Radiocarbon dating

4675:: what is the true relationship between two or more objects at an archaeological site? It frequently happens that a sample for radiocarbon dating can be taken directly from the object of interest, but there are also many cases where this is not possible. Metal grave goods, for example, cannot be radiocarbon dated, but they may be found in a grave with a coffin, charcoal, or other material which can be assumed to have been deposited at the same time. In these cases, a date for the coffin or charcoal is indicative of the date of deposition of the grave goods, because of the direct functional relationship between the two. There are also cases where there is no functional relationship, but the association is reasonably strong: for example, a layer of charcoal in a rubbish pit provides a date which has a relationship to the rubbish pit. 1467:. In Libby's 1949 paper he used a value of 5720 ± 47 years, based on research by Engelkemeir et al. This was remarkably close to the modern value, but shortly afterwards the accepted value was revised to 5568 ± 30 years, and this value was in use for more than a decade. It was revised again in the early 1960s to 5,730 ± 40 years, which meant that many calculated dates in papers published prior to this were incorrect (the error in the half-life is about 3%). For consistency with these early papers, it was agreed at the 1962 Radiocarbon Conference in Cambridge (UK) to use the "Libby half-life" of 5568 years. Radiocarbon ages are still calculated using this half-life, and are known as "Conventional Radiocarbon Age". Since the calibration curve (IntCal) also reports past atmospheric 4456:

no direct data was available. There is also a separate marine calibration curve, MARINE20. For a set of samples forming a sequence with a known separation in time, these samples form a subset of the calibration curve. The sequence can be compared to the calibration curve and the best match to the sequence established. This "wiggle-matching" technique can lead to more precise dating than is possible with individual radiocarbon dates. Wiggle-matching can be used in places where there is a plateau on the calibration curve, and hence can provide a much more accurate date than the intercept or probability methods are able to produce. The technique is not restricted to tree rings; for example, a stratified

33: 3838: 1869: 5327: 3614: 4765:), and subsequent research determined that the destruction of the forest was caused by the Valders ice readvance, the last southward movement of ice before the end of the Pleistocene in that area. Before the advent of radiocarbon dating, the fossilized trees had been dated by correlating sequences of annually deposited layers of sediment at Two Creeks with sequences in Scandinavia. This led to estimates that the trees were between 24,000 and 19,000 years old, and hence this was taken to be the date of the last advance of the 3198:

This effect is not uniform – the average effect is about 400 years, but there are local deviations of several hundred years for areas that are geographically close to each other. These deviations can be accounted for in calibration, and users of software such as CALIB can provide as an input the appropriate correction for the location of their samples. The effect also applies to marine organisms such as shells, and marine mammals such as whales and seals, which have radiocarbon ages that appear to be hundreds of years old.

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cases the scrolls were determined to be within 100 years of the palaeographically determined age. The Isaiah scroll was included in the testing and was found to have two possible date ranges at a 2σ confidence level, because of the shape of the calibration curve at that point: there is a 15% chance that it dates from 355 to 295 BC, and an 84% chance that it dates from 210 to 45 BC. Subsequently, these dates were criticized on the grounds that before the scrolls were tested, they had been treated with modern

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radiocarbon dates began to prove these ideas wrong in many instances, it became apparent that these innovations must sometimes have arisen locally. This has been described as a "second radiocarbon revolution". More broadly, the success of radiocarbon dating stimulated interest in analytical and statistical approaches to archaeological data. Taylor has also described the impact of AMS, and the ability to obtain accurate measurements from very small samples, as ushering in a third radiocarbon revolution.

4422: 4788: 3893:. The ions are accelerated and passed through a stripper, which removes several electrons so that the ions emerge with a positive charge. The ions, which may have from 1 to 4 positive charges (C to C), depending on the accelerator design, are then passed through a magnet that curves their path; the heavier ions are curved less than the lighter ones, so the different isotopes emerge as separate streams of ions. A particle detector then records the number of ions detected in the 4344:(usually represented by the Greek letter sigma as 1σ) on either side of the mean. However, a date range of 1σ represents only a 68% confidence level, so the true age of the object being measured may lie outside the range of dates quoted. This was demonstrated in 1970 by an experiment run by the British Museum radiocarbon laboratory, in which weekly measurements were taken on the same sample for six months. The results varied widely (though consistently with a 4451:. There are separate curves for the northern hemisphere (IntCal20) and southern hemisphere (SHCal20), as they differ systematically because of the hemisphere effect. The continuous sequence of tree-ring dates for the northern hemisphere goes back to 13,910 BP as of 2020, and this provides close to annual dating for IntCal20 much of the period, reduced where there are calibration plateaus, and increased when short term C spikes due to 4368: 4402:

rings that vary in thickness because of environmental factors such as the amount of rainfall in a given year. These factors affect all trees in an area, so examining tree-ring sequences from old wood allows the identification of overlapping sequences. In this way, an uninterrupted sequence of tree rings can be extended far into the past. The first such published sequence, based on bristlecone pine tree rings, was created by

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pollen purified from sediment sequences, or on small quantities of plant material or charcoal. Dates on organic material recovered from strata of interest can be used to correlate strata in different locations that appear to be similar on geological grounds. Dating material from one location gives date information about the other location, and the dates are also used to place strata in the overall geological timeline.

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fossil forest was used in an interlaboratory test, with results provided by over 70 laboratories. These tests produced a median age of 11,788 ± 8 BP (2σ confidence) which when calibrated gives a date range of 13,730 to 13,550 cal BP. The Two Creeks radiocarbon dates are now regarded as a key result in developing the modern understanding of North American glaciation at the end of the Pleistocene.

3981:. As with beta counting, both blank samples and standard samples are used. Two different kinds of blank may be measured: a sample of dead carbon that has undergone no chemical processing, to detect any machine background, and a sample known as a process blank made from dead carbon that is processed into target material in exactly the same way as the sample which is being dated. Any 2690: 3493:, or some mixture of the two. Calcium carbonate is very susceptible to dissolving and recrystallizing; the recrystallized material will contain carbon from the sample's environment, which may be of geological origin. If testing recrystallized shell is unavoidable, it is sometimes possible to identify the original shell material from a sequence of tests. It is also possible to test 4406:. Hans Suess used this data to publish the first calibration curve for radiocarbon dating in 1967. The curve showed two types of variation from the straight line: a long term fluctuation with a period of about 9,000 years, and a shorter-term variation, often referred to as "wiggles", with a period of decades. Suess said he drew the line showing the wiggles by "cosmic 2659: 358:. In addition to permitting more accurate dating within archaeological sites than previous methods, it allows comparison of dates of events across great distances. Histories of archaeology often refer to its impact as the "radiocarbon revolution". Radiocarbon dating has allowed key transitions in prehistory to be dated, such as the end of the 4874:

comparison and synchronization of events across great distances. The advent of radiocarbon dating may even have led to better field methods in archaeology since better data recording leads to a firmer association of objects with the samples to be tested. These improved field methods were sometimes motivated by attempts to prove that a

3818:). Each measuring device is also used to measure the activity of a blank sample – a sample prepared from carbon old enough to have no activity. This provides a value for the background radiation, which must be subtracted from the measured activity of the sample being dated to get the activity attributable solely to that sample's 4468:

based on the prior information that the sequence should be ordered in time. When Bayesian analysis was introduced, its use was limited by the need to use mainframe computers to perform the calculations, but the technique has since been implemented on programs available for personal computers, such as OxCal.

5200:: a) using the Libby half-life of 5568 years, rather than the currently accepted actual half-life of 5730 years; (b) the use of an NIST standard known as HOxII to define the activity of radiocarbon in 1950; (c) the use of 1950 as the date from which years "before present" are counted; (d) a correction for 4969:. With the development of AMS in the 1980s it became possible to measure these isotopes precisely enough for them to be the basis of useful dating techniques, which have been primarily applied to dating rocks. Naturally occurring radioactive isotopes can also form the basis of dating methods, as with 4826:

estimates were made of the age of 21 of the scrolls, and samples from most of these, along with other scrolls which had not been palaeographically dated, were tested by two AMS laboratories in the 1990s. The results ranged in age from the early 4th century BC to the mid 4th century AD. In all but two

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Archaeology is not the only field to make use of radiocarbon dating. Radiocarbon dates can also be used in geology, sedimentology, and lake studies, for example. The ability to date minute samples using AMS has meant that palaeobotanists and palaeoclimatologists can use radiocarbon dating directly on

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provide additional correlation. Radiocarbon dating earlier than the continuous tree ring sequence relies on correlation with more approximate records. SHCal20 is based on independent data where possible and derived from the northern curve by adding the average offset for the southern hemisphere where

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ratio had been constant historically. Although Libby had pointed out as early as 1955 the possibility that this assumption was incorrect, it was not until discrepancies began to accumulate between measured ages and known historical dates for artefacts that it became clear that a correction would need

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The calculation uses 8,033 years, the mean-life derived from Libby's half-life of 5,568 years, not 8,267 years, the mean-life derived from the more accurate modern value of 5,730 years. Libby's value for the half-life is used to maintain consistency with early radiocarbon testing results; calibration

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content; this can mean conversion to gaseous, liquid, or solid form, depending on the measurement technique to be used. Before this can be done, the sample must be treated to remove any contamination and any unwanted constituents. This includes removing visible contaminants, such as rootlets that may

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thus introduced takes a long time to percolate through the entire volume of the ocean. The deepest parts of the ocean mix very slowly with the surface waters, and the mixing is uneven. The main mechanism that brings deep water to the surface is upwelling, which is more common in regions closer to the

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ratio having remained the same over the preceding few thousand years. To verify the accuracy of the method, several artefacts that were datable by other techniques were tested; the results of the testing were in reasonable agreement with the true ages of the objects. Over time, however, discrepancies

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ratio as the atmosphere. These organisms contain about 1.3% of the carbon in the reservoir; sea organisms have a mass of less than 1% of those on land and are not shown in the diagram. Accumulated dead organic matter, of both plants and animals, exceeds the mass of the biosphere by a factor of nearly

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as would be expected if the ratio were the same as in the atmosphere. The time it takes for carbon from the atmosphere to mix with the surface ocean is only a few years, but the surface waters also receive water from the deep ocean, which has more than 90% of the carbon in the reservoir. Water in the

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in a sample into an estimated calendar age. The calculations involve several steps and include an intermediate value called the "radiocarbon age", which is the age in "radiocarbon years" of the sample: an age quoted in radiocarbon years means that no calibration curve has been used − the calculations

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The dating framework provided by radiocarbon led to a change in the prevailing view of how innovations spread through prehistoric Europe. Researchers had previously thought that many ideas spread by diffusion through the continent, or by invasions of peoples bringing new cultural ideas with them. As

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date was incorrect. Taylor also suggests that the availability of definite date information freed archaeologists from the need to focus so much of their energy on determining the dates of their finds, and led to an expansion of the questions archaeologists were willing to research. For example, from

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can be applied when there are several radiocarbon dates to be calibrated. For example, if a series of radiocarbon dates is taken from different levels in a stratigraphic sequence, Bayesian analysis can be used to evaluate dates which are outliers and can calculate improved probability distributions,

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To produce a curve that can be used to relate calendar years to radiocarbon years, a sequence of securely dated samples is needed which can be tested to determine their radiocarbon age. The study of tree rings led to the first such sequence: individual pieces of wood show characteristic sequences of

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Soil contains organic material, but because of the likelihood of contamination by humic acid of more recent origin, it is very difficult to get satisfactory radiocarbon dates. It is preferable to sieve the soil for fragments of organic origin, and date the fragments with methods that are tolerant of

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Any addition of carbon to a sample of a different age will cause the measured date to be inaccurate. Contamination with modern carbon causes a sample to appear to be younger than it really is: the effect is greater for older samples. If a sample that is 17,000 years old is contaminated so that 1% of

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Carbon is distributed throughout the atmosphere, the biosphere, and the oceans; these are referred to collectively as the carbon exchange reservoir, and each component is also referred to individually as a carbon exchange reservoir. The different elements of the carbon exchange reservoir vary in how

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before its final retreat marked the end of the Pleistocene in North America. In 1952 Libby published radiocarbon dates for several samples from the Two Creeks site and two similar sites nearby; the dates were averaged to 11,404 BP with a standard error of 350 years. This result was uncalibrated, as

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communities to waterproof baskets; the bitumen's radiocarbon age will be greater than is measurable by the laboratory, regardless of the actual age of the context, so testing the basket material will give a misleading age if care is not taken. A separate issue, related to re-use, is that of lengthy

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As a tree grows, only the outermost tree ring exchanges carbon with its environment, so the age measured for a wood sample depends on where the sample is taken from. This means that radiocarbon dates on wood samples can be older than the date at which the tree was felled. In addition, if a piece of

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in 2014 about radiocarbon date reporting conventions recommends that information should be provided about sample treatment, including the sample material, pretreatment methods, and quality control measurements; that the citation to the software used for calibration should specify the version number

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with the surface waters, and as a result water from some deep ocean areas has an apparent radiocarbon age of several thousand years. Upwelling mixes this "old" water with the surface water, giving the surface water an apparent age of about several hundred years (after correcting for fractionation).

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who had worked on the Scandinavian varve series, but his objections were eventually discounted by other geologists. In the 1990s samples were tested with AMS, yielding (uncalibrated) dates ranging from 11,640 BP to 11,800 BP, both with a standard error of 160 years. Subsequently, a sample from the

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For example, the uncalibrated date "UtC-2020: 3510 ± 60 BP" indicates that the sample was tested by the Utrecht van der Graaff Laboratorium ("UtC"), where it has a sample number of "2020", and that the uncalibrated age is 3510 years before present, ± 60 years. Related forms are sometimes used: for

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sequence in New Zealand, believed to predate human colonization of the islands, has been dated to 1314 AD ± 12 years by wiggle-matching. The wiggles also mean that reading a date from a calibration curve can give more than one answer: this occurs when the curve wiggles up and down enough that

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Over the next thirty years many calibration curves were published using a variety of methods and statistical approaches. These were superseded by the IntCal series of curves, beginning with IntCal98, published in 1998, and updated in 2004, 2009, 2013, and 2020. The improvements to these curves are

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A calibration curve is used by taking the radiocarbon date reported by a laboratory and reading across from that date on the vertical axis of the graph. The point where this horizontal line intersects the curve will give the calendar age of the sample on the horizontal axis. This is the reverse of

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can produce similar results, and can also reduce the apparent age if they are of more recent origin than the sample. The effect varies greatly and there is no general offset that can be applied; additional research is usually needed to determine the size of the offset, for example by comparing the

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ratio is lower in the southern hemisphere, with an apparent additional age of about 40 years for radiocarbon results from the south as compared to the north. This is because the greater surface area of ocean in the southern hemisphere means that there is more carbon exchanged between the ocean and

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For both the gas proportional counter and liquid scintillation counter, what is measured is the number of beta particles detected in a given time period. Since the mass of the sample is known, this can be converted to a standard measure of activity in units of either counts per minute per gram of

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To determine the age of a sample whose activity has been measured by beta counting, the ratio of its activity to the activity of the standard must be found. To determine this, a blank sample (of old, or dead, carbon) is measured, and a sample of known activity is measured. The additional samples

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of his own design. He converted the carbon in his sample to lamp black (soot) and coated the inner surface of a cylinder with it. This cylinder was inserted into the counter in such a way that the counting wire was inside the sample cylinder, in order that there should be no material between the

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The quantity of material needed for testing depends on the sample type and the technology being used. There are two types of testing technology: detectors that record radioactivity, known as beta counters, and accelerator mass spectrometers. For beta counters, a sample weighing at least 10 grams

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atoms; the bursts are proportional to the energy of the particle, so other sources of ionization, such as background radiation, can be identified and ignored. The counters are surrounded by lead or steel shielding, to eliminate background radiation and to reduce the incidence of cosmic rays. In

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ratio can be converted into each other exactly. For some time, beta counting methods were more accurate than AMS, but AMS is now more accurate and has become the method of choice for radiocarbon measurements. In addition to improved accuracy, AMS has two further significant advantages over beta

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activity is liquid scintillation counting, which was invented in 1950, but which had to wait until the early 1960s, when efficient methods of benzene synthesis were developed, to become competitive with gas counting; after 1970 liquid counters became the more common technology choice for newly

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prehistory possible by contributing a time scale that transcends local, regional and continental boundaries". It provides more accurate dating within sites than previous methods, which usually derived either from stratigraphy or from typologies (e.g. of stone tools or pottery); it also allows

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in a sample was to detect the radioactive decay of individual carbon atoms. In this approach, what is measured is the activity, in number of decay events per unit mass per time period, of the sample. This method is also known as "beta counting", because it is the beta particles emitted by the

4653:. Calibrated dates can also be expressed as "BP" instead of using "BC" and "AD". The curve used to calibrate the results should be the latest available IntCal curve. Calibrated dates should also identify any programs, such as OxCal, used to perform the calibration. In addition, an article in 5249:

is made. This effect is accounted for during calibration by using a different marine calibration curve; without this curve, modern marine life would appear to be 400 years old when radiocarbon dated. Similarly, the statement about land organisms is only true once fractionation is taken into

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concentration using this conventional age, any conventional ages calibrated against the IntCal curve will produce a correct calibrated age. When a date is quoted, the reader should be aware that if it is an uncalibrated date (a term used for dates given in radiocarbon years) it may differ

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Radiocarbon is also used to date carbon released from ecosystems, particularly to monitor the release of old carbon that was previously stored in soils as a result of human disturbance or climate change. Recent advances in field collection techniques also allow the radiocarbon dating of

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The reliability of the results can be improved by lengthening the testing time. For example, if counting beta decays for 250 minutes is enough to give an error of ± 80 years, with 68% confidence, then doubling the counting time to 500 minutes will allow a sample with only half as much

3512:. Of these, humins give the most reliable date as they are insoluble in alkali and less likely to contain contaminants from the sample's environment. A particular difficulty with dried peat is the removal of rootlets, which are likely to be hard to distinguish from the sample material. 3463:

It is common to reduce a wood sample to just the cellulose component before testing, but since this can reduce the volume of the sample to 20% of its original size, testing of the whole wood is often performed as well. Charcoal is often tested but is likely to need treatment to remove

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radiation are similar to measurements for the rest of the biosphere. Correcting for isotopic fractionation, as is done for all radiocarbon dates to allow comparison between results from different parts of the biosphere, gives an apparent age of about 400 years for ocean surface water.

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began to appear between the known chronology for the oldest Egyptian dynasties and the radiocarbon dates of Egyptian artefacts. Neither the pre-existing Egyptian chronology nor the new radiocarbon dating method could be assumed to be accurate, but a third possibility was that the

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atoms in the sample and not just the few that happen to decay during the measurements; it can therefore be used with much smaller samples (as small as individual plant seeds), and gives results much more quickly. The development of radiocarbon dating has had a profound impact on

4410:", by which he meant that the variations were caused by extraterrestrial forces. It was unclear for some time whether the wiggles were real or not, but they are now well-established. These short term fluctuations in the calibration curve are now known as de Vries effects, after 4770:

the need for calibration of radiocarbon ages was not yet understood. Further results over the next decade supported an average date of 11,350 BP, with the results thought to be the most accurate averaging 11,600 BP. There was initial resistance to these results on the part of

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of errors in the measurements), and included multiple date ranges (of 1σ confidence) that did not overlap with each other. The measurements included one with a range from about 4,250 to about 4,390 years ago, and another with a range from about 4,520 to about 4,690.

