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Sample records for ams radiocarbon dating

  1. AMS radiocarbon dating of cemetery of Jin Marquises in China

    CERN Document Server

    Wu, X; Wang, J; Guo, Z; Liu, K; Lü, X; Ma, H; Li, K; Yuan, J; Cai, L

    2000-01-01

    Bones are very important samples to determine the hosts of the cemetery of Jin Marquises which were excavated at Tianma-Qucun site in Shanxi Province in China. In order to obtain accurate AMS radiocarbon dates, bones were pretreated by two kinds of methods, the gelatin-extraction method and the amino-acid method. Charcoals collected from the same sites were also used. The measured dates agree with historical record.

  2. Radiocarbon Dating

    Energy Technology Data Exchange (ETDEWEB)

    Buchholz, B A

    2007-12-20

    Radiocarbon dating can be used to determine the age of objects that contain components that were once alive. In the case of human remains, a radiocarbon date can distinguish between a crime scene and an archeological site. Documents, museum artifacts and art objects can be dated to determine if their age is correct for the historical context. A radiocarbon date does not confirm authenticity, but it can help identify a forgery.

  3. From scrolls to Picasso: AMS radiocarbon dating applied to textiles, art works and artifacts

    Energy Technology Data Exchange (ETDEWEB)

    Jull, A.J.T.; Donahue, D.J.; Beck, J.W.; Burr, G.S.; O`Malley, J.; Hewitt, L.; Biddulph, D.; Hatheway, A.L.; Lange, T.E.; Toolin, J. [Arizona Univ., Tucson, AZ (United States). NSF Arizona Accelerator Mass Spectrometry Facility

    1997-12-31

    Full text: The use of accelerator mass spectrometry (AMS) for radiocarbon dating allows us to use very small samples of carbon, <1 mg. This has opened a vast array of applications of radiocarbon dating which were difficult to do before AMS, due to sample size limitations of decay counting. We have successfully applied AMS {sup 14}C to dating of many types of textiles, including silks and linens, art works, documents and artifacts fabricated from wood, parchment, ivory and bone. For many of these types of samples, the results are often important in questions of the authenticity of these works of art and artifacts. This has encompassed a wide range of art works ranging from the Dead Sea Scrolls, the Shroud of Turin and the Chinese silk trade to the works of Raphael, Rembrandt and Picasso. Most recently, we have also dated the Vinland Map, a controversial document which shows the eastern coast of North America apparently using information from Viking voyages. An important issue in such studies is also the radiocarbon calibration curve. For some periods, most notably 1700-1950 AD we know that several changes in the {sup 14}C composition of the atmosphere make it almost impossible to date a sample during this period more precisely than the entire range. However, before this period, we have successfully dated materials to high precision. We have also studied the use of the period l900-1950 AD for {sup 14}C measurements and will present some examples where the rapid decline in {Delta} {sup 14}C can be used to date art works. The period after 1950AD also allows us to identify works fabricated from recent materials using the `spike` in {sup 14}C due to atmospheric nuclear testing. This bomb {sup 14}C has also been successfully used to identify originals from copies of works purporting to be the originals. We will discuss some artifacts, art works and forgeries, where {sup 14}C can resolve problems of authenticity (authors).

  4. AMS radiocarbon dating of mortar: The case study of the medieval UNESCO site of Modena

    Science.gov (United States)

    Carmine, Lubritto; Caroselli, Marta; Lugli, Stefano; Marzaioli, Fabio; Nonni, Sara; Marchetti Dori, S.; Terrasi, Filippo

    2015-10-01

    The carbon dioxide contributing to binder formation during the set of a lime mortar reflects the atmospheric 14C content at the time of construction of a building. For this reason, the 14C dating of mortars is used with increasing frequencies in archaeological and architectural research. Mortars, however, may also contain carbonaceous contaminants potentially affecting radiocarbon dating. The Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) of the Second University of Naples (SUN) has recently obtained some promising results in mortar radiocarbon dating thanks to the development of a procedure (i.e. CryoSoniC/Cryo2SoniC) aiming to eliminate exogenous C contamination that may occur in a mortar. The construction history of the UNESCO World Heritage Site of Modena (Italy) is still controversial and represents a challenging case study for the application of absolute dating methodologies for different reasons. From the point of view of 14C dating, for example, given the high percentage of carbonate aggregates composing these samples, Modena mortars represent an experimental test particularly indicative of exogenous carbon sources suppression ensuring methodology accuracy. In this paper several AMS Radiocarbon dates were carried out on lime lumps with the aim to: (i) verify procedure accuracy by a comparison of the results obtainable from lime lumps dated after different treatments (i.e. bulk lime lumps vs. CryoSoniC purified lime lumps); (ii) compare different building phases absolute chronology for the medieval UNESCO site of Modena, with that assumed by historical sources in order to assess preliminary the 14C dating feasibility for of the site. Historical temporal constraints and mortar clustering, based on petrography, have been applied to define a temporal framework of the analyzed structure. Moreover, a detailed petrographic characterization of mortars was used both as a preliminary tool for the choice of samples and to infer about the

