Getting the good stuff. Sarsen #7.

How do you go about getting stuff?  I mean good stuff, not any old stuff.  Good oil that won’t ruin your engine.  Good netting that won’t rot.  Good brushes whose hairs won’t fall out.  Good shoelaces that won’t snap.  Good valves that won’t leak.  Good washers that will hold.

Maybe you rely on brand names, recommendations, or reviews.  Or look for kite marks or British Standards.  Perhaps you just buy what you always buy.  If you have a choice of, say, apples, most likely you use your senses and experience to make a selection.  You know what rotten apples look, smell and feel like.

I have been thinking about procurement – getting stuff – because of the problems that I’ve had recently, with wood in particular.  How to go about finding good stuff, not just any old stuff.  And how archaeologists can think about how people found good stuff in the past, when the landscape, ecology, and natural resources familiar and available in prehistory are so different now.  Not only good stuff – what about just making do with what you have got?  So I went for a walk, to think about where the Burderop Down sarsen stone came from.

Here’s the archaeological background.  During the 1970s Chris Gingell (1980, 1992) carried out fieldwork across parts of the Marlborough Downs.  At Burderop Down, the excavations revealed spreads of sarsen stone which were interpreted as working floors; the waste left over from the production of saddle querns in the later Bronze Age.  Sarsen boulders cleared from the surrounding fields were gathered together and shaped, by knapping, to make the querns.  The querns, “so common on Wessex sites”, were then distributed around the countryside (Gingell 1980, 215).

Now a lot of sarsen was recovered during these excavations.  A lot.  Last time I added up the Wiltshire Museum catalogue entries I counted nearly 400 bags of sarsen pieces from the Burderop Down dig.  The site is located on the north-facing slope of the chalk scarp on the northern edge of the Marlborough Downs, just to the east of Barbury Castle.  It is about 6km away from the best known areas of sarsen stone to the south, on Fyield Down for example, but well within the general geological range within which the rocks are found.

What evidence is there now for sarsen stone on Burderop Down?  Where did the people making those querns get their rocks from?  Good, fine-grained sarsen stone that could be broken in controlled ways to make the characteristic shapes of saddle querns.  And other types of stone, like flint, to make pecking stones to prepare the quern surfaces for crushing cereal grains.

Having left the car in the Barbury Castle car-park, the walk starts back down the lane for 200m before turning off to the footpath heading east on the 260m contour line.  Almost immediately comes the first sign that there is sarsen in the area:

Richard Jeffries memorial stone

A standing stone, looking out over the valley towards Ashbury and White Horse Hill there on the horizon.  The megalith isn’t prehistoric, though.  It’s a memorial stone, commemorating local author Richard Jefferies and poet Alfred Williams.  The memorial is a great example of how variable sarsen stone can be.  In this one boulder there are areas of fine-grained saccaroid sarsen, rough areas full of fossilized root holes, and a range of colors, because of the variety in the Tertiary deposits that were cemented together to make the sarsen.

Jefferies memorial stone

Walking along the footpath towards Burderop Down, there’s not much to suggest that there was ever much sarsen stone lying about here.  Here’s a piece in the track:

sarsen in the track

but there isn’t any more to be seen around.  And it’s only another 600m before we reach Chris Gingell’s sarsen working site, in the grassy area in the bottom right of the next photo.  That round earthwork, with those scrubby trees, is a large disc barrow first excavated by Passmore in the 1920s and again by Gingell in 1979.  Behind it is the sarsen quern manufactory.

Burderop Down disc barrow

I love the arguments between visitors, carried out in graffiti on the adjacent sign board, about what the disc barrow earthworks are thought be be:

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Hardly any sign of sarsen at all, until you look closely at the upcast from the molehills that are dotted about:

There are scrappy fragments here and there.  Unlike villages south of Broad Hinton on the Winterborne, or Avebury, or the Kennet valley villages for example, there aren’t even any sarsen gateposts to keep up the morale of the dejected sarsen-seeker.  It might look beautiful, but it doesn’t look like there’s any sarsen left on Burderop Down.

