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Radiocarbon Dating:     more books (100)

Radioactivity: Marie Curie, Nuclear Fission, Radionuclide, Half-Life, Fallout Shelter, Henri Becquerel, Radiocarbon Dating, Pierre Curie Bibliography of Radiocarbon Dating (American Journal of Science Radiocarbon Supplement, Volume 1) Radiocarbon dating of archaeological samples (sambaqui) using CO"2 absorption and liquid scintillation spectrometry of low background radiation [An article ... Journal of Environmental Radioactivity] by M.L.T.G. Mendonca, J.M. Godoy, et all Radiocarbon dating of bulk peat samples from raised bogs: non-existence of a previously reported 'reservoir effect'? [An article from: Quaternary Science Reviews] by M. Blaauw, J. van der Plicht, et all 2004-07-01 Precision and accuracy in applied ^1^4C dating: some findings from the Fourth International Radiocarbon Inter-comparison [An article from: Journal of Archaeological Science] by E. Scott, C. Bryant, et all 2004-09-01 Prehistoric Chronology and Radiocarbon Dating in India by D.P. Agrawal, 1974-01-01 RADIOCARBON DATING by JOHNSON (Frederick), 1951 RADIOCARBON DATING 1952 [AMERICAN SCIENTIFIC OFFPRINT] by JR. EDWARD S DEEVEY, 1952 Radiocarbon Dating. Memoirs of the Society for American Archaeology Number 8 Vegetation, climate and radiocarbon datings in the late Pleistocene of the Netherlands: Part II: Middle Weichselian (Mededelingen - Netherlands) by W. H Zagwijn, 1974 Radiometric Dating: Radiocarbon Dating, Rubidium-Strontium Dating, Radiocarbon 14 Dating of the Shroud of Turin, Environmental Radioactivity RADIOCARBON DATING: An entry from Charles Scribner's Sons' <i>Dictionary of American History</i> by Willard F. Libby, 2003 Zhongguo Kaoguxuezhong Tanshisi Niandai Shujuji - Radiocarbon Dating in Chinese Archaeology (1965-1981) by Zhongguo Keixueyuan Kaogu Yanjiusuo, 1983-01-01 Radiocarbon dating of minute gastropods and new constraints on the timing of late Quaternary spring-discharge deposits in southern Arizona, USA [An article ... Palaeoclimatology, Palaeoecology] by J.S. Pigati, J. Quade, et all 2004-02-20

lists with details

41. Antiquity Of Man Wadi Kubbaniya
    The impact on archaeology of radiocarbon dating by accelerator mass spectrometry, Philosophical Transactions of the Royal Society, London Series A 323 2343.  
    http://www.antiquityofman.com/wadi_kubbaniya.html
    
    Extractions: by Professor Fred Wendorf, et al. (Antiquity 62, 1988; reproduced with the permission of Professor Wendorf) Vegetable remains are a rarity in Palaeolithic contexts. These new determinations on material from southern Egypt establish securely the date of an intensive grass-tuber and fish economy in the Nile Valley towards 20,000 years ago. While the Kubbaniya excavations were still under way, it became possible to date very small samples, even individual cereal grains, by the then-new technology of the tandem accelerator mass spectrometer (AMS), and the Kubbaniya cereals and date-stones were among the first materials dated by this technology. The cereal grains were dated at the University of Arizona, Tucson, and the date-stones at the Oxford University facility; all were shown to be relatively modern contaminants. The idea that cereals and dates had been important components of the Late Palaeolithic economy of Wadi Kubbaniya was therefore abandoned (Wendorf et al. 1984; Gowlett 1987). Although we are still unable to agree on how apparently undisturbed archaeological horizons were contaminated by relatively modern plant materials, this experience demonstrates that we must be extremely cautious in evaluating the association of isolated plant fragments with archaeological contexts. At the very least, all such materials found outside their expected areal or temporal ranges should be subjected to direct (AMS) dating, and many of those within their expected ranges should also be dated (Harris 1986; 1987; Legge 1986).