  5. Radiocarbon dating of a Japanese ancient document 'Minamoto no Yoritomo Sodehan Migyosho' by AMS

    International Nuclear Information System (INIS)

    In this study, radiocarbon age of a Japanese ancient document 'Minamoto no Yoritomo Sodehan Migyosho' was measured by AMS. The purpose of this study is to judge whether the document is genuine or not. The document descended to the Matsugi family which had controlled the craftsmen of metal casting. The document has a description of the written age, AD1189. The content of the document is about the formal recognition of their authority over the craftsmen by Minamoto no Yoritomo who established the first military government in AD1192. This document is written on a slightly-blackish-paper sheet called Shukushi. Shukushi paper sheets had been commonly used for the official documents of the Emperor. Therefore, if the document was really issued by Minamoto no Yoritomo, it can be a sole example as the document of warrior class among the extant Shukushi paper. The paleographical views, however, suggested that the document may be a counterfeit written in several centuries later. Japanese paper fragment is a suitable sample for radiocarbon dating because there is little discrepancy between the calibrated radiocarbon age and the written age. The calibrated radiocarbon age of 'Minamoto no Yoritomo Sodehan Migyosho' indicated the 16th century or the first half of the 17th century. This age corresponds to the period when the ancestor of Matsugi family appeared in Japanese history. This result shows that the document was forged in the Warring State Period for the legitimacy of their control over the craftsmen. The Shukusi used for the counterfeit document of warrior class is the outcome of the forger's misunderstanding that Shukushi paper should be used for the important documents.

  6. Bomb pulse radiocarbon dating

    International Nuclear Information System (INIS)

    Modern forensic science has to deal not only with homicides and other traditional crimes but also with more global threats such as the smuggling of nuclear materials, clandestine production of weapons of mass destruction, stockpiling of illicit drugs by state controlled groups and war crimes. Forensic applications have always benefited from the use of advanced analytical tools that can characterize materials found at crime scenes. In this paper we will discuss the use of accelerator mass spectrometry (AMS) as an ultrasensitive tool for the crime laboratories of the third millennium. An important objective in forensic science is to order past events chronologically by analysing materials associated with criminal actions. Radiocarbon dating is known to the general public for its application to historical and prehistorical investigations. Examples of forensic significance include the assassination of the Inca Atahualpa by Francisco Pizarro in the early 1530s, the possible murder of the Tyrolean Ice Man (Oetzi) 5300 years ago and the analysis of the burial cloths allegedly associated with the crucifixion of Jesus Christ . Recent murders, including those associated with war crimes in the Balkans during the 1990s, can be studied using 14C bomb pulse dating. This method has other forensic applications, including investigation of frauds related to food and wine counterfeiting, dating of opium crops and dating of substances used in biological warfare. AMS extends the applicability of the radiocarbon method, allowing the analysis of 14C in submilligram organic samples. Specific molecular compounds extracted from bones, hair, skin and other carbon bearing substances of forensic significance can now be dated, enhancing the sensitivity and reliability of chronological determinations. AMS can also be used to analyse rare actinide isotopes released into the environment during the clandestine production of nuclear weapons or associated with the smuggling of nuclear materials. In

  7. Radiocarbon dating of artworks

    OpenAIRE

    Krajcar Bronić, Ines; Horvatinčić, Nada; Barešić, Jadranka; Sironić, Andreja

    2015-01-01

    Absolute dating of artworks and cultural heritage objects is one of the most important issues in art history studies and essential for evaluating original art objects, differentiating between originals and later imitations and/or frauds and recognizing subsequent repairs and restauration works. The radiocarbon dating (14C dating) method is one of the most well-known radiometric methods of absolute dating, which can be applied for dating materials of biogenic origin, such as wood, charcoal, bo...