Burderop Down panorama

But just a couple of hundred metres east, and look, what’s that in the hedge line? A sarsen!  From here, following the footpath south-east, there are some stones – dragged out of the cultivated areas and left at the field edge.

sarsen stone

As well as the occasional sarsen – and I mean very occasional – there is plenty of other agricultural rubbish, broken up chalk hauled up by the plough, and flinty bits.  Sure, you get similar rubbish around the farms a few kilometres to the south, but there you also trip up over all the sarsen.  Here you have to hunt it out.

The path continues south-east over the Holywell chalk bedrock where, at a point just west of Ogboune St George, it meets the Smeathe’s Ridge bridleway.  Turning north-west, I headed back towards Barbury Castle in the afternoon sun.  One sarsen boulder buried in the footpath was the last piece I would see until I found a grey wether impersonating a lamb hunkering against the fence line.

sarsen stone

There are still vast quantities of sarsen only a few kilometres to the south, even though people have been taking that stone for 4,500 years.  Why isn’t there more lying about here around Burderop too?  Where did all the stone for the quern manufactory come from?  Has it all been used up, moved, and taken away?  And when did that happen?   It’s a fascinating topic.  Selecting raw materials for certain qualities, using the stone, leaving the remains.  Now, the hillsides look so different, cultivation that began in prehistory never stopped.

I failed to find the good stuff on this trip.  The experience tells me that different things happened to sarsen on this patch of the Marlborough Downs, only a few kilometres away from sarsen around villages like Fyfield, Lockeridge, Clatford, Manton.  It will be fun to tell those different stories.

Rockley Downs

Gingell, C. (1980) “The Marlborough Downs in the Bronze Age: the first results of current results.”  In Barrett, J. and Bradley, R. Settlement and Society in the British Later Bronze Age  Oxford: BAR British Series 83 (i).

Gingell, C. (1992) The Marlborough Downs: a later Bronze Age Landscape and its Origins. Devizes: Wiltshire Archaeological and Natural History Society Monograph I.

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This is how Stonehenge used to look

When the huge sarsen standing stones were raised at Stonehenge around 2,500BC, they were pale and sparkly.  The natural, weathered, grey-brown surface had been knocked off many of the stones to create just the right shapes and surface effects.  Much of Stonehenge would have looked almost as white as the chalk dug out of the foundation pits for the stones to stand in.

dressed sarsen stone

Two years ago I spent a day out in north Wiltshire, filming with a team from October Films.  We spent most of the time amongst recumbent stones talking sarsen, but I also did a little bit of stone dressing for them (on a piece of waste sarsen on a local farm, collected up with lumps of hardcore, disused fencing, empty feed containers and other agricultural detritus).

The team used the footage in episode two of Stonehenge Empire (google it, mixed reviews but with some good bits plus much coverage of the awesome Hidden Landscapes project).  (And you can see me dressing a piece of sarsen in this cool English Heritage video, “People Moving Stones“.)

Two years on, and the dressed patches are gleaming.  The rain has washed away all the loose grains.  Lichens have yet to colonise the broken surface of the dressed stone.  Two and a half thousand years ago, sarsen stones at Stonehenge gleamed like this.

How long did it take for the weather to bring back the grey-brown, for the lichen to grow?   Two years is too soon.   Twenty?   Two hundred?  The fascinating report on the analysis of a laser scan carried out at Stonehenge in 2011 makes great reading.  Even after 2,500 years, it was possible to record and interpret the dressed surfaces on sarsens and  bluestones.  Some effects of dressing and shaping have lasted all this time.  But not the colours.

