churchyard, all from NW Pembs and some incorporated here into headstones for graves.  Some were brought from sites c 3 km away.  Does anybody care EXACTLY where they came from?  No -- we are all very happy as it is.

I have been quite entertained by the attempt, by fellow blogger Tim Daw, to deny the significance of the "Newall Boulder" on the grounds that we do not know EXACTLY where it came from.  It was found by Hawley and his fellow diggers in their 1924 dig in a "secondary" position, having been worked and then thrown away by one of our mysterious ancestors.  Kellaway thought it was of great importance as a "proof of glaciation" at Stonehenge, but Tim is having none of it.   "If it has been moved by humans, and there are no records where from, then it adds nothing to the argument." says Tim, rather grandly.  " If you don't know where the glacier left it, it don't mean a thing."

Well, I have been studying glacial erratics for most of my life, and I think I can claim to know a thing or two about them.  Let me assure Tim that the Newall Boulder does add a great deal to the argument, and confirms what some of us have been saying for years about the likelihood of glacial action in the Stonehenge landscape.  For a start, it's not unique -- there are glacial erratics all over the place, particularly in the bluestone circle.  And in heavily populated countries like the UK glaciasl erratics are very seldom found in EXACTLY the places where they were dumped by ice.  If you find an erratic boulder in till it is probably still in the place where it was dumped by the ice, but most of ther "free erratics" have been moved from fields into field boundaries or into stone clearance cairns, or gathered up for use in stone walls or built into dwellings and farm buildings.  Dare I say it, many thousands of them have been incorporated into Neolithic megalithic monuments, as pointed out by Stephen Briggs, Geoffrey Kellaway and then Olwen Williams-Thorpe and her co-workers many years ago.  The fact that these erratics have been collected and moved about does nothing to diminish their significance.  They help to present a coherent picture of where the ice came from, what the directions of movement were, and where the ice edge melted away.  A great part of the map of ice movements across the British Isles is based upon the evidence provided by erratics that are no longer EXACTLY where they were found.......

So the story of that lump of rock being shifted about the place in the Netherlands is a jolly little tale, of no significance whatsoever to the argument about Newall's Boulder.

I'll quote Kellaway again: "When found, the weathered boulder had been thrown away with chippings and other waste material. 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, already deeply weathered, would never have been of any practical value. To suggest it had been carried from North Wales lo Wiltshire only to be tested and thrown away as worthless would imply an astounding 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 solution cavities, then the presence of inferior material 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."

One further point.  It's a bit rich for people like Tim to argue that they must have absolute proof of the EXACT place where the Newall Boulder was emplaced, while accepting the fantasies about bluestone quarries at Rhosyfelin and Carn Goedog and a "lost stone circle" at Waun Mawn.  There is no hard proof from any of those sites of any Stonehenge-related Neolithic activity, just as there is no hard proof that any of the Stonehenge bluestones have been provenanced to "within a few square metres."  (The approximate provenancing -- to within a few sq km -- is good and should be applauded.  But EXACT provenancing?  Sorry, but that's just in the minds of the deluded.)

What's good for the goose should be good for the gander.




Thursday, 23 June 2022

SH62 -- Much ado about nothing very much

Stone 62 at Stonehenge -- a nice little shaped pillar made of unspotted dolerite.  Courtesy the Stones of Stonehenge web site.

 I have been sent a link to a new paper on the provenancing of Stone 62, one of the unpotted dolerites at Stonehenge.

Details:

Portable XRF investigation of Stonehenge -- Stone 62 and potential source dolerite outcrops in the Mynydd Preseli, west Wales. by Nick J.G. Pearce, Richard E. Bevins, and Rob A. Ixer.  Journal of Archaeological Science: Reports 44 (2022) 103525.

