Weathering of granite lying stones and standing stones

My thanks for Geo for bringing us back to this one.  Just a reminder of his earlier post on the blog:


"Dominque Sellier, Prof of physical geography at Nantes Uni and usually described as a geomorphologist has shown in two papers:  1) that the landscape around Kerlescan consisted of grantitic outcrops “Analyse morphologique des marques de la meteorisation des granites a partir de megalithes morbihannais 1991." And, following on from other studies relating to cleavage planes and the tendency of granite to fracture along orthogonal planes, which when quarried displays two main faces, one displaying the fresh face corresponding to the surface where the stone was broken away and the weathered face, a convex side of the stone that was initially exposed to the open air. A close inspection of the exposed face reveals traces of erosion called micromodeles and then in 2) Elements de reconstitution du paysage premegalthique sur les sites des alignemnets de kerlescan a partir des criteres geomorphologiques “(1995) defines two specific categories of micromodeles which can be used to distinguish between weathering before extraction and erosion after erection. Of course as has been mentioned before the Kerlescan alignment overlies and thus postdates a barrow."

I haven't been able to get at these two papers,  although they are referred to by Chris Scarre and others.  But I have been able to find this one:





MÉGALITHES ET MÉTÉORISATION DES GRANITES EN BRETAGNE LITTORALE, FRANCE DU NORD-OUEST

Yannick LAGEAT, Dominique SELLIER et Charles R. TWIDALE, respectivement: URA 1562 du CNRS, Université Biaise- Pascal, 29, boulevard Gergovia, 63037 Clermont-Ferrand, France; URA 1562 et UPR 403 du CNRS, Université de Nantes, chemin de la Sensive du Tertre, B.P. 1025,44036 Nantes, France; The University of Adelaide, GPO Box 498, Adelaide, South Australia 5001.

Géographie Physique et Quaternaire, 1994, vol. 48, n° 1, p. 107-113, 3 fig., 1 table.

ABSTRACT Megaliths and granite weathering in coastal Brittany, northwestern France. Menhirs are elongate granite blocks placed upright, i.e. with the long axis in the vertical, in Neolithic times. Granite menhirs are prominent in the Morbihan and Trégor districts of coastal Brittany. Two minor forms, rock basins (also known as gnammas) and flutings (grooves, Rillen, Karren), are developed on menhirs. Two distinct generations of forms can be distinguished : those that predate the menhirs being placed upright, and those that postdate erection. Several flat-floored basins (or pans) that must have originated on flattish surfaces are now found on steeply inclined surfaces. On the other hand, smaller basins have developed on the summits of the monuments. Several flutings score the steep upper slopes of the blocks. They are deepest where they cut into outwardly convex inclined rock faces. They also diverge over such protuber- ances and terminate well above ground level. Clearly both the younger generation of basins and the flutings have formed after the monuments had been placed in their present upright positions and by processes active under subaerial or epigene conditions. In this last respect they stand in contrast with similar forms reported from other parts of the world. In Brittany the estimated age of menhirs is about 5000 years. Thus the flutings have deepened at a rate of a few tens mm/1000 years. The implied rate of basin development varies between 4 and 30 mm/1000 years.

It seems to me that Dominique's work is essentially related to weathering rates,  and it's interesting to see that she and her colleagues have been able to identify flutings on sloping or vertical surfaces and small pans on flattish or horizontal surfaces which appear to have formed as a result of weathering and erosion (as a result of rainfall above all else) subsequent to the erection of the stones.  It's also interesting that many larger pans or weathering pits are found on the flanks of these menhirs, which must have been created over many thousands of years when the stone slabs were lying flat on the ground -- ie before collection and erection by the builders of the Carnac stone alignments. 

In my previous post on Carnac, here:

http://brian-mountainman.blogspot.co.uk/2011/05/carry-big-stones-long-way-non-merci-mon.html

I noted that according to Chris Scarre, "........ the stones in the Carnac alignments are very closely related to the local geology -- and in particular to the spacing of fissures in the local granite bedrock.  In turn, this influences the size and dimensions of the stones that litter (or used to, in the past) the ground surface and which are then used by the groups responsible for the alignments.  His little diagram, and the plot of stone heights, are fascinating and convincing.
The message seems to be this:  that the builders of Carnac, over quite a long period of time, used stones more or less where they found them.  Indeed, it could be argued that Carnac is where it is not because of some astronomical freak or even any great ritual or ceremonial obsession -- but simply because the stones were relatively easy to gather up and easy to erect.  Minimisation of effort, energy conservation, opportunism, rock scavenging -- call it what you will........ but the nice simple utilitarian message rather appeals to me." 

