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There are traces of 43 blue stones at Stonehenge. Stumps, pillars, boulders, and slabs, all sorts of shapes and sizes. The geologist Herbert Thomas realized that some of them had a very close geological match with a small area to the north of Preseli in West Wales. He, for some reason, did not believe what other geologists were saying, that glacial transport was probably responsible for transporting the stone from the one area to the other. And he came down very strongly on the side of human transport. He said, "Human beings must have carried the stones from Pembrokeshire to Stonehenge."
Since then, the debate has raged on. We're standing on quite a big tour at the moment, which is one of a little group of tours called Karin Esme. Beyond Owen, but this tour is a classic example of a of a rock outcrop made of dolerites that's been dramatically affected in the Ice Age, both by the work of glacier ice because the ice flowed over this area on two or three different occasions, most recently about 20,000 years ago. And so we can see when we look around here, many traces of glacial action on the rock surfaces. And also, there's a complete jumble of rocks here. This is a tour that's been almost literally smashed to pieces by ice action and also by the work of frost. Cry grafa lan is the name of this little crag behind me because this is one of the key locations in the in the discussion at the moment between archaeologists and earth scientists as to the mechanisms of rock removal and transport.
We'll go down now to have a look at this crag in a little bit more detail. In this area, on the tip of the spur, there are some lovely examples of the way in which the rock surfaces have been rounded off and abraded and smoothed off, both by ice action and by meltwater. And you can see, see it very clearly here in some of these areas. The pebbles and the sand and gravel and so on that was carried in this meltwater has rounded off what might previously have been quite sharp and jagged edges. So the evidence of glaciation and powerful glaciation in this is very strong indeed.
The two geologists who worked in the site, Robert Hicks and Richard Bevins, have claimed that they are able to identify to within a few square meters the area that some of the rocks at Stonehenge have actually come from at this location. They discovered a very peculiar type of fabric which is rather unique in rhyolites. The rock here is what's called a foliated rhyolite, which means it's got very, very tight bands in it which are running more or less in this direction. And they found that there was a very peculiar structure in the samples that they looked at, which they've called a Jovian fabric. And they gave it this name because it reminded them of some of the patterns on the surface of Jupiter. And they said there was a very close match here between sample number 8, which they took from somewhere around here, and this material at Stonehenge.
No two samples from Stonehenge and from Rowell are identical. So the accuracy of the claim has got to be questioned on that basis. If they have taken a sample from a foliated layer and analyzed that sample, it must also be true that the layer that they sampled has to outcrop over many other locations in this neighborhood. So there's no real reason why they should claim that they have sampled to that degree of accuracy. So I think that claim does have to be questioned at a fundamental level.
There was a very large pit excavated here, extending right the way up the slope here, behind that big stone and round the corner and out into the towards the center of the valley. So at a very extensive area, hundreds of tons of material were taken away and have subsequently been put back again. The full sequence at Draw Savelle in from examinations of the excavation pits when they were open or something like this. At the base, we've got heavily eroded bedrock and also broken debris that's come tumbling down from the crowd, probably at a time of very cold climate. Above that, we've got till, the glacial deposits, which are very nicely exposed in the middle part of the dig. Meltwater deposits or fluvio-glacial deposits, sands and gravels and boulders and cobbles of all sizes, which have been heavily abraded by the move of turbulent water carrying them down into the valley. And then above that, we've got some areas of iron staining to do with the position of the water table, probably in later of years after these sediments were laid down. And then above that, we've got a thick layer of Kalu via, more slope deposits. Some of these deposits have got a lot of stones in them, broken debris of all sorts, and other material is much, much finer. It's a sandy, silty material, sometimes quite heavily stained by soil-forming processes. And then on the very top of the sequence, on the ground surface, we have the modern soil. So it's quite a complicated sequence, but it's very, very similar to the sequence that we find right around the Pembrokeshire coast and also an inland sites as well. And none of this shows any evidence at all of human interference.
