- #1
Andre
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We did several threads about carbon dating. Main message, you've got to know what the caveats are and then it's a good and reliable way to estimate the age of organic material from the last 50,000 years.
A major point is calibration, which is improved and refined every few years. There is software around on the net to facilitate calibration, like Calib, Calpal, Oxcal etc. The problem is that it's sometimes not updated with the latest calibration table and another problem is, handling of carbon dating platforms. I see that the wiki does not elaborate, but due to relatively large changes of 14C concentrations in the past, the calibration curve has steeper and flatter parts. In the flat - near horizontal parts a 14C date can enclose a large real date range, introducing a large error.
So I made a bit of an improved version of my good old http://dl.dropbox.com/u/22026080/carbon-dating-converter-intcal09-02.xlsx that warns if it finds a 'platform'. It's in my dropbox, for anybody who wants to try it. Of course, tearing it down to pieces is welcomed, so that we could make an improved one.
Just enter the 14C date in B1 and either the error range in D1 or a basic error percentage in B2, or no error at all.
Enter for instance 10000 (14C years) and the output is 11395 Cal years BP (before present) +/- 5 (indicating the interval in which the value is chosen). However enter 10020 years and we see a carbon platform with the output 11500 Cal yars BP +/- 100 years, giving an impression of the length of platform.
You can find how it's done, in the second tab, 'intcal09table'.
A major point is calibration, which is improved and refined every few years. There is software around on the net to facilitate calibration, like Calib, Calpal, Oxcal etc. The problem is that it's sometimes not updated with the latest calibration table and another problem is, handling of carbon dating platforms. I see that the wiki does not elaborate, but due to relatively large changes of 14C concentrations in the past, the calibration curve has steeper and flatter parts. In the flat - near horizontal parts a 14C date can enclose a large real date range, introducing a large error.
So I made a bit of an improved version of my good old http://dl.dropbox.com/u/22026080/carbon-dating-converter-intcal09-02.xlsx that warns if it finds a 'platform'. It's in my dropbox, for anybody who wants to try it. Of course, tearing it down to pieces is welcomed, so that we could make an improved one.
Just enter the 14C date in B1 and either the error range in D1 or a basic error percentage in B2, or no error at all.
Enter for instance 10000 (14C years) and the output is 11395 Cal years BP (before present) +/- 5 (indicating the interval in which the value is chosen). However enter 10020 years and we see a carbon platform with the output 11500 Cal yars BP +/- 100 years, giving an impression of the length of platform.
You can find how it's done, in the second tab, 'intcal09table'.
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