4757:, the current geological epoch, begins about 11,700 years ago when the Pleistocene ends. Establishing the date of this boundary − which is defined by sharp climatic warming − as accurately as possible has been a goal of geologists for much of the 20th century. At 4052:

allow errors such as background radiation and systematic errors in the laboratory setup to be detected and corrected for. The most common standard sample material is oxalic acid, such as the HOxII standard, 1,000 lb (450 kg) of which was prepared by the

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to be measurable. Older dates have been obtained by using special sample preparation techniques, large samples, and very long measurement times. These techniques can allow measurement of dates up to 60,000 and in some cases up to 75,000 years before the present.

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Jull, A.J.T.; Pearson, C.L.; Taylor, R.E.; Southon, J.R.; Santos, G.M.; Kohl, C.P.; Hajdas, I.; Molnar, M.; Baisan, C.; Lange, T.E.; Cruz, R.; Janovics, R.; Major, I. (2018). "Radiocarbon dating and intercomparison of some early historical radiocarbon samples".

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Two recent estimates included 8–80 radiocarbon years over the last 1000 years, with an average of 41 ± 14 years; and −2 to 83 radiocarbon years over the last 2000 years, with an average of 44 ± 17 years. For older datasets an offset of about 50 years has been

3959:, for use in calculating the sample's radiocarbon age. The use of AMS, as opposed to simpler forms of mass spectrometry, is necessary because of the need to distinguish the carbon isotopes from other atoms or molecules that are very close in mass, such as 5313:

in the atmosphere decreases at the same rate as the reduction due to radiocarbon decay in the sample. For example, there was a plateau between around 750 and 400 BCE, which makes radiocarbon dates less accurate for samples dating to this period.

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counting: it can perform accurate testing on samples much too small for beta counting, and it is much faster – an accuracy of 1% can be achieved in minutes with AMS, which is far quicker than would be achievable with the older technology.

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concentrations in the neighbourhood of large cities are lower than the atmospheric average. This fossil fuel effect (also known as the Suess effect, after Hans Suess, who first reported it in 1955) would only amount to a reduction of 0.2% in

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in the atmosphere has varied significantly and as a result, the values provided by the equation above have to be corrected by using data from other sources. This is done by calibration curves (discussed below), which convert a measurement of

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equator. Upwelling is also influenced by factors such as the topography of the local ocean bottom and coastlines, the climate, and wind patterns. Overall, the mixing of deep and surface waters takes far longer than the mixing of atmospheric

1940:: comparison of overlapping series of tree rings allowed the construction of a continuous sequence of tree-ring data that spanned 8,000 years. (Since that time the tree-ring data series has been extended to 13,900 years.) In the 1960s, 4831:

in order to make the writing easier to read; it was argued that failure to remove the castor oil sufficiently would have caused the dates to be too young. Multiple papers have been published both supporting and opposing the criticism.

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in the sample before testing. This can be done with a thermal diffusion column. The process takes about a month and requires a sample about ten times as large as would be needed otherwise, but it allows more precise measurement of the

206:(the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by this process date to approximately 50,000 years ago (in this interval about 99.8% of the 4047:

The calculations to be performed on the measurements taken depend on the technology used, since beta counters measure the sample's radioactivity whereas AMS determines the ratio of the three different carbon isotopes in the sample.

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the radiocarbon age intercepts the curve in more than one place, which may lead to a radiocarbon result being reported as two separate age ranges, corresponding to the two parts of the curve that the radiocarbon age intercepted.

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Bousman, C. Britt; Vierra, Bradley J. (2012). "Chronology, Environmental Setting, and Views of the Terminal Pleistocene and Early Holocene Cultural Transitions in North America". In Bousman, C. Britt; Vierra, Bradley J. (eds.).

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the sample is modern carbon, it will appear to be 600 years younger; for a sample that is 34,000 years old, the same amount of contamination would cause an error of 4,000 years. Contamination with old carbon, with no remaining

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Errors in procedure can also lead to errors in the results. If 1% of the benzene in a modern reference sample accidentally evaporates, scintillation counting will give a radiocarbon age that is too young by about 80 years.

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The Northern hemisphere curve from IntCal20. As of 2020, this is the most recent version of the standard calibration curve. The diagonal line shows where the curve would lie if radiocarbon ages and calendar ages were the

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ratio in the atmosphere at that time. Equipped with the results of carbon-dating the tree rings, it became possible to construct calibration curves designed to correct the errors caused by the variation over time in the

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Heaton, Timothy J.; Köhler, Peter; Butzin, Martin; Bard, Edouard; Reimer, Ron W.; Austin, William E. N.; Ramsey, Christopher Bronk; Grootes, Pieter M.; Hughen, Konrad A.; Kromer, Bernd; Reimer, Paula J. (August 2020).

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has decayed, or the reservoir is receiving carbon that is not at the atmospheric baseline. The ocean surface is an example: it contains 2.4% of the carbon in the exchange reservoir, but there is only about 95% as much

2654:{\displaystyle \delta {\ce {^{13}C}}=\left({\frac {\left({\frac {{\ce {^{13}C}}}{{\ce {^{12}C}}}}\right)_{\text{sample}}}{\left({\frac {{\ce {^{13}C}}}{{\ce {^{12}C}}}}\right)_{\text{standard}}}}-1\right)\times 1000} 1944:

was able to use the tree-ring sequence to show that the dates derived from radiocarbon were consistent with the dates assigned by Egyptologists. This was possible because although annual plants, such as corn, have a

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Hogg, Alan G.; Heaton, Timothy J.; Hua, Quan; Palmer, Jonathan G.; Turney, Chris SM; Southon, John; Bayliss, Alex; Blackwell, Paul G.; Boswijk, Gretel; Ramsey, Christopher Bronk; Pearson, Charlotte (August 2020).

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activity if the additional carbon from fossil fuels were distributed throughout the carbon exchange reservoir, but because of the long delay in mixing with the deep ocean, the actual effect is a 3% reduction.

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The data on carbon percentages in each part of the reservoir is drawn from an estimate of reservoir carbon for the mid-1990s; estimates of carbon distribution during pre-industrial times are significantly

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Korff's paper actually referred to slow neutrons, a term that since Korff's time has acquired a more specific meaning, referring to a range of neutron energies that does not overlap with thermal neutrons.

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in a sample from a dead plant or animal, such as a piece of wood or a fragment of bone, provides information that can be used to calculate when the animal or plant died. The older a sample is, the less

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signal from the process blank measures the amount of contamination introduced during the preparation of the sample. These measurements are used in the subsequent calculation of the age of the sample.

3293:, will acquire carbonate ions. Similarly, groundwater can contain carbon derived from the rocks through which it has passed. These rocks are usually so old that they no longer contain any measurable 4418:

the way the curve is constructed: a point on the graph is derived from a sample of known age, such as a tree ring; when it is tested, the resulting radiocarbon age gives a data point for the graph.

3424:, causes an error in the other direction independent of age – a sample contaminated with 1% old carbon will appear to be about 80 years older than it truly is, regardless of the date of the sample. 1282: 4858:

The development of radiocarbon dating has had a profound impact on archaeology – often described as the "radiocarbon revolution". In the words of anthropologist R. E. Taylor, "

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ratio is taken as the indicator of age. To avoid this, all radiocarbon measurements are converted to the measurement that would have been seen had the sample been made of wood, which has a known δ

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Both beta counting and AMS results have to be corrected for fractionation. This is necessary because different materials of the same age, which because of fractionation have naturally different

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use, or delayed deposition. For example, a wooden object that remains in use for a lengthy period will have an apparent age greater than the actual age of the context in which it is deposited.

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During its life, a plant or animal is in equilibrium with its surroundings by exchanging carbon either with the atmosphere or through its diet. It will, therefore, have the same proportion of

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ratio of the water it enters, which can lead to apparent ages of thousands of years for both the affected water and the plants and freshwater organisms that live in it. This is known as the

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wood is used for multiple purposes, there may be a significant delay between the felling of the tree and the final use in the context in which it is found. This is often referred to as the

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ratio that reflects the atmospheric ratio at the time they were growing, trees only add material to their outermost tree ring in any given year, while the inner tree rings do not get their

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in the atmosphere transfers to the ocean by dissolving in the surface water as carbonate and bicarbonate ions; at the same time the carbonate ions in the water are returning to the air as

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Contamination is of particular concern when dating very old material obtained from archaeological excavations and great care is needed in the specimen selection and preparation. In 2014,

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Other materials that have been successfully dated include ivory, paper, textiles, individual seeds and grains, straw from within mud bricks, and charred food remains found in pottery.

239:, is now used to convert a given measurement of radiocarbon in a sample into an estimate of the sample's calendar age. Other corrections must be made to account for the proportion of 3780:

detectors are used; these record events outside the counter and any event recorded simultaneously both inside and outside the counter is regarded as an extraneous event and ignored.

3374:

ratio in the vicinity of the volcano is depressed relative to surrounding areas. Dormant volcanoes can also emit aged carbon. Plants that photosynthesize this carbon also have lower

9614: 4904:

Researchers have studied other isotopes created by cosmic rays to determine if they could also be used to assist in dating objects of archaeological interest; such isotopes include

3475:, one of the constituent amino acids in bone, was once thought to be a reliable indicator as it was not known to occur except in bone, but it has since been detected in groundwater. 8262:

Elder, Clayton D.; Xu, Xiaomei; Walker, Jennifer; Schnell, Jordan L.; Hinkel, Kenneth M.; Townsend-Small, Amy; Arp, Christopher D.; Pohlman, John W.; Gaglioti, Benjamin V. (2018).

1106:

decays at a known rate, the proportion of radiocarbon can be used to determine how long it has been since a given sample stopped exchanging carbon – the older the sample, the less

265:(reservoir effects). Additional complications come from the burning of fossil fuels such as coal and oil, and from the above-ground nuclear tests performed in the 1950s and 1960s. 3992:

signal from the machine background blank is likely to be caused either by beams of ions that have not followed the expected path inside the detector or by carbon hydrides such as

4855:

research laboratories. It quickly became apparent that the principles of radiocarbon dating were valid, despite certain discrepancies, the causes of which then remained unknown.

9619: 536:, independently dated to 2625 BC plus or minus 75 years, were dated by radiocarbon measurement to an average of 2800 BC plus or minus 250 years. These results were published in 395:

began experiments to determine if any of the elements common in organic matter had isotopes with half-lives long enough to be of value in biomedical research. They synthesized

6892:

Hogg, A.G.; Hua, Q.; Blackwell, P.G.; Niu, M.; Buck, C.E.; Guilderson, T.P.; Heaton, T.J.; Palmer, J.G.; Reimer, P.J.; Reimer, R.W.; Turney, C.S.M.; Zimmerman, S.R.H. (2013).

3130:

ratio in the exchange reservoir is constant all over the world, but it has since been discovered that there are several causes of variation in the ratio across the reservoir.

4570: 4521: 6354:

Reimer, Paula J.; Bard, Edouard; Bayliss, Alex; Beck, J. Warren; Blackwell, Paul G.; Ramsey, Christopher Bronk; Buck, Caitlin E.; Cheng, Hai; Edwards, R. Lawrence (2013).

4698:

at Withy Bed Copse, in England; the trackway was built from wood that had clearly been worked for other purposes before being re-used in the trackway. Another example is

9654: 2894:

values. The animal's own biochemical processes can also impact the results: for example, both bone minerals and bone collagen typically have a higher concentration of

7399:

Tuniz, C.; Zoppi, U.; Barbetti, M. (2004). "Radionuclide dating in archaeology by accelerator mass spectrometry". In Martini, M.; Milazzo, M.; Piacentini, M. (eds.).

3605:(0.35 ounces) is typically required. Accelerator mass spectrometry is much more sensitive, and samples containing as little as 0.5 milligrams of carbon can be used. 1802:

it contains will often give an incorrect result. There are several other possible sources of error that need to be considered. The errors are of four general types:

8667: 2260:

in the atmosphere, with the peak level occurring in 1964 for the northern hemisphere, and in 1966 for the southern hemisphere. The level has since dropped, as this

3806:

as they interact with a fluorescing agent added to the benzene. Like gas counters, liquid scintillation counters require shielding and anticoincidence counters.

1352:) is a more familiar concept than the mean-life, so although the equations above are expressed in terms of the mean-life, it is more usual to quote the value of 540:

in December 1949. Within 11 years of their announcement, more than 20 radiocarbon dating laboratories had been set up worldwide. In 1960, Libby was awarded the

4649:

For example, "cal 1220–1281 AD (1σ)" means a calibrated date for which the true date lies between AD 1220 and AD 1281, with a confidence level of '1 sigma', or

5073:

Some of Libby's original samples have since been retested, and the results, published in 2018, were generally in good agreement with Libby's original results.

5779:

Marine radiocarbon reservoir effects (MRE) in archaeology: temporal and spatial changes through the Holocene within the UK coastal environment (PhD thesis)

3889:

ratio directly. The sample, often in the form of graphite, is made to emit C ions (carbon atoms with a single negative charge), which are injected into an

1652:

deep ocean takes about 1,000 years to circulate back through surface waters, and so the surface waters contain a combination of older water, with depleted

528:

proceeded to test the radiocarbon dating theory by analyzing samples with known ages. For example, two samples taken from the tombs of two Egyptian kings,

4818:

texts because many of them contain the earliest known version of books of the Hebrew bible. A sample of the linen wrapping from one of these scrolls, the

4476:

Several formats for citing radiocarbon results have been used since the first samples were dated. As of 2019, the standard format required by the journal

1710:

ratio, the radiocarbon age of marine life is typically about 400 years. Organisms on land are in closer equilibrium with the atmosphere and have the same

2190:

A much larger effect comes from above-ground nuclear testing, which released large numbers of neutrons into the atmosphere, resulting in the creation of

4702:, which may be used as construction material. It is not always possible to recognize re-use. Other materials can present the same problem: for example, 217:

will have decayed), although special preparation methods occasionally make an accurate analysis of older samples possible. In 1960, Libby received the

5196:

The term "conventional radiocarbon age" is also used. The definition of radiocarbon years is as follows: the age is calculated by using the following

3735:

sample and the wire. Any interposing material would have interfered with the detection of radioactivity, since the beta particles emitted by decaying

1308:

ratio as the ratio in the atmosphere, and since the size of the sample is known, the total number of atoms in the sample can be calculated, yielding

6963:

Pasquier-Cardin, Aline; Allard, Patrick; Ferreira, Teresa; Hatte, Christine; Coutinho, Rui; Fontugne, Michel; Jaudon, Michel (1999). "Magma-derived

2844:

available for the photosynthetic reactions. Under these conditions, fractionation is reduced, and at temperatures above 14 °C (57 °F) the

7316:

L'Annunziata, Michael F.; Kessler, Michael J. (2012). "Liquid scintillation analysis: principles and practice". In L'Annunziata, Michael F. (ed.).

3565:

Once contamination has been removed, samples must be converted to a form suitable for the measuring technology to be used. Where gas is required,

485:, where he began his work on radiocarbon dating. He published a paper in 1946 in which he proposed that the carbon in living matter might include 2118:

Coal and oil began to be burned in large quantities during the 19th century. Both are sufficiently old that they contain little or no detectable

1791:

ratio in different parts of the carbon exchange reservoir means that a straightforward calculation of the age of a sample based on the amount of

4844:, universities around the world began establishing radiocarbon-dating laboratories, and by the end of the 1950s, there were more than 20 active 5135:(which determines the mean-life) was thought to be 5568 ± 30 years in 1952. The mean-life and half-life are related by the following equation: 4053: 521:

in 1947, in which the authors commented that their results implied it would be possible to date materials containing carbon of organic origin.

8311:"Ancient dissolved methane in inland waters revealed by a new collection method at low field concentrations for radiocarbon ( 14 C) analysis" 4246: 9322: 8998: 3454:

acid and carbonate contamination, but care has to be taken to avoid removing the part of the sample that contains the carbon to be tested.

515:. By contrast, methane created from petroleum showed no radiocarbon activity because of its age. The results were summarized in a paper in 3926:, needed for calibration) is too great for individual ion detection, counts are determined by measuring the electric current created in a 3255:

is removed from the southern atmosphere more quickly than in the north. The effect is strengthened by strong upwelling around Antarctica.

660:, and to a lesser degree by solar cosmic rays. These cosmic rays generate neutrons as they travel through the atmosphere which can strike 7089:Šilar, Jan (2004). "Application of environmental radionuclides in radiochronology: Radiocarbon". In Tykva, Richard; Berg, Dieter (eds.). 4762: 1562:

in the different reservoirs, and hence the radiocarbon ages of samples that originated in each reservoir. The atmosphere, which is where

320:

in the atmosphere, which reached a maximum in about 1965 of almost double the amount present in the atmosphere prior to nuclear testing.

5187:

Two experimentally determined values from the early 1950s were not included in the value Libby used: ~6,090 years, and 5900 ± 250 years.

478:, who was then at Berkeley, learned of Korff's research and conceived the idea that it might be possible to use radiocarbon for dating. 9624: 8709: 6636:

Suess, H.E. (1970). "Bristlecone-pine calibration of the radiocarbon time-scale 5200 B.C. to the present". In Olsson, Ingrid U. (ed.).

3210:

systems that are sufficiently independent of each other that there is a noticeable time lag in mixing between the two. The atmospheric

4325:

Radiocarbon dating is generally limited to dating samples no more than 50,000 years old, as samples older than that have insufficient

5580:

Anderson, E.C.; Libby, W.F.; Weinhouse, S.; Reid, A.F.; Kirshenbaum, A.D.; Grosse, A.V. (1947). "Radiocarbon from cosmic radiation".

4898: 3764:

created by nuclear weapons testing). These counters record bursts of ionization caused by the beta particles emitted by the decaying

6283: 4822:, was included in a 1955 analysis by Libby, with an estimated age of 1,917 ± 200 years. Based on an analysis of the writing style, 142:

by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of

7353: 5476: 5104:

migrates into the atmosphere. However, this pathway is estimated to be responsible for less than 0.1% of the total production of

3330:

effect because it is often associated with calcium ions, which are characteristic of hard water; other sources of carbon such as

2011:

ratio of the year it grew in. Carbon-dating the wood from the tree rings themselves provides the check needed on the atmospheric

7981: 2163:

ratio. Dating an object from the early 20th century hence gives an apparent date older than the true date. For the same reason,

4901:; the results pointed to 14th-century origins, raising doubts about the shroud's authenticity as an alleged 1st-century relic. 4658:

and any options or models used; and that the calibrated date should be given with the associated probabilities for each range.