It's a highly technical paper, involving a huge amount of time and expense in pursuit of a wild fantasy by Parker Pearson -- namely that one of the pits at Waun Mawn has the same cross-section as stone 62 at Stonehenge.  So the geologists have been roped in to help establish that as something accurate and reliable!  It's extraordinary, the lengths that people will go to in order to cofirm their biases.  I have seen the pit at Waun Mawn, and so have many others, and I have not found anybody who "sees the imprint" as Parker Pearson does.

So the intention is to SHOW that Stone 62 was, once upon a time, in that rather shallow and nondescript hollow in the ground.  First, there is a need to show where SH62 came from.  It's a nice little shaped pillar which looks as if it might have come from eastern Preseli, where there is columnar jointing in the unspotted and spotted dolerite -- but it has clearly been shaped and dressed rather carefully at Stonehenge.

The  paper cites earler attempts at provenancing and sampling,  and reports the results of recent pXRF work in Preseli and at Stonehenge.  That work is quite interesting, and I was very interested to read of the multiple sampling work done on rock surfaces on the east Preseli tors and the attempts to unravel the bias that might be introduced to the work when comparing results from weathered and unweathered surfaces. 

Anyway, the work points quite convincingly not to Cerrigmarchogion -- as previously speculated -- but to the small crag called Carn Ddu-bach, not far from Carn Ddafad-las at the eastern end of the ridge.  This is not far from the prominent peak of Foel Drygarn.  Interesting -- so we have yet another bluestone source and yet another setback for those who stick quite irrationally to the belief that the bluestones were sacred and special, and that they came from Neolithic quarries.  The new source crag is around 6 km from Waun Mawn.

The rational thing at this point would be for the geologists to say "Multiple dolerite sources = glacial entrainment and transport."   One might also wonder why our heroic ancestors might like to cart lumps of unspotted dolerite from Carn Ddu-bach all the way to Waun Mawn when there are perfectly fine outcrops of the same rock type within a couple of hundred metres......

But not a bit of it.  Nick Pearce and his colleagues are made of sterner stuff, and they are sticking to the Waun Mawn fantasy as if their lives depend on it, while pretending to keep a distance.  It's all more than a little obsessive, and rather sad.

Quote:

" Now that a source for Stone 62 has been established at approximately 6 km ESE of Waun Mawn (most probably at Garn Ddu Fach but possibly neighbouring Carn Ddafad-las), it is important to determine if any of the extant stones at Waun Mawn might have the same source. If confirmed, these outcomes may support the proposal of Parker Pearson et al. (2021), who suggested that Stonehenge Stone 62 once stood in stonehole 91 at Waun Mawn. Analysis of the extant stones at Waun Mawn is currently underway."

"IT IS IMPORTANT TO DETERMINE....." ???  Come off it, guys -- it is not in the least important, since the Waun Mawn fantasy has no archaeological or other value whatsoever, apart from the maintenance of MPP's rather ragged reputation.

This all brings to mind the Black Knight in "Monty Python and the Holy Grail" --  'Tis but a scratch!!".......


Wednesday, 22 June 2022

Dacites and the fictional orthostat

 Ixer and Bevins keep on publishing at a furious rate in conjunction with assorted colleagues-- I am not sure what the beloved WANHM magazine would do without them! The latest article is entitled "Stonehenge Dacite Group D -- fact or fiction?". WANHM Vol 115, pp xx - xx. Strange title, since if the group is a fiction it is fiction of their own inventing. It's like putting up an Aunt Sally in order to have the satisfaction of knocking it down.......

Anyway, the article is available via Academia for those who want to check it out.

We are all (and that includes the authors of this latest piece) confused by the sheer abundance of fragments (the authors never differentiate between "fragments" and pebbles or stones) of widely differing lithologies scattered across the Stonehenge landscape.  Most geologists, in their shoes, would have long since abandoned the very idea of bluestone quarries, since both monoliths and fragments are so hugely variable in their characteristics that they must have come from multiple locations in West Wales and further afield. But they insist on seeking to gather their samples into groups in an attempt to minimise the number of "provenences" because that is the only way they can maintain the human transport hypothesis;  it makes no sense at all for Neolithic tribesment to have wandered all over West West collecting up stones from here, there and everywhere just to cart them off to Stonehenge and then throw them away or break them up.

