Geometry.Net - Science: Radiocarbon Dating

Radiocarbon Dating Laboratory
radiocarbon dating Laboratory. Dept of Quaternary Geology. Tornavägen 13, SE22363 Lund, Sweden. To Quaternary Geology. radiocarbon dating in Lund. Introduction.
http://www.geol.lu.se/personal/gns/ec14lab.htm

Extractions: Sample description form To AMS lab To Quaternary Geology Radiocarbon Dating in Lund Introduction Many radionuclides, such as H, Be, C, Al, Si, Cl, Ar and Kr, are produced naturally in the terrestrial atmosphere as a result of nuclear reactions involving cosmic rays. C, produced by reactions between slow secondary cosmic neutrons and stable N nuclei in the upper atmosphere, is quickly incorporated mainly into molecules of carbon dioxide, which are mixed throughout the atmosphere and the hydrosphere, the latter being the main reservoir. A significant reservoir is provided by the biosphere because of the assimilation of carbon dioxide into plant tissue, and the consumption of these plants by animals. A secular equilibrium, constant to a first approximation, is maintained in the atmosphere, hydrosphere and thus also the biosphere by the continuous production of C in the atmosphere and the subsequent beta-decay of the radionuclide.
Accelerator Mass Spectrometry & Radiocarbon Dating, IsoTrace Laboratory, Toronto
Nuclear Instruments and Methods in Physics Research B172, 977pp. LIBBY, WF (1955)radiocarbon dating. University of Chicago Press, 2nd edition, 175pp.
http://www.physics.utoronto.ca/~isotrace/isow14c.html

Extractions: Diverse and Dynamic might best describe the radiocarbon applications undertaken by staff and customers at IsoTrace. The field itself has become so broad that most specialist users are probably unaware of the many uses of C analyses and age determinations. The expansion of applications surely exceeds the initial hopes for the field (Libby, 1955; Haury et al. , 1959) and two simple indications suggest that, at least in the case of AMS-derived dates, geological and environmental applications outstrip the well-known utility of C dates in archaeology. 1. Publications. A measure of progress and trends in AMS is provided by the specialist series of AMS conferences , eight of which have been staged between 1977 and 2000. A synopsis of applications articles in the last two conferences is revealing (Jull et al. , 1997, pp.241-507; Kutschera et al. , 2000, pp.473-950), although the following analysis is not definitive, as special symposia can add bias to the contents of individual meetings. Some 52 radiocarbon application articles published from these conferences include the following major subjects;
Radiocarbon Dating - Wikipedia
radiocarbon dating. radiocarbon dating is the use of a naturally occurringisotope of carbon to determine the age of organic materials.
http://www.wikipedia.org/wiki/Radiocarbon_dating

Extractions: Main Page Recent changes Edit this page Older versions Special pages Set my user preferences My watchlist Recently updated pages Upload image files Image list Registered users Site statistics Random article Orphaned articles Orphaned images Popular articles Most wanted articles Short articles Long articles Newly created articles All pages by title Blocked IP addresses Maintenance page External book sources Printable version Talk Other languages: Nederlands From Wikipedia, the free encyclopedia. Radiocarbon dating is the use of a naturally occurring isotope of carbon 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 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 atmosphere. When cosmic rays enter the atmosphere they undergo various transformations, including the production of neutrons . The resulting neutrons participate in the following reacion: This reaction is relatively common, as nitrogen constitutes nearly 80% of
Stalagmite Triples Radiocarbon Dating Effectiveness
Stalagmite Triples radiocarbon dating Effectiveness A team of American and Britishscientists report that radiocarbon levels in Earth's atmosphere during the
http://unisci.com/stories/20012/0514012.htm