If we want to, we can refer to the gathering and erection of the Carnac stones as "quarrying" -- but the weathering information is self-evident:  granite surfaces exposed to the atmosphere for a very long time (maybe millions of years) will be deeply weathered and even crumbly (the Breton granite is notoriously "crumbly" and edges and corners tend to be rather well worn where exposed to the atmosphere), whereas the buried surfaces of slabs will of course be much fresher (with sharper corners and edges).  These differences will of course be readily visible when a block or slab is lifted to a vertical position.

I'm not sure if Dominique and her colleagues have done detailed weathering depth measurements on the various faces of the standing stones, but that could be interesting too.  Most interesting of all would be cosmogenic dating on stone surfaces -- at Carnac, Stonehenge, Callanish and many other places as well.  That may tell us a lot, including the exposure ages of the various faces of the standing stones and it might also help to fix a date for the dressing of those faces which have obviously been interfered with by the megalith builders.  But as I have said before, there are so many variables involved in this sort of work (rock surface shading, orientation, vegetation interference, time spent recumbent and time spent vertical, inherited cosmic "damage" prior to stone movement etc etc) that it may take many years and literally hundreds of cosmogenic dates to sort it all out........

Some of the pans or solution / weathering pits on the surface of one of the Carnac menhirs.  As the caption says, this surface was once almost horizontal, either at or maybe beneath the ground surface.  (Weathering like this could be effective beneath a layer of turf or loose vegetation.)

A nearly frozen wave

A photo from Jonathan Nomerfroh, taken during the current cold spell on the coast of Nantucket, USA.  Yet another for the collection of "weird and wonderful" phenomena from the world of ice.....

This is what happens when a wave approaches the shore and has to pass through a shallow water zone where the sea is almost freezing -- with many ice crystals present.  So the wave appears to be passing through a slush zone.

This happens quite often in the polar regions, usually at the onset of winter -- but it is not often photographed........

New work at Stanton Drew

Thanks to John Oswin for sending info about new work at Stanton Drew.  The "Big Ground Mound" at Quoit Farm has been excavated (in 2014) and subjected to close scrutiny using various high-tech devices -- and the conclusion is that the mound is not a relic of a long barrow or anything else man-made, but is an entirely natural feature.

That may be disappointing for archaeologists, but speaking as a geomorphologist, I find that rather refreshing and honest -- and a sign of good science.

The 2015 report is entitled "Probing the Big Ground Mound" and is by Vince Simmonds, John Oswin and John Richards.  It's published by the Bath and Camerton Archaeological Society.
Two different versions of the report are available on the website: www.bacas.org.uk

The report also contains a report of an experimental laser survey of the stones that make up "The Cove" -- although I have to admit to being somewhat at a loss as to what the purpose of the survey actually was........

Volcano cross-section

The island of La Gomera is essentially a single very large volcanic peak which has had a complex history of eruptions.  There have not been so many huge catastrophic events here as on other islands, so there are no large calderas (as there are on Gran Canaria, for example.) 

The above photo shows part of the cliff above the beach of La Playa, Valle Gran Rey, more or less at the western tip of the island.  At the base of the cliff there are assorted basalts, grey ashes and ignimbrites, then above those we see a series of ash beds -- some of them grey but others red and buff in colour.  These beds have been disturbed / consumed by several intrusions, and we can see the basalt dykes pushed right through them, causing major disruptions in the bedding.  On the right we can see some of the huge rockfalls from slope collapses as the cliff has been eaten away by the sea.

Igneous dyke, La Gomera

For the geologists in our midst.  One of the most amazing images of a dyke you are ever likely to see.  This one is exposed in a road cutting on La Gomera, high up on the "cumbre" above Vallehermoso.  The dyke has been intruded into red layered volcanic ashes and as it has melted its way  towards the surface (which must have been much higher than the eroded surface we see today) it has simply gobbled up the ash layers, leaving an incredibly clean contact on either side.

The dyke is made of basalt (I think) and it is about 10m wide.  The stone wall marks the edge of the roadway.  Because the road here is relatively new, this exposure is remarkably fresh.  Within a few years it will no doubt degrade.

Submerged forest - Tywyn Beach

All hail to the photographer Howie Mudge for this fantastic photo of the submerged forest (mostly beds of peat) following the 2014 winter storms.  Published by the Welsh Photographers.