4621:

dates are frequently reported as "cal BP", "cal BC", or "cal AD", again with 'BP' referring to the year 1950 as the zero date.

2272:

Photosynthesis is the primary process by which carbon moves from the atmosphere into living things. In photosynthetic pathways

4375:

The calculations given above produce dates in radiocarbon years: i.e. dates that represent the age the sample would be if the

8680: 8656: 8628: 8605: 8527: 8495: 8429: 8397: 8086: 7574: 7508: 7483: 7408: 7333: 7275: 7250: 7186: 7098: 6858: 6818: 6781: 6546: 6491: 6466: 6426: 5820: 5197: 4897:, a piece of linen cloth thought by some to bear an image of Jesus Christ after his crucifixion. Three separate laboratories 4371:

The stump of a very old bristlecone pine. Tree rings from these trees (among others) are used in building calibration curves.

1226: 1206:– i.e. the average or expected time a given atom will survive before undergoing radioactive decay. The mean-life, denoted by 7177:(1996). "Applications of accelerator mass spectrometry to soil science". In Boutton, Thomas W.; Yamasaki, Shin-ichi (eds.). 5348: 1479:

substantially from the best estimate of the actual calendar date, both because it uses the wrong value for the half-life of

8769: 5423:

Korff, S.A. (1940). "On the contribution to the ionization at sea-level produced by the neutrons in the cosmic radiation".

3263:

If the carbon in freshwater is partly acquired from aged carbon, such as rocks, then the result will be a reduction in the

637:) is about 5,730 years, so its concentration in the atmosphere might be expected to decrease over thousands of years, but 3952:

to interfere with the measurements, to dissociate, so they are not detected. Most AMS machines also measure the sample's

3795:

constructed dating laboratories. The counters work by detecting flashes of light caused by the beta particles emitted by

808:

Carbon dioxide produced in this way diffuses in the atmosphere, is dissolved in the ocean, and is taken up by plants via

7241:

Killick, David (2014). "Using evidence from natural sciences in archaeology". In Chapman, Robert; Alison, Wylie (eds.).

9116: 7300: 5960: 5138: 9317: 8913: 8686: 4986: 3655:

atoms that are detected. In the late 1970s an alternative approach became available: directly counting the number of

1764: 6157:

Engelkemeir, Antoinette G.; Hamill, W.H.; Inghram, Mark G.; Libby, W.F. (1949). "The Half-Life of Radiocarbon (C)".

8953: 4042: 3841:

Simplified schematic layout of an accelerator mass spectrometer used for counting carbon isotopes for carbon dating

3478:

For burnt bone, testability depends on the conditions under which the bone was burnt. If the bone was heated under

8390:

From the Pleistocene to the Holocene: Human Organization and Cultural Transformations in Prehistoric North America

3077:

concentration almost exactly cancels out the decrease caused by the upwelling of water (containing old, and hence

1051:

as the atmosphere, or in the case of marine animals or plants, with the ocean. Once it dies, it ceases to acquire

7430: 4603:

yr BP" might be used to distinguish the uncalibrated date from a date derived from another dating method such as

2227:

had immediately been spread across the entire carbon exchange reservoir, it would have led to an increase in the

1203: 2349:

ratios in plants that differ from the ratios in the atmosphere. This effect is known as isotopic fractionation.

1513:

Simplified version of the carbon exchange reservoir, showing proportions of carbon and relative activity of the

5744: 1606:

in the atmosphere is taken as the baseline for the other reservoirs: if another reservoir has a lower ratio of

1125: 5854:: production and examples of its unique applications in studies of terrestrial and extraterrestrial processes" 9363: 9111: 7470:

Terasmae, J. (1984). "Radiocarbon dating: some problems and potential developments". In Mahaney, W.C. (ed.).

5093:, and in some circumstances (e.g. near the surface of snow accumulations, which are permeable to gases) this 4679: 3586: 3578: 392: 339: 305:

in the atmosphere as the carbon dioxide generated from burning fossil fuels began to accumulate. Conversely,

17: 9644: 9639: 9106: 7352:

Eriksson Stenström, Kristina; Skog, Göran; Georgiadou, Elisavet; Genberg, Johan; Johansson, Anette (2011).

4886:

the 1970s questions about the evolution of human behaviour were much more frequently seen in archaeology.

3837: 9669: 9659: 9634: 9296: 9166: 8102:

Higham, T.; et al. (2014). "The timing and spatiotemporal patterning of Neanderthal disappearance".

5018: 3632:

For decades after Libby performed the first radiocarbon dating experiments, the only way to measure the

3482:, it (and associated organic matter) may have been carbonized. In this case, the sample is often usable. 9506: 9486: 6760:

Maslin, Mark A.; Swann, George E.A. (2006). "Isotopes in marine sediments". In Leng, Melanie J. (ed.).

4978: 4672: 3777: 3677:

atoms in a given sample, via accelerator mass spectrometry, usually referred to as AMS. AMS counts the

3433: 323:

Measurement of radiocarbon was originally done with beta-counting devices, which counted the amount of

2974:

have been found by experiment for many plants, as well as for different parts of animals such as bone

9496: 9468: 9301: 9080: 8704: 4982: 4604: 3341:

eject large amounts of carbon into the air. The carbon is of geological origin and has no detectable

2905:

than is found in the animal's diet, though for different biochemical reasons. The enrichment of bone

2440:

because the former is much easier to measure, and the latter can be easily derived: the depletion of

8168:

Godwin, Harry (1961). "The Croonian Lecture: Radiocarbon dating and Quaternary history in Britain".

3829:. In addition, a sample with a standard activity is measured, to provide a baseline for comparison. 2813:

For marine organisms, the details of the photosynthesis reactions are less well understood, and the

294:. As a result, beginning in the late 19th century, there was a noticeable drop in the proportion of 9563: 8762: 4542: 4493: 3485:

Shells from both marine and land organisms consist almost entirely of calcium carbonate, either as

541: 218: 5082:

The interaction of cosmic rays with nitrogen and oxygen below the earth's surface can also create

4302:

curves include a correction for this, so the accuracy of final reported calendar ages is assured.

4092:, which are used to calculate Fm, the "fraction modern". This is defined as the ratio between the 9501: 9451: 9238: 9085: 4990: 4893:

Occasionally, radiocarbon dating techniques date an object of popular interest, for example, the

4650: 4362: 3207: 2820:

values for marine photosynthetic organisms are dependent on temperature. At higher temperatures,

2462:

is proportional to the difference in the atomic masses of the two isotopes, so the depletion for

2202: 1891:

In the early years of using the technique, it was understood that it depended on the atmospheric

1884: 306: 32: 5343: 2352:

To determine the degree of fractionation that takes place in a given plant, the amounts of both

1883:

for the northern and southern hemispheres, showing percentage excess above pre-bomb levels. The

1385:

will remain; a quarter will remain after 11,400 years; an eighth after 17,100 years; and so on.

496:

as well as non-radioactive carbon. Libby and several collaborators proceeded to experiment with

9664: 9401: 9202: 8948: 8847: 6838: 4974: 4478: 1199: 3746:

are so weak that half are stopped by a 0.01 mm (0.00039 in) thickness of aluminium.

9003: 5339: 5335: 4758: 2693: 1198:

is a constant that depends on the particular isotope; for a given isotope it is equal to the

482: 78: 7471: 6761: 5896:

Queiroz-Alves, Eduardo; Macario, Kita; Ascough, Philippa; Bronk Ramsey, Christopher (2018).

235:

in the atmosphere has been over the past 50,000 years. The resulting data, in the form of a

9436: 9377: 9353: 9348: 8322: 8275: 8224: 8177: 8111: 8045: 7832: 7780: 7720: 7669: 7442: 6905: 6834: 6578: 6367: 6298: 6246: 6166: 5912: 5865: 5700: 5636: 5589: 5554: 5432: 5355: 5023: 4994: 4766: 3890: 3750: 1490:, and because no correction (calibration) has been applied for the historical variation of 56: 8264:"Greenhouse gas emissions from diverse Arctic Alaskan lakes are dominated by young carbon" 5898:"The worldwide marine radiocarbon reservoir effect: Definitions, mechanisms and prospects" 3450:

have penetrated the sample since its burial. Alkali and acid washes can be used to remove

2249:

ratio of only a few per cent, but the immediate effect was to almost double the amount of

8: 9463: 9358: 9276: 9266: 9041: 8958: 8938: 8928: 8755: 4819: 4345: 3479: 423: 97: 8617: 8326: 8279: 8228: 8181: 8115: 8049: 7836: 7784: 7724: 7673: 7446: 6909: 6582: 6371: 6302: 6250: 6170: 5916: 5869: 5704: 5640: 5593: 5558: 5436: 4815:, a small Jewish sect. These scrolls are of great significance in the study of Biblical 3699:

ratio directly, instead of the activity of the sample, but measurements of activity and

2264:

or "bomb carbon" (as it is sometimes called) percolates into the rest of the reservoir.

1073:

within its biological material at that time will continue to decay, and so the ratio of

9588: 9568: 9431: 9416: 9338: 9137: 9101: 8903: 8418: 8291: 8193: 8135: 8074: 7922: 7906: 7748: 7325: 6933: 6703:"Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water" 6314: 6264: 6215: 6065: 6005: 5980: 5928: 5726: 5652: 5046: 4464: 4341: 3471:, the protein fraction that remains after washing away the bone's structural material. 3338: 2764: 2754: 2665: 1868: 1733:

3, and since this matter is no longer exchanging carbon with its environment, it has a

812:. Animals eat the plants, and ultimately the radiocarbon is distributed throughout the 501: 415: 71: 8486:

Taylor, R.E. (1997). "Radiocarbon dating". In Taylor, R.E.; Aitken, Martin J. (eds.).

7386:

Development of the Lund AMS System and the Evaluation of a New AMS Detection Technique

7017: 5545:

Libby, W.F. (1946). "Atmospheric helium three and radiocarbon from cosmic radiation".

5444: 4592:

example, "2.3 ka BP" means 2,300 radiocarbon years before present (i.e. 350 BC), and "

410:

was far longer than had been previously thought. This was followed by a prediction by

9396: 9192: 9187: 9031: 8867: 8676: 8652: 8624: 8601: 8523: 8516: 8491: 8425: 8393: 8350: 8197: 8139: 8127: 8082: 7992: 7926: 7914: 7752: 7570: 7563: 7504: 7479: 7472: 7404: 7329: 7296: 7271: 7246: 7182: 7094: 6854: 6814: 6777: 6762: 6542: 6487: 6462: 6422: 6318: 6010: 5956: 5816: 5804: 5730: 5660: 5605: 5380: 5260: 3613: 3290: 2964: 634: 517: 236: 165: 8295: 8211:

Dean, Joshua F.; Garnett, Mark H.; Spyrakos, Evangelos; Billett, Michael F. (2019).

6937: 6268: 5932: 5777: 5326: 3497:, an organic protein found in shell, but it constitutes only 1–2% of shell material. 9593: 9542: 9458: 9406: 9182: 9160: 9026: 8923: 8713: 8705:

Almonds, pottery, wood help date famed Kyrenia shipwreck - Phys.org - June 26, 2024

8340: 8330: 8283: 8242: 8232: 8213:"The potential hidden age of dissolved organic carbon exported by peatland streams" 8185: 8119: 8053: 7898: 7850: 7840: 7798: 7788: 7738: 7728: 7687: 7677: 7658:"The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP)" 7450: 7321: 7013: 6923: 6913: 6846: 6769: 6586: 6417:

Post, Wilfred M. (2001). "Carbon cycle". In Goudie, Andrew; Cuff, David J. (eds.).

6385: 6375: 6306: 6254: 6205: 6174: 6080: 6000: 5992: 5920: 5873: 5808: 5716: 5708: 5644: 5597: 5562: 5440: 5388: 5370: 5002: 4998: 4808: 4796: 4691: 2736: 1937: 1363:'s half-life than its mean-life. The currently accepted value for the half-life of 687: 60: 37: 6591: 6566: 4587:", referring to a reference date of 1950, so that "500 BP" means the year AD 1450. 4158:

ratio that would have been measured in 1950 had there been no fossil fuel effect.

1452:

The correction factor applied to radiocarbon years to produce the calibrated date.

9649: 9526: 9491: 9478: 9441: 9388: 9246: 9141: 9075: 9036: 8873: 8335: 8310: 7709:"Recent Developments in Calibration for Archaeological and Environmental Samples" 7091:

Man-made and Natural Radioactivity in Environmental Pollution and Radiochronology

6310: 5648: 5624: 5601: 5034: 5029: 4970: 4894: 4804: 4411: 4403: 3562:

ratio in old material and extends the maximum age that can be reliably reported.

3451: 3335:

radiocarbon age of deposited freshwater shells with associated organic material.

2697: 1989:

through radioactive decay. Hence each ring preserves a record of the atmospheric

1573:

is generated, contains about 1.9% of the total carbon in the reservoirs, and the

1374:

is 5,700 ± 30 years. This means that after 5,700 years, only half of the initial

525: 406:

using the laboratory's cyclotron accelerator and soon discovered that the atom's

6356:"IntCal13 and Marine13 Radiocarbon Age Calibration Curves 0–50,000 Years cal BP" 4574:

is the laboratory's determination of the age of the sample, in radiocarbon years

9426: 9224: 9212: 9156: 9151: 9145: 9070: 8993: 8918: 8309:

Dean, Joshua F.; Billett, Michael F.; Murray, Callum; Garnett, Mark H. (2017).

7527: 7174: 6918: 6893: 6850: 6419:

Encyclopedia of Global Change: Environmental Change and Human Society, Volume 1

6380: 6355: 6084: 5897: 5721: 4775: 4733: 4729: 4584: 3731: 3472: 3438:

Samples for dating need to be converted into a form suitable for measuring the

2048:

remaining in the sample), the carbon-dating equation allows the calculation of

809: 411: 324: 128: 124: 8287: 7455: 6210: 6193: 5878: 5842: 4421: 2714:

value of about −13‰, which is much higher than for sheep that feed on grasses.

1509: 224:

Research has been ongoing since the 1960s to determine what the proportion of

9608: 9343: 9261: 9256: 9207: 9197: 8837: 6773: 6702: 5625:"Age determinations by radiocarbon content: checks with samples of known age" 5566: 5384: 5041: 3930:. The large positive charge induced by the stripper forces molecules such as 475: 359: 82: 8710:

Radiocarbon Dating and Chronological Modelling: Guidelines and Best Practice

8263: 7902: 6178: 5375: 5245:

For marine life, the age only appears to be 400 years once a correction for

4744: 2873:

value for animals depends on their diet. An animal that eats food with high

9421: 9219: 8933: 8908: 8893: 8859: 8819: 8354: 8189: 8131: 7918: 7431:"Converting AMS data to radiocarbon values: considerations and conventions" 6014: 5664: 5609: 4944: 4918: 4823: 4787: 4771: 4452: 4448: 3404:

were found to have apparent ages that ranged from 250 years to 3320 years.

1540:

generated by cosmic rays to fully mix with them. This affects the ratio of

1388:

The above calculations make several assumptions, such as that the level of

973: 649: 419: 384: 269: 250:

in different types of organisms (fractionation), and the varying levels of

5392: 4625:

gives two options for reporting calibrated dates. A common format is "cal

3581:, the carbon must be in liquid form; the sample is typically converted to 3000:

and carbonate at the ocean surface is also subject to fractionation, with

1628:, it indicates that the carbon is older and hence that either some of the 1456:

Calculating radiocarbon ages also requires the value of the half-life for

9121: 9018: 8980: 8963: 8898: 8879: 8812: 8792: 8237: 8212: 8030: 7821:"Marine20—The Marine Radiocarbon Age Calibration Curve (0–55,000 cal BP)" 5996: 5985:

Journal of Research of the National Institute of Standards and Technology

5924: 4957: 4750: 4683: 4440: 3927: 3528:

Particularly for older samples, it may be useful to enrich the amount of

3509: 3233:

the atmosphere than in the north. Since the surface ocean is depleted in

1399:

in the atmosphere has remained constant over time. In fact, the level of

661: 653: 355: 68: 8424:. Berkeley, California: University of California Press. pp. 94–95. 8123: 7845: 7820: 7793: 7768: 7743: 7733: 7708: 7682: 7657: 6219: 5712: 5342:). The updated content was reintegrated into the Knowledge page under a 8888: 8883: 8778: 8718: 7910: 7886: 7855: 7692: 7351: 6442:

Aitken, Martin J. (2003). "Radiocarbon dating". In Ellis, Linda (ed.).

5895: 5656: 4997:, as well as techniques that depend on annual bands or layers, such as 4828: 4580:

is the laboratory's estimate of the error in the age, at 1σ confidence.

4444: 4292:{\displaystyle {\text{Age}}=-\ln({\text{Fm}})\cdot 8033{\text{ years}}} 3501: 3494: 3327: 3088:-depleted, carbon) from the deep ocean, so that direct measurements of 2700:, Scotland. In the winter, these sheep eat seaweed, which has a higher 2261: 1941: 657: 367: 101: 8345: 8247: 7803: 6928: 6390: 2033:

ratio: with a sample of known date, and a measurement of the value of

1182:

is the number of atoms of the isotope in the original sample (at time

860:. In addition, about 1% of the carbon atoms are of the stable isotope 9578: 9558: 9291: 9251: 8988: 8797: 8392:. College Station, Texas: Texas A&M University Press. p. 4. 8370: 8368: 8366: 8364: 8151: 8149: 8058: 6259: 6234: 5204:, based on a standard isotope ratio, and (e) the assumption that the 4707: 4699: 4686:

artifacts are too recent because of contamination by "young carbon".

3811: 3486: 3286: 2985:

value for that sample directly than to rely on the published values.

813: 597: 582: 567: 553: 407: 388: 363: 262: 192: 64: 8420:

Nature's Clocks: How Scientists Measure the Age of Almost Everything

7522: 7520: 7424: 7422: 7420: 7224: 7222: 6670: 6668: 6666: 6664: 6125: 6123: 6121: 5752: 2668:. Because the PDB standard contains an unusually high proportion of 9573: 9411: 9055: 8968: 7991:. University of Arizona. May 25, 2011. pp. 5–7. Archived from 7367: 7365: 6140: 6138: 6064:

Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021).

5406: 5404: 4905: 4800: 4754: 4695: 4536:

identifies the laboratory that tested the sample, and the sample ID

4367: 3815: 3468: 3022:

to dissolve in the ocean. The result is an overall increase in the

2975: 2863:

becomes more soluble and hence more available to marine organisms.

