by Melissa
What is radiocarbon dating?
Radiocarbon dating is a type of radiometric technique used by analysts to determine the absolute age of organic material objects. Now, there are a lot of terms in that sentence that should be explained more in order to grasp the concept behind this dating method. First off, radiometric dating is the measurement of decay for radioactive or unstable isotopes, and this could be performed with a number of different isotopic elements. However, the most common radiometric dating technique is radiocarbon dating, which deals with the ratio between unstable carbon-14 isotope’s and stable carbon-12 or carbon-13. This can create an absolute date because the decay of carbon-14 occurs at a known rate, which is called the half-life. In the case of carbon-14, the half-life is a span of 5,730 (±40) years. Additionally, it is important to note that radiocarbon dating needs to be corroborated by dendrochronology, or the . Furthermore, radiocarbon dating results in an age range, rather than one specific date because there is always a percentage of uncertainty attributed to the process. Radiocarbon dates must also be calibrated into calendar years in order to be better understood (uncalibrated radiocarbon dates are notated as BP, or before present, where ‘present’ refers to 1950).
How is radiocarbon dating conducted?
The main aspect of radiocarbon dating is, as stated previously, by measuring the ratio between carbon-14 and either carbon-13 or carbon-14 of an organic, or once living, material. This is done by using an Accelerator Mass Spectrometer (AMS), where the samples are converted to graphite and then are subjected to high kinetic energy which allows the different weighted carbon ions (carbon-14 is the heaviest, carbon-12 is the lightest) are separated, allowing for a mass analysis (for more about AMS see Beta: Accelerator). While this method is the most implemented, there are other ways to determine a radiocarbon date by using beta particles; this can be done by gas proportional counting or liquid scintillation counting, they take a longer amount of time and require a larger sample size.
Why is radiocarbon dating important?
Radiocarbon dating is important in the scientific analysis of material objects for two main reasons. Firstly, it revolutionized the dating of extremely ancient objects by providing absolute age ranges, when before dates had to be guessed at (most notably, radiocarbon dating proved that humans have been on Earth for more than the biblically estimated four thousand years). Furthermore, in knowing the relative date of an historic or artistic object, conservation practices can be chosen in a more informed and precise way.
For more general information concerning radiocarbon dating, consult:
Beta Analytic Testing Laboratory.How Does Carbon Dating Work. 2018. https://www.radiocarbon.com/about-carbon-dating.htm. Accessed April 28 2018.
Doménech-Carbó A., Doménech-Carbó M.T., Costa V. (2009) Application of Instrumental Methods in the Analysis of Historic, Artistic and Archaeological Objects. In: Doménech-Carbó A., Doménech-Carbó M.T., Costa V. (eds) Electrochemical Methods in Archaeometry, Conservation and Restoration. Monographs in Electrochemistry. Springer, Berlin, Heidelberg https://link.springer.com/chapter/10.1007%2F978-3-540-92868-3_1 Accessed April 26 2018.
Greene, Kevin & Moore, Tom (2010) Archaeology: An Introduction. (5th edition). Oxon: Routledge.
Scientific Analysis & Conservation Tech 