No particular reason for this apart from the joy of sharing!  And of course it is a reminder of climate change and the Holocene sea level rise.....

Some old comments

Apologies, all -- I have just found an assortment of posts on a strange "moderation page" on Blogger which haven't been notified to me in the usual way.  Not at all sure why........ anyway, I have pasted them in now -- even though some are more than a month old.

I also notice that there are some "Anonymous" posts that are making perfectly sensible points worthy of discussion.  But because my system is primed to dump ALL anonymous posts into the Trash (it's the only way to deal with spam) I do not even look at them.  So I urge any punters who wish to make comments to use either their names or pseudonyms, and by doing that the comments will come to my attention.  Thanks!!

Erratic boulder shapes and megalithic settings

The two photos above show assorted boulders (mostly made of dolerite and rhyolite) in Pembrokeshire moraines.  The top photo shows the boulders projecting through the ground surface on the Pont Ceunant Moraine, near Newport, and the lower photo shows boulders excavated recently from the Cilgwyn Moraine, on the south side of Carningli, during building work.  As in all moraines, we see some well rounded boulders, some sub-rounded, some sub-angular and some angular -- with shape determined above all else by the distance a boulder has been transported by the ice.

Now let's take a look at some of the stones found in megalithic structures in Pembrokeshire:

Just a few of Pembrokeshire's megalithic structures.  From the top:  Llech y Drybedd, Trefael, Harold Stone (Skomer Island), Waun Mawn standing stone, Parc y Cromlech (Penrhiw), Devil's Quoit (Broomhill Burrows), Pentre Ifan, Ffyst Samson (Trellys), Carreg Coetan Arthur (Newport) and Carreg Samson (near Trevine).

Some of the stones used in these structures are quite sharp-edged or angular, and could have been taken from nearby rocky outcrops, but in general the stones used by the megalith builders have rounded or sub-angular edges and have clearly been picked up from the morainic / erratic materials readily available across the Pembrokeshire landscape.  One day I'd like to do a detailed analysis.  Some of the stones used are quite interesting -- for example, the capstone at Pentre Ifan has a glaciated upper surface and a fresh or broken underside.  Before being used as a capstone, was it embedded in the ground and smoothed by over-riding ice?

As suggested by many authors, the key determinant of megalith location has nothing to do with ley lines, solar or lunar alignments or astronomical observations and everything to do with the availability of convenient stones.

What was true for Wales was no doubt also true for Stonehenge........

The Infamous Rhosyfelin "Proto-Orthostat"

 

 

 The Infamous Rhosyfelin "Proto-orthostat"

White elephant, red herring and aberration

Why is it that the most famous slab of rock in the archaeological firmament at the moment is this big lump of foliated rhyolite from Rhosyfelin, not far from Brynberian in North Pembrokeshire? 

Well, part of the answer lies in the fact that the geologists have made a pretty accurate match between the foliated rhyolites in an outcropping crag at this site and some of the "rhyolitic debitage" at Stonehenge. Any sensible earth scientist would say "Fine.  Interesting research.  It's always satisfying when erratic material at one place can be matched with a provenance a long way off, no matter what the mode of transport might have been between source and resting place."  He or she would then ponder on transport mechanisms and assume that glacier ice was probably involved, since other evidence on the record suggests that the ice of the Irish Sea Glacier extended at one stage at least as far as central Somerset.........

The other part of the answer lies in the fact that certain archaeologists have "taken possession" of the Rhosyfelin site and have pontificated, in their infinite wisdom, that glacier ice cannot possibly have extended all the way from Pembrokeshire to Salisbury Plain and that there must, therefore, have been a "bluestone quarry" at Rhosyfelin.  They had decided this even before they started digging on the site in 2011 -- and when a large slabby rock was found among the rockfall debris near the degraded rock face they all shouted "Bingo!" and proceeded to tell the world that this was indeed a bluestone quarry and that the "proto-orthostat" would have been taken off to Stonehenge if cruel fate had not intervened.  And from that point on, an extremely elaborate story has been put together by Pof MPP and his colleagues....... and heavily promoted through popular articles, press releases and lectures.

All terribly exciting.  But hang on for a moment.  Let's look at this in the cold light of day.

Is there any evidence of Rhosyfelin foliated rhyolite being used as a standing stone at Stonehenge?  Er, no....... apart from some chips of rock found in the debitage during excavations. 