I wonder what stories about Stonehenge were passed down the generations.  The monument we know today has had an extraordinarily long prehistoric life.  How long was it before the gleaming whiteness of the sarsens was forgotten, or the journeys of the bluestones, or what it was like to make the Avenue?  When the axe carvings were made on the sarsens, Stonehenge was almost 1,000 years old.  Had the sarsen weathered back by then, did the little Bronze Age axe head shapes stand out all white from the surrounding grey-brown?

Given that two years is no-way long enough, an archaeological experiment to investigate changing colours at Stonehenge from a phenomenological perspective is probably not on the cards.  More’s the pity.  But take it from me – that’s how Stonehenge used to look, for a while, anyway.

Operation Stonehenge episode 2

The forecast for the December day made it look cold and grey outside, even though it was still dark at 6am.   In the brightly-lit farm kitchen the sizzling bacon smelt fabulous.   We all tucked in – bacon rolls, bowls of cereal, mugs of coffee and tea.

As daylight broke, we drove up towards the Down.   In Pickledean, the cameraman set up gear including a crane for overhead shots and a bed for controlled panning at grass level, while the sound guy complained about the rustling made by synthetic fibres of modern outdoors clothing.

sarsens

Sarsens

Much ambling about the stones later, and talking, and filming, and more talking, and it was time for lunch.

In the afternoon, the sky grew ever more grey as the sarsen slowly grew more white.  This is what they had really come for.   Action shots; noisy shots; things that look good on telly.   Technology; experience; knowledge; clever prehistoric people who did amazing things with simple materials.   Other things that might surprise the general viewer – who knew that bits of Stonehenge were once gleaming white?*

Worked sarsen

Worked sarsen

A day’s work for a few minutes of a TV programme.   Possibly the hardest thing I’ve ever done yet.   It’s easy to extemporize on a subject; less easy to stick to a story line and give the Director exactly the words and style of delivery he’s after with only a few minutes of instruction.   I think I’d do it much better if I was asked again.

You’ll be able to watch it via the BBC iplayer for a bit, and no doubt there’ll be repeats.   Operation Stonehenge, episode 2, was broadcast on BBC2 on 18 and 20 September.

* all of the Stonehenge sarsens, according to the Production team, rather than just the ones that were worked, and the ones that didn’t have too much brown iron oxide running through them.

Sarsen #5

Blogging about what archaeologists can learn from toolmarks left by the sharp edges of metal tools – and how ephemeral those marks can be – reminded me of one of my all-time favourite archaeological features.

Last Saturday I was in Avebury to see what a pasture to the north of the Manor House would be like for a Young Archaeologists’ Club activity.   Lovely earthworks, probably medieval, quiet and secluded without being remote, and great views out to Windmill Hill and back to the church and manor – so it’s perfect for a surveying session.

The weather was holding up.   Heading east out of the village up Green Street, I was reminded just how enclosed, protected, encircled, claustrophobic, it feels inside the prehistoric earthworks of the huge henge monument.   Green Street – the herepath on the way to Marlborough – felt faintly like an Anglo-Saxon military way as runners participating in the Marlborough Downs Challenge plodded uphill and teenagers working on their Bronze Duke of Edinburgh Award splashed down.

I was heading for the Valley of Stones and the open-access area of Totterdown.   Crossing the Ridgeway, the rise is broached at 236m above sea level on Overton Down and three landmarks come into view; the remains of a barrow in a cluster of wind-blown hawthorns, the Experimental Earthwork hung with more stunted trees, and another barrow crowning the south-east facing spur of the hill.   The first hint of what’s to come appears in the light scattering of grey wethers on the slope below.

The view to the east from the Ridgeway, over Overton Down.

The view to the east from the Ridgeway, over Overton Down.

Having enjoyed the best part of three hours amongst the sarsen stones in a small area around Delling, taking photos and gathering data, it was time to head back down to Avebury.   Dark downpours of freezing rain had been interspersed with bright, blowsy sun.   Sometimes it felt heavenly up on the heights – sometimes it was impossible to imagine just how the prehistoric farmers had teased life out of their cold, wet arable fields now shadowed under sheep-run pasture.