42. The British Museum, Department Of Scientific Research: Radiocarbon Dating
    radiocarbon dating. radiocarbon dating can only be applied to organisms that were once alive and is a means of determining how long ago they died.  
    http://www.thebritishmuseum.ac.uk/science/techniques/sr-tech-c14.html
    
    Extractions: One of the most important questions asked about any ancient object is just how old it really is. There are a number of scientific techniques which can be used to date antiquities, but probably the best known and most frequently used is radiocarbon or C dating. Radiocarbon dating can only be applied to organisms that were once alive and is a means of determining how long ago they died. Radiocarbon dating is possible because of the existence in nature of a tiny amount of C, or radiocarbon, a radioactive isotope of carbon. This isotope is produced in the upper atmosphere by the action of cosmic rays on N. This C combines with oxygen to produce carbon dioxide (CO ) and is taken in by plants during photosynthesis. From plants this C is absorbed into the tissues of every living thing via the food chain. Since it is radioactive, it is unstable and decays away at a known rate. While any plant or animal is alive the C lost by radioactive decay is constantly replaced through the food chain, but when that organism dies, no more

43. SCIENTISTS SPEAK ABOUT RADIOCARBON DATING
    SCIENTISTS SPEAK ABOUT radiocarbon dating. Carbon 116117. UNFORTUNATELY, radiocarbon dating LENGTHENS DATES TOO FAR INTO THE PAST. But  
    http://www.pathlights.com/ce_encyclopedia/06dat5.htm

44. Accuracy Of Radiocarbon Dating
    Accuracy of radiocarbon dating By John Stockwell. Regarding the known age. 1952 Libby publishes first book on radiocarbon dating.  
    http://home.tiac.net/~cri/1999/c14hist.html
    
    Extractions: By John Stockwell Regarding the often misquoted and maligned (by creationists) 14C dating method, here is a partial chronology of the development of the calibration of 14C, which includes consideration of sources of fluctuations in the background level of 14C. Much of creationist commentary on the possible errors in 14C is intended to portray the scientific community as being either incompetent or dishonest regarding such issues as the consideration of potential errors in radiometric dating methods. Creationists never discuss the fact that given these analyses, scientists have found ways of identifying and mitigating the effects of these sources of error. What follows is a summary from chapter 14.1.3, p.364-366 of Dickin [1995]: 1941: Thellier proposed that Earth's magnetic field experiences secular variations. 1949: Arnold and Libby publish radiocarbon dates of items of known age. 1952: Libby publishes first book on radiocarbon dating. 1954: Forbush observed that the 11-year cycle of sunspot activity was inversely correlated with cosmic-ray intensity.

45. SURRC: RADIOCARBON DATING LAB
    Part of the Scottish Universities Research and Reactor Centre at Glasgow.  
    http://www.gla.ac.uk/Acad/SURRC/Rcl/
    
    Extractions: The Centre, including its radiocarbon dating unit, is primarily involved in environmental research, using both stable and radioactive isotopes. The original SUERC radiocarbon laboratory was set up under the direction of Dr Doug Harkness soon after the centre was founded in 1963. The laboratory was an immense success and in 1970, it moved to an adjacent building on site when its remit changed to that of a central facility for the UK's Natural Environment Research Council ( NERC ), providing dating support in the environmental sciences. A radiocarbon facility was restored at SUERC in 1986 when the Glasgow University Radiocarbon Laboratory, which had also been established in the early 1960s, was relocated at SUERC under the direction of Dr Gordon Cook . Currently, both the NERC and the SUERC Radiocarbon Dating Laboratories are administered by SUERC. The laboratory can undertake radiometric C dating by converting gram quantities of sample carbon to benzene. Subsequent analysis is by liquid scintillation spectrometry using one of its five low level Packard spectrometers. The laboratory can also undertake accelerator mass spectrometry (

