Explain the process of thermoluminescence dating

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This unstable isotope of Carbon then enters the food chain, and in doing so, forms part of all organic matter (Bayliss et al. Broadly speaking, anything that was once alive can therefore theoretically have measured the levels of radiocarbon it now contains.

It is also possible to obtain radiocarbon determinations from inorganic materials if the process of producing the finished state includes the incorporation of carbon; examples of where this might be possible is the application of lime mortar as carbon dioxide is absorbed by the surface when the mortar hardens (Bowman 19).

Radiocarbon dating is predicated on the assumption that the level of C in the atmosphere at the time and that these levels of both biosphere and atmosphere are consistent over the entire globe.

It is now known that this is not the case, and that there are localised reservoir effects which need to be compensated for in the calibration process.

An interesting example of this was the evidence for Bronze Age mummies at Cladh Hallan (Parker Pearson et al.

2005), and many other examples from British Prehistory (Booth 2008).

Most of the C in the atmosphere originates in the action of cosmic rays on Nitrogen in the upper atmosphere.For example, as Hamilton (2011) argued, there is no way of knowing whether the artefact that has been subjected to radiocarbon dating is an heirloom that has been curated for a given period of time, or whether the deposit itself has been reworked in some way as to render the date invalid when applied to anything other than the sample itself.This is not necessarily a weakness of radiocarbon dating, more a pitfall of the application of the technique.The lesson here is that although a sample may be retrieved from a given context, there is every cause to question whether that was in fact the context from which it originated.The question of residuality, that is, how long artefacts have been in existence before they enter the archaeological record, is also a factor that can affect the accuracy of radiocarbon dates when applied to a given context.

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