One of the first things they discovered when they started digging was this very large stone. Thought first of all to weigh about two tons, but if you measure it carefully, it it clearly weighs about eight tons, which is far, far bigger than any of the blue stones at Stonehenge. They persisted in believing that this was actually an author stat, so-called, that had been quarried from the rock face here. And since 2011, they've elaborated this theory by talking about all sorts of other things, including so-called railway tracks here along which the stone is supposed to have been slid. They pointed to some damage on the rock surfaces down below where they assumed that other rocks had actually been rolled or or slid over the rock surfaces and that caught some some damage in the process. And they've also described pillars or rocks which are actually placed underneath this big stone in order to hold it up and in order to make it easier to to pull it away.
Well, the problem is that when you look at these little features in detail, the conclusion has to be that they are entirely natural. There's no sign at all anywhere around this stone of any quarrying activity. There are no wedges, there are no levers, there are no hammer stones, there are no chips of rock where the rock might have been chipped away to make the Stoneham in which smaller. There's no antler picks. There is no sign of human activity anywhere around here.
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I'm standing now against the rock face at Rowell in. This is what the archaeologists refer to as the quarrying face, which is an interesting term because of course that assumes that the face itself has been created by human beings, by the quarrymen in the Neolithic. When the archaeologists arrived here in 2011, there were gorse bushes everywhere, there were brambles and a huge amount of rockfall debris. So the rock face as we see it today is in a sense created by the archaeologists because what they've done to it is they've simply cleaned it up by taking away everything that obscured the face as they wanted to see it. The rock is in a very, very fragile position, which explains why so much material has come crashing down from the crag up above and accumulating at the bottom here in this great layer of debris. Large rocks of all shapes and sizes, a lot of smaller debris and very fine-grained material as well, filling in all the gaps. There is no sign here, as far as we can see, of human involvement or interference in what has been a very long history of natural processes with this accumulated rock debris just building up your over year over year for something like 20,000 years since the end of the last glacial episode.
There are three other features that can't be examined any longer because the excavation pits have been filled in. The first one is a so-called platform. It's a big flat stone, and the archaeologists refer to this as being a transshipment point from which author stats were transferred onto rafts or sledges and taken away into the distance. The second one is a revetment, so-called, or a sort of quay side, which they claim was built up with stone walling and so on, again representing the point at which stones were loaded onto sledges or rafts for transport away. The third one is a trackway, which they claim runs away from the revetment down the valley, showing the route along which the sledges or the rafts were hauled by the Neolithic quarrymen. We, as geomorphologists, have actually seen no sign of any human involvement in the creation of these features. We think they are actually figment of somebody's imagination, and I think they've been given labels as engineering features simply in order to bolster up the hypothesis that this is actually a quarrying site.
There's a long history of human occupation of this site, but what we do need to ask is whether any of it actually relates to quarrying activities. We've got a vast range of radiocarbon dates now collected by the archaeologists. They date from about 9,000 years ago in the Mesolithic right through to the Middle Ages. This is a perfect site for intermittent occupation by hunting parties who were looking for fish in the river, for example, hunting animals in the in the thick woodland, and maybe visiting this site to pick up little sharp-edged pieces of rhyolite which they could use as tools for skinning animals and butchering animals and so on. My view, and the view of many others who visited this site, is that it's nothing to do with quarrying. It's simply to do with the fact that there were there were nice sharp-edged fragments of rock that could be used here in the disposable sort of fashion.
We need to ask this question: why would anybody want to come and quarry for rather soft and broken up rhyolites in a place like this? The truth of the matter is that if you were a Neolithic tribe wanting to take stones from North Pembrokeshire to Stonehenge, why would you bother to come down into a very narrow valley like this and try to hew the rock from a rather broken, heavily fractured crag in a very inconvenient place down on the bottom of a valley floor, when all you actually needed to do if you wanted to collect rocks were simply wander about in the landscape and pick them up because there are glacial erratics of very convenient shapes and sizes dotted around by the thousands all over the landscape in this area.
If you want to find out anything more about the debate concerning the Stonehenge bluestones, or about some of the evidence that we've shown in this video, or about the conclusions drawn, you can take a look at a new book recently published called "The Stonehenge Bluestones," which is available in all good book shops.
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