46. SURRC: RADIOCARBON DATING LAB
    Overview. The Centre, including its radiocarbon dating unit, is primarily involved in environmental research, using both stable and radioactive isotopes.  
    http://www.gla.ac.uk/centres/surrc/rcl/
    
    Extractions: The Centre, including its radiocarbon dating unit, is primarily involved in environmental research, using both stable and radioactive isotopes. The original SUERC radiocarbon laboratory was set up under the direction of Dr Doug Harkness soon after the centre was founded in 1963. The laboratory was an immense success and in 1970, it moved to an adjacent building on site when its remit changed to that of a central facility for the UK's Natural Environment Research Council ( NERC ), providing dating support in the environmental sciences. A radiocarbon facility was restored at SUERC in 1986 when the Glasgow University Radiocarbon Laboratory, which had also been established in the early 1960s, was relocated at SUERC under the direction of Dr Gordon Cook . Currently, both the NERC and the SUERC Radiocarbon Dating Laboratories are administered by SUERC. The laboratory can undertake radiometric C dating by converting gram quantities of sample carbon to benzene. Subsequent analysis is by liquid scintillation spectrometry using one of its five low level Packard spectrometers. The laboratory can also undertake accelerator mass spectrometry (

47. C14lab, Lab. For Isotope Geology, (NRM)
    Welcome to the radiocarbon dating Facility at the Swedish Museum of Natural History. Written by Magnus Hedberg. Further information about radiocarbon dating.  
    http://www.nrm.se/lig/carbon14/c14home.html.en
    
    Extractions: the Swedish Museum of Natural History Written by Magnus Hedberg The Radiocarbon dating facility at the Swedish Museum of Natural History was closed in 1998. The following pages, however, give a general description of the Carbon 14 method of dating, as well as some information of historical interest regarding the Stockholm Radiocarbon facility. There exist various radiometric dating methods. Some are used to measure the age of our planet and to explore its evolution. Others, like the well-known radiocarbon method, are used to examine more recent events. The radioactive carbon-14 isotope is continuously produced in the Earth's outer atmosphere in a reaction initiated by cosmic radiation. This carbon-14 isotope has given archaeologists and geologists an important tool to investigate and understand our history, and the radiocarbon method has developed into standard technique for determination of the age of archaelogical finds and other organic material. It is also a valuable tool in several other fields of science such as hydrology and oceanography. Battle-axe and pot from the younger Stone Age.

48. The Pitfalls Of Radiocarbon Dating
    Previous Main The Pitfalls of radiocarbon dating. Offering in 1952 his new radiocarbon method for calculating the age of organic  
    http://www.varchive.org/ce/c14.htm
    
    Extractions: The Pitfalls of Radiocarbon Dating Offering in 1952 his new radiocarbon method for calculating the age of organic material (the time interval since the plant or the animal died), W. F. Libby clearly saw the limitations of the method and the conditions under which his theoretical figures would be valid: A. Of the three reservoirs of radiocarbon on earth—the atmosphere, the biosphere, and the hydrosphere, the richest is the last—the oceans with the seas. The correctness of the method depends greatly on the condition that in the last 40 or 50 thousand years the quantity of water in the hydrosphere (and carbon diluted in it) has not substantially changed. : B. The method depends also on the condition that during the same period of time the influx of cosmic rays or energy particles coming from the stars and the sun has not suffered substantial variations. To check on the method before applying it on various historical and paleontological material, Libby chose material of Egyptian archaeology, under the assumption that no other historical material from over 2,000 years ago is so secure as to its absolute dating. When objects of the Old Kingdom and Middle Kingdom of Egypt yielded carbon dates that appeared roughly comparable with the historical dates, Libby made his method known. But as the method was refined, it started to show rather regular anomalies. First, it was noticed that, when radiocarbon dated, wood grown in the 20th century appears more ancient than wood grown in the 19th century. Suess explained the phenomenon by the fact that the increased industrial use of fossil carbon in coal and in oil changed the ratio between the dead carbon C12 and the C14 (radiocarbon) in the atmosphere and therefore also in the biosphere. In centuries to come a body of a man or animal who lived and died in the 20th century would appear paradoxically of greater age since death than the body of a man or animal of the 19th century, and if the process of industrial use of fossil, therefore dead, carbon continues to increase, as it is expected will be the case, the paradox will continue into the forthcoming centuries.

