Chronometric dating

Chronometric dating is a process of archaeological and geological age determination. Often confused with Absolute dating, Chronometric dating measures time through consistent natural processes (such as the degradation of the C14 atom) and provides a date range, not an absolute date, to the dated event.

Luminescence dating

Thermoluminescence

Thermoluminescence dating also dates items to the last time they were heated. This technique is based on the principle that all objects absorb radiation from the environment. This process frees electrons within minerals that remain caught within the item.

Amino acid dating

Amino acid dating is a dating technique used to estimate the age of a specimen in paleobiology, archaeology, forensic science, taphonomy, sedimentary geology and other fields. This technique relates changes in amino acid molecules to the time elapsed since they were formed. All biological tissues contain amino acids. All amino acids except glycine (the simplest one) are optically active, having an asymmetric carbon atom. This means that the amino acid can have two different configurations, "D" or "L" which are mirror images of each other.

With a few important exceptions, living organisms keep all their amino acids in the "L" configuration. When an organism dies, control over the configuration of the amino acids ceases, and the ratio of D to L moves from a value near 0 towards an equilibrium value near 1, a process called racemization. Thus, measuring the ratio of D to L in a sample enables one to estimate how long ago the specimen died.

References

  1. ↑ Schwarcz, Henry P. (2002-08-01). "Chronometric Dating in Archaeology: A Review". Accounts of Chemical Research. 35 (8): 637–643. doi:10.1021/ar010039o. ISSN 0001-4842.
  2. ↑ "Vista de Datación absoluta por termoluminiscencia: un ejemplo de aplicación arqueológica". tp.revistas.csic.es (in European Spanish). Archived from the original on 2024-02-11. Retrieved 2025-06-03.
  3. ↑ Bada, J. L. (1985). "Amino Acid Racemization Dating of Fossil Bones". Annual Review of Earth and Planetary Sciences. 13: 241–268. Bibcode:1985AREPS..13..241B. doi:10.1146/annurev.ea.13.050185.001325.
  4. ↑ Canoira, L.; García-Martínez, M. J.; Llamas, J. F.; Ortíz, J. E.; Torres, T. D. (2003). "Kinetics of amino acid racemization (epimerization) in the dentine of fossil and modern bear teeth". International Journal of Chemical Kinetics. 35 (11): 576. doi:10.1002/kin.10153.
  5. ↑ Bada, J.; McDonald, G. D. (1995). "Amino Acid Racemization on Mars: Implications for the Preservation of Biomolecules from an Extinct Martian Biota" (PDF). Icarus. 114 (1): 139–143. Bibcode:1995Icar..114..139B. doi:10.1006/icar.1995.1049. PMID 11539479.
  6. ↑ Johnson, B. J.; Miller, G. H. (1997). "Archaeological Applications of Amino Acid Racemization". Archaeometry. 39 (2): 265. doi:10.1111/j.1475-4754.1997.tb00806.x.
  7. ↑ 2008 Archived 2015-01-22 at the Wayback Machine quote: The results provide a compelling case for applicability of amino acid racemization methods as a tool for evaluating changes in depositional dynamics, sedimentation rates, time-averaging, temporal resolution of the fossil record, and taphonomic overprints across sequence stratigraphic cycles.
  8. ↑ "Amino Acid Geochronology Laboratory, Northern Arizona University". Archived from the original on 2012-03-14. Retrieved 2012-10-15.