HOME

TheInfoList



OR:

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 Chronology (from Latin ''chronologia'', from Ancient Greek , ''chrónos'', "time"; and , ''-logia'') is the science of arranging events in their order of occurrence in time. Consider, for example, the use of a timeline or sequence of even ...
. 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 History (derived ) is the systematic study and the documentation of the human activity. The time period of event before the invention of writing systems is considered prehistory. "History" is an umbrella term comprising past events as well ...
,
archaeology Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, biofacts or ecofacts, sites, and cultural landsc ...
,
geology Geology () is a branch of natural science concerned with Earth and other Astronomical object, astronomical objects, the features or rock (geology), rocks of which it is composed, and the processes by which they change over time. Modern geology ...
,
paleontology Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...
,
astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...
and even
forensic science Forensic science, also known as criminalistics, is the application of science to criminal and civil laws, mainly—on the criminal side—during criminal investigation, as governed by the legal standards of admissible evidence and criminal ...
, since in the latter it is sometimes necessary to investigate the moment in the past during which the death of a
cadaver A cadaver or corpse is a dead human body that is used by medical students, physicians and other scientists to study anatomy, identify disease sites, determine causes of death, and provide tissue to repair a defect in a living human being. Stud ...
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 Relative dating is the science of determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their absolute age (i.e., estimated age). In geology, rock or superficial dep ...
and
absolute dating Absolute dating is the process of determining an age on a specified chronology in archaeology and geology. Some scientists prefer the terms chronometric or calendar dating, as use of the word "absolute" implies an unwarranted certainty of accurac ...
.


Relative dating

Relative dating Relative dating is the science of determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their absolute age (i.e., estimated age). In geology, rock or superficial dep ...
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 Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...
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 In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as e ...
, respectively. But this method is also useful in many other disciplines. Historians, for example, know that Shakespeare's play ''
Henry V Henry V may refer to: People * Henry V, Duke of Bavaria (died 1026) * Henry V, Holy Roman Emperor (1081/86–1125) * Henry V, Duke of Carinthia (died 1161) * Henry V, Count Palatine of the Rhine (c. 1173–1227) * Henry V, Count of Luxembourg (121 ...
'' was not written before 1587 because Shakespeare's primary source for writing his play was the second edition of
Raphael Holinshed Raphael Holinshed ( – before 24 April 1582) was an English chronicler, who was most famous for his work on ''The Chronicles of England, Scotlande, and Irelande'', commonly known as ''Holinshed's Chronicles''. It was the "first complete printe ...
'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 Cross-cutting relationships is a principle of geology that states that the geologic feature which cuts another is the younger of the two features. It is a relative dating technique in geology. It was first developed by Danish geological pioneer ...
*
Fluorine absorption dating Fluorine absorption dating is a method used to determine the amount of time an object has been underground. Fluorine absorption dating can be carried out based on the fact that groundwater contains fluoride ions. Items such as bone that are in t ...
*
Harris matrix The Harris matrix is a tool used to depict the temporal succession of archaeological contexts and thus the sequence of depositions and surfaces on a 'dry land' archaeological site, otherwise called a 'stratigraphic sequence'. The matrix reflec ...
* Law of included fragments *
Law of superposition The law of superposition is an axiom that forms one of the bases of the sciences of geology, archaeology, and other fields pertaining to geological stratigraphy. In its plainest form, it states that in undeformed stratigraphic sequences, the ...
*
Lichenometry In archaeology, palaeontology, and geomorphology, lichenometry is a geomorphic method of geochronologic dating that uses lichen growth to determine the age of exposed rock, based on a presumed specific rate of increase in radial size over time. ...
* Marine isotope stages, based on the oxygen isotope ratio cycle * Melt inclusions * Morphology (archaeology) * Nitrogen dating *
Palynology Palynology is the "study of dust" (from grc-gre, παλύνω, palynō, "strew, sprinkle" and ''-logy'') or of "particles that are strewn". A classic palynologist analyses particulate samples collected from the air, from water, or from deposit ...
, the study of modern-dated pollens for the relative dating of archaeological strata, also used in forensic palynology. *
Paleomagnetism Paleomagnetism (or palaeomagnetismsee ), is the study of magnetic fields recorded in rocks, sediment, or archeological materials. Geophysicists who specialize in paleomagnetism are called ''paleomagnetists.'' Certain magnetic minerals in roc ...
* 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 Sequence dating, an archaeological relative dating method, allows assemblages to be arranged in a rough serial order, which is then taken to indicate time. Sequence dating is a method of seriation developed by the Egyptologist Sir William Matthew ...
(a type of seriation) * Tephrochronology *
Typology (archaeology) In archaeology, a typology is the result of the classification of things according to their physical characteristics. The products of the classification, i.e. the classes, are also called types. Most archaeological typologies organize portable ...
* Uranium–lead dating. Lead corrosion dating (exclusively used in archaeology) * Varnish microlamination * Vole clock