49. The Official Graham Hancock Website: Forum
    WHAT IS radiocarbon dating AND IS IT A RELIABLE METHOD OF DATING ARCHAEOLOGICAL SITES? radiocarbon dating, a development in atomic physics, is a case in point.  
    http://www.grahamhancock.com/forum/HancockS1-p1.htm
    
    Extractions: December 2000 "Everything that has come down to us from heathendom is wrapped in a thick fog; it belongs to a space of time that we cannot measure. We know that it is older than Christendom, but whether by a couple of years or a couple of centuries, or even by more than a millennium we can do no more than guess" [ Rasmus Nyerup 1806 Many of us are intimidated by science. Radiocarbon dating, a development in atomic physics, is a case in point. The importance of this scientific method, however, is far reaching, influencing a multitude of various and independent disciplines such as hydrology, geology, atmospheric science and archaeology to name but a few. However, we leave the actual task of understanding radiocarbon dating to the boffin elite - we accept their conclusions blindly, respect the precision of their equipment and admire their genius. In truth, the principles of radiocarbon dating are astoundingly simple and readily accessible. Furthermore, the presumption that radiocarbon dating is an "exact science" is erroneous and in all fairness few scientists make this claim anyway. The problem is that the many individuals across many disciplines that employ radiocarbon dating as a dating device do not understand its nature or purpose. Lets put the record straight. References: Rasmus Nyerup Oversyn over foedrelandets mindesmaerker fra oldtiden

50. Carbon 14 Dating
    radiocarbon dating (C14). History. Rutherford and Soddy observed in Advantages of radiocarbon dating. - dates are the same regardless  
    http://www.duke.edu/~clc8/radiocarbon.html
    
    Extractions: Since plants and animals intake carbon throughout their lives, the amount of 14C in their bodies remains in equilibrium with the atmospheric levels of 14C throughout their lifetime. When a plant or animal dies, it stops intaking carbon dioxide and the amount of 14C present in their body is reduced as the 14C decays and no additional 14C is incorporated to replace it. This unstable carbon-14 decays by the following process: The amount of time it takes for half of all the radioactive carbon to decay is referred to as the half-life. If one knows the atmospheric level of 14C and measures the amount of 14C in an organic sample, one can calculate the number of half lifes that have elapsed since the organism died and estimate the how long ago the organism died. Since the half-life of carbon is approximately 5730 years, this method is best used to date objects under 60,000 years old because after 10 or so half-lives there is just not enough 14C left to be measured accurately. There are other radioactive elements with longer half-lives that can be used to measure older samples.

51. Online Encyclopedia - Radiocarbon Dating
    , Encyclopedia Entry for radiocarbon dating. Dictionary Definition of radiocarbon dating. radiocarbon datingEncyclopedia  
    http://www.yourencyclopedia.net/Radiocarbon_dating.html
    
    Extractions: Radiocarbon dating is the use of a naturally occurring isotope of carbon in radiometric dating to determine the age of organic materials Carbon has two stable isotopes: carbon-12 ( C), and carbon-13 ( C). In addition, there are tiny amounts of the unstable ( radioactive ) isotope carbon-14 C) on earth C has a half-life of just under 6000 years, and so would have long ago vanished from the earth, were it not for its constant formation by cosmic ray impacts on nitrogen in the earth's atmosphere . When cosmic rays enter the atmosphere they undergo various transformations, including the production of neutrons . The resulting neutrons participate in the following reaction: This reaction is relatively common, as nitrogen constitutes nearly 80% of Earth 's atmosphere. The highest rate of carbon-14 production takes place at altitudes of 30,000-50,000 feet , and at higher geomagnetic lattitudes, but the carbon-14 spreads evenly throughout the atmosphere and reacts with oxygen to form carbon dioxide . Carbon dioxide also permeates the oceans , dissolving in the water. Since it is assumed that the cosmic ray flux is constant over long periods of time, carbon-14 is assumed to be continuously produced at a constant rate and therefore that the proportion of radioactive to non-radioactive carbon throughout the Earth's atmosphere and oceans is constant.