2201:. From about 1950 until 1963, when atmospheric nuclear testing was 2066:

in the sample at the time the tree ring was formed – and hence the

969: 460: 105: 8361: 8146: 6962: 4753:

is a geological epoch that began about 2.6 million years ago. The

3173:

from the atmosphere into the surface waters of the ocean, but the

1186:= 0, when the organism from which the sample was taken died), and 9583: 8807: 8802: 8170:

Proceedings of the Royal Society of London B: Biological Sciences

7517: 7417: 7219: 6661: 6118: 4931: 4812: 4725: 4703: 4639:

is the range of dates corresponding to the given confidence level

3582: 3490: 1688:

ratios as the water they live in, and as a result of the reduced

746: 611:), also known as "radiocarbon", is radioactive. The half-life of 563: 533: 497: 283:

to decay below detectable levels, fossil fuels contain almost no

7769:"SHCal20 Southern Hemisphere Calibration, 0–55,000 Years cal BP" 7362: 6894:"SHCal13 Southern Hemisphere Calibration, 0–50,000 Years cal BP" 6135: 5401: 4981:. Other dating techniques of interest to archaeologists include 3108:

Libby's original exchange reservoir hypothesis assumed that the

2851:

values are correspondingly higher, while at lower temperatures,

2496: 2305:. The differential uptake of the three carbon isotopes leads to 1448: 504:

their samples they were able to demonstrate that they contained

4457: 3628:

is now most commonly done with an accelerator mass spectrometer

3589:, solid graphite targets are the most common, although gaseous 3505: 3401: 3397: 2978:, but when dating a given sample it is better to determine the 750: 559: 120: 9630:

Knowledge articles published in peer-reviewed literature (W2J)

7885:

Guilderson, Tom; Reimer, Paula; Brown, Tom (21 January 2005).

5981:"The remarkable metrological history of radiocarbon dating II" 4682:

and co-workers suggested that many of the dates published for

4340:

Radiocarbon dates are generally presented with a range of one

1936:

ratio had changed over time. The question was resolved by the

1120:

The equation governing the decay of a radioactive isotope is:

9008: 8747: 6839:"Diet reconstruction and ecology using stable isotope ratios" 6156: 5955:. Bristol, UK: Institute of Physics Publishing. p. 343. 5006: 4436: 4432: 3331: 2396:

ratio is then compared to a standard ratio known as PDB. The

529: 268:

Because the time it takes to convert biological materials to

8651:(2nd ed.). Walnut Creek, California: Left Coast Press. 6539:

Paleoclimates: Understanding Climate Change Past and Present

5291:

A plateau in the calibration curve occurs when the ratio of

4791:

Part of the Great Isaiah Scroll, one of the Dead Sea Scrolls

4398:

to be applied to radiocarbon ages to obtain calendar dates.

1348:

The half-life of a radioactive isotope (usually denoted by t

8942: 8824: 8081:. Strasbourg: European Science Foundation. pp. 48–49. 7320:(3rd ed.). Oxford: Academic Press. pp. 423–573 . 6813:. Hoboken, New Jersey: John Wiley & Sons. p. 276. 2689: 1828:

ratio in the atmosphere, both geographically and over time;

1221:

is 8,267 years, so the equation above can be rewritten as:

8735: 8210: 6281: 5579: 4059:

The results from AMS testing are in the form of ratios of

3753:, which were less affected by bomb carbon (the additional 8842: 5785:. Glasgow, Scotland UK: University of Glasgow. p. 16 4811:, most of which are thought to have been produced by the 4745:

Pleistocene/Holocene boundary in Two Creeks Fossil Forest

4241:

ratio is known, a "radiocarbon age" is calculated using:

3467:

Unburnt bone can be tested; it is usual to date it using

1584:

it contains mixes in less than seven years. The ratio of

1529:

much carbon they store, and in how long it takes for the

1341:

atoms currently in the sample, allows the calculation of

36:

Radiocarbon dating helped verify the authenticity of the

9615:

Knowledge articles published in peer-reviewed literature

8729: 8308: 7243:

Material Evidence: Learning From Archaeological Practice

6565:

Hua, Quan; Barbetti, Mike; Rakowski, Andrzej Z. (2013).

5689: 5259:"PDB" stands for "Pee Dee Belemnite", a fossil from the 4645:

indicates the confidence level for the given date range.

4183:

ratios, will appear to be of different ages because the

4136:

ratio in modern carbon, which is in turn defined as the

3396:

ratios: for example, plants in the neighbourhood of the

2832:

has poor solubility in water, which means there is less

1021:

nucleus reverts to the stable (non-radioactive) isotope

8079:

Handbooks for Archaeologists: No. 3: Radiocarbon Dating

7976: 7974: 7972: 7315: 3285:

ratio in the water. For example, rivers that pass over

1277:{\displaystyle t=\ln(N_{0}/N)\cdot {\text{8267 years}}} 272:

is substantially longer than the time it takes for its

9620:

Knowledge articles published in WikiJournal of Science

8724: 8031:"Conventions for reporting radiocarbon determinations" 7817: 7295:. Singapore: World Scientific Publishing. p. 24. 7093:. Dordrecht: Kluwer Academic Publishers. p. 166. 7004:

content of plants growing in Furnas caldera, Azores".

1286:

The sample is assumed to have originally had the same

8741: 8101: 7884: 6421:. Oxford: Oxford University Press. pp. 128–129. 6353: 5815:. Princeton: Princeton University Press. p. 35. 5141: 4545: 4496: 4322:

to be measured with the same error term of 80 years.

4249: 2510: 1229: 1128: 8261: 7969: 6063: 4840:

Soon after the publication of Libby's 1949 paper in

2707:

content than grass; samples from these sheep have a

1677:

Creatures living at the ocean surface have the same

500:

collected from sewage works in Baltimore, and after

9323:

Global Boundary Stratotype Section and Point (GSSP)