Is there any evidence of the Rhosyfelin rhyolite being "special" in some way,  or of it being used in megalithic contexts in Pembrokeshire?  Er, no...... 

Does the Rhosyfelin "proto-orthostat" look like any of the standing or recumbent bluestones at Stonehenge?  Er, no..... 

Is there any evidence of slabs of rock being levered off rock faces by Neolithic quarrymen anywhere else in Pembrokeshire?  Er, no..... 

Is there any indisputable evidence of quarrying activity at Rhosyfelin itself?  Er no...... but if you give us long enough we'll certainly find it......

Any archaeologist who knows southern Britain must admit, if he is honest, that the Rhosyfelin "proto-orthostat" is an aberration.  There is no other word for it.  It is nothing like the standing dolerite bluestones of the Stonehenge bluestone horseshoe, and it is nothing like the collection of smoothed and rounded stumps, slabs, blocks and boulders found in the Stonehenge bluestone circle.  The Rhosyfelin stone is sharp-edged and angular, with a remarkably fresh appearance -- as you would expect of a rock which has fallen from a nearby cliff or rock face.  The Stonehenge bluestones (or at least those that are undressed) are rounded or well-rounded and very irregular in shape -- they show signs of considerable abrasion during prolonged transport by ice.

The conclusion has to be that the Rhosyfelin "proto-orthostat" is simply a big stone in a random position, having fallen from the cliff face at some time during the Holocene.  It has no archaeological significance, either for Stonehenge or anywhere else -- unless some powerful evidence emerges to suggest otherwise.

"But wait," say the archaeologists. "We have the evidence!  Look at the way the big stone just lies there on its props and pillars, in glorious isolation, ready to be moved off down the valley."  To which I reply that when you do an excavation and strip away all the stones and soil that once surrounded the big stone, of course it sits there in isolation, resting on the stones that are beneath it.  You have created an artifice rather than revealed something significant.

"But there's more!" say the archaeologists. "We have yet more evidence, and this time it's indisputable!  Signs of Neolithic occupation and radiocarbon dates to show that this was an important Neolithic site and that quarrymen were at work here at just the right time to move stones off to Stonehenge."  That will all come rather soon in one or more papers from the digging team.  We shall see what the colour of the evidence is -- but my instinct (from what has thus far been revealed) is to respond that Rhosyfelin was a perfect site for a temporary Neolithic camp -- in the shelter of the rock, protected by trees and the steep valley sides from the wild winter winds of West Wales, and convenient for both hunting and fishing.  If there was a camp here, used over many millennia -- was it in any way unique?  How many similar camps were there in the deep valleys of Pembrokeshire, and how many might be revealed if the archaeologists were to check them out with the same level of financial investment and manpower commitment as we have seen at Rhosyfelin?  (There is always a danger (in geomorphology, geology and archaeology) of referring to a field discovery as unique or significant when it may be nothing of the sort -- it may be unique IN YOUR EXPERIENCE because you haven't yet discovered all the other sites where the same thing occurs.)

If there was a settlement site at Rhosyfelin, that's really interesting.  But I hope to goodness that the archaeologists do not use that discovery to push their ruling hypothesis that this was a QUARRYING SETTLEMENT and that those in residence during the Neolithic were intent on shipping off a rather large rhyolite stone to Stonehenge until orders came down from their site managers that work should stop, since their client had cancelled the order.

Understanding the Bluestone Circle

  

Stones 34 (above) and 37 (below) of the Bluestone Circle at Stonehenge.  Both stones are made of spotted dolerite.  The one above is best described as a rounded boulder set on end, and the lower stone is best described as an irregular slab; we are looking at the flattest face in the photo.  No self-respecting Neolithic orthostat collector would give these stones a second glance, let alone go all the way to West Wales to collect them.  They are heavily worn glacial erratics, carried a long way by ice and probably collected from the Stonehenge landscape by the builders of the monument. 

(Photos from the Stones of Stonehenge web site.)

Work in progress.........