52. Radiocarbon Dating Laboratory
    radiocarbon dating Laboratory. Quaternary Geology. Geocentrum II, Sölvegatan 12, S223 62 Lund, Sweden. radiocarbon dating in Lund. Introduction.  
    http://www.geol.lu.se/personal/gns/ec14lab.xtm
    
    Extractions: Sample description form Radiocarbon Dating in Lund News!! New AMS-machine to GeoBiosphere Science Centre During the summer of 2004 a new machine for Accelerator Mass Spectrometry to be installed at the GeoBiosphere Science Centre. It is a compact machine (ca 6,5 x 4,5 m ) and based on some new technology. It is to be used for C-dating and for quantification of C-labelled substances with applications within radioechology, echology, medicine and biomedicine. The plan is to have the AMS-machine in operation during the autumn of 2004. Pictures of the new Accelerator Mass Spectrometer (Single Stage AMS): Supplier is National Electrostatic Corp. (NEC), Wisconsin, USA.

53. Radiocarbon Dating Laboratory
    Natural 14 C can be used in numerous applications, of which radiocarbon dating, with the possibility for dating back to about 50 000 years, is among the best  
    http://www.geol.lu.se/personal/gns/c14lab.xtm
    
    Extractions: Kol-14 datering i Lund Under sommaren 2004 kommer en ny maskin för acceleratormasspektrometri att installeras vid Centrum för Geobiosfärsvetenskap. Den nya maskinen bygger delvis på ny teknologi och har betydligt mindre dimensioner (6,5x4,5 m) än tidigare system för acceleratormasspektrometri. Den är avsedd att användas för C-datering och för kvantifiering av C-märkta substanser med tillämpningar för forskning inom radioekologi, ekologi, medicin och biomedicin. Maskinen planeras att tas i drift under hösten 2004. Bilder av den nya acceleratormasspektrometern (Single Stage AMS): Tillverkare är National Electrostatic Corp. (NEC), Wisconsin, USA. Projektet är finansierat av medel från Knut och Alice Wallenbergs stiftelse och från Vetenskapsrådet. Introduction Many radionuclides, such as

54. Bear Lake Methods: Radiocarbon Dating
    US Geological Survey Earth Surface Processes 14 C (radiocarbon) Dating. Virtually Dargaud. Learn more about radiocarbon dating from these sites.  
    http://climchange.cr.usgs.gov/info/lacs/radiocarbon.htm
    
    Extractions: Virtually every life form on earth takes in isotopes of carbon, including C and C, for growth and food. The relative amount of carbon isotopes in the cells differs with each plant and animal because of a process called fractionation . Isotopic fractionation occurs when the absorption of one isotope is favoured over another, often because of the energy differences between isotopes. For instance, during photosynthesis the isotope C is preferred over C. This leaves the plant cells with less C for each atom of C than in the atmosphere. When this occurs, we say the plant tissue is depleted in C and enriched in C. The table below shows some of the fractionation effects for various plants and animals. d C indicates the difference between the sample's C/ C ratio and that of a standard. When the value is negative, it means that the isotope C is depleted compared to the standard. The more negative it is, the more fractionation has occurred. The fractionation values for d C is twice that of d C. Most radiocarbon labs assume

55. Tree Ring And C14 Dating
    to use C14 to fix an absolute date for just one end of this dynasty it is therefore an all or nothing situation in which radiocarbon dating has to be  
    http://www.mystae.com/restricted/streams/thera/dating.html
    