Extractions: Stalagmite Triples Radiocarbon Dating Effectiveness A team of American and British scientists report that radiocarbon levels in Earth's atmosphere during the last Ice Age were more than twice as high as today, higher even than the nuclear weapons tests of nearly half a century ago. They also reported in the May 11 issue of the journal Science of having extended the record for atmospheric radiocarbon more than 45,000 years. The researchers, who come from the University of Arizona, University of Bristol (U.K.) and the University of Minnesota, were able to extract a precise and near-continuous record of atmospheric carbon dioxide levels in a half-meter-long stalagmite that formed during the last glacial period in a cave that now lies underwater in the Bahamas. Marking time with carbon 14 requires an accurate record of atmospheric radiocarbon through time. Archaeologists, for example, use the radiocarbon time scale to date artifacts, but dates were only accurate as far back as 16,000 years. The information contained in the stalagmite effectively triples the calibration period. University of Arizona physicist J. Warren Beck and his colleagues also discovered that atmospheric carbon 14 levels soared dramatically between 45,000 and 33,000 years ago. Beck says even more interesting was a dramatic spike in radiocarbon levels during a millennium that began 44,300 years ago, nearly twice as high as the "bomb pulse" produced during nuclear weapons testing in the 1950s and 60s.
Radiocarbon Dating Of Dead Sea Scrolls Confirm Paleographic Dates
radiocarbon dating of Dead Sea Scrolls Confirm Paleographic Dates. byDonna Kent Researchers in the Arizona Accelerator Mass Spectrometer
http://physics.arizona.edu/physics/news/matters/summer95/deadsea.html

Extractions: Confirm Paleographic Dates by Donna Kent Researchers in the Arizona Accelerator Mass Spectrometer (AMS) Laboratory at the University of Arizona have carbon-14 dated samples of the Dead Sea Scrolls, and their results are consistent with ages determined by paleographic research. A. J. Timothy Jull, Research Scientist, and Douglas J. Donahue, Physics Professor and Director of the AMS facility, measured the amount of radioactive carbon in samples of 18 texts and two textiles from four Qumran Caves and from Nahal Hever, both in the Dead Sea region. Timothy Jull (left) and >Douglas Donahue (right) discuss their work with Guy Atchley (center) of KGUN news Carbon-14 dating of milligram samples taken from ragged edges of manuscript margins determined the ages of the scrolls to range from the third century B.C.E. (Before Common Era) to 68 C.E., nearly 2,000 years ago. These dates support earlier paleographic research, which estimated the ages of the scrolls by analyzing the handwriting styles, materials, and formatting of the manuscripts. The Dead Sea Scrolls were found in jars inside a Qumran cave by young Bedouin shepherds in 1947. Coming from the late Second Temple Period, a time when Jesus of Nazareth lived, they are older than any other surviving biblical manuscripts by almost one thousand years.
Radiocarbon Dating By Accelerator Mass Spectrometry With High Precision And Accu
radiocarbon dating by Accelerator Mass Spectrometry with High Precisionand Accuracy. GUO Zhiyu. (Institute of Heavy Ion Physics, Peking
http://www.pku.edu.cn/academic/xb/98/_98e209.html

Extractions: The precision and accuracy of AMS C dating have been studied. The main source of error comes from the statistical error of C counting and the instability of beam transmission efficiency. For high precision measurement the non-linearity error of current-frequency- conversion in beam current integrator and the time-dependent fractionation introduced by crater effect in ion source should also be considered. To meet the requirement of Xia-Shang-Zhou Chronology Project, PKUAMS upgrade was carried out. The stability of power supplies and the system vacuum were improved. The ion source has been replaced by a new one with better performance and reliability. With new data acquisition system the precision of lived time readout could reach 0.005%-0.01%. In order to obtain high precision age data, it is necessary not only to improve the precision of C measurements, but also to use the series samples in dendrological calibration by wiggle-matching method based on the Bayesian approach. The reliability of sample age depends on suitable sample selection and preparation, as well as the elimination of systematic error in measurement.
Companies Index: Radiocarbon Dating
Articles Books Courses Directory Events. radiocarbon dating. Rafter RadiocarbonLaboratory; SURRC radiocarbon dating Laboratory; University of Bradford;
http://www.buildingconservation.com/directory/ro.htm
Waikato Radiocarbon Dating Laboratory
Introduces the Waikato radiocarbon dating Laboratory at the University ofWaikato, Hamilton, New Zealand. Waikato radiocarbon dating Laboratory.
http://calendar.waikato.ac.nz/academicconsultancy/radiocarbondating.html

