Anglo-Saxon CSI: Sittingbourne


Happy birthday x-rays!
November 8, 2010, 11:19 pm
Filed under: Conservation, news

Seeing the Google doodle today I see that x-rays are 115 years old today.  Happy birthday x-rays!

Google doodle celebrating 115 years of x-rays

X-rays can be really useful for conservators working with most any type of material, but particularly archaeological finds, and they have been used extensively during the work in the CSI: lab.  You can read more about the use of x-rays in an earlier post.  This post, however, is a gallery of just some of the x-rays that have been taken for objects in the lab – most are swords.

Sword from grave 158 with copper alloy ring and knife fragment

X-ray of block-lift containing a sword and knife

X-ray of block-lifted sword containing an interestingly detailed silver buckle and pattern welded blade

Middle of a sword from grave 182

Tip of the sword from grave 182

 

X-ray image of Anglo-Saxon brooches and buckle

Archaeologists are baffled by this x-ray

OK, the last one isn’t one of ours, but it’s pretty cool.

If you want to find out more about x-rays have a look at the links below.

English Heritage Guidelines on the X-radiography of archaeological metalwork

Wikipedia x-rays

Also, kind of related to x-rays and bones (…well bones at least), is Paul Evans’ blog ‘Osteography‘.  I noticed this advertised in the corridor at university and it appears to be quite interesting, so well worth having a look at.  Have a look also at his earlier project, ‘Origin 09‘.

click to enlarge

 

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Fingerprints…
October 27, 2010, 8:48 pm
Filed under: Conservation, Grave Objects



Knife before treatment

This iron knife from grave 168 has been cleaned by volunteer Shirley.  The grave was that of a male and other finds included a shield boss with fittings and a second knife.

Although quite a small find, the object has presented several areas of interest for the volunteers, conservators and archaeologists.

As mentioned in other posts on this blog, there was very little bone found due to the high acidity of the soil.  In some cases volunteers have managed to find evidence of bone attached to some objects and this find is one such case where this has occurred.



The thumbprint in the knife discovered during conservation

Extensive areas of bug pupae cases were also found during the investigative conservation process of this object.  If identified, this evidence may help determine what time of the year the person died and the grave was made.

Yellow-coloured patches uncovered in the soil suggests the presence of leather, perhaps a sheath or handle for the knife or maybe even an item of clothing that was in close contact with the object.

However, perhaps the most exciting evidence found on this object is the possible fingerprints of the man preserved in the corrosion products.  The presence of such evidence suggests that the knife was being held by the person within the burial.

For anyone not familiar with conservation and the importance of carrying out such work on objects like this only need to take a look at an object such as this.  What might seem a fairly standard and pretty uninteresting object on the face of things has proved to be an extremely valuable and interesting object that has given us a great deal of interesting information.

This type of object is also a small find that might otherwise not have been worked on.  As the volunteers and conservators involved in CSI: Sittingbourne are working on nearly all the finds from the graves there is a greater ability to understand and work on these finds to find out even more information than would be possible in other circumstances.  This is an excellent aspect of this project



Mystery Object update…
May 22, 2010, 11:34 am
Filed under: Conservation, Grave Objects

This isn’t really new news as the image was posted up a couple of months ago, but I completely missed it!

Following a topic about the CSI: “mystery object” on Ða Engliscan Gesiðas (The English Companions) discussion group forum, “the society for people interested in all aspects of Anglo-Saxon language and culture”, this image was posted by Æscwine (aka John Wills).

Suggestion to the likelihood of the "mystery object"

Here is John’s theory and what he had to say;

“Looking at all the possibilities I think we can discount a brooch as a leather and wood backing on a brooch does seem right at all. Why would a piece of horse tack have wood on it? If it was a scabbard or sheath fitting then where is the weapon? If it is a “plain” shield decoration or repair where is the shield boss and the associated rivets?

It looks to me to be part of a belt pouch, I suggest that it was pouch similar to the Sutton Hoo purse, i.e. one with a “hard lid” with a soft bag behind. If this is the case then the lid was made of a thin sheet of wood covered in leather and this disk fitted to the front of the lid. The three holes had thongs woven through them which then came out through the centre hole to act as a fastener.

It’s a bit of a stab in the dark but if it was anything else then where is the rest of it? If leather and wood have survived then I find it improbable that a seax, sword, shield boss would corrode away leaving just this or that the guys putting this chap in the ground would put an empty sheath or half a shield in with their kin. This leaves it as an attachment to a reinforce leather object and down by the hand at the side of the body it just screams purse/pouch, the chap was hardly wearing a wooden belt or trousers!”

In my limited knowledge I think this is a very credible suggestion from John.  Do you agree with his suggestion or do you reckon he’s talking rubbish?  Why not leave your own suggestion or any other information that you think may help.

Also, if you would like to find out more about Ða Engliscan Gesiðas why not visit the website?  There are regional groups and a quarterly periodical is published for members.  Click here to discover more. 




SEM
May 15, 2010, 5:43 pm
Filed under: Conservation

CSI: Sittingbourne was given a few valuable funded hours to carry out scanning electron microscopy (SEM) on a selection of interesting objects from the site.  The availability of time for such analysis is valuable and CSI: Sittingbourne would like to give credit to Greenwich University science department for donating use of the SEM, as well as everyone who also helped out.

SEM image showing gilding and intricate tooling to one of the brooches

Despite the majority of volunteers not having any formal university training in conservation, they have shown themselves to be brilliant at discovering and identifying interesting things on there objects.  In previous posts it has been mentioned that a great deal of mineral-preserved organics have been found and it was mainly these that were analysed further with the SEM.