Absolute dating

Absolute dating Absolute dating is the process of determining an age on a specified chronology in archaeology and geology. Some scientists prefer the terms chronometric or calendar dating, as use of the word "absolute" implies an unwarranted certainty of accurac ...
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 Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares ...
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 Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest ...
*
Carbon dating Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was de ...
: Reveals the age of artifact, which is used to establish the chronology of the culture. The oldest dates that can be reliably measured by this process date to approximately 50,000 years ago. **
Radiocarbon dating Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was de ...
* 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 Dendrochronology (or tree-ring dating) is the scientific method of dating tree rings (also called growth rings) to the exact year they were formed. As well as dating them, this can give data for dendroclimatology, the study of climate and atm ...
* Electron spin resonance dating * Fission track dating *
Geochronology Geochronology is the science of determining the age of rocks, fossils, and sediments using signatures inherent in the rocks themselves. Absolute geochronology can be accomplished through radioactive isotopes, whereas relative geochronology is ...
* Herbchronology *
Iodine–xenon dating Iodine-129 (129I) is a long-lived radioisotope of iodine which occurs naturally, but also is of special interest in the monitoring and effects of man-made nuclear fission products, where it serves as both tracer and potential radiological contamin ...
* Potassium–argon dating *
Lead–lead dating Lead–lead dating is a method for dating geological samples, normally based on 'whole-rock' samples of material such as granite. For most dating requirements it has been superseded by uranium–lead dating (U–Pb dating), but in certain special ...
*
Luminescence dating Luminescence dating refers to a group of methods of determining how long ago mineral grains were last exposed to sunlight or sufficient heating. It is useful to geologists and archaeologists who want to know when such an event occurred. It uses var ...
**
Thermoluminescence dating Thermoluminescence dating (TL) is the determination, by means of measuring the accumulated radiation dose, of the time elapsed since material containing crystalline minerals was either heated ( lava, ceramics) or exposed to sunlight ( sed ...
** Optically stimulated luminescence ** Optically stimulated luminescence thermochronometry *
Molecular clock The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleo ...
(used mostly in
phylogenetics In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups ...
and
evolutionary biology Evolutionary biology is the subfield of biology that studies the evolutionary processes (natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life ...
) *
Obsidian hydration dating Obsidian hydration dating (OHD) is a geochemical method of determining age in either absolute or relative terms of an artifact made of obsidian. Obsidian is a volcanic glass that was used by prehistoric people as a raw material in the manufactur ...
(exclusively used in archaeology) * Oxidizable carbon ratio dating * Rehydroxylation dating * Rubidium–strontium dating *
Samarium–neodymium dating Samarium–neodymium dating is a radiometric dating method useful for determining the ages of rocks and meteorites, based on the alpha decay of the long-lived samarium isotope () to the stable radiogenic neodymium isotope (). Neodymium isotope ra ...
* 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


Dating methods in archaeology

Just like
geologist A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althou ...
s or paleontologists,
archaeologists Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, biofacts or ecofacts, sites, and cultural landscapes ...
are also brought to determine the age of both ancient and recent humans. Thus, to be considered as archaeological, the remains, objects or artifacts to be dated must be related to human activity. It is commonly assumed that if the remains or elements to be dated are older than the human species, the disciplines which study them are sciences such geology or paleontology, among some others. Nevertheless, the range of time within archaeological dating can be enormous compared to the average lifespan of a singular human being. As an example Pinnacle Point's caves, in the southern coast of
South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...
, provided evidence that marine resources (shellfish) have been regularly exploited by humans as of 170,000 years ago. On the other hand, remains as recent as a hundred years old can also be the target of archaeological dating methods. It was the case of an 18th-century
sloop A sloop is a sailboat with a single mast typically having only one headsail in front of the mast and one mainsail aft of (behind) the mast. Such an arrangement is called a fore-and-aft rig, and can be rigged as a Bermuda rig with triangular sa ...
whose
excavation Excavation may refer to: * Excavation (archaeology) * Excavation (medicine) * ''Excavation'' (The Haxan Cloak album), 2013 * ''Excavation'' (Ben Monder album), 2000 * ''Excavation'' (novel), a 2000 novel by James Rollins * '' Excavation: A Mem ...
was led in
South Carolina )''Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no) , anthem = " Carolina";" South Carolina On My Mind" , Former = Province of South Carolina , seat = Columbia , LargestCity = Charleston , LargestMetro = ...
(
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
) in 1992.Clydesdale Plantation 18th-Century Sloop Excavation
,
Institute of Nautical Archaeology The Institute of Nautical Archaeology (INA) is the world's oldest organization devoted to the study of humanity's interaction with the sea through the practice of archaeology. History INA's founder Dr. George Bass pioneered the science of underw ...
, Texas, USA Thus, from the oldest to the youngest, all
archaeological site An archaeological site is a place (or group of physical sites) in which evidence of past activity is preserved (either prehistoric or historic or contemporary), and which has been, or may be, investigated using the discipline of archaeology an ...
s are likely to be dated by an appropriate method. Dating material drawn from the
archaeological record The archaeological record is the body of physical (not written) evidence about the past. It is one of the core concepts in archaeology, the academic discipline concerned with documenting and interpreting the archaeological record. Archaeological t ...
can be made by a direct study of an artifact, or may be deduced by association with materials found in the
context Context may refer to: * Context (language use), the relevant constraints of the communicative situation that influence language use, language variation, and discourse summary Computing * Context (computing), the virtual environment required to s ...
the item is drawn from or inferred by its point of discovery in the
sequence In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is called ...
relative to datable contexts. Dating is carried out mainly
post excavation Post-excavation analysis constitutes processes that are used to study archaeological materials after an excavation is completed. Since the advent of "New Archaeology" in the 1960s, the use of scientific techniques in archaeology has grown in impor ...
, but to support good practice, some preliminary dating work called "spot dating" is usually run in tandem with
excavation Excavation may refer to: * Excavation (archaeology) * Excavation (medicine) * ''Excavation'' (The Haxan Cloak album), 2013 * ''Excavation'' (Ben Monder album), 2000 * ''Excavation'' (novel), a 2000 novel by James Rollins * '' Excavation: A Mem ...
. Dating is very important in archaeology for constructing models of the past, as it relies on the integrity of dateable objects and samples. Many disciplines of archaeological science are concerned with dating evidence, but in practice several different dating techniques must be applied in some circumstances, thus dating evidence for much of an archaeological sequence recorded during excavation requires matching information from known absolute or some associated steps, with a careful study of stratigraphic relationships. In addition, because of its particular relation with past human presence or past human activity, archaeology uses almost all the dating methods that it shares with the other sciences, but with some particular variations, like the following:


