A calendrical date that applies to a site, artifact, or feature; calendar dating: The procedure of assessing an age of a clearly and explicitly stated chronology in geology and archaeology is termed absolute dating.

An absolute dating system of assessing the age or determining a date of an artifact: Radiocarbon dating was invented by the American chemist Willard f. Libby (1908-1980) while conducting atom bomb research.

Today the method can provide a reliable date using a single grain of wheat.

It takes advantage of the fact that all organic materials contain mesurable amounts of radioactive carbon (Carbon 14).

At death, the radiocarbon begins to disintegrate at a known rate. By measuring the amount of radioactive carbon left, scientists can determine how long ago the organism died.

The latest versions of the technique can date objects up to 70,000 years old.

Any system of dating that is not based on a calendrical system: By using relative dating, artifacts or sites are described as being earlier or later than other artifacts or sites.