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Sunday, 10 February 2019

Were some Stonehenge sarsens transported by ice?


Once upon a time, prior to the Anglian Glaciation, might there have been a landscape something like this to the west of Stonehenge, with abundant sarsen stones available for transport eastwards by overriding ice? Please ignore the sheep.........


Christopher Green's map of sarsen distribution.  Sarsens are not completely absent from the chalklands west of Stonehenge, but they are rather rare.  Green says that there is no record in south Wiltshire of any sarsen stone more than 5m long.  he also says that there are only 11 sites where two sarsens lie close together, and just 28 sites where single sarsens are found.  Could it be that the majority -- and maybe all of the big ones -- were picked up and moved eastwards by overriding glacier ice, and dumped (together with the bluestones) in the vicinity of Stonehenge? This is a question which is hardly ever asked, since it has been widely assumed, since the days of Richard Atkinson, that the 53 sarsens used as pillars and lintels at Stonehenge were carried from the Marlborough Downs and the Vale of Pewsey, c 32 km to the north.  That assumption has never been proved, and of course it is nowadays openly questioned, even by many archaeologists.

But on this blog we are in the business of asking questions, and trying to provide answers to some of them........

So what is the evidence on the ground?

Map of recorded sarsen locations in southern England.  From Ulyott and Nash 2006.  
Click to enlarge.

As we can see from this map, the chalk downs to the west of Avebury and Silbury Hill have high concentrations of surface sarsens -- and as Steve Marshall points out in his fine book called "Exploring Avebury", the sarsen drifts were far more extensive in 1885 when Rev Smith did his original survey.  But on the downs west of Stonehenge there are just a few clusters and other occurrences of single stones.


A reconstruction by David Field of Phase 1 of Stonehenge, with just two large sarsens erected as monoliths, and a great litter of other sarsens just lying around, waiting to be collected up......

As I have mentioned on a number of occasions, David Field has suggested that many of the sarsens used at Stonehenge were picked up in the immediate vicinity.

See this post:
https://brian-mountainman.blogspot.com/2013/08/where-did-stonehenge-sarsens-come-from.html 

In an Email exchange with Edward Pegler, David said:

.....There are quite a few smaller sarsens around on Salisbury Plain and some were indeed incorporated into long barrows. Knook Barrow had a cairn of sarsen, Arn Hill long barrow had a standing stone, Corton long barrow had a ‘massive boulder’. Cunnington said that sarsens can be found all over the downs beneath the turf and that farmers plough them up in the area north of Stonehenge (Larkhill west of barracks) from time to time. There is a long barrow there (Figheledean 31-see attached) with three in the ditch and another six in a line where they were disturbed when the military built a rifle range. Quite a few around Bulford, aside from the Cuckoo stone (attached), Togstone and the one in the river, there is one from a round barrow that had a burial beneath an ‘immense sarsen’ and a number of others noted on early maps. One of the King Barrows formerly had a sarsen circle or kerb around it. Today the Imber to Chittern valley has many small boulders and cobbles on the slopes and in the stream and presumably many more were once visible when the area was cultivated.

As you rightly say, none of these are large in trilithon terms, but then neither are any of those on the Marlborough Downs where they rarely exceed a couple of metres – three at the most. The big ones there seem to have been reserved for the Cove and blocking stones at West Kennet. The survival of many on the Marlborough Downs can be put down to lack of agriculture (it’s a degree colder there than Salisbury Plain) for they get in the way of ploughs and soon get cleared and broken up or buried. You can trace the clearance process at Overton/Fyfield from undisturbed sarsens on the summits, to the clearance to field edges to create ‘Celtic’ Fields in the Bronze Age on the upper slopes, to the development of lyncheted fields that cover the sarsens around the edge in the Roman and medieval periods on the lower slopes. If the same processes took place on Salisbury Plain where there was widespread agriculture in Roman, medieval and post-medieval times there will be many other sarsens buried beneath the field lynchets.
So where did the big ones come from?”

Much of interest there -- but I was especially taken with this:
"Today the Imber to Chittern valley has many small boulders and cobbles on the slopes and in the stream and presumably many more were once visible when the area was cultivated."

David does not say whether he is talking specifically about sarsen small boulders and cobbles, or about stones of other lithologies, and potentially from other locations.  In other words, might they be glacial erratics, and might there be traces of till in the Imber- Chitterne valley?  From the old photos, the valley looks interesting......  does anybody out there know anything about it?

On the map that follows, there is a clay pit marked, south of Chitterne.  I'n not sure of this, but since Heytesbury and Boles Barrow are not very far to the west and north-west respectively, this might be the claypit mentioned by Kellaway in one of his papers, when musing on the origin of the Boles Barrow bluestone.  Boles (Bowls) Barrow lies 3 km to the SW of Imber.


A little film about the ghost village of Imber, abandoned in 1943 so that it could be used for training in house-to-house fighting, prior to the D-Day landings:


Of course, if we are to argue that some sarsens might well have been transported eastwards from their source areas by overriding ice, we need to examine the characteristics of the sarsens and decide whether any of them bear signs of glacial action -- faceted surfaces, smoothed surfaces and striations, fractured faces etc.  I'll do another post on this.......











2 comments:

  1. David Field, in one of his co - authored books on Wiltshire/ Wessex since 2016 days that the Stonehenge sarsen monoliths may have 2 or more provenances, based on their colour and appearance.

    I have commented on other Posts about the clay pit South of Chitterne. I attended a guided walk which included Dave Field fairly near that clay pit.

    It is certainly interesting to ponder about glacial till etc along that Imber to Chitterne valley ( and below Chitterne)

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  2. There are two basic sarsen categories, as described by the geologists. But within those two groups there are lots of variations, so there is a strong chance that the Stonehenge sarsens were either picked up locally, having come from multiple locations, or else fetched from multiple locations not too far away. The recent papers by Nash, Ixer and Bevins are relevant -- covered in other posts on this blog..

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