7765: 6891: 6564: 6541:. New York: Columbia University Press. p. 35. 4671:A key concept in interpreting radiocarbon dates is 2916:also implies that excreted material is depleted in 1345:, the age of the sample, using the equation above. 771:) in the atmosphere to form first carbon monoxide ( 342:has become the method of choice; it counts all the 8616: 8515: 8417: 7562: 7398: 6567:"Atmospheric Radiocarbon for the Period 1950–2010" 6191: 5171: 4564: 4515: 4291: 2653: 1423:for radiocarbon years assume that the atmospheric 1276: 1165: 77:The method was developed in the late 1940s at the 9655:Conservation and restoration of cultural heritage 7429:McNichol, A.P.; Jull, A.T.S.; Burr, G.S. (2001). 6481: 6066:"The NUBASE2020 evaluation of nuclear properties" 5172:{\displaystyle T_{\frac {1}{2}}=0.693\cdot \tau } 2941:makes up about 1% of the carbon in a sample, the 2111:ratio. These curves are described in more detail 622:(the time it takes for half of a given amount of 85:, based on the constant creation of radiocarbon ( 9606: 7498: 7428: 7136: 7134: 7132: 7130: 7128: 7126: 7124: 7122: 7072: 7070: 7068: 7066: 7064: 7062: 5477:"Radiocarbon Dating – American Chemical Society" 4761:, in Wisconsin, a fossil forest was discovered ( 3832: 1095:in its remains will gradually decrease. Because 547: 8217:Journal of Geophysical Research: Biogeosciences 6640:. New York: John Wiley & Sons. p. 303. 6198:Memoirs of the Society for American Archaeology 3783:The other common technology used for measuring 2141:released substantially diluted the atmospheric 7706: 7006:Journal of Volcanology and Geothermal Research 6811:Fundamentals of Contemporary Mass Spectrometry 6638:Radiocarbon Variations and Absolute Chronology 5974: 5972: 4899:dated samples of linen from the Shroud in 1988 4054:National Institute of Standards and Technology 8763: 8509: 8507: 8386: 8072: 7868: 7866: 7355:A guide to radiocarbon units and calculations 7119: 7059: 6651: 6649: 6647: 6631: 6629: 6627: 6532: 6530: 6528: 6515: 6513: 6511: 6509: 6507: 6505: 6503: 6108: 6106: 6104: 6102: 6100: 6098: 6096: 6094: 5803: 2294:, which in turn is more easily absorbed than 1326:atoms in the original sample. Measurement of 8522:. London: Academic Press. pp. 143–146. 8445: 8443: 8441: 7612: 7610: 7569:. London: Academic Press. pp. 125–126. 7530:. Woods Hole Oceanographic Institution. 2007 7268:A Consumer's Guide to Archaeological Science 7157: 7155: 7153: 7151: 7149: 7049: 7047: 7045: 7043: 7041: 7039: 6872: 6870: 6732: 6730: 6728: 6726: 6724: 6722: 6720: 6685: 6683: 6614: 6612: 6610: 6608: 6606: 6604: 6602: 6446:. New York: Garland Publishing. p. 506. 5891: 5889: 5573: 4431:based on new data gathered from tree rings, 3044:ratio in the ocean of 1.5%, relative to the 1504: 7290: 6887: 6885: 6833: 6827: 6759: 6755: 6753: 6751: 6749: 6747: 6745: 6560: 6558: 6450: 6349: 6347: 5969: 5622: 5528: 5526: 5524: 5522: 5520: 5518: 5516: 5456: 5454: 5246: 5201: 4763:Two Creeks Buried Forest State Natural Area 3206:The northern and southern hemispheres have 8770: 8756: 8504: 8490:. New York: Plenum Press. pp. 65–97. 8415: 7863: 7167: 6644: 6624: 6525: 6500: 6435: 6332: 6232: 6091: 6057: 5836: 5834: 5832: 5514: 5512: 5510: 5508: 5506: 5504: 5502: 5500: 5498: 5496: 5354:Mike Christie; et al. (1 June 2018). 5352:). The version of record as reviewed is: 4714: 4485:Uncalibrated dates should be reported as " 4056:(NIST) in 1977 from French beet harvests. 3749:Libby's method was soon superseded by gas 3608: 3577:is widely used. For samples to be used in 3457: 3066:ratio in the atmosphere. This increase in 1856:ratio in different parts of the reservoir; 1663:, and water recently at the surface, with 874:The equation for the radioactive decay of 648:is constantly being produced in the lower 8438: 8344: 8334: 8246: 8236: 8057: 7887:"The Boon and Bane of Radiocarbon Dating" 7854: 7844: 7802: 7792: 7742: 7732: 7691: 7681: 7607: 7554: 7542: 7454: 7146: 7036: 6927: 6917: 6867: 6717: 6680: 6599: 6590: 6475: 6389: 6379: 6258: 6209: 6004: 5953:Nuclear Methods in Science and Technology 5950: 5886: 5877: 5771: 5769: 5720: 5671: 5416: 5374: 4305: 2374:isotopes are measured, and the resulting 2267: 2205:, it is estimated that several tonnes of 1166:{\displaystyle N=N_{0}\,e^{-\lambda t}\,} 1162: 1145: 191:there is to be detected, and because the 9318:Global Standard Stratigraphic Age (GSSA) 8732:, indexing service for radiocarbon dates 8642:(2nd (1955) ed.). Chicago: Phoenix. 8411: 8409: 8380: 7469: 7463: 7265: 7259: 7245:. Abingdon, UK: Routledge. p. 166. 7181:. New York: Marcel Dekker. p. 318. 7173: 6882: 6764:Isotopes in Palaeoenvironmental Research 6742: 6555: 6482:Ferronsky, V.I.; Polyakov, V.A. (2012). 6398: 6344: 5451: 4786: 4420: 4366: 3836: 3612: 2988:The carbon exchange between atmospheric 2688: 1867: 1863: 1758: 1755:ratio lower than that of the biosphere. 1508: 1447: 31: 27:Method of determining the age of objects 8028: 7707:van der Plicht, J; et al. (2020). 7528:"Radiocarbon Data Calculations: NOSAMS" 7501:Radioactivity: Introduction and History 7388:. Lund: University of Lund. p. 16. 7383: 7377: 7240: 7234: 6461:. London: Academic Press. p. 690. 6456: 6185: 5946: 5944: 5942: 5840: 5829: 5797: 5775: 5683: 5493: 4739: 3523: 3500:The three major components of peat are 1190:is the number of atoms left after time 127:, which is incorporated into plants by 14: 9607: 8647:Taylor, R.E.; Bar-Yosef, Ofer (2014). 8513: 8485: 8479: 8167: 7982:"Radiocarbon: Information for authors" 7655: 7560: 6843:A Companion to Biological Anthropology 6536: 6441: 6410: 6275: 6226: 5978: 5813:Chemical Markers in Aquatic Ecosystems 5766: 5616: 2283:is absorbed slightly more easily than 459:would be more likely to be created by 448:. It had previously been thought that 153:it contains begins to decrease as the 8751: 8675:. Chichester: John Wiley & Sons. 8406: 8066: 7651: 7649: 7492: 7403:. Amsterdam: IOS Press. p. 395. 7392: 7347: 7345: 7309: 7088: 7082: 6635: 6282:van der Plicht, J.; Hogg, A. (2006). 5544: 5471: 5469: 5422: 4661: 3941:, which has a weight close enough to 437:in the upper atmosphere would create 7503:. Amsterdam: Elsevier. p. 528. 6808: 6802: 6768:. Dordrecht: Springer. p. 246. 6695: 6416: 5939: 3201: 3103: 2963:ratio can be accurately measured by 1887:went into effect on 10 October 1963. 1674:in equilibrium with the atmosphere. 1010:nucleus changes to a proton and the 474:. At some time during World War II, 8598:Science-based Dating in Archaeology 7358:. Lund: Lund University. p. 3. 6486:. New York: Springer. p. 372. 6484:Isotopes of the Earth's Hydrosphere 6459:Chemistry of the Natural Atmosphere 4782: 4706:is known to have been used by some 3867:in a given sample, determining the 3011:in the atmosphere more likely than 2887:than one that eats food with lower 24: 9117:Adoption of the Gregorian calendar 8488:Chronometric Dating in Archaeology 7656:Reimer, P.J.; et al. (2020). 7646: 7478:. Amsterdam: Elsevier. p. 5. 7342: 7318:Handbook of Radioactivity Analysis 7284: 7270:. New York: Springer. p. 96. 6845:. Oxford: Blackwell. p. 446. 6841:. In Larsen, Clark Spencer (ed.). 5623:Arnold, J.R.; Libby, W.F. (1949). 5466: 4803:that proved to contain writing in 4799:were discovered in caves near the 4471: 1978:replenished and instead only lose 775:), and ultimately carbon dioxide ( 767:quickly combines with the oxygen ( 338:atoms in a sample. More recently, 25: 9681: 9625:Externally peer reviewed articles 8721:, radiocarbon calibration program 8698: 7499:L'Annunziata, Michael F. (2007). 7293:Measurement of Weak Radioactivity 6284:"A note on reporting radiocarbon" 5425:Journal of the Franklin Institute 4987:optically stimulated luminescence 4666: 1765:Radiocarbon dating considerations 1445:ratio has not changed over time. 596:) are stable and nonradioactive; 8623:. London: British Museum Press. 8572: 8560: 8548: 8536: 8467: 8455: 8302: 8255: 8204: 8161: 8095: 8022: 8010: 7957: 7945: 7933: 7878: 7326:10.1016/b978-012436603-9/50010-7 6444:Archaeological Method and Theory 5325: 5285: 5226:ratio has not changed over time. 4694:. One example is the Bronze Age 4043:Calculation of radiocarbon dates 3904:stream, but since the volume of 3725: 3407: 3258: 3133: 2216:were created. If all this extra 2112: 968:By emitting a beta particle (an 393:Radiation Laboratory at Berkeley 8999:English and British regnal year 8595: 7939: 7811: 7759: 7700: 7634: 7622: 7616: 7595: 7583: 7401:Physics Methods in Archaeometry 7371: 7207: 7195: 7161: 7107: 7076: 7030: 7024: 6956: 6944: 6790: 6689: 6150: 6129: 6112: 6051: 6045: 6033: 6021: 5737: 5677: 5275: 5266: 5253: 5239: 5229: 5190: 5181: 5118: 5076: 5067: 4465:Bayesian statistical techniques 4036: 3162:. This exchange process brings 838:is approximately 1.25 parts of 8777: 5841:Lal, D.; Jull, A.J.T. (2001). 5538: 5330:This article was submitted to 5058: 4565:{\displaystyle {\ce {{}^14C}}} 4516:{\displaystyle {\ce {{}^14C}}} 4356: 4275: 4267: 3289:, which is mostly composed of 3244:because of the marine effect, 1263: 1242: 999:), one of the neutrons in the 168:. Measuring the proportion of 13: 1: 9112:Old Style and New Style dates 8744:, global radiocarbon database 8738:, global radiocarbon database 8543:Taylor & Bar-Yosef (2014) 8474:Taylor & Bar-Yosef (2014) 8450:Taylor & Bar-Yosef (2014) 8375:Taylor & Bar-Yosef (2014) 8017:Taylor & Bar-Yosef (2014) 7964:Taylor & Bar-Yosef (2014) 7641:Taylor & Bar-Yosef (2014) 7629:Taylor & Bar-Yosef (2014) 7602:Taylor & Bar-Yosef (2014) 7202:Taylor & Bar-Yosef (2014) 7018:10.1016/S0377-0273(99)00076-1 6951:Taylor & Bar-Yosef (2014) 6797:Taylor & Bar-Yosef (2014) 6656:Taylor & Bar-Yosef (2014) 6592:10.2458/azu_js_rc.v55i2.16177 6405:Taylor & Bar-Yosef (2014) 6339:Taylor & Bar-Yosef (2014) 6028:Taylor & Bar-Yosef (2014) 5461:Taylor & Bar-Yosef (2014) 5445:10.1016/s0016-0032(40)90838-9 5411:Taylor & Bar-Yosef (2014) 5320: 3833:Accelerator mass spectrometry 3730:Libby's first detector was a 3587:accelerator mass spectrometry 3579:liquid scintillation counters 1501:in the atmosphere over time. 1035: 690:is the main pathway by which 548:Physical and chemical details 373: 340:accelerator mass spectrometry 9064:Pre-Julian / Julian 8336:10.1016/j.watres.2017.03.009 6311:10.1016/j.quageo.2006.07.001 5649:10.1126/science.110.2869.678 5602:10.1126/science.105.2735.576 5026:, archaeological chronology 4114:ratio in the sample and the 3304:, so this carbon lowers the 2502:, is calculated as follows: 481:In 1945, Libby moved to the 7: 9297:Geological history of Earth 9167:Astronomical year numbering 8665: 8638:Libby, Willard F. (1965) . 8614: 8578: 8566: 8554: 8155: 8029:Millard, Andrew R. (2014). 7951: 7872: 7589: 7548: 7228: 7213: 7140: 7113: 7053: 6736: 6674: 6618: 6519: 6192:Johnson, Frederick (1951). 6144: 5951:Tsipenyuk, Yuri M. (1997). 5532: 5012: 2664:where the ‰ sign indicates 675:) atoms and turn them into 362:, and the beginning of the 63:by using the properties of 10: 9686: 8637: 8615:Bowman, Sheridan (1995) . 8588: 8461: 7291:Theodórsson, Páll (1996). 7266:Malainey, Mary E. (2010). 7179:Mass Spectrometry of Soils 6919:10.2458/azu_js_rc.55.16783 6876: 6851:10.1002/9781444320039.ch25 6537:Cronin, Thomas M. (2010). 6381:10.2458/azu_js_rc.55.16947 6235:"Half-life of Radiocarbon" 6039: 5272:The PDB value is 11.2372‰. 4673:archaeological association 4360: 4040: 3434:Radiocarbon dating samples 3431: 3427: 2880:values will have a higher 2473:is twice the depletion of 1762: 551: 422:, that the interaction of 378: 119:combines with atmospheric 9551: 9535: 9519: 9477: 9469:Thermoluminescence dating 9387: 9376: 9364:Samarium–neodymium dating 9331: 9310: 9284: 9275: 9237: 9175: 9130: 9094: 9063: 9054: 9017: 8979: 8858: 8833: 8785: 8669:Quaternary Dating Methods 8416:Macdougall, Doug (2008). 8288:10.1038/s41558-017-0066-9 7474:Quaternary Dating Methods 7456:10.1017/S0033822200038169 6211:10.1017/S0081130000000873 5979:Currie, Lloyd A. (2004). 5879:10.1017/S0033822200041394 5481:American Chemical Society 4835: 4560: 4511: 2618: 2604: 2571: 2557: 2526: 2418:ratio is used instead of 2055:– the number of atoms of 1505:Carbon exchange reservoir 9183:Chinese sexagenary cycle 8646: 8542: 8473: 8449: 8374: 8016: 7963: 7640: 7628: 7601: 7384:Wiebert, Anders (1995). 7201: 6950: 6835:Schoeninger, Margaret J. 6796: 6774:10.1007/1-4020-2504-1_06 6705:. US Department of State 6655: 6404: 6338: 6291:Quaternary Geochronology 6085:10.1088/1674-1137/abddae 6027: 5776:Russell, Nicola (2011). 5567:10.1103/PhysRev.69.671.2 5460: 5410: 5052: 4555: 4549: 4506: 4500: 3845:AMS counts the atoms of 2613: 2607: 2599: 2593: 2566: 2560: 2552: 2546: 2521: 2515: 2037:(the number of atoms of 656:, primarily by galactic 542:Nobel Prize in Chemistry 309:increased the amount of 219:Nobel Prize in Chemistry 59:of an object containing 9397:Amino acid racemisation 7903:10.1126/science.1104164 6457:Warneck, Peter (2000). 6179:10.1103/PhysRev.75.1825 5019:774–775 carbon-14 spike 4991:electron spin resonance 4715:Use outside archaeology 4363:Radiocarbon calibration 3609:Measurement and results 3458:Material considerations 3208:atmospheric circulation 2484:. The fractionation of 1885:Partial Test Ban Treaty 1831:isotopic fractionation; 414:, then employed at the 131:; animals then acquire 9402:Archaeomagnetic dating 8914:Era of Caesar (Iberia) 8190:10.1098/rspb.1961.0001 6982:emissions recorded in 6809:Dass, Chhabil (2007). 5363:WikiJournal of Science 5332:WikiJournal of Science 5173: 4971:potassium–argon dating 4792: 4732:, which are important 4566: 4517: 4427: 4372: 4306:Errors and reliability 4293: 3842: 3629: 2927:relative to the diet. 2715: 2655: 2268:Isotopic fractionation 2129:and, as a result, the 1888: 1525: 1453: 1278: 1167: 502:isotopically enriching 370:in different regions. 100:by the interaction of 41: 9302:Geological time units 8666:Walker, Mike (2005). 8596:Aitken, M.J. (1990). 8514:Taylor, R.E. (1987). 8268:Nature Climate Change 7561:Taylor, R.E. (1987). 5905:Reviews of Geophysics 5376:10.15347/WJS/2018.006 5174: 4979:uranium series dating 4790: 4567: 4518: 4424: 4370: 4294: 3840: 3810:carbon (cpm/g C), or 3751:proportional counters 3616: 2694:North Ronaldsay sheep 2692: 2686:values are negative. 2656: 1871: 1864:Atmospheric variation 1769:The variation in the 1759:Dating considerations 1512: 1451: 1279: 1168: 974:electron antineutrino 745:where n represents a 483:University of Chicago 79:University of Chicago 47:(also referred to as 35: 9354:Law of superposition 9349:Isotope geochemistry 8725:IntCal working group 8238:10.1029/2018JG004650 5997:10.6028/jres.109.013 5925:10.1002/2017RG000588 5843:"In-situ cosmogenic 5809:Canuel, Elizabeth A. 5356:"Radiocarbon dating" 5336:academic peer review 5139: 5024:Chronological dating 4995:fission track dating 4767:Wisconsin glaciation 4740:Notable applications 4543: 4494: 4247: 3814:per kg (Bq/kg C, in 3524:Preparation and size 2967:. Typical values of 2508: 1227: 1126: 327:emitted by decaying 123:to form radioactive 9645:American inventions 9640:1940s introductions 9487:Fluorine absorption 9464:Luminescence dating 9359:Luminescence dating 9267:Milankovitch cycles 9107:Proleptic Gregorian 8939:Hindu units of time 8692:on 13 October 2017. 8600:. London: Longman. 