Interesting dating technique

[Dinosaur]

Presumably for ancient buried materials (which the original technique didn't have to deal with), they have the nightmare of having to assess the changes in burial environment over time, particularly since no two bits of ground are the same so they'd have to 'guesstimate' the absorbtion rrate for every sample from scratch - can see this going the same way as DNA dating, good idea but will it actually work in practice on buried archaeological materials?

[Sarah-Jane Clelland]

Hi,

I am a RA working on the RHX validation project. Glad the newsletter has been well received.

The application of this method as an archaeological dating technique is a happy accident, the 2009 paper proved that RHX can work on bricks and tiles. The research was originally intended to help with the design of brick built structures, using medieval and Roman bricks demonstrated that the rate law that had been discovered works over long time scales. The reason that nothing has happened since 2009 is that we have been attempting to secure funding and samples to do a validation study to determine if RHX can be a dating technique for archaeological materials.

@ pdurdin Yes, the website is in need of much work and I am currently writing the content. I hope to build the website and have the new content up and running by mid of June.

@ Wax The event that RHX would be dating is when it was last heated to over 500 degree celcius. So, for most artefacts that will be when it was taken out of the kiln. There may be situations when there is evidence to suggest that it was heated to that temperature again, for example in a building fire. Cooking vessels (repeated heating events) may present a problem, which we will be investigating.

@ dinosaur We are hoping that it will be a widely available technique. It is too early to be able to give any indication of the costs involved. RHX is still very much in the research/development stage.
With regards to your other concerns, RHX is a self calibrating method so the adsorption (not absorption, as the moisture chemically combines with the ceramic material) rate is specific to each individual ceramic. Furthermore, the moisture requirements for the RHX reaction are very small so we do not need to estimate the amount of water present in the burial environment. However, as it is a chemical reaction, we do need to get an estimate of the average temperature that the artefact has been at during it's lifetime. Our colleagues at Edinburgh have developed a model that can calculate this. The current study will be looking at many different burial environments (for example marine, cave, freshwater, temperature, tropical) to determine if any specific burial environment may be a problem.

@ kevin wooldridge Yes you are correct about the precision. Another aspect of the current study is to collect sufficient data to be able to quantify the errors involved and get an idea of the precision that can be obtained by this method. Regarding prehistoric pottery, I have only been involved in this project for 2 months but how well fired the ceramic is may not present a significant problem. I know that very well fired material, such as porcelain, currently cannot be dated by RHX as most of the ceramic has become fused. Although the RHX reaction is still occuring, the mass gain is so minute it is beyond current instrumentation to measure. Again, the ability for RHX to date poorly fired ceramics is something that we will be investigating over the next two years.

[Wax]

great to get the facts from source thanks Sarah-Jane:face-approve:

[Dinosaur]

Hi S-JC!

Extremely helpful post, thanks, have given you a green thumbs-up (not as bad as it sounds, honest). If the technique can be got to work reliably on prehistoric pot it may get us around all those pesky 'plateau' in the C14 curve

[P Prentice]

will you be able to date pottery after taking the grog out sarah-jane?

[Unitof1]

The rate of absorption of water is affected by the ambient temperature. Just how senstive is the result? Seems that there is some model which claims or is it needs accuracy of 0.1 degrees over something or other? How realistic is that? Whats the model?

[Sarah-Jane Clelland]

@ P Prentice You raise an interesting point about grog. As it is after all fired ceramic, so what which would we be measuring the RHX reaction of, the grog or the main ceramic body? I am currently performing a series of experiments to see what is the best

[Unitof1]

This discriminating mob are interested in you if you are an indian or a china person

http://www.nature.com/naturejobs/science...n-Citizens

has the Effective Lifetime Temperature model been published anywhere?

[Sarah-Jane Clelland]

This discriminating mob are interested in you if you are an indian or a china person

http://www.nature.com/naturejobs/science...n-Citizens

has the Effective Lifetime Temperature model been published anywhere?

I understand that a paper explaining effective lifetime temperature and describing the modelling has been submitted for peer review.

[Unitof1]

I look forward to reading it. I am hoping that it will use find a use for all the physical stratigraphy recorded around the dated object. Be great if it started to make archaeologist try and interpret time frames for the context accumulation. Harris always said that the future was in the context boundaries. Any ideas on how to record ambient temperature?