Striations at Stonehenge

We have had some recent discussion on this, and Myris has kindly brought to my attention the enclosed -- written by HH Thomas for the BGS Annual Report -- I'd hazard a guess and say the date was around 1920.

The text is almost a hundred years old, and much has moved on since then (including our understanding of glacier behaviour), but what's interesting is a reference to a large flake of bluestone showing "good" glacial striations.  On the whole I would trust HHT on whether the marks were glacial striations or not -- he had after all seen a lot of them in his time in Wales.

Others have also mentioned striae on bluestone monoliths, but they seem to be very indistinct and open to other interpretations too.  Mind you, we should not be surprised.  The mottley collection of stones and stumps of all shapes and sizes is after all best explained as a suite of glacial erratics  -- as we might have mentioned before.....

Four cheers for William Smith

Good for William Smith!  This was William Smith's map that started it all -- with a recognition that rocks were arranged regularly and according to certain rules, that they could be identified by their textures, colours and fossil contents, and that all rocks exposed today represent the conditions that prevailed when they were originally emplaced.  This followed Hutton's revolutionary Principle of Uniformitarianism of 1785.

This map, showing the spatial arrangements of rocks in the UK, underpinned the vast interest in the tracing of glacial erratics in the 1800's -- a process that involved many academic geologists and amateurs as well.  So this is where it all began -- the provenancing work of Rob Ixer and Richard Bevins today is a recent manifestation of this instinct for geological detective work.

This looks like a really interesting exhibition in the National Museum of Wales.....

http://www.museumwales.ac.uk/cardiff/whatson/8508/Reading-the-Rocks-the-Remarkable-Maps-of-William-Smith/

A Long History of Rhosyfelin (4th version)

 

I have revised this document to take account of the latest information.  It's essentially a guide to what happened in the Ice Age, with a simple explanation how the regional chronology is represented at this site.   The more promotion there is for the quarry idea, the less convincing it becomes.  If you go to Craig Rhosyfelin "cold" and with no preconceived notions fixed in your head, and ask yourself what you are looking at, what you find is a rather beautiful craggy rock in a wooded valley, with a long history of landscape evolution and an interesting set of Quaternary sediments.  And signs of occasional settlement by hunters or travellers.  End of story.

A Long History of Rhosyfelin (4th version) 

https://www.scribd.com/doc/282418569/A-Long-History-of-Rhosyfelin-4th-version

This is an informal explanation of the history of landscape evolution, and sediment accumulation, at Craig Rhosyfelin in North Pembrokeshire. The site is claimed by archaeologists to be a Neolithic bluestone quarry, but that is not supported by the evidence on the ground.

Bluestones and the "smoking gun"

About a year ago I published a post on this blog relating to a 2011 paper from the team involved in the Rhosyfelin and Carn Goedog digs.  It represents their thinking at the time the project started.  It's interesting to look at it again, since this article contains their most comprehensive assessment of the glacial transport hypothesis.  It is to the credit of the team members that they did at least consider some of the pros and cons, and give some time and space to looking at the arguments presented by Olwen Williams-Thorpe and her colleagues in 1991.  Here is the piece:

 http://brian-mountainman.blogspot.co.uk/2014/09/the-discrediting-of-glacial-transport.html

It will come as no surprise to anybody that I think the arguments presented against the glacial transport hypothesis are faulty -- as I state in my blog piece.  Also unsurprisingly, the human transport hypothesis is then accepted as fact, with analysis devoted to "how" and "why" the stones were carried / dragged / pushed / sailed / punted all the way from West Wales to Stonehenge.  The essential acceptance of the hypothesis is based upon no facts at all, but on a string of speculations and fantasies.  There is no itemisation of the flaws in the human transport thesis, as there is in the case of the glacial transport thesis.  The authors should have noted the following:

1.  There is no sound evidence from anywhere in the British Neolithic / Bronze Age record of large stones being hauled over long distances for incorporation in a megalithic monument.
2.  The builders of Neolithic monuments across the UK simply used whatever large stones were at hand.
3. If ancestor stones were being transported to Stonehenge, why have all of the known bluestones come from the west, and not from any other points of the compass?
4.  There is no evidence either from West Wales or from anywhere else of bluestones (or spotted dolerite in particular) being used preferentially in megalithic monuments, or revered in any way.
5.  If long-distance stone haulage was "the great thing" for the builders of Stonehenge, why is there no evidence of the development of the appropriate haulage technology leading up to the late Neolithic, and a decline afterwards?  It is a complete technological aberration.
6. The evidence for quarrying activity in key locations is questionable, to put it mildly.
7.  The sheer variety of bluestone types  (I still insist the figure is somewhere near 30 when one includes packing stones and debris) argues against selection and human transport.  There cannot possibly have been up to 30 "bluestone quarries" scattered about West Wales.
8.  No physical evidence has ever been found of ropes, rollers, trackways, sledges, abandoned stones, quarrymen's camps, or anything else that might bolster the hypothesis.
9.  Bits and pieces of experimental archaeology on stone haulage techniques (normally in "ideal" conditions) have done nothing to show that our ancestors could cope with the sheer physical 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.  Aubrey Burl made this point forcefully many years ago, and it remains forceful today.
10.  And if there was a "proto-Stonehenge" somewhere, built of assorted local stones and then dismantled and taken off to Stonehenge, where was it?

