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A recent news item on the BBC caught my eye:
http://news.bbc.co.uk/1/hi/scotland/edin...058185.stm
In it a new scientific analysis technique for absolute dating of ceramics was announced. It is called rehydroxylation and relies on the uptake of water.
The thing that worries me is surely a pot used to stew vegetables by the fire is going to take up a lot more water into it's structure than one which is displayed on a dresser in a fairly dry atmosphere.
What does everyone think of this new technique?
Singer of dodgy songs, teller of tall stories, maker of pretty things and prehistoric performer.
Singer of dodgy songs, teller of tall stories, maker of pretty things and prehistoric performer.
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I think it has wonderful potential but i'll have to look up the paper next time I go to a library before I can fully comment. It will be interesting to see the degree of accuracy and confidence in their results (and potentially how much such analysis would cost).
I wouldn't worry too much about secondary absorbtion as the levels and types of absorbtion achieved during firing is likely to be at much higher temperatures than during cooking and therefore of limited influence, althoug like i said i need to read a bit more into the science before being certain.
Nonetheless, this looks a like a wonderful advancement in archaeological science.
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The paper is a good read. The technique is relatively simple compared to other ceramic dating techniques like Thermoluminescence (TL), and potentially cheaper as it doesn't require 'much' specialised equipment or radioactive sources.
However, there are probably hidden costs to some applications of the technique. The key requirement is to reconstruct the temperature history as the rate of recombination is dependent on temperature. Relatively easy for post-medieval, historical samples especially in the UK as there is decent records. If only a general tenperature is required and not a highly detailed study thats probably fine. Palaeoenvironmental proxy reconstructions might be good enough for very old ceramic contexts, pollen and other techniques might do it in NW Europe, but getting high-quality pollen in the Med, Africa and other semi-arid and arid environments is a lot more patchy. Oxygen Stable isotopes from carbonates might be more precise here, but we're getting into the glorious world of inter-disciplinary research projects and increased costs.
It would be interesting to check further sub-samples, and samples through thick ceramics to check for variations in the matrix. The mechanism of rehydroxylation is technically supposed to be unaffected by saturated capillary water. It is the constant rate of recombination of water molecules with the clay matrix that is measured. Clearly testing the technique on older samples from securely dated contexts is a must. Some very early ceramics are presumably going to be precious commodities so taking 3-5 g sub-samples may not be possible for all cases.
Hopefully I can have a go at this over the next year or so...simple methodology, some effective science with some very nice potential for reassessing our pottery typologies and all the associated chronological links. Good work, Wilson et al.
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Excellent post... thanks for this nugget of potential pure gold (ceramicly dating speaking)
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This technique has of course wider implications than just pottery dating and I believe the trial involved looking at some of the Museum of London's extensive brick and tile collection.
With peace and consolation hath dismist, And calm of mind all passion spent...
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This seems to point to both good and bad science as there are several 'problems' perhaps addressed in the full report. Glazed material for example - how can this absorb moisture? a brick has its clock reset if subjected to fire (as in the medieval bricks dated to 66 years old, but being caught up in the Coventry bombing in WWII.) so a brick dated to 350 years old, may be from a fire in the Civil War, rather than the date of the actual brick manufacture. Once again, you will rely on associate evidence to tie the brick to an earlier period. I do think it is a good path to follow, but there is a lot of work to do before it becomes the 'new C14'
"Entrepreneurs are simply those who understand that there is little difference between obstacle and opportunity and are able to turn both to their advantage."
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David - I think that residuality and context is a problem that we need to address with any artefact type. In fact the examples that you suggest combined with the new dating technique, may be very helpful in dealing with dating structures rather than finds i.e a pit full of 'medieval' tile that the new technique dates to AD1941 is almost certainly a modern-pit irrespective of the apparent age of the finds assemblage.
Us old-school stratigraphists would welcome that distinction being re-mphasised.....sometimes the glee of 'artefactists' triumphing the singularity of objects rather than the context in which they are found, can be hurtful to our sensitive, stratified, Faustian souls.....
With peace and consolation hath dismist, And calm of mind all passion spent...
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Quote:quote:Originally posted by kevin wooldridge
David - I think that residuality and context is a problem that we need to address with any artefact type. In fact the examples that you suggest combined with the new dating technique, may be very helpful in dealing with dating structures rather than finds i.e a pit full of 'medieval' tile that the new technique dates to AD1941 is almost certainly a modern-pit irrespective of the apparent age of the finds assemblage.
Us old-school stratigraphists would welcome that distinction being re-mphasised.....sometimes the glee of 'artefactists' triumphing the singularity of objects rather than the context in which they are found, can be hurtful to our sensitive, stratified, Faustian souls.....
With peace and consolation hath dismist, And calm of mind all passion spent...
I agree - especially important when you find 'reversed' stratigraphy - as we did with an old WWII bomb crater a while back. Newest stuff at the bottom, oldest at the top - looks like they bulldozed the archaeology into the hole then! That's not what the people who dug the original test pit thought though. They just looked at what they'd found, not where they found it......
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I know its early days and there are a lot of wrinkles to sort out but I for one think is potentially of major importance, and could be something worth getting genuinely excited about for a change. There may be some pottery specialists with red faces out there in about ten years time....
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I'm excited...... whooooop the thought of pottery specialists with red faces, fills me with joy
seriously though, it will need serious looking at and further study, however, if it does work it is a good thing.
"Entrepreneurs are simply those who understand that there is little difference between obstacle and opportunity and are able to turn both to their advantage."
Niccolo Machiavelli