Extractions: Webmaster The Waikato Laboratory is a national facility, offering radiocarbon dates by both radiometric methods (liquid scintillation spectrometry by Wallac Quantulus) and accelerator mass spectrometry. The laboratory is funded from external commercial research dating services and is used to support radiocarbon dating and School of Science and Technology research programmes. Staff in the unit are actively involved in palaeoclimate and archaeological research and have a leading role in international calibration programmes. Calendar 2003 Contents
Quaternary Palaeoenvironments Group (QPG) » Protocol For AMS Radiocarbon Dating
Protocol for AMS radiocarbon dating of plant macrofossil material (QuaternaryPalaeoenvironments Group, Geography, Cambridge) radiocarbon dating.
http://www-qpg.geog.cam.ac.uk/14C/14Cprotocol.html

Extractions: QPG Home About Research People ... what's new? You are in: QPG home Resources Protocol for AMS radiocarbon dating Store your bulk samples or cores refrigerated and well-wrapped against fungal attack. However, do think about radiocarbon dating as early as possible, because even well-wrapped cores may go mouldy. The first thing to bear in mind before preparation is contamination. If your samples are old (i.e. >25,000 years old), then you have to be very careful, especially since AMS samples are so small. Similarly, if they are younger, the level of precision you require will be higher. Either way, any contamination that you introduce could be crucial. Of course there is also the possibility of contamination that was introduced during burial, but you can't do much about that - though see later. You can do something about this.
IRadiocarbon Introduction
radiocarbon dating. The radiocarbon dating method was developed in the 1940'sby Willard F. Libby and a team of scientists at the University of Chicago.
http://vcourseware4.calstatela.edu/VirtualDating/files/RC0/RC_0.html
ISGS - Radiocarbon Dating
RADIOCARBON ( 14 C) DATING. Liquid Scintillation Counting (LSC) Method is currentlyemployed in our radiocarbon dating laboratory for Carbon 14 analysis.
http://www.isgs.uiuc.edu/isotope/radio.html
Palaeoenvironmental Records And Radiocarbon Dating At Niah Caves In North-easter
Palaeoenvironmental records and radiocarbon dating at Niah Caves innortheastern Sarawak. M. Bird, C. Hunt and G. Barker. The Niah
http://wwwrses.anu.edu.au/environment/eePages/eePalaeoclimate/ep_annrepÄ/bird.h

Extractions: M. Bird, C. Hunt and G. Barker The Niah caves are located on the edge of the Gunong Subis, a limestone massif on the coastal plain of northeastern Sarawak. Deposits in the caves contain a remarkable record of human occupation dating back into the Pleistocene. The caves were first excavated in the 1950s and the most notable discovery at that time was a human skull (the so-called "Deep Skull"), together with charcoal that yielded a radiocarbon date of c .40,000 years BP. The skull provides the earliest evidence for human settlement on Borneo, but both the stratigraphic context of the skull and the validity of the radiocarbon dates are uncertain, due to a poor understanding of the stratigraphy during the initial excavations and to the fact that radiocarbon dating was in its infancy at the time the samples were dated. Sediment cores immediately outside the cave penetrated a mangrove peat relating to a mid-Holocene sea-level highstand, confirming that the caves were situated on an island during the mid-Holocene. The carbon-isotope record of another core from a freshwater lake 50 km east of the caves at 240 m a.s.l., suggests a dominance of forest vegetation in the region back to at least 8,000 BP. Taken together, the sparse isotopic evidence available at the present time suggests a continuity of forest cover in the area since before theLast Glacial Maximum. BACK TO INDEX
MICROBES THREATEN RADIOCARBON DATING
MICROBES THREATEN radiocarbon dating. Their glee was unbounded when radiocarbondating proved that the shroud could not be older than 700 years.
http://www.science-frontiers.com/sf100/sf100a01.htm

Extractions: ONLINE No. 100: Jul-Aug 1995 Issue Contents Sourcebook Project Sourcebook Subjects In the 1980s, skeptics had a lot of fun debunking the Shroud of Turin, the supposed burial cloth wrapped around Christ. Their glee was unbounded when radiocarbon dating "proved" that the shroud could not be older than 700 years. The skeptics may have been too quick to celebrate, because the samples that were sent to the radiocarbon lab may not have been wholly cloth. The reality of our biosphere is that virtually everything is permeated with microbes and their products. S.J. Mattingly and L.A. Garza-Valdes, of the University of Texas at San Antonio, have been studying "biogenic varnishes" for years. These plastic-like coatings are produced by bacteria and fungi. Sure enough, microscopic examination of a few linen fibers from the Shroud of Turin show that they, too, are coated with such varnishes. These biogenic varnishes may introduce carbon that has been recently fixed from the atmosphere and thus make the sample's age appear younger than it really is. (Travis, John; "Microbes Muddle Shroud of Turin's Age,"
Particle Accelerators For Radiocarbon Dating In Archaeology
31 No. 6 Particle accelerators for radiocarbon dating in archaeology. Fig 4 Prototypeof a new compact radiocarbon dating facility at the ETH campus in Zurich.
http://www.ph.adfa.edu.au/h-timmers/Health02/C14.html