8327:2017WatRe.115..236D 8280:2018NatCC...8..166E 8229:2019JGRG..124..328D 8182:1961RSPSB.153..287G 8124:10.1038/nature13621 8116:2014Natur.512..306H 8050:2014Radcb..56..555M 7846:10.1017/RDC.2020.68 7837:2020Radcb..62..779H 7794:10.1017/RDC.2020.59 7785:2020Radcb..62..759H 7734:10.1017/RDC.2020.22 7725:2020Radcb..62.1095V 7683:10.1017/RDC.2020.41 7674:2020Radcb..62..725R 7447:2001Radcb..43..313M 6910:2013Radcb..55.1889H 6583:2013Radcb..55.2059H 6372:2013Radcb..55.1869R 6303:2006QuGeo...1..237V 6251:1962Natur.195..984G 6233:Godwin, H. (1962). 6171:1949PhRv...75.1825E 5917:2018RvGeo..56..278A 5870:2001Radcb..43..731L 5722:20.500.11850/263957 5713:10.1017/RDC.2018.18 5705:2018Radcb..60..535J 5641:1949Sci...110..678A 5594:1947Sci...105..576A 5559:1946PhRv...69..671L 5437:1940TeMAE..45..133K 4820:Great Isaiah Scroll 4346:normal distribution 4219:Once the corrected 3516:small sample sizes. 3480:reducing conditions 1938:study of tree rings 756:Once produced, the 749:and p represents a 57:determining the age 9670:Radiometric dating 9660:Isotopes of carbon 9635:Radiocarbon dating 9589:Terminus post quem 9569:Synchronoptic view 9536:Linguistic methods 9497:Obsidian hydration 9432:Radiometric dating 9417:Incremental dating 9339:Chronostratigraphy 8649:Radiocarbon Dating 8640:Radiocarbon Dating 8619:Radiocarbon Dating 8518:Radiocarbon Dating 7565:Radiocarbon Dating 7175:Trumbore, Susan E. 5805:Bianchi, Thomas S. 5553:(11–12): 671–672. 5263:in South Carolina. 5169: 5047:Radiometric dating 4983:thermoluminescence 4975:argon–argon dating 4793: 4662:Use in archaeology 4605:thermoluminescence 4562: 4513: 4428: 4373: 4342:standard deviation 4289: 3843: 3630: 3601:can also be used. 3339:Volcanic eruptions 2716: 2666:parts per thousand 2651: 1889: 1834:variations in the 1806:variations in the 1526: 1454: 1274: 1163: 416:Franklin Institute 98:Earth's atmosphere 55:) is a method for 45:Radiocarbon dating 42: 9602: 9601: 9515: 9514: 9372: 9371: 9233: 9232: 9188:Geologic Calendar 9050: 9049: 8682:978-0-470-86927-7 8658:978-1-59874-590-0 8630:978-0-7141-2047-8 8607:978-0-582-49309-4 8529:978-0-12-433663-6 8497:978-0-306-45715-9 8431:978-0-520-24975-2 8399:978-1-60344-760-7 8110:(7514): 306–309. 8088:978-2-903148-44-7 7998:on 10 August 2013 7576:978-0-12-433663-6 7551:, pp. 38–39. 7510:978-0-444-52715-8 7485:978-0-444-42392-4 7410:978-1-58603-424-5 7335:978-0-12-384873-4 7277:978-1-4419-5704-7 7252:978-0-415-83745-3 7188:978-0-8247-9699-0 7100:978-1-4020-1860-2 7056:, pp. 27–30. 6860:978-1-4051-8900-2 6820:978-0-471-68229-5 6783:978-1-4020-2503-7 6739:, pp. 20–23. 6692:, pp. 71–72. 6548:978-0-231-14494-0 6493:978-94-007-2855-4 6468:978-0-12-735632-7 6428:978-0-19-514518-2 6073:Chinese Physics C 5822:978-0-691-13414-7 5749:www.c14dating.com 5680:, pp. 60–61. 5635:(2869): 678–680. 5588:(2765): 576–577. 5261:Pee Dee formation 5154: 5124:The half-life of 4651:approximately 68% 4583:'BP' stands for " 4556: 4554: 4553: 4552: 4507: 4505: 4504: 4503: 4287: 4273: 4253: 3291:calcium carbonate 3202:Hemisphere effect 3104:Reservoir effects 2965:mass spectrometry 2811: 2810: 2632: 2629: 2620: 2614: 2612: 2611: 2610: 2600: 2598: 2597: 2596: 2582: 2573: 2567: 2565: 2564: 2563: 2553: 2551: 2550: 2549: 2522: 2520: 2519: 2518: 1524:in each reservoir 1272: 463:interacting with 237:calibration curve 166:radioactive decay 104:with atmospheric 72:isotope of carbon 16:(Redirected from 9677: 9594:ASPRO chronology 9543:Glottochronology 9459:Tephrochronology 9407:Dendrochronology 9385: 9384: 9282: 9281: 9081:Proleptic Julian 9071:Pre-Julian Roman 9061: 9060: 8856: 8855: 8772: 8765: 8758: 8749: 8748: 8714:Historic England 8693: 8691: 8685:. Archived from 8674: 8662: 8643: 8634: 8622: 8611: 8582: 8576: 8570: 8564: 8558: 8552: 8546: 8540: 8534: 8533: 8521: 8511: 8502: 8501: 8483: 8477: 8471: 8465: 8459: 8453: 8447: 8436: 8435: 8423: 8413: 8404: 8403: 8384: 8378: 8372: 8359: 8358: 8348: 8338: 8306: 8300: 8299: 8259: 8253: 8252: 8250: 8240: 8208: 8202: 8201: 8176:(952): 287–320. 8165: 8159: 8153: 8144: 8143: 8099: 8093: 8092: 8070: 8064: 8063: 8061: 8059:10.2458/56.17455 8035: 8026: 8020: 8014: 8008: 8007: 8005: 8003: 7997: 7986: 7978: 7967: 7961: 7955: 7949: 7943: 7937: 7931: 7930: 7882: 7876: 7870: 7861: 7860: 7858: 7848: 7815: 7809: 7808: 7806: 7796: 7763: 7757: 7756: 7746: 7736: 7704: 7698: 7697: 7695: 7685: 7653: 7644: 7638: 7632: 7626: 7620: 7619:, p. 66–67. 7614: 7605: 7599: 7593: 7587: 7581: 7580: 7568: 7558: 7552: 7546: 7540: 7539: 7537: 7535: 7524: 7515: 7514: 7496: 7490: 7489: 7477: 7467: 7461: 7460: 7458: 7426: 7415: 7414: 7396: 7390: 7389: 7381: 7375: 7369: 7360: 7359: 7349: 7340: 7339: 7313: 7307: 7306: 7288: 7282: 7281: 7263: 7257: 7256: 7238: 7232: 7226: 7217: 7211: 7205: 7199: 7193: 7192: 7171: 7165: 7159: 7144: 7138: 7117: 7111: 7105: 7104: 7086: 7080: 7074: 7057: 7051: 7034: 7028: 7022: 7021: 7012:(1–2): 200–201. 7003: 7001: 7000: 6992: 6990: 6989: 6981: 6980: 6979: 6971: 6970: 6960: 6954: 6948: 6942: 6941: 6931: 6921: 6904:(4): 1889–1903. 6889: 6880: 6874: 6865: 6864: 6831: 6825: 6824: 6806: 6800: 6794: 6788: 6787: 6767: 6757: 6740: 6734: 6715: 6714: 6712: 6710: 6699: 6693: 6687: 6678: 6672: 6659: 6653: 6642: 6641: 6633: 6622: 6616: 6597: 6596: 6594: 6577:(4): 2059–2072. 6562: 6553: 6552: 6534: 6523: 6517: 6498: 6497: 6479: 6473: 6472: 6454: 6448: 6447: 6439: 6433: 6432: 6414: 6408: 6402: 6396: 6395: 6393: 6383: 6366:(4): 1869–1887. 6351: 6342: 6336: 6330: 6329: 6327: 6325: 6288: 6279: 6273: 6272: 6262: 6260:10.1038/195984a0 6230: 6224: 6223: 6213: 6189: 6183: 6182: 6154: 6148: 6142: 6133: 6127: 6116: 6110: 6089: 6088: 6079:(3): 030001-22. 6070: 6061: 6055: 6049: 6043: 6037: 6031: 6025: 6019: 6018: 6008: 5976: 5967: 5966: 5948: 5937: 5936: 5902: 5893: 5884: 5883: 5881: 5853: 5851: 5850: 5838: 5827: 5826: 5801: 5795: 5794: 5792: 5790: 5784: 5773: 5764: 5763: 5761: 5760: 5751:. Archived from 5741: 5735: 5734: 5724: 5687: 5681: 5675: 5669: 5668: 5620: 5614: 5613: 5577: 5571: 5570: 5542: 5536: 5535:, pp. 9–15. 5530: 5491: 5490: 5488: 5487: 5473: 5464: 5458: 5449: 5448: 5420: 5414: 5408: 5396: 5378: 5360: 5351: 5340:reviewer reports 5329: 5315: 5312: 5310: 5309: 5301: 5299: 5298: 5289: 5283: 5279: 5273: 5270: 5264: 5257: 5251: 5243: 5237: 5233: 5227: 5225: 5223: 5222: 5214: 5212: 5211: 5194: 5188: 5185: 5179: 5178: 5176: 5175: 5170: 5156: 5155: 5147: 5134: 5132: 5131: 5122: 5116: 5114: 5112: 5111: 5103: 5101: 5100: 5092: 5090: 5089: 5080: 5074: 5071: 5065: 5062: 5003:tephrochronology 4999:dendrochronology 4967: 4965: 4964: 4954: 4952: 4951: 4941: 4939: 4938: 4928: 4926: 4925: 4915: 4913: 4912: 4884: 4882: 4881: 4868: 4866: 4865: 4854: 4852: 4851: 4783:Dead Sea Scrolls 4734:greenhouse gases 4692:old wood problem 4620: 4618: 4617: 4602: 4600: 4599: 4571: 4569: 4568: 4563: 4561: 4550: 4548: 4522: 4520: 4519: 4514: 4512: 4501: 4499: 4396: 4394: 4393: 4385: 4383: 4382: 4335: 4333: 4332: 4321: 4319: 4318: 4298: 4296: 4295: 4290: 4288: 4285: 4274: 4271: 4254: 4251: 4240: 4238: 4237: 4229: 4227: 4226: 4215: 4213: 4212: 4204: 4202: 4201: 4193: 4191: 4190: 4182: 4180: 4179: 4171: 4169: 4168: 4157: 4155: 4154: 4146: 4144: 4143: 4135: 4133: 4132: 4124: 4122: 4121: 4113: 4111: 4110: 4102: 4100: 4099: 4091: 4089: 4088: 4080: 4078: 4077: 4069: 4067: 4066: 4032: 4030: 4029: 4021: 4019: 4018: 4010: 4009: 4008: 4000: 3999: 3991: 3989: 3988: 3980: 3978: 3977: 3969: 3967: 3966: 3955: 3951: 3949: 3948: 3940: 3938: 3937: 3925: 3923: 3922: 3914: 3912: 3911: 3903: 3901: 3900: 3888: 3886: 3885: 3877: 3875: 3874: 3866: 3864: 3863: 3855: 3853: 3852: 3828: 3826: 3825: 3805: 3803: 3802: 3793: 3791: 3790: 3774: 3772: 3771: 3763: 3761: 3760: 3745: 3743: 3742: 3720: 3718: 3717: 3709: 3707: 3706: 3698: 3696: 3695: 3687: 3685: 3684: 3676: 3674: 3673: 3665: 3663: 3662: 3654: 3652: 3651: 3642: 3640: 3639: 3627: 3625: 3624: 3600: 3599: 3598: 3576: 3575: 3574: 3561: 3559: 3558: 3550: 3548: 3547: 3538: 3536: 3535: 3448: 3446: 3445: 3423: 3421: 3420: 3395: 3393: 3392: 3384: 3382: 3381: 3373: 3371: 3370: 3362: 3360: 3359: 3351: 3349: 3348: 3325: 3323: 3322: 3314: 3312: 3311: 3303: 3301: 3300: 3284: 3282: 3281: 3273: 3271: 3270: 3254: 3252: 3251: 3243: 3241: 3240: 3231: 3229: 3228: 3220: 3218: 3217: 3196: 3195: 3194: 3183: 3181: 3180: 3172: 3170: 3169: 3161: 3160: 3159: 3149: 3148: 3147: 3129: 3127: 3126: 3118: 3116: 3115: 3098: 3096: 3095: 3087: 3085: 3084: 3076: 3074: 3073: 3065: 3063: 3062: 3054: 3052: 3051: 3043: 3041: 3040: 3032: 3030: 3029: 3021: 3019: 3018: 3010: 3008: 3007: 2999: 2998: 2997: 2981: 2970: 2962: 2960: 2959: 2951: 2949: 2948: 2940: 2938: 2937: 2926: 2924: 2923: 2915: 2913: 2912: 2904: 2902: 2901: 2890: 2883: 2876: 2869: 2862: 2861: 2860: 2847: 2843: 2842: 2841: 2831: 2830: 2829: 2816: 2804: 2803: 2802: 2785: 2784: 2783: 2727: 2718: 2717: 2710: 2703: 2696:on the beach in 2682: 2679:, most measured 2678: 2676: 2675: 2660: 2658: 2657: 2652: 2644: 2640: 2633: 2631: 2630: 2627: 2625: 2621: 2619: 2608: 2605: 2594: 2591: 2584: 2583: 2580: 2578: 2574: 2572: 2561: 2558: 2547: 2544: 2537: 2527: 2516: 2499: 2494: 2492: 2491: 2483: 2481: 2480: 2472: 2470: 2469: 2461: 2459: 2458: 2450: 2448: 2447: 2439: 2437: 2436: 2428: 2426: 2425: 2417: 2415: 2414: 2406: 2404: 2403: 2395: 2393: 2392: 2384: 2382: 2381: 2373: 2371: 2370: 2362: 2360: 2359: 2348: 2346: 2345: 2337: 2335: 2334: 2326: 2324: 2323: 2315: 2313: 2312: 2304: 2302: 2301: 2293: 2291: 2290: 2282: 2280: 2279: 2259: 2257: 2256: 2248: 2246: 2245: 2237: 2235: 2234: 2226: 2224: 2223: 2215: 2213: 2212: 2200: 2198: 2197: 2185: 2183: 2182: 2173: 2171: 2170: 2162: 2160: 2159: 2151: 2149: 2148: 2140: 2139: 2138: 2128: 2126: 2125: 2110: 2108: 2107: 2099: 2097: 2096: 2087: 2085: 2084: 2076: 2074: 2073: 2065: 2063: 2062: 2047: 2045: 2044: 2032: 2030: 2029: 2021: 2019: 2018: 2010: 2008: 2007: 1999: 1997: 1996: 1988: 1986: 1985: 1977: 1975: 1974: 1966: 1964: 1963: 1955: 1953: 1952: 1935: 1933: 1932: 1924: 1922: 1921: 1912: 1910: 1909: 1901: 1899: 1898: 1882: 1880: 1879: 1855: 1853: 1852: 1844: 1842: 1841: 1827: 1825: 1824: 1816: 1814: 1813: 1801: 1799: 1798: 1790: 1788: 1787: 1779: 1777: 1776: 1754: 1752: 1751: 1743: 1741: 1740: 1731: 1729: 1728: 1720: 1718: 1717: 1709: 1707: 1706: 1698: 1696: 1695: 1687: 1685: 1684: 1673: 1671: 1670: 1662: 1660: 1659: 1650: 1648: 1647: 1638: 1636: 1635: 1627: 1625: 1624: 1616: 1614: 1613: 1605: 1603: 1602: 1594: 1592: 1591: 1583: 1581: 1580: 1572: 1570: 1569: 1561: 1559: 1558: 1550: 1548: 1547: 1539: 1537: 1536: 1523: 1521: 1520: 1500: 1498: 1497: 1489: 1487: 1486: 1477: 1475: 1474: 1466: 1464: 1463: 1444: 1442: 1441: 1433: 1431: 1430: 1421: 1419: 1418: 1409: 1407: 1406: 1398: 1396: 1395: 1384: 1382: 1381: 1373: 1371: 1370: 1362: 1360: 1359: 1340: 1338: 1337: 1330:, the number of 1325: 1323: 1322: 1315:, the number of 1307: 1305: 1304: 1296: 1294: 1293: 1283: 1281: 1280: 1275: 1273: 1270: 1259: 1254: 1253: 1220: 1218: 1217: 1172: 1170: 1169: 1164: 1161: 1160: 1144: 1143: 1116: 1114: 1113: 1105: 1103: 1102: 1094: 1092: 1091: 1083: 1081: 1080: 1072: 1070: 1069: 1061: 1059: 1058: 1050: 1048: 1047: 1031: 1029: 1028: 1020: 1018: 1017: 1009: 1007: 1006: 998: 997: 996: 995: 988: 985: 984: 965: 964: 963: 962: 955: 952: 951: 942: 941: 940: 933: 932: 924: 923: 922: 915: 914: 905: 904: 903: 896: 895: 884: 882: 881: 870: 868: 867: 859: 857: 856: 848: 846: 845: 837: 835: 834: 826: 824: 823: 805: 796: 786: 785: 784: 774: 770: 766: 764: 763: 741: 740: 739: 732: 731: 722: 721: 720: 713: 712: 700: 698: 697: 688:nuclear reaction 686:. The following 685: 683: 682: 674: 672: 671: 647: 645: 644: 632: 630: 629: 621: 619: 618: 610: 608: 607: 595: 593: 592: 580: 578: 577: 562:exists as three 514: 512: 511: 495: 493: 492: 473: 471: 470: 458: 456: 455: 447: 445: 444: 436: 434: 433: 424:thermal neutrons 405: 403: 402: 352: 350: 349: 337: 335: 334: 319: 317: 316: 304: 302: 301: 293: 291: 290: 282: 280: 279: 260: 258: 257: 249: 247: 246: 234: 232: 231: 216: 214: 213: 205: 203: 202: 190: 188: 187: 178: 176: 175: 163: 161: 160: 152: 150: 149: 141: 139: 138: 118: 116: 115: 108:. The resulting 95: 93: 92: 61:organic material 53:carbon-14 dating 38:Dead Sea scrolls 21: 9685: 9684: 9680: 9679: 9678: 9676: 9675: 9674: 9605: 9604: 9603: 9598: 9547: 9531: 9527:Molecular clock 9520:Genetic methods 9511: 9492:Nitrogen dating 9479:Relative dating 9473: 9442:Potassium–argon 9389:Absolute dating 9379: 9368: 9327: 9306: 9271: 9247:Cosmic Calendar 9239:Astronomic time 9229: 9171: 9126: 9090: 9076:Original Julian 9046: 9013: 8975: 8874:Ab urbe condita 8852: 8829: 8781: 8776: 8701: 8696: 8689: 8683: 8672: 8659: 8631: 8608: 8591: 8586: 8585: 8577: 8573: 8565: 8561: 8553: 8549: 8541: 8537: 8530: 8512: 8505: 8498: 8484: 8480: 8472: 8468: 8460: 8456: 8448: 8439: 8432: 8414: 8407: 8400: 8385: 8381: 8373: 8362: 8307: 8303: 8260: 8256: 8209: 8205: 8166: 8162: 8154: 8147: 8100: 8096: 8089: 8075:Waterbolk, H.T. 8071: 8067: 8033: 8027: 8023: 8015: 8011: 8001: 7999: 7995: 7984: 7980: 7979: 7970: 7962: 7958: 7950: 7946: 7938: 7934: 7883: 7879: 7871: 7864: 7816: 7812: 7764: 7760: 7705: 7701: 7654: 7647: 7639: 7635: 7627: 7623: 7615: 7608: 7600: 7596: 7588: 7584: 7577: 7559: 7555: 7547: 7543: 7533: 7531: 7526: 7525: 7518: 7511: 7497: 7493: 7486: 7468: 7464: 7441:(2A): 313–320. 7427: 7418: 7411: 7397: 7393: 7382: 7378: 7370: 7363: 7350: 7343: 7336: 7314: 7310: 7303: 7289: 7285: 7278: 7264: 7260: 7253: 7239: 7235: 7227: 7220: 7212: 7208: 7200: 7196: 7189: 7172: 7168: 7160: 7147: 7139: 7120: 7112: 7108: 7101: 7087: 7083: 7075: 7060: 7052: 7037: 7029: 7025: 6999: 6997: 6996: 6995: 6994: 6988: 6986: 6985: 6984: 6983: 6978: 6975: 6974: 6973: 6969: 6967: 6966: 6965: 6964: 6961: 6957: 6949: 6945: 6890: 6883: 6875: 6868: 6861: 6832: 6828: 6821: 6807: 6803: 6795: 6791: 6784: 6758: 6743: 6735: 6718: 6708: 6706: 6701: 6700: 6696: 6688: 6681: 6673: 6662: 6654: 6645: 6634: 6625: 6617: 6600: 6563: 6556: 6549: 6535: 6526: 6518: 6501: 6494: 6480: 6476: 6469: 6455: 6451: 6440: 6436: 6429: 6415: 6411: 6403: 6399: 6352: 6345: 6337: 6333: 6323: 6321: 6286: 6280: 6276: 6231: 6227: 6190: 6186: 6159:Physical Review 6155: 6151: 6143: 6136: 6128: 6119: 6111: 6092: 6068: 6062: 6058: 6050: 6046: 6038: 6034: 6026: 6022: 5977: 5970: 5963: 5949: 5940: 5900: 5894: 5887: 5864:(2B): 731–742. 5849: 5847: 5846: 5845: 5844: 5839: 5830: 5823: 5802: 5798: 5788: 5786: 5782: 5774: 5767: 5758: 5756: 5743: 5742: 5738: 5688: 5684: 5676: 5672: 5621: 5617: 5578: 5574: 5547:Physical Review 5543: 5539: 5531: 5494: 5485: 5483: 5475: 5474: 5467: 5459: 5452: 5421: 5417: 5409: 5402: 5358: 5353: 5347: 5323: 5318: 5308: 5306: 5305: 5304: 5303: 5297: 5295: 5294: 5293: 5292: 5290: 5286: 5280: 5276: 5271: 5267: 5258: 5254: 5244: 5240: 5234: 5230: 5221: 5219: 5218: 5217: 5216: 5210: 5208: 5207: 5206: 5205: 5195: 5191: 5186: 5182: 5146: 5142: 5140: 5137: 5136: 5130: 5128: 5127: 5126: 5125: 5123: 5119: 5110: 5108: 5107: 5106: 5105: 5099: 5097: 5096: 5095: 5094: 5088: 5086: 5085: 5084: 5083: 5081: 5077: 5072: 5068: 5063: 5059: 5055: 5035:Relative dating 5030:Absolute dating 5015: 4963: 4961: 4960: 4959: 4958: 4950: 4948: 4947: 4946: 4945: 4937: 4935: 4934: 4933: 4932: 4924: 4922: 4921: 4920: 4919: 4911: 4909: 4908: 4907: 4906: 4895:Shroud of Turin 4880: 4878: 4877: 4876: 4875: 4864: 4862: 4861: 4860: 4859: 4850: 4848: 4847: 4846: 4845: 4838: 4785: 4747: 4742: 4717: 4669: 4664: 4644: 4638: 4631: 4628: 4616: 4614: 4613: 4612: 4611: 4598: 4596: 4595: 4594: 4593: 4579: 4573: 4547: 4546: 4544: 4541: 4540: 4535: 4528: 4524: 4498: 4497: 4495: 4492: 4491: 4488: 4482:is as follows. 