There are nineteen visible stones in the Bluestone Circle and also assorted buried stumps.  Here is an attempt at itemising the full list, with reference to stone shapes, surface characteristics and petrology:

31 -- damaged and heavily worn slab.  Standing.  Recent damage close to ground level.  Spotted dolerite with few spots.
32 -- heavily worn slightly elongated boulder.  Fallen -- resting on stone 150.  Spotted dolerite with pinkish spots -- like stones 150, 34, 35A, 35B (one stone), 39 (?), 47, 49, 64, 67, 69, 70
32c -- altered volcanic ash.  Like 33d.  Foliated rhyolite related to Rhosyfelin debitage?
32d -- another foliated rhyolite stump?  Related to Rhosyfelin material?
32e -- Dolerite stump -- characteristics unknown
33 -- well worn short and stumpy pillar.  Standing.  Signs of shaping -- meant as a lintel?  Spotted dolerite with whitish spots.
33e -- altered volcanic ash (stump).  Like 32c
33f -- altered volcanic ash (stump).  Laminated -- like 40c and 41d
34 -- well rounded small boulder, placed on end.  Spotted dolerite with pinkish spots -- like 32?
35 a and 35 b -- irregular and well worn boulder, embedded in the ground and only just visible.  Spotted dolerite with pinkish spots -- like 32?
36 -- an irregular and heavily worn boulder, slightly elongated.  Modern damage on one edge.  Recumbent
37 -- smallish well-rounded boulder, slightly slab-shaped and set on end.  Spotted dolerite with moderate spots.
38 --  smallish irregular boulder, well worn, fallen and under another stone.  Rhyolite, ignimbrite. Dacitic ash-flow tuff.
39 -- another smallish boulder, well worn, slightly slab-shaped, with some later damage.  Leaning, almost recumbent.  Spotted dolerite with pinkish spots -- like 32?
40 -- Rhyolite, ignimbrite. Dacitic ash-flow tuff. Stump beneath ground? Laminated --  like 33f and 41d?
40c -- stump. Laminated calcareous ash
40g -- below ground stump -- irregular shape. Micaceous andstone. Lower Palaeozoic?
41 --  recumbent elongated boulder with heavy wear -- very well rounded edges
41d -- stump.  Altered volcanic ash.  Laminated -- like 33f and 40c
42 -- recumbent wedge-shaped stone with heavy wear on edges.  Densely spotted dolerite?
42c -- stump.  Sandstone (micaceous).  Lower Palaeozoic?
43 -- recumbent slightly flattened boulder with heavy wear on edges.  Densely spotted dolerite?
44 -- heavily worn boulder just visible in the turf -- recumbent.  Spotted dolerite?  Similar to Boles Barrow dolerite?
45 -- recumbent elongated boulder with heavy wear on edges.  Unspotted dolerite? Different from 44.
46 -- slightly slab-shaped boulder set on edge.  Flaky -- considerable recent surface damage.  Rhyolitic ash-flow tuff like stone 48? Or is it a lava?
47 -- slab with heavy wear on edges -- set on end.  Spotted dolerite with pinkish spots -- like 32?
48 -- small recumbent boulder with heavy wear --  just projecting through the turf.  Rhyolitic ash-flow tuff (flinty blue) but not like stone 46?
49 -- small irregular slab with quite sharp edges.  Upright.  Signs of dressing? Intended as a lintel?  Spotted dolerite with pinkish spots -- like 32?

Note that there are at least a dozen dolerites in this collection -- so not all of the available dolerites were placed into the Bluestone Horseshoe.  The dolerite slabs and boulders of assorted shapes and sizes were used in the Bluestone Circle, and the more elongated dolerites (the pillars) were used in the Horseshoe.  So it can NOT be argued that the builders of Stonehenge were intent on collecting dolerite PILLARS from Preseli to the exclusion of all other dolerite shapes.  Here they have used a weird assortment of dolerites of all shapes and sizes.  As suggested in earlier posts, the presence of slabs, roughly rectangular blocks and boulders -- for the most part with rounded-off edges and corners and with an overall shape we will refer to as "sub-rounded" -- is highly suggestive of long-distance glacier transport.  It is logical to assume that these stones (we won't call them "orthostats") are not simply glacial erratics but glacial erratics that have travelled a long way.  In other words, they have in all probability been collected from Salisbury Plain or somewhere near it.

The OU team (which involved Olwen Williams-Thorpe and Rob Ixer) had consent from EH to sample 11 of the dolerite orthostats in the Bluestone Horseshoe and 4 of the "rhyolite" orthostats in the Bluestone Circle.  that means that cores were taken.  Were there any measurements and analyses of the weathering crusts revealed in these cores?

Blackrock Dolmen

We are a civilized bunch on this blog, well known throughout the western world for our sophisticated arguments and artistic leanings.....

For no other reason than that I think this rather beautiful, here is a pic of "Blackrock Dolmen",  a 1987 sculpture by Rowan Gillespie now installed in Blackrock, Dublin, Ireland.