But I could hardly take the short route back and not visit this:

The polissoir - a grinding stone for polishing stone axe heads - one of a number on the Downs but the only one with this variety of toolmarks.

The polissoir – a grinding stone for polishing stone axe heads – one of a number on the Downs but the only one with this variety of toolmarks.

This magnificent sarsen stone is a polissoir, just to the east of the Ridgeway at grid reference SU 1283 7150.   It’s a large version of the grindstones and honing blocks I use to sharpen my steel axe edges – but it was used in the Neolithic to put smooth surfaces onto stone axe heads.   Sarsen is a sandstone: not so finely grained that it won’t rip off material from an axe head; but nicely regular and evenly textured to work down a flaked surface.

Not every Neolithic axe head was ground and polished – and some were only partially worked –  but those that were have beautifully finished surfaces.   You get a hint of this if you touch the dished corner of the polissoir, run a finger along the grooves, and stroke the glossy surface which you can see shining in the sunlight.

This polissoir has probably lost part of its prehistoric grinding surface.   It was split by the stone cutters who used to work this area, and who removed the whole of the west side of the stone, taking some of the worn area with it.   Before being used as a grinding bench it had perhaps been a standing stone.   Excavations in 1963 revealed the remains of a pit at the northern end of the stone, interpreted as a socket in which the sarsen had once stood (Fowler 2000:66-8).

This is not the only polissoir in this area to have been one thing, then another.   For example, one of the sarsens used to construct the chambers of the West Kennet long barrow (no more than about 4km away to the south-west) bears a similar dished, glossy grinding area.   There is a portion of a polissoir, with a shallower but still glossy surface, incorporated as a block in the farmyard wall at North Farm, West Overton (just over 2km to the south).

The stone tools ground and polished on this sarsen have left their marks.   Knapped axe heads, like the flint one below made recently by Karl Lee, lost their flake scars and ridges; but in the process of becoming smooth, cut and marked the sarsen.   For such a hard, tough stone, these cuts are deep.

Flint axe head knapped by Karl Lee - Neolithic form, 20cm long.

Flint axe head knapped by Karl Lee – Neolithic form, 20cm long.

Fowler, P.J. (2000)  Landscape Plotted and Pieced   London: The Society of Antiquaries

Sarsen #4

I have finished the two facsimile sarsen hammerstones that I was making for the Stonehenge Visitor Centre Education Team.

Small quartzite sarsen hammerstone, 2013

Small quartzite sarsen hammerstone, 2013

The smaller hammerstone (Facsimile 1) is an effective pecking stone.   A “dimple” in the cortex of the quartzite nodule became part of the stone’s grip; by accident, not design.   The larger hammerstone (Facsimile 2) is considerably heavier and has to be held with two hands.   It is good for attritional work, removing grains from the surface of a saccaroid sarsen stone.   The last thing I did with it before packing it up was to cut a channel along the surface of the stone that I was shaping.

Large quartzite sarsen hammerstone, 2013

Large quartzite sarsen hammerstone, 2013

I made these two objects with a mix of “modern” and “prehistoric” techniques: that is, I quickly removed material from each original nodule using some of my iron mason’s tools before finishing them by using them as hammers on saccaroid sarsen.   This means that I can’t use data from them in my research to understand how the prehistoric tools got the way we find them.   But it is interesting to do the numbers.

As expected, both nodules lost weight as I worked on them.   This seems a silly thing to point out.   It is important, however, for a number of reasons; not least because archaeologists and curators have tended to describe and present the excavated artefacts as though they all represent the same finished state.   Tools change during their life, however, and this change can tell us things about how they were made and used.   The small nodule weighed 536g – the hammerstone weighs 444g.   The large nodule weighed 2149g – the hammerstone it became weighs 1818g.

