Absolute dating provides a numerical age or range in contrast with relative dating which places events in order without any measure of the age between events.
In archaeology, absolute dating is usually based on the physical, chemical, and life properties of the materials of artifacts, buildings, or other items that have been modified by humans and by historical associations with materials with known dates (coins and written history).
Petrologists study rocks and paleontologists study fossils.
However both these disciplines are covered in the broader training of a geologist. Here is the fossil type and example(s): cast fossils (filled in with molds), trace fossils (burrows, gastroliths, footprints), and true form fossils (real animal or real animal part).
Trace fossils are marks that have been left by animal, such as footprints.
The relatively short half-life of carbon-14, 5,730 years, makes dating reliable only up to about 50,000 years.
The technique often cannot pinpoint the date of an archeological site better than historic records, but is highly effective for precise dates when calibrated with other dating techniques such as tree-ring dating.
This is a radiometric technique since it is based on radioactive decay.
Cosmic radiation entering the earth’s atmosphere produces carbon-14, and plants take in carbon-14 as they fix carbon dioxide.