Extractions: W hen the first electrostatic accelerators were built around 1930 by Cockroft and Walton and by Van de Graaff, nobody thought that these accelerator concepts could ever by used for dating purposes in archaeology or geology [1]. Later on, cyclotrons and other configurations with RF- fields became more important for nuclear and particle physics research. In the sixties, a new successful era of electrostatic accelerator began with the development of Tandem Van de Graaff accelerators. These types of accelerators became flexible instruments to study ion-atom interaction and ion solid interaction. In material sciences and especially in semiconductor industry, tandem accelerators became important tools for material analysis and ion implantation. Independent of all the accelerator developments, Willard F. Libby and his coworker developed the radiocarbon dating technique after World War II. Based on the novelty of the method and its success in many fields of research, Libby was awarded the Nobel price for chemistry in 1960. Libby's technique is based on the decay counting of radiocarbon ( C, t
Radiocarbon Dating - Www.ezboard.com
Subject, Author. radiocarbon dating, evolutionisstupid. Ok. Moderator Posts1892 1/6/03 92457 am Reply. Re radiocarbon dating, Elephanticity.
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Re: Radiocarbon Dating - Www.ezboard.com
Subject, Author. Re radiocarbon dating, Elephanticity. Funny, Walther33, 12/27/02111229 am. radiocarbon dating? Inaccurate, evolutionisstupid, 1/5/03 90604pm.
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Site Name
Bodies of Evidence. Under the microscope. radiocarbon dating. Top. DNA fingerprinting.radiocarbon dating. Archaeological radiography. Skull reconstruction.
http://www.channel4.com/history/microsites/B/bodies/science/tscience02.html

Extractions: Bodies of Evidence All living things contain carbon, which they either absorb from the atmosphere (plants) or take in as their food (animals). Most of that carbon is a stable form called C12 but a tiny proportion is an unstable, radioactive form called C14 or radiocarbon. Radiocarbon decays very slowly at a constant rate. Top DNA fingerprinting Radiocarbon dating Archaeological radiography Skull reconstruction Find out more Home ... Access advice
Forest:How Do We Know?:Radiocarbon Dating
This section will describe two methods that scientists use today todate objects and events relative dating and radiocarbon dating.
http://www.museum.state.il.us/muslink/forest/htmls/how_rcarbon.html

Extractions: Prior to the availability of radiocarbon dates (and when there is no material suitable for a radiocarbon date) scientists used a system of relative dating. Relative dating establishes the sequence of physical or cultural events in time. Knowing which events came before or after others allows scientists to analyze the relationships between the events. For example, archaeologists might date materials based upon relative depth of burial in a site. The archaeologists record and analyze the changes in types and styles of human-made items from different levels according to the principle explained below. General principle
Problems With Radiocarbon Dating Methods
Assumptions and Problems of Radioactive Methods. Radioactive Dating in conflict (lotsof graphics in this link, so be patient while it loads), Dating in conflict,
http://www.creationists.org/radioisotopes.html

Extractions: Problems with radioactive dating methods Home Audio Buy Contact ... Videos See these links: Assumptions and Problems of Radioactive Methods Radioactive Dating in conflict (lots of graphics in this link, so be patient while it loads) Dating in conflict Potassium-Argon and Argon-Argon Dating of Crustal Rocks and the Problem of Excess Argon Radio interview of Dr. Russell Humphreys, Nuclear Physicist Suggested Reading. Click on the image below for more information about this book, and to order it. Home
How Good Are Those Young-Earth Arguments Radiocarbon Dating
Treering dating (see Topic 27) gives us a wonderful check on theradiocarbon dating method for the last 8000 years. That is, we
http://www.talkorigins.org/faqs/hovind/howgood-c14.html

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