In relation to point (8) on the above list, the authors of the article have argued on a number of occasions that the discovery of a genuine bluestone quarry would be the "smoking gun" that would sort the issue out once and for all.  The quarry hunt has become something of an obsession.  Well, that's all very well, except that the evidence for ancient quarrying is incredibly difficult to interpret since we are dealing with the pre-metal tools era and with acidic environments in which bone and other organic materials do not survive for very long.  As we have seen at Rhosyfelin and Carn Goedog, one man's Neolithic quarry is another man's natural rock outcrop.  In my book the supposed trackways, platforms, ramps, pivots, scratches, rails, revetments, pillars and so forth at Rhosyfelin and Carn Goedog are figments of a fertile imagination -- and some of them have even been unconsciously "manufactured" by those involved in the archaeological digs.

Actually there are scores of "smoking guns" that might sort out the bluestone transport arguments.  One would be a discovery of a bluestone monolith on a sledge, buried in the mud of the Severn Estuary.  Another would be a discovery of an unequivocal glacial deposit on Salisbury Plain.  Another would be a collection of erratics scattered about in the Stonehenge landscape, or not far from it.  Another would be a sunken Neolithic boat somewhere in Carmarthen Bay, with a bluestone monolith in it.   Another might be a bluestone monolith abandoned somewhere near Abergavenny, with the remails of a haulage contractor crushed beneath it..........

Dream on, folks -- there must be plenty of other possibilities........

========================
The paper:

"STONEHENGE: CONTROVERSIES OF THE BLUESTONES"JOURNAL OF ANDALUSIAN PREHISTORY
No 1, 01 // 2011, pp 219-252
 
Summary

Whilst the sarsen stones of Stonehenge were brought from a short distance of about 30km away,
the smaller bluestones originate in Wales, over 200km to the west. This remarkable distance for the
movement of megaliths is unparalleled anywhere in the prehistoric world; some geologists have
suggested that the bluestones were carried by glaciers in a previous Ice Age but others point out
that there is no evidence for past glaciations ever having reached Salisbury Plain or even close to it.
This paper proposes that the bluestones were dragged by Neolithic people around 3000 BC, taking
a largely overland route except for a crossing of the River Severn. This contrasts with the conventional thinking that the stones were carried on boats across the sea from Milford Haven in south Wales to southeast England. It presents evidence for new sources of some of the bluestones on the northern flanks of the Preseli hills, as well as rejecting the long-held notion that the sandstone Altar Stone came from the area of Milford Haven. Finally, it proposes that the Preseli bluestones were selected for transport to Stonehenge because they represented the ancestry of one line of Britain’s
earliest farming migrants who arrived in the Preseli region shortly before 4000 BC.

Authors:

Mike Parker Pearson (Department of Archaeology, University of Sheffield). 
[ M.Parker-Pearson@sheffield.ac.uk ]
Joshua Pollard (Department of Archaeology, University of Southampton). 
[ Joshua.Pollard@bris.ac.uk ]
Colin Richards (School of Arts, Histories and Cultures, University of Manchester). 
[ colin.c.richards@manchester.ac.uk ]
Julian Thomas (School of Arts, Histories and Cultures, University of Manchester). 
[ julian.thomas@manchester.ac.uk ]
Kate Welham (School of Conservation Sciences, Bournemouth University).
Richard Bevins (National Museum of Wales, Cardiff).
Robert Ixer (Freelance geological consultant, Sutton Coldfield).
Peter Marshall (Honorary lecturer, University of Sheffield).
Andrew Chamberlain (Department of Archaeology, University of Sheffield). 

The Millennium Stone Fiasco

Just in case there is still somebody out there who thinks that the bluestones at Stonehenge were transported by enthusiastic (or reluctant) human beings all the way from West Wales to Stonehenge, here is the chapter from my book that deals with the great Millennium Stone Fiasco, just to put you right off the idea.......

https://www.scribd.com/doc/231584137/The-Millennium-Stone-Fiasco

Of course, Prof MPP now thinks that all this stuff about sledges and rollers and rafts is nonsense.  The stones were simply carried by groups of volunteers, resting on a sort of lattice work of bamboo (oops -- sorry -- substitute oak or whatever, and forget the weight of the lattice cradle....).  The latest theory is that the stones were carried in relays of about 2 miles at a time, with one carrying team passing the load on to another all the way along the A40 and thence to Bristol and thence to Salisbury Plain.

Rhosyfelin -- goodbye to the evidence

 Rhosyfelin after restoration, 20th September 2015

Sad to say, I went over with my wife and son to pick blackberries and crab apples in the Brynberian Valley today, and this is the sight that met us when we got to Craig Rhosyfelin.  The whole of the dig has been filled in, and that huge pile of spoil adjacent to the two dig sites has been dumped back into place, making it impossible to make any further examinations of the stratigraphy which was so beautifully exposed.  The whole site has also been re-seeded.

