13. Geochronology

Summary

Geochronology, the scientific discipline concerned with the order and age of events in the Earth's history, is often an essential component of multidisciplinary paleoanthropological research. This chapter provides an overview of the most widely used chronometric techniques in paleoanthropology. It discusses three basic categories of dating methods: radiometric, dosimetry, and relative. Radiometric dating is based on quantifying the decay in a sample of a naturally occurring radioactive isotope to its products. Radiometric dating techniques discussed include radiocarbon, K-Ar and its derivative ⁴⁰Ar/³⁹Ar, uranium series disequilibrium, terrestrial cosmogenic nuclides, and fission-track dating. Dosimetry dating methods including electron spin resonance and luminescence dating are based on an evaluation of the rate and duration of radiation damage acquired by a sample in a sedimentary environment. Relative dating methods are techniques for sorting out the ordering of geologic events and the temporal linking of disparate stratigraphic sections. These methods include magnetostratigraphy and tephrochronology.