Archaeology Term: Radiocarbon Dating
Radiocarbon dating is an archaeology/absolute-dating'>absolute dating technique used to determine the age of organic materials that are less than 50,000 years old.
It works by analyzing the reduction of the unstable carbon-14 isotope, which is absorbed by living organisms throughout their lives and begins to decay at a known rate after death.
The decay rate of carbon-14 is constant, allowing scientists to measure time in terms of half-lives, with one half-life equaling approximately 5730 ± 40 years. This means that after 5730 years, half of the original carbon-14 in the material will have decayed, providing a basis for calculating the age of an organic sample.
Because carbon-14 decays predictably, it serves as a useful clock for dating ancient materials, such as bones, wood, and other plant and animal remains.
However, the dates generated by radiocarbon dating must be calibrated against other absolute dating methods to improve accuracy. Calibration techniques, like comparing radiocarbon dates with tree-ring data (dendrochronology) or ice core data, help adjust for fluctuations in atmospheric carbon-14 levels over time.
Variations in carbon-14 production can result from natural factors like solar radiation, meaning that uncalibrated radiocarbon dates may not precisely align with calendar years.
Radiocarbon dating has become one of archaeology’s most valuable tools for dating ancient sites, artifacts, and biological remains, providing dates that are central to constructing historical timelines. The method's effectiveness is limited to organic materials, as non-organic substances, such as stone and metal, do not contain carbon-14 and cannot be dated using this technique.
Despite its limitations, radiocarbon dating remains widely used because of its reliability and the relatively small sample sizes needed. This method has revolutionized fields beyond archaeology, including geology, climatology, and paleontology, allowing researchers to study environmental changes and human history with greater precision.
In modern applications, radiocarbon dating has been enhanced through accelerator mass spectrometry (AMS), which allows for dating very small samples with increased accuracy. AMS techniques also improve the method's range, making it possible to date materials closer to the upper limit of 50,000 years with better confidence.
Radiocarbon dating, therefore, continues to be a cornerstone of archaeological research, helping to uncover and verify the age of historical and prehistoric remains across the globe.