    Extractions: (1) Bristlecone Pine Dating "The third Thera Conference [Athens 1990] turned into a battleground between archaeology and the newer disciplines of dendrochronology and radiocarbon (C14) dating. Findings from these fields were thrown into the ring, and their supporters argued strongly that the eruption was to be dated more than a hundred years earlier to 1628/7 B.C. - J. V. Luce, "The Changing Face of the Thera Problem" "In several locations of the western United States lives the oldest known living thing on Earth: this is the Bristlecone pine (Pinus longaeva). In one location at Campito Mountain in the White Mountains of California, living trees and deadwood pieces provide an accurate year-by-year tree ring sequence back to 3435 BC, a continuous record for five and one-half thousand years! "V. C. LaMarche and Katherine Hirsckboeck have recently reported, in the magazine Nature, on a study of the frost damage in the rings of the Bristlecone pine. In the recent tree-ring records, they find a remarkable correlation between frost damage rings and the known date of large eruptions. For example, in the past 100 years, there have been four climactically important events: Krakatoa (1883), Pelee, Soufriere (1902), Katami (1912), and Agung (1963). In each case, a ring of frost damage was found and always in the same year if the eruption was early in the year or, otherwise, the next year. The frost ring never preceded the volcanic event, which seems to prove that the frost rings are the result of the eruption.

56. The Biblical Chronologist Feature On Radiocarbon Dating
    A discussion of the radiocarbon dating method s, its accuracy, and its precision. You are here Home ~ Features ~ radiocarbon dating.  
    http://www.biblicalchronologist.org/features/radiocarbon.php
    
    Extractions: Is it reliable? Radiocarbon dating is used by scientists to determine the age of once-living things. This makes it well-suited for use by archaeologists. Wood, charcoal, grains, cloth, etc. from ancient archaeological sites can be radiocarbon-dated, yielding absolute dates (as opposed to dates relative to the dates of other events) with a range of uncertainty. These date ranges can be a valuable tool for checking pottery-based chronologies or choosing between competing chronological theories. But are the dates given by radiocarbon dating accurate? Some scientists and public speakers say no. They say the theory behind radiocarbon dating is based on assumptions, or that the method is flawed and unreliable. Much of the information on these pages has been supplied by Dr. Gerald E. Aardsma, a Ph.D. scientist specializing in radiometric dating techniques such as radiocarbon. Dr. Aardsma's works have been published in scientific journals such as Radiocarbon . He is a conservative Christian and a recent-creation creationist. With this feature, we hope to provide objective information about the theory and practice of radiocarbon dating. We want you to be informed so you can decide for yourself if radiocarbon dating is reliable or not. Follow the links below to learn more.

57. Is Radiocarbon Dating Based On Assumptions?
    You are here Home ~ Answers ~ radiocarbon dating Assumptions. Is radiocarbon dating based on assumptions? Combatting Misinformation with Facts  
    http://www.biblicalchronologist.org/answers/c14_assumptions.php
    
    Extractions: Combatting Misinformation with Facts Unfortunately, a lot of misinformation about radiocarbon dating has been circulated by individuals who are not trained in this area. We hope to provide fair discussion of the issue, and that requires correcting false, yet common, misconceptions. Assertion 1: Radiocarbon dates are based on the assumption that the atmospheric C to C ratio has been constant in the past. This idea is advanced, for example, by John D. Morris in The Young Earth and Ken Ham, Andrew Snelling, and Carl Wieland in The Answers Book It is well known that the industrial revolution, with its burning of huge masses of coal, etc., has upset the natural carbon balance by releasing huge quantities of C into the air, for example. Tree-ring studies can tell us what the C/ C ratio was like before the industrial revolution, and all radiocarbon dating is made with this in mind. How do we know what the ratio was before then, thoughsay, thousands of years ago? It is assumed that the ratio has been constant for a very long time before the industrial revolution. Is this assumption correct (for on it hangs the whole validity of the system)? (Ham 68)