It is very difficult to describe the shape of these irregular objects in a meaningful way – a way that can be replicated.   When I analysed the Stonehenge hammerstone assemblage (a forthcoming publication), I used a technique developed and used in geology.   It makes it possible to document and follow the changing shape of the nodules as they become hammerstones.

The small nodule’s shape was “oblate spheroid”.   By the time I had finished, the hammerstone shape still fell into this class, but now at the less elongated and ‘fatter’ end of the scale.   This reflects how material was knocked off the circumference of the small nodule, making the tool more rounded than the nodule.

The large nodule’s shape was “sub-equant spheroid”.   On completion, the hammerstone shape still fell into the same range of this class.   This is a reflection of the blocky shape of the un-worked nodule which I chose specially for this quality; and the way that I concentrated on using one end of the nodule for hammering.

Had I continued using the hammerstones, their weights shapes would have changed.   As it is, they are now with the Education Team and will take their place with the rest of the objects in the new handling collection.

Sarsen #3

I’ve been working on two facsimile tools for the Education Team’s object handling collection at the new English Heritage Stonehenge Visitor Centre.

Amongst a whole range of replica and facsimile artefacts, the Team needs a hammerstone; a copy of one of the tools interpreted as hammers or mauls used to shape the stones at Stonehenge.   This copy will be handled by visiting school classes so that they can get a feel for the archaeological examples that will be on display.   I’m making two (different size and weight so the Team can chose which to use with different-aged children).

The hammerstones are almost exclusively made of quartzite sarsen – nodules of this hard material that have been beaten and bashed until they break up or, less commonly, become rounded and smoothed through attrition.   It takes hours and hours of use for a quartzite sarsen nodule to reach this state.

Perhaps this is a good time to define “replica” and “facsimile” artefact.

The words mean different things to different people, but I choose the following definitions:

Replica – an object made with the techniques, tools and materials known or thought to have been used at the time of the original exemplar.

Facsimile – an object made using modern (or a mix of modern and historical) techniques, tools and materials to create something that looks like the original exemplar.

I am making facsimiles, rather than replicas, because I am using some modern techniques and tools in the process.   This is necessary because of the long time that it would take to do the job just by working a piece of saccaroid sarsen with the nodules – I would be unlikely to meet my deadline!

The process involves removing some of each quartzite sarsen nodule with an iron mason’s pick and punch to remove the more angular parts and some of the “case-hardened” cortex, before using the newly-broken surfaces to work a piece of saccaroid sarsen in the prehistoric manner.   This action then ‘finishes’ the surface of the hammerstone.

Small quartzite sarsen nodule, 2013

Small quartzite sarsen nodule, 2013

The first nodule was a small piece of yellow-brown quartzite sarsen that appears to have been broken from a larger piece.   It had cortex on one side and showed its grey interior colour on the broken side.   It weighed 536g.   The second nodule was darker in colour, also showing its grey interior where it had been broken in the past.   It weighed 2149g.

Large quartzite sarsen nodule, 2013

Large quartzite sarsen nodule, 2013

Both were collected from a farm on the Marlborough Downs.   They were taken from modern clearance piles of waste stones and other farm rubbish such as old concrete fence posts.   This was to ensure that they weren’t taken from one of the designated or protected areas of the farm, or from an archaeological context.

I shall post photos of the finished objects when they are done.

Sarsen #2

Before I write more about sarsen objects, sarsen tools and sarsen working, I thought I would summarise sarsen geology.

Sarsen is a silcrete sandstone, formed through the surface or near-surface silicification of other deposits.   In Wiltshire, sarsen stones probably represent locally-silicified zones in the 4m to 5m thick Paleocene deposits overlying Cretaceous chalk; perhaps the Reading Beds or upper Bagshot Beds.   The sand, silt and mud of these layers are thought to have been cemented by water-borne silica, aided by silica-rich plants growing at the time.  It is possible that this silicification happened rapidly, over some 30,000 years or more.   The cementation was, however, uneven.   As the Paleocene deposits eroded, the scattered silicified patches were left on the surface.   You can see these most clearly on the Marlborough Downs, in the Fyfield National Nature Reserve, where sarsen stones lie sleeping across the beautiful landscape.