If you want to use this to prove that the sculptor knows something the rest of us don't -- namely that the cromlechs of Ireland were built by elves -- that's your privilege.  By the way, are there elves on Salisbury Plain as well?

The Erratic Bluestone Circle

With grateful thanks to "The Stones of Stonehenge" blog site, the bluestones from the bluestone circle pictured above are (from the top) stones 31, 34, 35a, 39, 45 and 47

I've been having a good look at the splendid photos featured on "The Stones of Stonehenge" site, and had forgotten what a grubby and random collection of stones of all shapes and sizes they actually are.  Most of them are so heavily worn on their edges that they would not be out of place in a modern moraine close to a glacier snout.  The idea that they might have been quarried from a Neolithic quarry by our heroic ancestors is totally ludicrous.  We are looking at the traces of severe wear by natural processes -- either in a fluvio-glacial environment or ((much more likely) in a glacial one.

This is a collection of glacial erratics, or I will eat my hat.  From an examination of Simon's photos, here are my brief notes.  Any other observations would be welcome.

Nineteen stones in the Bluestone Circle:

31 -- damaged and heavily worn slab.  Standing.  Recent damage close to ground level
32 -- heavily worn slightly elongated boulder.  Fallen -- resting on another stone
33 -- well worn short and stumpy pillar.  Standing.  Signs of shaping -- meant as a lintel?
34 -- well rounded small boulder, placed on end
35 a and 35 b -- irregular and well worn boulder, embedded in the ground and only just visible
36 -- an irregular and heavily worn boulder, slightly elongated.  Modern damage on one edge.  Recumbent
37 -- smallish well-rounded boulder, slightly slab-shaped and set on end
38 --  smallish irregular boulder, well worn, fallen and under another stone
39 -- another smallish boulder, well worn, slightly slab-shaped, with some later damage.  Leaning, almost recumbent
40g -- below ground stump -- irregular shape
41 --  recumbent elongated boulder with heavy wear -- very well rounded edges
42 -- recumbent wedge-shaped stone with heavy wear on edges
43 -- recumbent slightly flattened boulder with heavy wear on edges
44 -- heavily worn boulder just visible in the turf -- recumbent
45 -- recumbent elongated boulder with heavy wear on edges
46 -- slightly slab-shaped boulder set on edge.  Flaky -- considerable recent surface damage
47 -- slab with heavy wear on edges -- set on end
48 -- small recumbent boulder with heavy wear --  just projecting through the turf
49 -- small irregular slab with quite sharp edges.  Upright.  Signs of dressing? Intended as a lintel?

And here's another thought.  If the archaeologists insist that Stonehenge was carefully planned, with  dolerites brought in for the bluestone horseshoe and everything else destined for the bluestone circle, the famous "proto-orthostat" lying on the ground at Rhosyfelin would be a complete anomaly.  With its sharp edges (typical of a rockfall slab) it is far larger than any of the other bluestone circle stones and completely different in its physical characteristics.  I am more convinced than ever that NONE of the Stonehenge bluestones was quarried from the solid rock -- in Pembrokeshire or anywhere else.  The stones at Stonehenge were already very ancient -- and heavily worn -- well before they were gathered up and built into the monument.  Some of them (especially those in the horseshoe) were of course damaged or dressed either before or after arrival at the site, but most of those in the bluestone circle appear to be largely in their natural state.

Just take one look at the Rhosyfelin stone, and compare it with the above photos (or any of the others on Simon's blog) and you will have to agree that the archaeologists are wasting everybody's time with all this quarrying nonsense.

 

The 43 Stonehenge Bluestones

Anthony Johnson's invaluable "stone plan" for the stony section of Stonehenge.  The numbering may be indistinct -- if you cannot read the numbers please refer to the last post.

