Dendrochronology dating definition
Other radiometric dating techniques are available for earlier periods.
One of the most widely used is potassium–argon dating (K–Ar dating).
Techniques include tree rings in timbers, radiocarbon dating of wood or bones, and trapped-charge dating methods such as thermoluminescence dating of glazed ceramics.
By measuring the carbon-14 in organic material, scientists can determine the date of death of the organic matter in an artifact or ecofact.
The relatively short half-life of carbon-14, 5,730 years, makes the reliable only up to about 50,000 years.
For this reason, many archaeologists prefer to use samples from short-lived plants for radiocarbon dating.
The development of accelerator mass spectrometry (AMS) dating, which allows a date to be obtained from a very small sample, has been very useful in this regard.