Anyway, here we go again, with 8 rather inconvenient fragments analysed and found not to match up with anything in particular.  They do seem to match with one another.  The authors do not know where they came from, and assume (without any foundation) that they must have come from a missing orthostat, and that they have most probably come from North Pembrokeshire.   They also consider that the fragmants are "true bluestones", whatever that may mean.

For the sake of completeness, here is the latest classification:


Hmmm -- just as we were getting used to Volcanic Group B, it's disappeared into thin air, to be replaced by Dacite Group B.  Whatever next?

In their conclusion the authors do consider the possibility that the unassigned dacite fragments might have been introduced to the area as glacial erratics, but they dismiss that option on the grounds that no other "unequivocal" glacial erratic has ever been found in the Stonehenge landscape.  One might ask: "What about all those bluestone boulders that make up the bluestone circle?"  And one might also ask: "What about Newall's ignimbrite boulder?"  Of which more anon.

And who gets to decide what is equivocal and what is unequivocal?  Are the famous bluestone quarries "unequivocal"?   Is MPP's "lost circle" unequivocal"?  Ixer and his friends may think so, but there are very many of us who beg to differ.





Kellaway text on the Newall Boulder






Because the text on the scanned version of this 1991 report is not easy to read, I have done an OCR scan and here it is again.

RSN 18 ignimbritic tuff-lava

Description by RK Harrison: “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 (compressed 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 represent a complex of originally viscous glassy lava and welded vitric tuff, all presumably of rhyolitic composition.”

The dimensions and general appearance of the rock are shown in Plates 35 & 36.

Comparison of this ignimbritic rock with other Welsh Ordovician volcanic rocks suggests that it is more closely related to the known ignimbrites of North Wales than to those of the Mynydd Preseli area of Dyfed. On the other hand none of the ignimbrites available for comparison provided a sufficiently good match to enable a link to be made with one specific locality. At the time. this conclusion appeared to be disaappointingly vague and out of line with some of the more dogmatic slatements made in respect of Stonehenge rocks. In the light of more recent work, however, Mr Harrison's cautious approach has been fully justified.

If the ignimbritic tuff-lava is indeed an erratic of North Wales origin and the ice which conveyed it is as old as it appears, then careful consideration must be given to the value of implying direct derivation from individual exposures or outcrops which exist at the present day. In the 247 Ma which may have elapsed since this Pliocene glaciation occurred, the mountainous parts of Wales (both north and south) have undergone substantial changes of relief. While, therefore, it may be justifiable to compare the Stonehenge rocks with suites of Welsh Palaeozoic igneous and metamorphic rocks on a regional basis, it may not be possible to give precise locations without having more information about the Pliocene relief and surface geology of Wales than is currently available. (Note: Kellaway was fascinated by the idea of a very large Pliocene Glaciation which occured when the landscape looked very different to that of today. Most of his ideas are well supported by modern research, but not this one!)

The weathered zone seen on the surface of the ignimbritic boulder is similar to other weathered exteriors of specimens examined by Mr R. Sanderson (Appendix Ill). This type of weathering is to be seen at the present day in peaty or humic environments and could have occurred before the rock was moved in ice from Wales to Salisbury Plain. Reporting on some of the ophitic dolerites from Stonehenge, Mr Harrison commented that "In order to ascertain the differences between the altered outer crust of pale dolerite and the fresher, blue-grey interior, X-ray diffraction photographs were taken of powders drilled from the respective zones in ENQ 2301, the outer crust here being about 5 mm thick. Mr B.R. Young reports that both samples contain chlorite, quartz, feldspar, pyroxene and amphibole. The crust contains more quartz and less feldspar than the interior. Kaolinite was not detected. Superficial leaching by acid water has broken down the feldspar, leaving residual silica."

