14th April 2012, 02:55 PM
My understanding is that it isn't necessarily year specific, but possibly within a decade or two. The process relies on the weight of the clay now and the weight immediately after firing. The difference is due to the ceramic reabsorbing moisture and the computation of that at a consistent rate equalling the length of time since the initial firing. I think there are some problems with the technique particularly with prehistoric pottery fired at lower temperatures or with ceramic that has been re-fired as part of the manufacturing process or subject to subsequent heating, but in theory the principle and the maths are sound.
Why it hasn't taken off as a common place technique in the past 3 years might be due to a number of factors. Specialist labs with extremely precise weighing machinery for one, widespread distribution of the background data needed to make the computation and perhaps inherent conservatism amongst archaeologists i.e the date ranges we have for ceramics or fired clay are precise enough for day to day analysis and further clarification is an unnecessary expense...
Why it hasn't taken off as a common place technique in the past 3 years might be due to a number of factors. Specialist labs with extremely precise weighing machinery for one, widespread distribution of the background data needed to make the computation and perhaps inherent conservatism amongst archaeologists i.e the date ranges we have for ceramics or fired clay are precise enough for day to day analysis and further clarification is an unnecessary expense...
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