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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Chronological dating | 1/2 | https://en.wikipedia.org/wiki/Chronological_dating | reference | science, encyclopedia | 2026-05-05T09:55:24.404740+00:00 | kb-cron |
Chronological dating, or simply dating, is the process of attributing to an object or event a date in the past, allowing such object or event to be located in a previously established chronology. This usually requires what is commonly known as a "dating method". Several dating methods exist, depending on different criteria and techniques, and some very well known examples of disciplines using such techniques are, for example, history, geology, paleontology, archaeology, astronomy and even forensic science, since in the latter it is sometimes necessary to investigate the moment in the past during which the death of a cadaver occurred. These methods are typically identified as absolute, which involves a specified date or date range, or relative, which refers to dating which places artifacts or events on a timeline relative to other events and/or artifacts. Other markers can help place an artifact or event in a chronology, such as nearby writings and stratigraphic markers.
== Absolute and relative dating == Dating methods are most commonly classified following two criteria: relative dating and absolute dating.
=== Relative dating ===
Relative dating methods are unable to determine the absolute age of an object or event, but can determine the impossibility of a particular event happening before or after another event of which the absolute date is well known. In this relative dating method, Latin terms ante quem and post quem are usually used to indicate both the most recent and the oldest possible moments when an event occurred or an artifact was left in a stratum, respectively. But this method is also useful in many other disciplines. Historians, for example, know that Shakespeare's play Henry V was not written before 1587 because Shakespeare's primary source for writing his play was the second edition of Raphael Holinshed's Chronicles, not published until 1587. Thus, 1587 is the post quem dating of Shakespeare's play Henry V. That means that the play was without fail written after (in Latin, post) 1587. The same inductive mechanism is applied in archaeology, geology and paleontology, by many ways. For example, in a stratum presenting difficulties or ambiguities to absolute dating, paleopalynology can be used as a relative referent by means of the study of the pollens found in the stratum. This is admitted because of the simple reason that some botanical species, whether extinct or not, are well known as belonging to a determined position in the scale of time. For a non-exhaustive list of relative dating methods and relative dating applications used in geology, paleontology or archaeology, see the following:
Cross-cutting relationships Fluorine absorption dating Harris matrix Law of included fragments Law of superposition Lichenometry Marine isotope stages, based on the oxygen isotope ratio cycle Melt inclusions Morphology (archaeology) Nitrogen dating Palynology, the study of modern-dated pollens for the relative dating of archaeological strata, also used in forensic palynology. Paleomagnetism Paleopalynology, also spelt "Palaeopalynology", the study of fossilized pollens for the relative dating of geological strata. Principle of original horizontality Principle of lateral continuity Principle of faunal succession Seriation (archaeology) Sequence dating (a type of seriation) Tephrochronology Typology (archaeology) Uranium–lead dating. Lead corrosion dating (exclusively used in archaeology) Varnish microlamination Vole clock
=== Absolute dating ===
Absolute dating methods seek to establish a specific time during which an object originated or an event took place. While the results of these techniques are largely accepted within the scientific community, there are several factors which can hinder the discovery of accurate absolute dating, including sampling errors and geological disruptions. This type of chronological dating utilizes absolute referent criteria, mainly the radiometric dating methods. Material remains can be absolutely dated by studying the organic materials which construct the remains. For example, remains that have pieces of brick can undergo the process of thermoluminescence (TL) dating in order to determine approximately how many years ago the material was fired. This technique was used to discover the date of St. James Church in Toruń by testing the thermoluminescence of removed bricks. In this example, an absolute date was determined which filled a gap in the historical knowledge of the church.
These techniques are utilized in many other fields as well. Geologists, for example, apply absolute dating methods to rock sediment in order to discover their period of origin.
Some examples of both radiometric and non-radiometric absolute dating methods are the following:
Amino acid dating Archaeomagnetic dating Argon–argon dating Astronomical chronology Carbon dating: Also known as radiocarbon dating, it can reveal the age of organic material in artifacts as well as human and animal remains. This process can reliably measures dates up to approximately 50,000 years ago. Cementochronology, this method does not determine a precise moment in a scale of time but the age at death of a dead individual. Datestone (exclusively used in archaeology) Dendrochronology Electron spin resonance dating Fission track dating Geochronology Herbchronology Iodine–xenon dating Potassium–argon dating Lead–lead dating Luminescence dating Thermoluminescence dating Optically stimulated luminescence Optically stimulated luminescence thermochronometry Molecular clock (used mostly in phylogenetics and evolutionary biology) Obsidian hydration dating (exclusively used in archaeology) Oxidizable carbon ratio dating Rehydroxylation dating Rubidium–strontium dating Samarium–neodymium dating Tephrochronology Uranium–lead dating Uranium–thorium dating Uranium–uranium dating, useful in dating samples between about 10,000 and 2 million years Before Present (BP), or up to about eight times the half-life of 234U. Wiggle matching