Further to the last post about Simon's excellent new blog, here are some further notes about the bluestones which we know about.  Adapted from the relevant chapter in The Bluestone Enigma:

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

Immediately inside the sarsen circle there is a circular setting of smaller standing stones without lintels. These are all bluestones, in what is currently called “The Bluestone Circle.” This is how Aubrey Burl describes them: “In contrast to the towering sarsens, they are like unkempt urchins slouching and flopping beneath the disapproving glares of their elders.” Rodney Castleden says “...... they skulk among the sarsens, like dwarfs among giants, in an irregular ring.......” However many there may have been originally, only six are still standing. Another thirteen are leaning or have fallen over onto the ground. That makes 19 stones, numbered 31-49 in the "stone catalogue" started by Flinders Petrie.  The “stumps” of ten others have been found during excavations at or beneath the ground surface.  That makes a total of 29 stones. Archaeologists assume that many of the original "bluestone circle" stones have been removed or broken up, and the evidence for this is based upon findings of flakes and chips in holes and in the "debitage". The remaining standing stones are about 2m tall and weigh between 2 and 4 tonnes apiece. At least two of the bluestones have been trimmed, probably for use as lintels, and the possibility must be considered that many of the “missing” bluestones were small sarsens later rejected or used in a later phase of building as lintels for the sarsen circle.

The “Bluestone Horseshoe” is an arrangement of smaller stones inside the sarsen horseshoe. There may originally have been nineteen or more, of which six are still in position with a further five fallen. There are two “stumps” below ground level. So there are 13 stones here which are capable of examination. They are numbered 61-72 and the group includes stone 61A. It is assumed by the archaeologists that a further six (at least) have disappeared. All of those that remain above the ground surface are dressed into square-section pillars about 60 cm across. As with the free-standing trilithons, the shortest stones (up to 2 m tall) were at the ends of the horseshoe, and the longest (about 2.5 m tall) stood immediately beneath the Great Trilithon on the axis of the monument. Because at least six of the bluestones bear traces of mortise and tenon joints and other signs of working, it is argued that they must have been used at one time in a setting of bluestone trilithons. In his book "The Making of Stonehenge" Rodney Castleden develops this idea to a considerable degree; but it’s fair to say that most other authors are more circumspect. Castleden also claims that the stones in the bluestone horseshoe were smoothed into alternating tall slim pillars and tapering triangles, presumably intended to portray “male and female” shapes; and he claims to have seen “humanoid” parallels in other monuments. Most other authors mention no such arrangement or intent, and this may be another example of an author finding what he wanted to see.

Lying on the ground inside the apex of the bluestone horseshoe is a large slab of grey-green sandstone about 5 m long and weighing between 6 and 9 tonnes. This is (by one calculation) the 43rd big “foreign” stone on the site, and it was possibly the last one to be put into position. Or was it the first one, found lying on the ground, and ultimately responsible for the location of Stonehege? It is referred to, fancifully, as the Altar Stone, but some archaeologists believe that it once stood upright as an impressive pillar. Rodney Castleden refers to the Altar Stone as a revered “goddess stone” which was once standing proudly as the centre-piece of the whole monument. Aubrey Burl begs to differ -- and he argues that the stone was laid flat quite deliberately and used more or less as an altar in a church might be used today. It is not known how or when it came to be in its present position, but two fallen members of the Great Trilithon rest upon it, and it seems even today to be surrounded by a mayhem of fallen and leaning stones.

Nobody is quite sure how many “bluestones” there are today at Stonehenge. The traditional numbering system has proved difficult with these smaller stones, and originally some “stumps” were uncounted. Later on, they were counted in and given letters as well as numbers. And to make matters worse, some were fragments of stones already counted, while some that were assumed to be parts of a single monolith later turned out to be geologically distinct from one another. So there is a good deal of double counting and false counting. Let us assume, at any rate, that there are 43, including the Altar Stone -- as indicated in the careful geological study by Olwen Williams-Thorpe and colleagues from the Open University in 1991. These stones are observable. They can be analysed and even sampled. Rodney Castleden says that 29 bluestones have disappeared, including 11 from the Bluestone Circle and 8 from the Bluestone Horseshoe.  He gives no evidence to support the view that the stones were bluestones rather than sarsens. Others have speculated that there may have been between 50 and 82 genuine bluestones in total, and indeed we know from historical records that many have been smashed up and taken away. But until the Stonehenge scribes can demonstrate the characteristics of those “assumed stones” we will leave their figures on one side.

So for the moment we will continue to assume that there are 43 known bluestones on the site, with 19 (numbered 31-49) in the Bluestone Circle, 13 (numbered 61-71 and including stone 61A) in the Bluestone Horseshoe, making a total of 32 stones that are visible and accessible, and a further 11 buried stones or stumps whose positions are known but which can only be reached by excavation.

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

When Simon has done some more work on his site and has added notes about the geology of the stones and the references which deal with petrology and provenancing, it will be incredibly valuable for researchers and argumentative bloggers.