58. C14 Dating Of The Shroud
    The radiocarbon dating Controversy. Perhaps the most convincing and hence the most attacked data is the nowfamous C14 dating of the Shroud.  
    http://web.mountain.net/~havoc/rational/turinrc.html
    
    Extractions: The Radiocarbon Dating Controversy Perhaps the most convincing and hence the most attacked data is the now-famous C14 dating of the Shroud. This is a process by which radioactive isotopes of carbon are analyzed. As a living organism maintains its cellular processes, it continuously supplies itself with fresh carbon. All natural carbon occurs in three isotopes...carbon-12 and -13, non-radioactive, and carbon-14, a radioactive isotope. These isotopes occur in certain, constant ratios when fresh, and have a known half-life. When an organism dies (or like a plant, is harvested), it ceases to replace the carbon. As the carbon-14 decays, it is no longer replaced in the object. By measuring the amount of carbon-14 present in any formerly living object, it's age can be measured. Samples of shroud material were sent to four labs in 1988. Each lab, one each in Zurich, Switzerland; Oxford, England; Tucson, Arizona, USA; and Centre d'Etudes des Faibles Radioactivites in France. All four laboratories, working independently, came up with the same result: the material from the Shroud was made somewhere from 1260 to 1390 AD. As radiocarbon dating has been considered "hard" evidence by most archaeologists, this had the effect of bringing research in the shroud (termed "sidonology" by those spending most of their time on it) to a screeching halt. Under most circumstances, it is likely that very little further work would have been conducted and the case closed. But, as is common with matters of great religious import, there were people determined to "prove" that this was the burial cloth of Jesus Christ.

59. BBC - H2g2 - Radiocarbon Dating
    Created 25th October 2001, radiocarbon dating. and environmental science. radiocarbon dating. Carbon usually exists as 12 C atoms.  
    http://www.bbc.co.uk/dna/h2g2/A637418
    
    Extractions: Radiocarbon dating is probably the most important scientific method used by archaeologists to date objects. It is also an indispensable tool to researchers in other fields such as geology, geophysics and environmental science. Radiocarbon Dating Carbon usually exists as C atoms. Radiocarbon is the unstable isotope C. It is produced by cosmic rays in the upper atmosphere, and quickly diffuses through the atmosphere as carbon dioxide, dissolves in the oceans and enters all living matter through photosynthesis and the food chain. As C is unstable it will eventually decay by emitting an electron or beta particle. It reaches an equilibrium concentration in all living matter and gives it a small natural radioactivity. The principle behind radiocarbon dating is that when a plant or animal dies, there is no more exchange of carbon with the atmosphere. As the C will decay exponentially, we can find the age of the lifeform from the amount of

60. Physical Geography: Radiocarbon Dating Laboratory
    RADIOCARBON LABORATORY Winterthurerstrasse 190 8057 Zurich, Switzerland. The Radiocarbon Laboratory at the University of Zurich has been running since 1975.  
    http://www.geo.unizh.ch/c14/
    
    Extractions: Contents of this page General Information The Radiocarbon Laboratory at the University of Zurich has been running since 1975. It was founded by Dr. W.A. Keller and Prof. G. Furrer of the Physical Geography Division . Dr. Keller is still the head of the laboratory service and uses his many years of experience in geomorphology to help the customer with the interpretation of the results. back to the contents Measurement methods Conventional Liquid Scintillation Counting (LSC) The laboratory determines the C activity of benzene (prepared from the sample) through the measurement of its beta-decay. The benzene is produced as follows: carbon dioxide, obtained by burning the sample, reacts with metallic lithium to form lithium carbide. The lithium carbide is hydrolysed to acetylene which is subseqently converted to benzene by catalytic trimerisation. A small amount of carbon dioxide is taken during the above process to enable the measurement of the stable isotope ratio C / C. Scintillation counting results are statistically analysed and reported as conventional radiocarbon ages corrected with

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