Archaeologists tend to talk about two types of sarsen in Wiltshire.   The most common – and the one of which the standing stones at Avebury and Stonehenge are comprised – is “saccaroid” sarsen.   The less common is “quartzite” sarsen, which appears in the archaeological record as the principal hammerstone material at Stonehenge.

Saccaroid sarsen

Saccaroid sarsen

Saccaroid sarsen’s fresh break is white to grey in colour.   The name is derived from the similarity of the fresh break’s surface to broken sugar loaf.   It is made up of quartz sand grains and is usually found in large boulders.

quartzite sarsen

Quartzite sarsen

Quartzite sarsen is usually a darker grey-brown colour, comprising much finer grained, clayey silts.   It is usually found as nodules up to c. 60cm diameter.   Fossils are rarely found in sarsens; but root voids and silicified roots are common, part of the characteristically  gnarled look of much sarsen.

These two distinctions are useful although they mask sarsen’s subtle variations.   For example, pebbles can be found cemented into the mix; varying amounts of iron oxide stain the stone red-brown; the cementation varies, leaving some grains of sand more-or-less well “glued” together.   The “case-hardening” effect brought about by atmospheric weathering also affects texture and hardness.   These variations can be found between stones and within individual boulders.   And the shapes and sizes of sarsen stones vary immensely; from smooth, rounded boulders to irregular, contorted, pitted blocks.

Geddes, I. (2000, 2003) Hidden Depths: Wiltshire’s Geology and Landscapes   Bradford on Avon: Ex Libris Press

Summerfield, M.A. and Goudie, A.S. (1980) “The sarsens of southern England: their palaeoenvironmental interpretation with reference to other silcretes”   In Jones, D.K.C. (ed) The Shaping of Southern England   Institute of British Geographers Special Publication 11   London: Academic Press

Sarsen #1

I haven’t posted for a while, because I’ve been preoccupied with preparations for a forthcoming project.   This is a piece of work that has been on the back-burner since 2010 when I completed my Masters thesis on the Stonehenge hammerstones – more on those later.

Sarsen stone is a strange and wonderful rock, and I shall write about its geology and mythology in the future.   In Britain there is a family of sarsen stones, conglomerates, that can be found in a band from Wiltshire all the way to Essex.   In Wiltshire, sarsen stone is usually made up of quartz sand in a siliceous cement.   In Hertfordshire, much larger pebbles are cemented together – known as “puddingstone”.   In Essex the stone is better known for its high iron content.

Perhaps the best-known sarsen stones are those that were used to build the prehistoric monuments of Stonehenge and Avebury.   Whatever form it takes, it is jolly hard stuff – but it has its uses.   For example, in Wiltshire sarsen has been used for building and street furniture, and in Hertfordshire there are objects made of puddingstone.   Visit Verulamium Museum and you’ll even see a rotary quern made of puddingstone.   So it is possible to work and use sarsen stone, and sarsen has been turned into objects throughout the past 4500 years or so.

There is a great deal to learn about how the techniques and tools of sarsen working have changed over time.   Much of our understanding of prehistoric sarsen working is theoretical; we have seventeenth- and eighteenth-century accounts of sarsen breaking; and the skills of the modern sarsen industry were lost when new materials and techniques were adopted for road building.

I recently spent a sunny afternoon starting to prepare some tools for prehistoric sarsen working.   These tools vary depending on their purpose and have their own chaine operatoire from procurement to abandonment.   Here are some photos of an object that I made to trial some of the sarsen working tools – an axe carving in a piece of sarsen stone.

Arreton type axe and sarsen stone

Arreton type axe and sarsen stone

Axe carving in sarsen

Axe carving in sarsen