The Scanning Electron Microscope, or SEM, is an incredible tool for observing complex microstructures of materials.  Where conventional light microscopes use a series of lenses to bend light waves and create a magnified image, SEM uses electrons instead to create images.  These images are able to show in much more detail the complexity and topography of a surface, which can aid in the identification of various materials.  Click the images to see full size.

Complex wool structure shown using SEM

As well as looking at the surface, SEM can also be used to find out the composition of materials.  Metals such as copper alloy, for example, can be examined to establish what metals have been used, which can also inform us of the technology utilised in the manufacturing.   X-ray fluorescence (XRF) was employed for the same application with the spearhead.

The presence of bug pupae can help establish the time of year when the grave was made

The images show intricate handmade wires and gilding, but also include insect wing casings, wool, pupae and textile.

Intricate handmade wires

The images have not only helped with the interpretation of the site and the objects, but have also provided new display in the CSI: lab.  The enlarged pictures were put on display at the celebration day held in March and are still on display for visitors to CSI: Sittingbourne to see.

Like the pupae, the presence of insects may help determine the season the person was buried and if the grave was left open

To find out more about SEM have a look at these links:

Iowa State University

Museum of Science



completed brooch
March 6, 2010, 4:18 pm
Filed under: Conservation | Tags: , ,

Saucer brooch partially cleaned for "press shots"

There were only a few brooches discovered at The Meads.  The saucer brooch featured in an earlier post about conserved objects, and pictured above, has now been completed.  The brooch was carefully mechanically cleaned using a scalpel to remove the bulk of the surface soil.  The remainder was cleaned by swabbing with a paste of IMS and marble flour.  The results are impressive and give us a much clearer  idea of the design and manufacture of the object.  Unfortunately, one of the garnets became detached but this is very common and can be easily rectified.

The completed brooch following conservation



spearhead
March 6, 2010, 3:47 pm
Filed under: Conservation, Grave Objects | Tags: , ,

There were around 29 spearheads uncovered during the excavation at The Meads: these are always found in male graves.  Conservation has presented us with the usual mineral preserved organics on these objects.  Wood is usually found preserved in the socketed ferrule where the spearhead attaches to the wooden shaft, and grass has been discovered on the surface of some suggesting the grave was lined or covered with grass before the person and objects were buried under soil (…although I doubt this was for their comfort).

Gold makers mark on the iron spearhead

This spearhead was discovered in grave 192 and is perhaps a bit more interesting than similar examples.  What differs from the others from this site is the presence of a makers mark inlaid in the iron.  This appeared to be a square with an arrow on the top, and could be clearly seen on the x-ray image so the volunteer working on this object knew that extra care needed to be taken.  The spearhead was cleaned using a scalpel and air abrasion in order to reveal the mark.  The mark looked to be gold: this was later confirmed when CSI: Sittingbourne were able to use a portable XRF (x-ray fluoresence) machine to positively identify the type of metal used.

Drawing of the makers mark present on this spearhead

Hopefully we can find similar examples of this on some of the other objects that are being worked on.  If you want to see what’s going on the CSI: lab is still open for visitors to come and see what is being worked on.  The exhibition opposite is open at the same time so you will be able to see some of the other objects and discuss the site with whoever is in charge.



sword fittings
March 5, 2010, 10:47 pm
Filed under: Conservation | Tags: , , , , ,

There were two of these decorative fittings found in grave 174 at The Meads.  Grave 174 is a male grave consisting of a number of objects including a shield boss, spearhead, sword and one object said to be Bronze Age.  The grave also contained some human remains, one of the few where some survived.

Photo of the excavation of grave 174 (Image copyright Canterbury Archaeological Trust)

These decorative pyramidal decorations were found associated with the sword.  They were located close to the mouth of the sword scabbard, and are perhaps part of some kind of strap due to the appearance from the back.

Plan of grave 174 - objects 7 and 8: click to enlarge (Image copyright Canterbury Archaeological Trust)

The objects measure just over 1cm square and are manufactured from silver.  The peak is flat and is inset with a red garnet.  Behind this is gold foil, something that would have made the stone sparkle a little more: we also see this on many of the brooches.  Some other good examples of this can be seen on finds from Sutton Hoo and the recent Staffordshire Hoard.

Pyramid mount before conservation

The sloped sides of the pyramids have some decorative “cut-outs” that appear to be gold plated.  Niello decoration is also present.  Niello is a black metallic alloy consisting of silver, copper, sulfur and lead.  It is used to inlay metals, and was utilised extensively throughout the Anglo-Saxon period.  Perhaps the finest example of this is the great gold buckle which was discovered at Sutton Hoo.  These were heated and fused much like with the production of enamels in jewellery and glassware.

The objects were mechanically cleaned using a scalpel and then swabbed using a paste of IMS and marble flour.  The marble flour acts as a very fine abrasive in order to help remove the more stubborn soil.  Whilst swabbing one of the pyramids some niello came loose.  This gave us a chance to see the fineness of the detail present on these interesting little objects.

Pyramid mount after conservation

“It was nice to be able to work on such an interesting object.  Iron can be very interesting and can preserve a lot of valuable information that can tell us a lot about the object and the people, but it is nice to be able to work on different materials and objects, especially jewellery.  It is much easier to establish when to stop cleaning on objects like this and the results are really pleasing.”