Written markers

*
Epigraphy Epigraphy () is the study of inscriptions, or epigraphs, as writing; it is the science of identifying graphemes, clarifying their meanings, classifying their uses according to dates and cultural contexts, and drawing conclusions about the w ...
– analysis of inscriptions, via identifying graphemes, clarifying their meanings, classifying their uses according to dates and cultural contexts, and drawing conclusions about the writing and the writers. *
Numismatics Numismatics is the study or collection of currency, including coins, tokens, paper money, medals and related objects. Specialists, known as numismatists, are often characterized as students or collectors of coins, but the discipline also inc ...
– many coins have the date of their production written on them or their use is specified in the historical record. *
Palaeography Palaeography ( UK) or paleography ( US; ultimately from grc-gre, , ''palaiós'', "old", and , ''gráphein'', "to write") is the study of historic writing systems and the deciphering and dating of historical manuscripts, including the analysi ...
– the study of ancient writing, including the practice of deciphering, reading, and dating historical manuscripts.


Seriation

Seriation is a relative dating method (see, above, the list of relative dating methods). An example of a practical application of seriation, is the comparison of the known
style Style is a manner of doing or presenting things and may refer to: * Architectural style, the features that make a building or structure historically identifiable * Design, the process of creating something * Fashion, a prevailing mode of clothing ...
of artifacts such as
stone tool A stone tool is, in the most general sense, any tool made either partially or entirely out of stone. Although stone tool-dependent societies and cultures still exist today, most stone tools are associated with prehistoric (particularly Stone A ...
s or pottery.


Age-equivalent stratigraphic markers

*
Paleomagnetism Paleomagnetism (or palaeomagnetismsee ), is the study of magnetic fields recorded in rocks, sediment, or archeological materials. Geophysicists who specialize in paleomagnetism are called ''paleomagnetists.'' Certain magnetic minerals in roc ...
(a relative dating method, see the corresponding list above) * Marine isotope stages based on the oxygen isotope ratio cycle (a relative dating method, see the corresponding list above) * Tephrochronology (an absolute dating method, see the corresponding list above)


Stratigraphic relationships

The
stratigraphy Stratigraphy is a branch of geology concerned with the study of rock layers ( strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...
of an archaeological site can be used to date, or refine the date, of particular activities ("contexts") on that site. For example, if a context is sealed between two other contexts of known date, it can be inferred that the middle context must date to between those dates.


See also

*
Astronomical chronology Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest ...
**
Age of Earth The age of Earth is estimated to be 4.54 ± 0.05 billion years This age may represent the age of Earth's accretion, or core formation, or of the material from which Earth formed. This dating is based on evidence from radiometric age-dating of ...
** Age of the universe *
Geochronology Geochronology is the science of determining the age of rocks, fossils, and sediments using signatures inherent in the rocks themselves. Absolute geochronology can be accomplished through radioactive isotopes, whereas relative geochronology is ...
**
Geologic time scale The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochr ...
** Geological history of Earth * Archaeological science


References

{{Authority control Chronology *