The two pits as they appeared during the 2015 dig -- exposing a fascinating sequence of glacial and post-glacial sediments on the valley floor. Both of the pits seen here are now filled in.

Actually I'm not criticising the dig team for this piece of restoration. All digs come to an end, and all dig sites have to be restored as carefully as possible, to meet the terms of the consents they have received from the planning authorities and the landowners.  So all the evidence has now disappeared, which might of course be very convenient indeed for anybody who does not wish it to be scrutinized by experts who might raise certain uncomfortable issues.......

I just wish that the closure of the pits could have been deferred.  I did ask the National Park if parts of the excavation site could be kept open so that other geomorphologists could take a look over the coming months, but my letter was ignored.  I wonder why?  What's the hurry? 

Anyway, I just hope that the archaeologists have a detailed plan of exactly where the outlines of these pits are located.  Inside those outlines, future work will clearly be a waste of time, since the sedimentary sequence is destroyed, but on the outside it will still be possible for other researchers to open up pits or to put down drill holes which might help geomorphologists to resolve outstanding problems.

Thank goodness that I have a good photographic record.......

This photo, from a couple of weeks ago, shows the extended dig site from 2014 and the new pit to the left.  The whole of this area has now been filled in with spoil, masking all of the sedimentary exposures.

Were Rhosyfelin fragments used as tools?

I was chasing around for information on lithics and stone tools used in the Neolithic, and I came across this piece on Mike Pitts's blog from the year 2011.  Interesting.  He suggests here that rhyolite is rather useful for the making of tools of various kinds -- especially for cutting things -- and that maybe some of the Rhosyfelin rhyolite found in the Stonehenge debitage is associated with tool-making either in conjunction with orthostat destruction or with tool manufacture at Rhosyfelin itself.  This is something I have suggested before, many times, on this blog.  The illustration above comes from his blog, and presumably shows various rhyolite chips and flakes up to 5 cm long.

Pitts on rhyolite chips and flakes...

https://mikepitts.wordpress.com/2011/12/20/bluestones-on-news-at-ten/

"One of the distinctive features of the rhyolitic rocks is that they are flinty – they have a good conchoidal fracture. That makes them relatively easy to break up, if they are standing as monoliths at Stonehenge. But it also makes them pretty good for making tools, or portable artefacts of some kind. There are plenty of flaked bluestone “tools” in museum collections from Stonehenge (some of them from my own dig, as illustrated above, from my PPS report). Which of these are made from debris created when stones were dressed on site? Which are made from broken up megaliths? And which were made in Wales and brought to Stonehenge by people visiting, perhaps on a pilgrimage of some kind? Clearly the distinction has important implications for how we understand Stonehenge.

These are questions that future research can answer, through excavation in Wales and at Stonehenge and study of the debris – that we can do this is a reflection of the quality and utility of the new research. Ixer and Bevins identified five groups of rock amongst the rhyolitic pieces they studied, of which three (by far the bulk of all they saw) they have matched to the Pont Saeson outcrops. There is one buried stump at Stonehenge (stone 32e) that they say could well be from Pont Saeson (to be confirmed), but the four standing rhyolitic stones are different. One of the latter (stone 48) belongs to one of the two very rare classes that Ixer and Bevins identified, which have yet to be matched to a source. One way excavation at Stonehenge would help us, is in allowing modern identification of the stumps and other bits of megaliths at the site."

Wiki:  In lithic stone tools, conchoidal fractures form the basis of flint knapping, since the shape of the broken surface is controlled only by the stresses applied, and not by some preferred orientation of the material. This property also makes such fractures useful in engineering, since they provide a permanent record of the stress state at the time of failure. As conchoidal fractures can be produced only by mechanical impact, rather than frost cracking for example, they can be a useful method of differentiating prehistoric stone tools from natural stones. .............  A swelling appears at the point of impact called the bulb of percussion. Shock waves emanating outwards from this point leave their mark on the stone as ripples. Other conchoidal features include small fissures emanating from the bulb of percussion.

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

This is all a nice idea, but it's worth making the point that there are no -- or very few -- conchoidal fractures in the Rhosyfelin foliated rhyolites.   The fractures are not curved and crescentic, but tend towards being straight and flat.  Just take a look at this photo of rather typical splintered or shattered fragments from the rockfall debris on the flank of the crag:

In my discussions with visitors to Rhosyfelin we have had many duscussions about whether fresh flakes and slivers, either picked up or knocked off the edges of exposed rock surfaces, or even knocked off orthostats at Stonehenge, would make desirable and valuable tools for cutting flesh, skinning animals etc.  Some of us think the foliated rhyolite is rather soft to be used for long-lasting tools, and others disagree.  Edges are certainly very sharp indeed.  Maybe such flakes were so abundant that they could be treated as disposable items, rather like plastic knives are used as cheap substitutes for knives made of Sheffield steel?

This is an interesting dilemma, which maybe needs some input from lithics experts.  What do others think?