Dendrochronology absolute dating method
Calibration is not only done before an analysis but also on analytical results as in the case of radiocarbon dating—an analytical method that identifies the age of a material that once formed part of the biosphere by determining its carbon-14 content and tracing its age by its radioactive decay.Carbon-14 is a naturally occurring isotope of the element carbon.
There have been many calibration curves published since Suess’s curve, but their proliferation brought more problems than solutions.
The first calibration curve for radiocarbon dating was based on a continuous tree-ring sequence stretching back to 8,000 years.
This tree-ring sequence, established by Wesley Ferguson in the 1960s, aided Hans Suess to publish the first useful calibration curve.
Nowadays, the internationally agreed upon calendar calibration curves reach as far back as about 48000 BC (Reimer et.
al., INTCAL13 and Marine13 radiocarbon age calibration curves 0 – 50000 yrs cal BP, Radiocarbon 55(4), 2013).



The science of dendrochronology is based on the phenomenon that trees usually grow by the addition of rings, hence the name tree-ring dating.