If the weathering does date from before the translation of the rock to Wiltshire then the stone must have been conveyed either by hand or in ice. If the bleaching and weathering took place after arrival at Salisbury Piain then the boulder might have been carried by fluviatile or fuvioglacial transportation, though the weakness of the rock (due to shearing) argues strongly against fluviatile transport from Wales, or rounding in any medium other than ice.

When found, the weathered boulder had been thrown away with chippings and other waste material. 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, already deeply weathered, would never have been of any practical value. To suggest it had been carried from North Wales lo Wiltshire only to be tested and thrown away as worthless would imply an astounding 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 solution cavities, then the presence of inferior material 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.

It is worth noting that Sir A. C. Ramsay (1863) observed that the foreign stones of Stonehenge include rocks which are petrologically similar to those of North Pembrokeshire and that others resemble rocks from Caernarvonshire and the Lilandeilo Flag district of Montgomeryshire west of the Stiper Stones. This appears to be the first published suggestion that the bluestones may include rocks similar to these found both in southwest and North Wales.

----------------------------

From: 1991: "The older Plio-Pleistocene glaciations of the region around Bath." In Kellaway, GA (ed) Hot Springs of Bath, pp 243-41.

Tuesday, 21 June 2022

Stockholm Archipelago glacial clasts

 

My art installation consisting of 11 clasts of diminishing size.  These were picked up at random from washed till on the foreshore of Blido.  They are all made of PreCambrian basement rock -- granite, gneiss, basalt, volcanic ash etc.  Only two or three of these rocks are bullet shaped.

You can pluck glacial erratic clasts out of till exposures and washed till all over the place in the islands of the Stockholm Archipelago -- they are generally clean and easy to find becuase the finer materials have been removed by "washing" as the land has risen from the sea during the process of isostatic recovery.  A. couple of things are noteworthy:

1.  The clasts do NOT carry traces of ancient weathered crusts or surfaces; all the facets and edges are equally unweathered, although some parts of the clasts have been stained or modified / abraded / fractured more recently than others.

2.  Rough blocks and slabs predominate, with multiple facets.  Maybe about ten percent of clasts have a bullet shape.

Some clasts have nine or ten facets -- some abraded and others clearly originating as fracture scars.  Some scars are old and some are young; some of the older ones are modified by later abrasion and by smaller and later fractures.  Almost all combinastions are possible.


Variations on a theme.  Three small clasts collected from a till exposure on Blido.  From the left: white granite, greenish volcanic ash and pink granite.  All have at least six facets.  All three have quite fresh fracturs scars on their lee (blunt) ends, and all have heavily abraded edges.  Interestingly, all three have lost their bullet tips (stoss ends) through fracturing.  A point is always vulnerable.


The greenish ash clast, showing a big fracture scar on the lee end and another smaller pressure fracture scar.  Subsequent abrasion has modified the sharpness of these features.


Striations on the same clast -- a deep one sub-parallel to the long axis but others running across it -- showing that at some stage the long axis has been at 90 degrees to the direction of ice flow and clast transport.

Monday, 20 June 2022

The mysterious boulder 38


The strange mis-shapen boulder referred to as SH38, partly obscured by sarsen SH14. Courtesy the Stones of Stonehenge web site. Its place of origin is still a mystery.

In checking out what the score is with regard to dark blue flinty welded tuffs and so forth, I wondered whether this boulder might be related to the Newall boulder. There is a chance, but much more geology needs to be done by the experts. I checked back to a previous post about SH38 and the assorted volcanics at Stonehenge and in the surroundingt landscape:

https://brian-mountainman.blogspot.com/2015/04/new-paper-on-bluestone-38.html

Hard ‘Volcanics with sub-planar texture’ in the Stonehenge Landscape by Rob A. Ixer, Richard E. Bevins and Andy P. Giże
Wilts Arch & Nat Hist Mag 108 (2015), pp 1-14