4474: 4472:Reporting dates 4412:Hessel de Vries 4404:Wesley Ferguson 4392: 4390: 4389: 4388: 4387: 4381: 4379: 4378: 4377: 4376: 4365: 4359: 4331: 4329: 4328: 4327: 4326: 4317: 4315: 4314: 4313: 4312: 4308: 4284: 4270: 4250: 4248: 4245: 4244: 4236: 4234: 4233: 4232: 4231: 4225: 4223: 4222: 4221: 4220: 4216:value of −25‰. 4211: 4209: 4208: 4207: 4206: 4200: 4198: 4197: 4196: 4195: 4189: 4187: 4186: 4185: 4184: 4178: 4176: 4175: 4174: 4173: 4167: 4165: 4164: 4163: 4162: 4153: 4151: 4150: 4149: 4148: 4142: 4140: 4139: 4138: 4137: 4131: 4129: 4128: 4127: 4126: 4120: 4118: 4117: 4116: 4115: 4109: 4107: 4106: 4105: 4104: 4098: 4096: 4095: 4094: 4093: 4087: 4085: 4084: 4083: 4082: 4076: 4074: 4073: 4072: 4071: 4065: 4063: 4062: 4061: 4060: 4045: 4039: 4028: 4026: 4025: 4024: 4023: 4017: 4015: 4014: 4013: 4012: 4007: 4004: 4003: 4002: 3998: 3996: 3995: 3994: 3993: 3987: 3985: 3984: 3983: 3982: 3976: 3974: 3973: 3972: 3971: 3965: 3963: 3962: 3961: 3960: 3958: 3953: 3947: 3945: 3944: 3943: 3942: 3936: 3934: 3933: 3932: 3931: 3921: 3919: 3918: 3917: 3916: 3910: 3908: 3907: 3906: 3905: 3899: 3897: 3896: 3895: 3894: 3884: 3882: 3881: 3880: 3879: 3873: 3871: 3870: 3869: 3868: 3862: 3860: 3859: 3858: 3857: 3851: 3849: 3848: 3847: 3846: 3835: 3824: 3822: 3821: 3820: 3819: 3801: 3799: 3798: 3797: 3796: 3789: 3787: 3786: 3785: 3784: 3778:anticoincidence 3770: 3768: 3767: 3766: 3765: 3759: 3757: 3756: 3755: 3754: 3741: 3739: 3738: 3737: 3736: 3728: 3716: 3714: 3713: 3712: 3711: 3705: 3703: 3702: 3701: 3700: 3694: 3692: 3691: 3690: 3689: 3683: 3681: 3680: 3679: 3678: 3672: 3670: 3669: 3668: 3667: 3661: 3659: 3658: 3657: 3656: 3650: 3648: 3647: 3646: 3645: 3638: 3636: 3635: 3634: 3633: 3623: 3621: 3620: 3619: 3618: 3611: 3597: 3594: 3593: 3592: 3590: 3573: 3570: 3569: 3568: 3566: 3557: 3555: 3554: 3553: 3552: 3546: 3544: 3543: 3542: 3541: 3534: 3532: 3531: 3530: 3529: 3526: 3460: 3444: 3442: 3441: 3440: 3439: 3436: 3430: 3419: 3417: 3416: 3415: 3414: 3410: 3400:caldera in the 3391: 3389: 3388: 3387: 3386: 3380: 3378: 3377: 3376: 3375: 3369: 3367: 3366: 3365: 3364: 3358: 3356: 3355: 3354: 3353: 3347: 3345: 3344: 3343: 3342: 3321: 3319: 3318: 3317: 3316: 3310: 3308: 3307: 3306: 3305: 3299: 3297: 3296: 3295: 3294: 3280: 3278: 3277: 3276: 3275: 3269: 3267: 3266: 3265: 3264: 3261: 3250: 3248: 3247: 3246: 3245: 3239: 3237: 3236: 3235: 3234: 3227: 3225: 3224: 3223: 3222: 3216: 3214: 3213: 3212: 3211: 3204: 3193: 3190: 3189: 3188: 3186: 3179: 3177: 3176: 3175: 3174: 3168: 3166: 3165: 3164: 3163: 3158: 3155: 3154: 3153: 3151: 3146: 3143: 3142: 3141: 3139: 3136: 3125: 3123: 3122: 3121: 3120: 3114: 3112: 3111: 3110: 3109: 3106: 3094: 3092: 3091: 3090: 3089: 3083: 3081: 3080: 3079: 3078: 3072: 3070: 3069: 3068: 3067: 3061: 3059: 3058: 3057: 3056: 3050: 3048: 3047: 3046: 3045: 3039: 3037: 3036: 3035: 3034: 3028: 3026: 3025: 3024: 3023: 3017: 3015: 3014: 3013: 3012: 3006: 3004: 3003: 3002: 3001: 2996: 2993: 2992: 2991: 2989: 2984: 2979: 2973: 2968: 2958: 2956: 2955: 2954: 2953: 2947: 2945: 2944: 2943: 2942: 2936: 2934: 2933: 2932: 2931: 2922: 2920: 2919: 2918: 2917: 2911: 2909: 2908: 2907: 2906: 2900: 2898: 2897: 2896: 2895: 2893: 2888: 2886: 2881: 2879: 2874: 2872: 2867: 2859: 2856: 2855: 2854: 2852: 2850: 2845: 2840: 2837: 2836: 2835: 2833: 2828: 2825: 2824: 2823: 2821: 2819: 2814: 2801: 2798: 2797: 2796: 2794: 2782: 2779: 2778: 2777: 2775: 2746:Marine plankton 2730: 2725: 2713: 2708: 2706: 2701: 2698:North Ronaldsay 2685: 2680: 2674: 2672: 2671: 2670: 2669: 2626: 2606: 2592: 2590: 2586: 2585: 2579: 2559: 2545: 2543: 2539: 2538: 2536: 2535: 2531: 2514: 2509: 2506: 2505: 2497: 2490: 2488: 2487: 2486: 2485: 2479: 2477: 2476: 2475: 2474: 2468: 2466: 2465: 2464: 2463: 2457: 2455: 2454: 2453: 2452: 2446: 2444: 2443: 2442: 2441: 2435: 2433: 2432: 2431: 2430: 2424: 2422: 2421: 2420: 2419: 2413: 2411: 2410: 2409: 2408: 2402: 2400: 2399: 2398: 2397: 2391: 2389: 2388: 2387: 2386: 2380: 2378: 2377: 2376: 2375: 2369: 2367: 2366: 2365: 2364: 2358: 2356: 2355: 2354: 2353: 2344: 2342: 2341: 2340: 2339: 2333: 2331: 2330: 2329: 2328: 2322: 2320: 2319: 2318: 2317: 2311: 2309: 2308: 2307: 2306: 2300: 2298: 2297: 2296: 2295: 2289: 2287: 2286: 2285: 2284: 2278: 2276: 2275: 2274: 2273: 2270: 2255: 2253: 2252: 2251: 2250: 2244: 2242: 2241: 2240: 2239: 2233: 2231: 2230: 2229: 2228: 2222: 2220: 2219: 2218: 2217: 2211: 2209: 2208: 2207: 2206: 2196: 2194: 2193: 2192: 2191: 2181: 2179: 2178: 2177: 2176: 2169: 2167: 2166: 2165: 2164: 2158: 2156: 2155: 2154: 2153: 2147: 2145: 2144: 2143: 2142: 2137: 2134: 2133: 2132: 2130: 2124: 2122: 2121: 2120: 2119: 2106: 2104: 2103: 2102: 2101: 2095: 2093: 2092: 2091: 2090: 2083: 2081: 2080: 2079: 2078: 2072: 2070: 2069: 2068: 2067: 2061: 2059: 2058: 2057: 2056: 2054: 2043: 2041: 2040: 2039: 2038: 2028: 2026: 2025: 2024: 2023: 2017: 2015: 2014: 2013: 2012: 2006: 2004: 2003: 2002: 2001: 1995: 1993: 1992: 1991: 1990: 1984: 1982: 1981: 1980: 1979: 1973: 1971: 1970: 1969: 1968: 1962: 1960: 1959: 1958: 1957: 1951: 1949: 1948: 1947: 1946: 1931: 1929: 1928: 1927: 1926: 1920: 1918: 1917: 1916: 1915: 1908: 1906: 1905: 1904: 1903: 1897: 1895: 1894: 1893: 1892: 1878: 1876: 1875: 1874: 1873: 1866: 1851: 1849: 1848: 1847: 1846: 1840: 1838: 1837: 1836: 1835: 1823: 1821: 1820: 1819: 1818: 1812: 1810: 1809: 1808: 1807: 1797: 1795: 1794: 1793: 1792: 1786: 1784: 1783: 1782: 1781: 1775: 1773: 1772: 1771: 1770: 1767: 1761: 1750: 1748: 1747: 1746: 1745: 1739: 1737: 1736: 1735: 1734: 1727: 1725: 1724: 1723: 1722: 1716: 1714: 1713: 1712: 1711: 1705: 1703: 1702: 1701: 1700: 1694: 1692: 1691: 1690: 1689: 1683: 1681: 1680: 1679: 1678: 1669: 1667: 1666: 1665: 1664: 1658: 1656: 1655: 1654: 1653: 1646: 1644: 1643: 1642: 1641: 1634: 1632: 1631: 1630: 1629: 1623: 1621: 1620: 1619: 1618: 1612: 1610: 1609: 1608: 1607: 1601: 1599: 1598: 1597: 1596: 1590: 1588: 1587: 1586: 1585: 1579: 1577: 1576: 1575: 1574: 1568: 1566: 1565: 1564: 1563: 1557: 1555: 1554: 1553: 1552: 1546: 1544: 1543: 1542: 1541: 1535: 1533: 1532: 1531: 1530: 1519: 1517: 1516: 1515: 1514: 1507: 1496: 1494: 1493: 1492: 1491: 1485: 1483: 1482: 1481: 1480: 1473: 1471: 1470: 1469: 1468: 1462: 1460: 1459: 1458: 1457: 1440: 1438: 1437: 1436: 1435: 1429: 1427: 1426: 1425: 1424: 1417: 1415: 1414: 1413: 1412: 1405: 1403: 1402: 1401: 1400: 1394: 1392: 1391: 1390: 1389: 1380: 1378: 1377: 1376: 1375: 1369: 1367: 1366: 1365: 1364: 1358: 1356: 1355: 1354: 1353: 1351: 1336: 1334: 1333: 1332: 1331: 1321: 1319: 1318: 1317: 1316: 1314: 1303: 1301: 1300: 1299: 1298: 1292: 1290: 1289: 1288: 1287: 1269: 1255: 1249: 1245: 1228: 1225: 1224: 1216: 1214: 1213: 1212: 1211: 1181: 1150: 1146: 1139: 1135: 1127: 1124: 1123: 1112: 1110: 1109: 1108: 1107: 1101: 1099: 1098: 1097: 1096: 1090: 1088: 1087: 1086: 1085: 1079: 1077: 1076: 1075: 1074: 1068: 1066: 1065: 1064: 1063: 1057: 1055: 1054: 1053: 1052: 1046: 1044: 1043: 1042: 1041: 1038: 1027: 1025: 1024: 1023: 1022: 1016: 1014: 1013: 1012: 1011: 1005: 1003: 1002: 1001: 1000: 994: 991: 990: 989: 986: 983: 981: 980: 979: 978: 977: 961: 958: 957: 956: 953: 950: 948: 947: 946: 945: 944: 939: 937: 936: 935: 931: 929: 928: 927: 926: 921: 919: 918: 917: 913: 910: 909: 908: 907: 902: 900: 899: 898: 894: 891: 890: 889: 888: 880: 878: 877: 876: 875: 866: 864: 863: 862: 861: 855: 853: 852: 851: 850: 849:to 10 parts of 844: 842: 841: 840: 839: 833: 831: 830: 829: 828: 822: 820: 819: 818: 817: 816:. The ratio of 803: 799: 794: 790: 783: 780: 779: 778: 776: 772: 768: 762: 760: 759: 758: 757: 738: 736: 735: 734: 730: 727: 726: 725: 724: 719: 717: 716: 715: 711: 708: 707: 706: 705: 696: 694: 693: 692: 691: 681: 679: 678: 677: 676: 670: 668: 667: 666: 665: 643: 641: 640: 639: 638: 628: 626: 625: 624: 623: 617: 615: 614: 613: 612: 606: 604: 603: 602: 601: 591: 589: 588: 587: 586: 576: 574: 573: 572: 571: 556: 550: 544:for this work. 510: 508: 507: 506: 505: 491: 489: 488: 487: 486: 469: 467: 466: 465: 464: 454: 452: 451: 450: 449: 443: 441: 440: 439: 438: 432: 430: 429: 428: 427: 401: 399: 398: 397: 396: 381: 376: 348: 346: 345: 344: 343: 333: 331: 330: 329: 328: 315: 313: 312: 311: 310: 307:nuclear testing 300: 298: 297: 296: 295: 289: 287: 286: 285: 284: 278: 276: 275: 274: 273: 261:throughout the 256: 254: 253: 252: 251: 245: 243: 242: 241: 240: 230: 228: 227: 226: 225: 212: 210: 209: 208: 207: 201: 199: 198: 197: 196: 186: 184: 183: 182: 181: 174: 172: 171: 170: 169: 159: 157: 156: 155: 154: 148: 146: 145: 144: 143: 137: 135: 134: 133: 132: 114: 112: 111: 110: 109: 91: 89: 88: 87: 86: 28: 23: 22: 15: 12: 11: 5: 9683: 9673: 9672: 9667: 9662: 9657: 9652: 9647: 9642: 9637: 9632: 9627: 9622: 9617: 9600: 9599: 9597: 9596: 9591: 9586: 9581: 9576: 9571: 9566: 9564:New Chronology 9561: 9555: 9553: 9552:Related topics 9549: 9548: 9546: 9545: 9539: 9537: 9533: 9532: 9530: 9529: 9523: 9521: 9517: 9516: 9513: 9512: 9510: 9509: 9504: 9499: 9494: 9489: 9483: 9481: 9475: 9474: 9472: 9471: 9466: 9461: 9456: 9455: 9454: 9449: 9444: 9439: 9429: 9427:Paleomagnetism 9424: 9419: 9414: 9409: 9404: 9399: 9393: 9391: 9382: 9374: 9373: 9370: 9369: 9367: 9366: 9361: 9356: 9351: 9346: 9341: 9335: 9333: 9329: 9328: 9326: 9325: 9320: 9314: 9312: 9308: 9307: 9305: 9304: 9299: 9294: 9288: 9286: 9279: 9273: 9272: 9270: 9269: 9264: 9259: 9254: 9249: 9243: 9241: 9235: 9234: 9231: 9230: 9228: 9227: 9225:New Earth Time 9222: 9217: 9216: 9215: 9210: 9200: 9195: 9190: 9185: 9179: 9177: 9173: 9172: 9170: 9169: 9164: 9154: 9149: 9134: 9132: 9128: 9127: 9125: 9124: 9119: 9114: 9109: 9104: 9098: 9096: 9092: 9091: 9089: 9088: 9086:Revised Julian 9083: 9078: 9073: 9067: 9065: 9058: 9052: 9051: 9048: 9047: 9045: 9044: 9039: 9034: 9029: 9023: 9021: 9015: 9014: 9012: 9011: 9006: 9004:Lists of kings 9001: 8996: 8994:Canon of Kings 8991: 8985: 8983: 8977: 8976: 8974: 8973: 8972: 8971: 8966: 8961: 8956: 8946: 8936: 8931: 8926: 8921: 8919:Before present 8916: 8911: 8906: 8901: 8896: 8891: 8886: 8877: 8870: 8864: 8862: 8853: 8851: 8850: 8845: 8840: 8834: 8831: 8830: 8828: 8827: 8822: 8817: 8816: 8815: 8805: 8800: 8795: 8789: 8787: 8783: 8782: 8775: 8774: 8767: 8760: 8752: 8746: 8745: 8739: 8733: 8727: 8722: 8716: 8707: 8700: 8699:External links 8697: 8695: 8694: 8681: 8663: 8657: 8644: 8635: 8629: 8612: 8606: 8592: 8590: 8587: 8584: 8583: 8571: 8559: 8547: 8535: 8528: 8503: 8496: 8478: 8466: 8454: 8437: 8430: 8405: 8398: 8379: 8360: 8315:Water Research 8301: 8274:(2): 166–171. 8254: 8223:(2): 328–341. 8203: 8160: 8145: 8094: 8087: 8065: 8044:(2): 555–559. 8021: 8009: 7968: 7966:, pp. 148–149. 7956: 7954:, pp. 207–209. 7944: 7942:, pp. 103–105. 7932: 7877: 7862: 7831:(4): 779–820. 7810: 7779:(4): 759–778. 7758: 7699: 7668:(4): 725–757. 7645: 7633: 7621: 7606: 7594: 7582: 7575: 7553: 7541: 7516: 7509: 7491: 7484: 7462: 7416: 7409: 7391: 7376: 7361: 7341: 7334: 7308: 7302:978-9810223151 7301: 7283: 7276: 7258: 7251: 7233: 7218: 7206: 7204:, pp. 103–104. 7194: 7187: 7166: 7145: 7118: 7106: 7099: 7081: 7058: 7035: 7023: 6998: 6987: 6976: 6968: 6955: 6943: 6881: 6866: 6859: 6826: 6819: 6801: 6789: 6782: 6741: 6716: 6694: 6679: 6660: 6643: 6623: 6598: 6554: 6547: 6524: 6499: 6492: 6474: 6467: 6449: 6434: 6427: 6409: 6397: 6343: 6331: 6297:(4): 237–240. 6274: 6225: 6194:"Introduction" 6184: 6149: 6134: 6117: 6090: 6056: 6044: 6032: 6020: 5991:(2): 185–217. 5968: 5962:978-0750304221 5961: 5938: 5911:(1): 278–305. 5885: 5848: 5828: 5821: 5796: 5765: 5736: 5699:(2): 535–548. 5682: 5670: 5615: 5572: 5537: 5492: 5465: 5450: 5431:(6): 777–779. 5415: 5399: 5398: 5322: 5319: 5317: 5316: 5307: 5296: 5284: 5274: 5265: 5252: 5238: 5228: 5220: 5209: 5189: 5180: 5168: 5165: 5162: 5159: 5153: 5150: 5145: 5129: 5117: 5109: 5098: 5087: 5075: 5066: 5056: 5054: 5051: 5050: 5049: 5044: 5039: 5038: 5037: 5032: 5021: 5014: 5011: 4962: 4949: 4936: 4923: 4910: 4879: 4872: 4863: 4849: 4837: 4834: 4784: 4781: 4776:palaeobotanist 4746: 4743: 4741: 4738: 4730:carbon dioxide 4716: 4713: 4668: 4667:Interpretation 4665: 4663: 4660: 4647: 4646: 4642: 4640: 4636: 4629: 4626: 4615: 4597: 4589: 4588: 4585:before present 4581: 4577: 4575: 4559: 4539: 4537: 4533: 4526: 4510: 4490: 4486: 4473: 4470: 4391: 4380: 4361:Main article: 4358: 4355: 4330: 4316: 4307: 4304: 4283: 4280: 4277: 4269: 4266: 4263: 4260: 4257: 4235: 4224: 4210: 4199: 4188: 4177: 4166: 4152: 4141: 4130: 4119: 4108: 4097: 4086: 4075: 4064: 4041:Main article: 4038: 4035: 4027: 4016: 4005: 3997: 3986: 3975: 3964: 3957: 3946: 3935: 3920: 3909: 3898: 3883: 3872: 3861: 3850: 3834: 3831: 3823: 3800: 3788: 3769: 3758: 3740: 3732:Geiger counter 3727: 3724: 3715: 3704: 3693: 3682: 3671: 3660: 3649: 3637: 3622: 3610: 3607: 3595: 3571: 3556: 3545: 3533: 3525: 3522: 3521: 3520: 3517: 3513: 3498: 3483: 3476: 3473:Hydroxyproline 3465: 3459: 3456: 3443: 3432:Main article: 3429: 3426: 3418: 3409: 3406: 3390: 3379: 3368: 3357: 3346: 3320: 3309: 3298: 3279: 3268: 3260: 3257: 3249: 3238: 3226: 3215: 3203: 3200: 3191: 3178: 3167: 3156: 3144: 3135: 3132: 3124: 3113: 3105: 3102: 3093: 3082: 3071: 3060: 3049: 3038: 3027: 3016: 3005: 2994: 2983: 2972: 2957: 2946: 2935: 2921: 2910: 2899: 2892: 2885: 2878: 2871: 2857: 2849: 2838: 2826: 2818: 2809: 2808: 2805: 2799: 2790: 2789: 2786: 2780: 2771: 2770: 2767: 2761: 2760: 2757: 2751: 2750: 2747: 2743: 2742: 2739: 2733: 2732: 2729: 2722: 2712: 2705: 2684: 2673: 2650: 2647: 2643: 2639: 2636: 2624: 2617: 2603: 2589: 2577: 2570: 2556: 2542: 2534: 2530: 2525: 2513: 2489: 2478: 2467: 2456: 2445: 2434: 2423: 2412: 2401: 2390: 2379: 2368: 2357: 2343: 2332: 2321: 2310: 2299: 2288: 2277: 2269: 2266: 2254: 2243: 2232: 2221: 2210: 2195: 2180: 2168: 2157: 2146: 2135: 2123: 2105: 2094: 2082: 2071: 2060: 2052: 2042: 2027: 2016: 2005: 1994: 1983: 1972: 1961: 1950: 1930: 1919: 1907: 1896: 1877: 1865: 1862: 1861: 1860: 1859:contamination. 