Every Stonehenge Stone

This is great news -- to be welcomed by all!  A new site which will provide photos and info about every stone at Stonehenge.   Thanks to Stonehenge News for passing on the alert.  Take a look at it -- it's work in progress, but there are already many splendid photos on the site.  No doubt text will follow.  I'm not sure who is behind this enterprise, but the new site will certainly be an invaluable tool when we want to refer to one stone or another in the course of our discussions.......

The Stones of Stonehenge. A new web site with a page devoted to each stone at Stonehenge.

by stonehengenews
http://blog.stonehenge-stone-circle.co.uk/2015/02/11/the-stones-of-stonehenge-a-new-web-site-with-a-page-devoted-to-each-stone-at-stonehenge/

Strange as it may seem, there isn't a useful reference work that shows photographs of every stone at Stonehenge from all (easily) available angles, until now.  The website is a work in progress toward that end. Not all stones currently have pages, but eventually they will have.

Stone Numbering System
The numbering system for the stones is that devised by W.M. Flinders Petrie in the late 19th century and which is still in use by researchers and archaeologists to this day.

Petrie carried out one of the first highly (and dependably) accurate surveys of Stonehenge and decided that all previous systems of numbering the stones were inadequate in one way or another.
He resolved to number the stones in ascending order clockwise from the main axis of the monument and beginning with the sarsen immediately to the east of the axis in the outer circle as seen from the centre. This is Stone 1. All the actual and supposed positions of sarsen stones are numbered, whether or not there is a stone (or fragment of stone) at or near the position.
The horizontal lintels of the outer sarsen circle are numbered by adding 100 to the number for the higher of the two uprights that support each one. So the lintel supported by Stones 4 and 5 is numbered 105, and that supported by Stones 21 and 22 is numbered 122.
There is a single exception to this rule for the lintel spanning Stones 30 and 1 across the main entrance into the monument which is numbered 101 rather than 130. This is because the number 130 is already in use for the neighbouring lintel that is supported by Stones 29 and 30.
The bluestones of the circle within the sarsen circle are similarly numbered clockwise from the main axis beginning with Stone 31. In the case of the bluestones, Petrie did not assign numbers to the supposed positions of any that are missing.
The sarsens in the horseshoe of massive trilithons are numbered clockwise starting from Stone 51 round to Stone 60. Their respective five lintels (or "imposts" as Petrie called these huge lintels) are numbered 152, 154, 156, 158 and 160.
The bluestones of the innermost horseshoe arrangement are numbered clockwise from Stone 61.
The Altar Stone is Stone 80. The two remaining Station Stones outside the circle are numbered 91 (eastern stone) and 93 (western stone). Station Stones 92 and 94 are missing. The Slaughter Stone is Stone 95 and the Heel Stone is Stone 96.
Fragments of stones which are clearly associated with each other are given alphabetical indices, for example Stones 55a and 55b are the two parts of the broken fallen sarsen upright of the Great Trilithon.
http://www.stonesofstonehenge.org.uk/

Neolithic Gift Shop found at Stonehenge

Discovery Of Neolithic Gift Shop Suggests Stonehenge Always Meant As Tourist Attraction

This is from the well-known scientific journal called THE ONION -- so it must be true.... finally an explanation of the debitage, to satisfy the most sceptical.





http://www.theonion.com/articles/discovery-of-neolithic-gift-shop-suggests-stonehen,37945/?utm_source=Facebook&utm_medium=SocialMarketing&utm_campaign=LinkPreview%3A1%3ADefault

WILTSHIRE, ENGLAND—In a significant finding that sheds new light on the mysterious monument’s past, a team of archaeologists working near Stonehenge this week unearthed the remnants of a primitive gift shop, suggesting that the site had always served as a tourist attraction. “After uncovering piles of Stone Age goblets, deer-hide tunics, and animal-bone bracelets all etched with images of Stonehenge, we realized that this was not an ancient Celtic ritual site or Druidic pilgrimage destination as previously thought, but instead a popular attraction for Neolithic vacationers,” said lead researcher Amelia Stroud of Oxford University, who explained that preserved footprints found at the site indicated that ancient visitors had to walk through the gift area on their way out of the circular stone structure. “We also found a wide array of ancient coins at the site, clear evidence that large bands of Romans and Anglo-Saxon tribesmen came from far away to visit the attraction and were charged exorbitant prices while there.” Stroud went on to speculate that numerous small rocks found scattered around the site were most likely the remains of prehistoric “Make Your Own Stonehenge” kits.