On giving the paper a fresh read, I am impressed by how strongly biased it is towards the ruling human transport hypothesis, with -- over and again -- a "forcing" of analysis and interpretation into the following assumptions: (a) that the bulk of bluestone fragments in the debitage MUST have come from North Pembrokehire; and (b) that bluestone fragments can only exist at Stonehenge if they have been knocked off past or present monoliths transported by our heroic ancestors. So the paper is deeply unsatisfactory since it completely fails to address the possibilities that the bluestone monoliths might have been glacially transported, and that large numbers of fragments in the debitage might have nothing whatsoever to do with the known monoliths. Furthermore, many of the small boulders, pebbles and broken fragments might have nothing whatsoever to do with Pembrokeshire. They could be glacial erratics from closer to home, or maybe from further afield.

Putting all that to one side, it's tempting to suggest that there might be a link between the Newall boulder and SH38, and that the "welded vitric acid tuff" might be related to other rock samples looked at by Ixer and his colleagues and identified as Volcanic Group B.  Ixer and his colleagues referred to "small, often sub-rounded, rather than angular flaked, fragments throughout Stonehenge and its environs."

That comment has always caused me -- and others -- to wonder whether the geologists have been looking at glacially-transported or glaciofluvially-transported stones in the Stonehenge sediments without recognising what they have been looking at..........  Again, this suggests a possible link with the Newall boulder, which is faceted and almost certainly glacially transported.

Quote:
"...........
Volcanic Group B, hard rocks that are partially characterised by an unusual mineralogy including two forms of graphitising carbon. Only twelve Volcanic Group B samples have been recognised from the Stonehenge debitage."

Quote:

"Conclusions 
 
Orthostat SH38 and twelve pieces of debitage that constitute the new Volcanic Group B class of debitage are sufficiently uniform in terms of their mineralogy, grain size and textures that it seems probable that they are all from the same rock rather than just from the same outcrop.

Although this debitage is numerically rare it has a wide spatial distribution in the Stonehenge Landscape notably within the Darvill and Wainwright April 2008 excavation and Heelstone Ditch but also including within Trench 45 in The Avenue and Aubrey Hole 7 in Stonehenge. Although a lithic with graphitising carbon was found from close to the Stonehenge Greater Cursus no SH38 debitage has been recognised from there with any certainty. The SH38 debitage distribution is similar to that found for orthostat SH48 but is more extensive than that for the Altar Stone.

The temporal distribution of the SH38 debitage is very similar to that for SH48 in that most pieces are found from post Neolithic contexts but are less ‘bunched’ than that from the Altar Stone.

The newly reported SH38 debitage has extended the range of petrographical features beyond those seen in orthostat SH38, notably to include the presence of large zircons, rare earth-bearing minerals, tube pumice and a significant fine-grained siliceous component. This in turn suggests that were the single geochemical analysis for SH38 (Thorpe et al. 1991) and taken from a very small sample , to be augmented by new analyses from the present samples, a geochemistry that was closer to the bulk geochemistry for SH38 could be achieved. An enhanced petrography plus a more representative geochemistry would help to narrow the possible geographical sources for the orthostat. On present knowledge this is still expected to be found within the Ordovician Volcanic sequences, in the north Pembrokeshire area but the net is tightening."

Petrologist RK Harrison on the petrology of the Newall Boulder: “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 (compressed 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 represent a complex of originally viscous glassy lava and welded vitric tuff, all presumably of rhyolitic composition.”.   

I wonder whether that is a description of one of the rock types now referred to by Rob Ixer and his colleagues as "Volcanic Group B" or "Dacite Group B" ??

Match all this with the 1971-72 descriptions of the welded acid vitric tuffs examined in 1971-72 by Kellaway, Harrison, Smith, Howells and Nutt, and we have an intriguing possibility that there is rather more glacially transported material lying around in the Stonehenge landscape than the geologists would have us believe.