1857: 1850: 1839: 1832: 1829: 1822: 1811: 1796: 1785: 1774: 1763:Main article: 1760: 1757: 1749: 1738: 1726: 1715: 1704: 1693: 1682: 1668: 1657: 1645: 1633: 1622: 1611: 1600: 1589: 1578: 1567: 1556: 1545: 1534: 1518: 1506: 1503: 1495: 1484: 1472: 1461: 1439: 1428: 1416: 1404: 1393: 1379: 1368: 1357: 1349: 1335: 1320: 1312: 1302: 1291: 1268: 1265: 1262: 1258: 1252: 1248: 1244: 1241: 1238: 1235: 1232: 1215: 1179: 1159: 1156: 1153: 1149: 1142: 1138: 1134: 1131: 1117:will be left. 1111: 1100: 1089: 1078: 1067: 1056: 1045: 1037: 1034: 1026: 1015: 1004: 992: 982: 959: 949: 938: 930: 920: 911: 901: 892: 879: 865: 854: 843: 832: 821: 810:photosynthesis 801: 800:CO + OH → CO 792: 781: 761: 737: 728: 718: 709: 695: 680: 669: 642: 627: 616: 605: 590: 575: 552:Main article: 549: 546: 509: 490: 468: 453: 442: 431: 412:Serge A. Korff 400: 380: 377: 375: 372: 347: 332: 325:beta radiation 314: 299: 288: 277: 255: 244: 229: 221:for his work. 211: 200: 185: 173: 158: 147: 136: 129:photosynthesis 125:carbon dioxide 113: 90: 26: 9: 6: 4: 3: 2: 9682: 9671: 9668: 9666: 9665:Radioactivity 9663: 9661: 9658: 9656: 9653: 9651: 9648: 9646: 9643: 9641: 9638: 9636: 9633: 9631: 9628: 9626: 9623: 9621: 9618: 9616: 9613: 9612: 9610: 9595: 9592: 9590: 9587: 9585: 9582: 9580: 9577: 9575: 9572: 9570: 9567: 9565: 9562: 9560: 9557: 9556: 9554: 9550: 9544: 9541: 9540: 9538: 9534: 9528: 9525: 9524: 9522: 9518: 9508: 9505: 9503: 9500: 9498: 9495: 9493: 9490: 9488: 9485: 9484: 9482: 9480: 9476: 9470: 9467: 9465: 9462: 9460: 9457: 9453: 9450: 9448: 9445: 9443: 9440: 9438: 9435: 9434: 9433: 9430: 9428: 9425: 9423: 9420: 9418: 9415: 9413: 9410: 9408: 9405: 9403: 9400: 9398: 9395: 9394: 9392: 9390: 9386: 9383: 9381: 9378:Chronological 9375: 9365: 9362: 9360: 9357: 9355: 9352: 9350: 9347: 9345: 9344:Geochronology 9342: 9340: 9337: 9336: 9334: 9330: 9324: 9321: 9319: 9316: 9315: 9313: 9309: 9303: 9300: 9298: 9295: 9293: 9290: 9289: 9287: 9283: 9280: 9278: 9277:Geologic time 9274: 9268: 9265: 9263: 9262:Metonic cycle 9260: 9258: 9257:Galactic year 9255: 9253: 9250: 9248: 9245: 9244: 9242: 9240: 9236: 9226: 9223: 9221: 9218: 9214: 9211: 9209: 9206: 9205: 9204: 9201: 9199: 9198:ISO week date 9196: 9194: 9191: 9189: 9186: 9184: 9181: 9180: 9178: 9174: 9168: 9165: 9162: 9158: 9155: 9153: 9150: 9147: 9143: 9139: 9136: 9135: 9133: 9129: 9123: 9120: 9118: 9115: 9113: 9110: 9108: 9105: 9103: 9100: 9099: 9097: 9093: 9087: 9084: 9082: 9079: 9077: 9074: 9072: 9069: 9068: 9066: 9062: 9059: 9057: 9053: 9043: 9040: 9038: 9035: 9033: 9030: 9028: 9025: 9024: 9022: 9020: 9016: 9010: 9007: 9005: 9002: 9000: 8997: 8995: 8992: 8990: 8987: 8986: 8984: 8982: 8978: 8970: 8967: 8965: 8962: 8960: 8957: 8955: 8952: 8951: 8950: 8947: 8944: 8940: 8937: 8935: 8932: 8930: 8927: 8925: 8922: 8920: 8917: 8915: 8912: 8910: 8907: 8905: 8904:Byzantine era 8902: 8900: 8897: 8895: 8892: 8890: 8887: 8885: 8881: 8878: 8876: 8875: 8871: 8869: 8866: 8865: 8863: 8861: 8860:Calendar eras 8857: 8854: 8849: 8846: 8844: 8841: 8839: 8836: 8835: 8832: 8826: 8823: 8821: 8818: 8814: 8811: 8810: 8809: 8806: 8804: 8801: 8799: 8796: 8794: 8791: 8790: 8788: 8784: 8780: 8773: 8768: 8766: 8761: 8759: 8754: 8753: 8750: 8743: 8740: 8737: 8734: 8731: 8728: 8726: 8723: 8720: 8717: 8715: 8711: 8708: 8706: 8703: 8702: 8688: 8684: 8678: 8671: 8670: 8664: 8660: 8654: 8650: 8645: 8641: 8636: 8632: 8626: 8621: 8620: 8613: 8609: 8603: 8599: 8594: 8593: 8581:, pp. 93–162. 8580: 8579:Walker (2005) 8575: 8568: 8567:Walker (2005) 8563: 8556: 8555:Walker (2005) 8551: 8544: 8539: 8531: 8525: 8520: 8519: 8510: 8508: 8499: 8493: 8489: 8482: 8475: 8470: 8463: 8458: 8451: 8446: 8444: 8442: 8433: 8427: 8422: 8421: 8412: 8410: 8401: 8395: 8391: 8383: 8376: 8371: 8369: 8367: 8365: 8356: 8352: 8347: 8342: 8337: 8332: 8328: 8324: 8320: 8316: 8312: 8305: 8297: 8293: 8289: 8285: 8281: 8277: 8273: 8269: 8265: 8258: 8249: 8244: 8239: 8234: 8230: 8226: 8222: 8218: 8214: 8207: 8199: 8195: 8191: 8187: 8183: 8179: 8175: 8171: 8164: 8157: 8156:Bowman (1995) 8152: 8150: 8141: 8137: 8133: 8129: 8125: 8121: 8117: 8113: 8109: 8105: 8098: 8090: 8084: 8080: 8076: 8069: 8060: 8055: 8051: 8047: 8043: 8039: 8032: 8025: 8018: 8013: 7994: 7990: 7983: 7977: 7975: 7973: 7965: 7960: 7953: 7952:Walker (2005) 7948: 7941: 7940:Aitken (1990) 7936: 7928: 7924: 7920: 7916: 7912: 7908: 7904: 7900: 7897:(5708): 363. 7896: 7892: 7888: 7881: 7874: 7873:Walker (2005) 7869: 7867: 7857: 7852: 7847: 7842: 7838: 7834: 7830: 7826: 7822: 7814: 7805: 7800: 7795: 7790: 7786: 7782: 7778: 7774: 7770: 7762: 7754: 7750: 7745: 7740: 7735: 7730: 7726: 7722: 7718: 7714: 7710: 7703: 7694: 7689: 7684: 7679: 7675: 7671: 7667: 7663: 7659: 7652: 7650: 7642: 7637: 7630: 7625: 7618: 7617:Aitken (1990) 7613: 7611: 7603: 7598: 7591: 7590:Bowman (1995) 7586: 7578: 7572: 7567: 7566: 7557: 7550: 7549:Bowman (1995) 7545: 7529: 7523: 7521: 7512: 7506: 7502: 7495: 7487: 7481: 7476: 7475: 7466: 7457: 7452: 7448: 7444: 7440: 7436: 7432: 7425: 7423: 7421: 7412: 7406: 7402: 7395: 7387: 7380: 7373: 7372:Aitken (1990) 7368: 7366: 7357: 7356: 7348: 7346: 7337: 7331: 7327: 7323: 7319: 7312: 7304: 7298: 7294: 7287: 7279: 7273: 7269: 7262: 7254: 7248: 7244: 7237: 7230: 7229:Walker (2005) 7225: 7223: 7215: 7214:Walker (2005) 7210: 7203: 7198: 7190: 7184: 7180: 7176: 7170: 7163: 7162:Aitken (1990) 7158: 7156: 7154: 7152: 7150: 7142: 7141:Bowman (1995) 7137: 7135: 7133: 7131: 7129: 7127: 7125: 7123: 7115: 7114:Bowman (1995) 7110: 7102: 7096: 7092: 7085: 7078: 7077:Aitken (1990) 7073: 7071: 7069: 7067: 7065: 7063: 7055: 7054:Bowman (1995) 7050: 7048: 7046: 7044: 7042: 7040: 7032: 7031:Aitken (1990) 7027: 7019: 7015: 7011: 7007: 6959: 6952: 6947: 6939: 6935: 6930: 6925: 6920: 6915: 6911: 6907: 6903: 6899: 6895: 6888: 6886: 6878: 6873: 6871: 6862: 6856: 6852: 6848: 6844: 6840: 6836: 6830: 6822: 6816: 6812: 6805: 6798: 6793: 6785: 6779: 6775: 6771: 6766: 6765: 6756: 6754: 6752: 6750: 6748: 6746: 6738: 6737:Bowman (1995) 6733: 6731: 6729: 6727: 6725: 6723: 6721: 6704: 6698: 6691: 6690:Aitken (1990) 6686: 6684: 6676: 6675:Bowman (1995) 6671: 6669: 6667: 6665: 6657: 6652: 6650: 6648: 6639: 6632: 6630: 6628: 6620: 6619:Bowman (1995) 6615: 6613: 6611: 6609: 6607: 6605: 6603: 6593: 6588: 6584: 6580: 6576: 6572: 6568: 6561: 6559: 6550: 6544: 6540: 6533: 6531: 6529: 6521: 6520:Bowman (1995) 6516: 6514: 6512: 6510: 6508: 6506: 6504: 6495: 6489: 6485: 6478: 6470: 6464: 6460: 6453: 6445: 6438: 6430: 6424: 6420: 6413: 6406: 6401: 6392: 6387: 6382: 6377: 6373: 6369: 6365: 6361: 6357: 6350: 6348: 6340: 6335: 6320: 6316: 6312: 6308: 6304: 6300: 6296: 6292: 6285: 6278: 6270: 6266: 6261: 6256: 6252: 6248: 6245:(4845): 984. 6244: 6240: 6236: 6229: 6221: 6217: 6212: 6207: 6203: 6199: 6195: 6188: 6180: 6176: 6172: 6168: 6164: 6160: 6153: 6146: 6145:Bowman (1995) 6141: 6139: 6131: 6130:Aitken (1990) 6126: 6124: 6122: 6114: 6113:Aitken (1990) 6109: 6107: 6105: 6103: 6101: 6099: 6097: 6095: 6086: 6082: 6078: 6074: 6067: 6060: 6053: 6052:Aitken (1990) 6048: 6041: 6036: 6029: 6024: 6016: 6012: 6007: 6002: 5998: 5994: 5990: 5986: 5982: 5975: 5973: 5964: 5958: 5954: 5947: 5945: 5943: 5934: 5930: 5926: 5922: 5918: 5914: 5910: 5906: 5899: 5892: 5890: 5880: 5875: 5871: 5867: 5863: 5859: 5855: 5837: 5835: 5833: 5824: 5818: 5814: 5810: 5806: 5800: 5781: 5780: 5772: 5770: 5755:on 2018-10-12 5754: 5750: 5746: 5740: 5732: 5728: 5723: 5718: 5714: 5710: 5706: 5702: 5698: 5694: 5686: 5679: 5678:Aitken (1990) 5674: 5666: 5662: 5658: 5654: 5650: 5646: 5642: 5638: 5634: 5630: 5626: 5619: 5611: 5607: 5603: 5599: 5595: 5591: 5587: 5583: 5576: 5568: 5564: 5560: 5556: 5552: 5548: 5541: 5534: 5533:Bowman (1995) 5529: 5527: 5525: 5523: 5521: 5519: 5517: 5515: 5513: 5511: 5509: 5507: 5505: 5503: 5501: 5499: 5497: 5482: 5478: 5472: 5470: 5462: 5457: 5455: 5446: 5442: 5438: 5434: 5430: 5426: 5419: 5412: 5407: 5405: 5400: 5397: 5394: 5390: 5386: 5382: 5377: 5372: 5368: 5364: 5357: 5350: 5345: 5341: 5337: 5334:for external 5333: 5328: 5288: 5278: 5269: 5262: 5256: 5248: 5247:fractionation 5242: 5232: 5203: 5202:fractionation 5199: 5193: 5184: 5166: 5163: 5160: 5157: 5151: 5148: 5143: 5121: 5079: 5070: 5061: 5057: 5048: 5045: 5043: 5042:Geochronology 5040: 5036: 5033: 5031: 5028: 5027: 5025: 5022: 5020: 5017: 5016: 5010: 5008: 5004: 5000: 4996: 4992: 4988: 4984: 4980: 4976: 4972: 4968: 4955: 4942: 4929: 4916: 4902: 4900: 4896: 4891: 4887: 4870: 4856: 4843: 4833: 4830: 4825: 4824:palaeographic 4821: 4816: 4814: 4810: 4806: 4802: 4798: 4789: 4780: 4777: 4773: 4768: 4764: 4760: 4756: 4752: 4737: 4735: 4731: 4727: 4721: 4712: 4709: 4705: 4701: 4697: 4693: 4687: 4685: 4681: 4680:Thomas Higham 4676: 4674: 4659: 4656: 4652: 4641: 4635: 4634: 4633: 4624: 4608: 4606: 4586: 4582: 4576: 4557: 4538: 4532: 4531: 4530: 4508: 4483: 4481: 4480: 4469: 4466: 4462: 4459: 4454: 4453:Miyake events 4450: 4446: 4442: 4438: 4434: 4423: 4419: 4415: 4413: 4409: 4405: 4399: 4369: 4364: 4354: 4350: 4347: 4343: 4338: 4323: 4303: 4299: 4281: 4278: 4264: 4261: 4258: 4255: 4242: 4217: 4159: 4057: 4055: 4049: 4044: 4034: 3929: 3892: 3839: 3830: 3817: 3813: 3807: 3781: 3779: 3752: 3747: 3733: 3726:Beta counting 3723: 3615: 3606: 3602: 3588: 3584: 3580: 3563: 3518: 3514: 3511: 3507: 3503: 3499: 3496: 3492: 3488: 3484: 3481: 3477: 3474: 3470: 3466: 3464:contaminants. 3462: 3461: 3455: 3453: 3435: 3425: 3408:Contamination 3405: 3403: 3399: 3340: 3336: 3333: 3329: 3292: 3288: 3259:Other effects 3256: 3209: 3199: 3134:Marine effect 3131: 3101: 2986: 2977: 2966: 2928: 2864: 2807:−32‰ to −13‰ 2806: 2792: 2791: 2787: 2773: 2772: 2768: 2766: 2763: 2762: 2759:−30‰ to −22‰ 2758: 2756: 2753: 2752: 2749:−22‰ to −17‰ 2748: 2745: 2744: 2740: 2738: 2735: 2734: 2723: 2720: 2719: 2699: 2695: 2691: 2687: 2667: 2662: 2648: 2645: 2641: 2637: 2634: 2622: 2615: 2601: 2587: 2575: 2568: 2554: 2540: 2532: 2528: 2523: 2511: 2503: 2501: 2350: 2265: 2263: 2204: 2188: 2116: 2114: 2051: 2036: 1943: 1939: 1886: 1870: 1858: 1833: 1830: 1805: 1804: 1803: 1766: 1756: 1675: 1511: 1502: 1450: 1446: 1386: 1346: 1344: 1329: 1311: 1284: 1266: 1260: 1256: 1250: 1246: 1239: 1236: 1233: 1230: 1222: 1209: 1205: 1201: 1197: 1193: 1189: 1185: 1178: 1173: 1157: 1154: 1151: 1147: 1140: 1136: 1132: 1129: 1121: 1118: 1033: 975: 971: 966: 886: 872: 815: 811: 806: 797: 788: 754: 752: 748: 743: 702: 689: 663: 659: 655: 651: 636: 599: 584: 569: 565: 561: 555: 545: 543: 539: 535: 531: 527: 522: 520: 519: 503: 499: 484: 479: 477: 476:Willard Libby 462: 425: 421: 417: 413: 409: 394: 390: 386: 371: 369: 365: 361: 357: 341: 326: 321: 308: 271: 266: 264: 238: 222: 220: 194: 167: 130: 126: 122: 107: 103: 99: 84: 83:Willard Libby 80: 75: 73: 70: 66: 62: 58: 54: 50: 49:carbon dating 46: 39: 34: 30: 19: 18:Carbon-dating 9507:Stratigraphy 9452:Uranium–lead 9446: 9422:Lichenometry 9220:Winter count 9203:Mesoamerican 9131:Astronomical 8949:Mesoamerican 8934:Sothic cycle 8909:Seleucid era 8894:Bosporan era 8882: / 8872: 8820:Paleontology 8687:the original 8668: 8648: 8639: 8618: 8597: 8574: 8569:, pp. 57–77. 8562: 8557:, pp. 77–79. 8550: 8538: 8517: 8487: 8481: 8469: 8462:Libby (1965) 8457: 8452:, pp. 38–42. 8419: 8389: 8382: 8377:, pp. 34–37. 8318: 8314: 8304: 8271: 8267: 8257: 8220: 8216: 8206: 8173: 8169: 8163: 8158:, pp. 53–54. 8107: 8103: 8097: 8078: 8073:Mook, W.G.; 8068: 8041: 8037: 8024: 8012: 8000:. Retrieved 7993:the original 7988: 7959: 7947: 7935: 7894: 7890: 7880: 7875:, pp. 35–37. 7828: 7824: 7813: 7776: 7772: 7761: 7744:11585/770537 7716: 7712: 7702: 7665: 7661: 7643:, pp. 53–54. 7636: 7624: 7597: 7592:, pp. 40–41. 7585: 7564: 7556: 7544: 7532:. Retrieved 7500: 7494: 7473: 7465: 7438: 7434: 7400: 7394: 7385: 7379: 7374:, pp. 82–85. 7354: 7317: 7311: 7292: 7286: 7267: 7261: 7242: 7236: 7209: 7197: 7178: 7169: 7164:, pp. 76–78. 7143:, pp. 31–37. 7116:, pp. 37–42. 7109: 7090: 7084: 7079:, pp. 86–89. 7033:, pp. 85–86. 7026: 7009: 7005: 6958: 6953:, pp. 74–75. 6946: 6901: 6897: 6877:Libby (1965) 6842: 6829: 6810: 6804: 6792: 6763: 6707:. Retrieved 6697: 6677:, pp. 43–49. 6658:, pp. 50–52. 6637: 6621:, pp. 16–20. 6574: 6570: 6538: 6522:, pp. 24–27. 6483: 6477: 6458: 6452: 6443: 6437: 6418: 6412: 6407:, pp. 26–27. 6400: 6363: 6359: 6334: 6322:. Retrieved 6294: 6290: 6277: 6242: 6238: 6228: 6201: 6197: 6187: 6165:(12): 1825. 6162: 6158: 6152: 6132:, pp. 92–95. 6115:, pp. 61–66. 6076: 6072: 6059: 6047: 6040:Libby (1965) 6035: 6023: 5988: 5984: 5952: 5908: 5904: 5861: 5857: 5812: 5799: 5787:. Retrieved 5778: 5757:. Retrieved 5753:the original 5748: 5745:"The method" 5739: 5696: 5692: 5685: 5673: 5632: 5628: 5618: 5585: 5581: 5575: 5550: 5546: 5540: 5484:. Retrieved 5480: 5428: 5424: 5418: 5366: 5362: 5344:CC-BY-SA-3.0 5331: 5324: 5287: 5277: 5268: 5255: 5241: 5231: 5192: 5183: 5120: 5078: 5069: 5060: 5009:chronology. 4903: 4892: 4888: 4869:data made a 4857: 4841: 4839: 4817: 4794: 4772:Ernst Antevs 4748: 4722: 4718: 4688: 4677: 4670: 4654: 4648: 4622: 4609: 4590: 4529:BP", where: 4484: 4477: 4475: 4463: 4449:foraminifera 4441:macrofossils 4429: 4416: 4407: 4400: 4374: 4351: 4339: 4324: 4309: 4300: 4243: 4218: 4160: 4058: 4050: 4046: 4037:Calculations 3844: 3808: 3782: 3748: 3729: 3631: 3603: 3564: 3527: 3437: 3411: 3337: 3262: 3205: 3137: 3107: 2987: 2929: 2865: 2812: 2774:Atmospheric 2769:−15‰ to −9‰ 2663: 2504: 2451:relative to 2351: 2271: 2189: 2117: 2049: 2034: 1890: 1872:Atmospheric 1768: 1676: 1527: 1455: 1387: 1347: 1342: 1327: 1309: 1285: 1223: 1207: 1195: 1191: 1187: 1183: 1176: 1174: 1122: 1119: 1039: 972:, e) and an 967: 887: 873: 807: 798: 789: 755: 744: 703: 701:is created: 650:stratosphere 557: 537: 526:James Arnold 523: 516: 480: 420:Philadelphia 389:Samuel Ruben 385:Martin Kamen 382: 360:last ice age 322: 270:fossil fuels 267: 223: 76: 52: 48: 44: 43: 29: 9447:Radiocarbon 9122:Dual dating 8981:Regnal year 8959:Short Count 8899:Bostran era 8880:Anno Domini 8813:Big History 8793:Archaeology 8321:: 236–244. 8038:Radiocarbon 7989:Radiocarbon 7856:10023/20464 7825:Radiocarbon 7773:Radiocarbon 7719:(4): 1095. 7713:Radiocarbon 7693:10023/20465 7662:Radiocarbon 7435:Radiocarbon 6898:Radiocarbon 6571:Radiocarbon 6360:Radiocarbon 6204:(8): 1–19. 5858:Radiocarbon 5789:11 December 5693:Radiocarbon 4751:Pleistocene 4684:Neanderthal 4655:Radiocarbon 4623:Radiocarbon 4610:Calibrated 4479:Radiocarbon 4445:speleothems 4357:Calibration 4286: years 3928:Faraday cup 3891:accelerator 3510:fulvic acid 2495:, known as 662:nitrogen-14 658:cosmic rays 654:troposphere 558:In nature, 356:archaeology 102:cosmic rays 69:radioactive 65:radiocarbon 9609:Categories 9042:Vietnamese 8954:Long Count 8889:Anno Mundi 8884:Common Era 8786:Key topics 8779:Chronology 8346:1893/25135 8248:1893/28684 7804:1893/31560 6929:10289/7799 6709:2 February 6391:10289/8955 6324:9 December 5759:2016-10-09 5486:2016-10-09 5321:References 5282:estimated. 5236:different. 4829:castor oil 4759:Two Creeks 4643:confidence 4637:date-range 4632:", where: 4630:confidence 4627:date-range 4534:laboratory 4487:laboratory 3812:becquerels 3776:addition, 3617:Measuring 3502:humic acid 3495:conchiolin 3328:hard water 2262:bomb pulse 1942:Hans Suess 1271:8267 years 1200:reciprocal 1062:, but the 1036:Principles 652:and upper 524:Libby and 374:Background 368:Bronze Age 164:undergoes 9579:Year zero 9559:Chronicle 9502:Seriation 9437:Lead–lead 9311:Standards 9292:Deep time 9252:Ephemeris 9138:Lunisolar 9102:Gregorian 9095:Gregorian 9056:Calendars 9019:Era names 8989:Anka year 8868:Human Era 8798:Astronomy 8476:, p. 288. 8198:140692260 8140:205239973 8002:1 January 7927:128466798 7753:219087775 7604:, p. 155. 7534:27 August 6799:, p. 125. 6341:, p. 287. 6319:128628228 5731:134723966 5463:, p. 269. 5413:, p. 268. 5393:Q55120317 5385:2470-6345 5346:license ( 5338:in 2017 ( 5198:standards 5167:τ 5164:⋅ 4795:In 1947, 4708:Neolithic 4700:driftwood 4279:⋅ 4265:⁡ 4259:− 3644:decaying 3487:aragonite 3352:, so the 3287:limestone 2765:C4 plants 2755:C3 plants 2646:× 2635:− 2512:δ 1267:⋅ 1240:⁡ 1204:mean-life 1155:λ 1152:− 814:biosphere 795:→ CO + O 598:carbon-14 583:carbon-13 568:Carbon-12 554:Carbon-14 461:deuterons 408:half-life 383:In 1939, 364:Neolithic 263:biosphere 193:half-life 96:) in the 9574:Timeline 9412:Ice core 9285:Concepts 9032:Japanese 8964:Tzolk'in 8929:Egyptian 8730:IntChron 8545:, p. 13. 8464:, p. 84. 8355:28284090 8296:90232027 8132:25143113 8077:(1985). 8019:, p. 29. 7919:15661996 7631:, p. 59. 7231:, p. 23. 7216:, p. 20. 6938:59269731 6837:(2010). 6269:27534222 6220:25146610 6147:, p. 42. 6054:, p. 59. 6042:, p. 42. 6030:, p. 33. 6015:27366605 5933:59153548 5811:(2011). 5665:15407879 5610:17746224 5389:Wikidata 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