Absolute dating 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. Other radiometric dating techniques are available for earlier periods. One of the most widely used is potassium–argon dating (K–Ar dating). Potassium-40 is a radioactive isotope of potassium that decays into argon-40. The half-life of potassium-40 is 1.3 billion years, far longer than that of carbon-14, allowing much older samples to be dated. Potassium is common in rocks and minerals, allowing many samples of geochronological or archeological interest to be dated. Argon,
Archaeological science archaeological strata and artifacts. Some of the most important dating techniques include: Another important subdiscipline of archaeometry is the study of artifacts. Archaeometrists have used a variety of methods to analyze artifacts, either to determine more about their composition, or to determine their provenance. These techniques include: Lead, strontium and oxygen isotope analysis can also test human remains to estimate the diets and even the birthplaces of a study's subjects. Provenance analysis has the potential to determine the original source of the materials used, for example, to make a particular artifact. This can show how far the artifact has traveled