  8. AMS radiocarbon dating of medieval textile relics: The frocks and the pillow of St. Francis of Assisi

    International Nuclear Information System (INIS)

    Since natural textiles usually originate from short-lived organisms, they can represent a useful material to date samples from historical periods with a good accuracy. In this work, we present a set of radiocarbon measurements on medieval textile relics: two woollen habits and a pillow traditionally associated with St. Francis of Assisi, the saint patron of Italy. The strategy in choosing samples for radiocarbon dating is first discussed and the procedures for measurements - performed at the 3 MV Tandetron accelerator of Laboratorio di Tecniche Nucleari per i Beni Culturali (LABEC), Florence - are described; AMS results for the two frocks showed that only one of them, presently kept in the church of St. Francis in Cortona, is compatible with the Saint's period of life, as is the pillow also kept in Cortona. Another frock attributed to St. Francis appears to date from at least 80 years after his death. However, the goal of these measurements was not a bare authentication/disconfirmation of the relics; they just represent an example of how scientific analysis can integrate with humanistic studies. Indeed, AMS results, combined with a thorough analysis of the textiles typologies, confirmed the historical hypotheses based on documentary studies and on tradition. The overall conclusions contributed to the decisions taken for conservation, and have as a whole enhanced the religious importance of the relics

  9. Radiocarbon Dating the Anthropocene

    Science.gov (United States)

    Chaput, M. A.; Gajewski, K. J.

    2015-12-01

    The Anthropocene has no agreed start date since current suggestions for its beginning range from Pre-Industrial times to the Industrial Revolution, and from the mid-twentieth century to the future. To set the boundary of the Anthropocene in geological time, we must first understand when, how and to what extent humans began altering the Earth system. One aspect of this involves reconstructing the effects of prehistoric human activity on the physical landscape. However, for global reconstructions of land use and land cover change to be more accurately interpreted in the context of human interaction with the landscape, large-scale spatio-temporal demographic changes in prehistoric populations must be known. Estimates of the relative number of prehistoric humans in different regions of the world and at different moments in time are needed. To this end, we analyze a dataset of radiocarbon dates from the Canadian Archaeological Radiocarbon Database (CARD), the Palaeolithic Database of Europe and the AustArch Database of Australia, as well as published dates from South America. This is the first time such a large quantity of dates (approximately 60,000) has been mapped and studied at a global scale. Initial results from the analysis of temporal frequency distributions of calibrated radiocarbon dates, assumed to be proportional to population density, will be discussed. The utility of radiocarbon dates in studies of the Anthropocene will be evaluated and potential links between population density and changes in atmospheric greenhouse gas concentrations, climate, migration patterning and fire frequency coincidence will be considered.

  10. Radiocarbon dating for contributors

    International Nuclear Information System (INIS)

    This report describes the radiocarbon facility at the Institute of Nuclear Sciences, and is written for potential contributors, current users, and for those who advise others. The report briefly outlines the principles and practices of C-14 dating; with emphasis on factors that enable contributors to judge whether C-14 work is appropriate, and to assist them with the procedures to be followed in order to get the best results. Age determinations, being the main requirements by contributors, have been discussed in detail

  11. AMS radiocarbon chemistry at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, G. [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia). Physics Division

    1999-11-01

    The purpose of this paper is to demystify the `black box` of AMS chemistry. For many, a sample is sent and eventually a date is received. Little is known of what happens to the sample beyond that it is treated chemically and then measured in the tandem accelerator. In this overview I will discuss the fate of your radiocarbon samples once they have arrived here at ANSTO with a focus on the chemistry. The AMS measurement of radiocarbon samples has been discussed previously (Lawson 1999). There are three main aims when it comes to the chemistry: 1) to remove extraneous carbon, ie contamination, 2) to convert the carbon to a form suitable for measurement in the tandem accelerator and 3) not to contaminate the sample while doing 1 and 2. Before measurement the sample goes through a number of distinct stages, these being registration, pretreatment, carbon extraction, graphitisation and pressing. Of these I am going to deal mainly with the pretreatment stage, as it is at this stage that contamination is removed for which the accuracy of the final measurement is dependant 12 refs.

  12. AMS radiocarbon chemistry at ANSTO

    International Nuclear Information System (INIS)

    The purpose of this paper is to demystify the 'black box' of AMS chemistry. For many, a sample is sent and eventually a date is received. Little is known of what happens to the sample beyond that it is treated chemically and then measured in the tandem accelerator. In this overview I will discuss the fate of your radiocarbon samples once they have arrived here at ANSTO with a focus on the chemistry. The AMS measurement of radiocarbon samples has been discussed previously (Lawson 1999). There are three main aims when it comes to the chemistry: 1) to remove extraneous carbon, ie contamination, 2) to convert the carbon to a form suitable for measurement in the tandem accelerator and 3) not to contaminate the sample while doing 1 and 2. Before measurement the sample goes through a number of distinct stages, these being registration, pretreatment, carbon extraction, graphitisation and pressing. Of these I am going to deal mainly with the pretreatment stage, as it is at this stage that contamination is removed for which the accuracy of the final measurement is dependant

  13. Radiocarbon dates XXI

    International Nuclear Information System (INIS)

    This list includes 105 radiocarbon age determinations on 104 geological samples made by the Radiocarbon Dating Laboratory. They are on samples from various areas as follows: Labrador Shelf (2); Newfoundland (12); Nova Scotia (2); New Brunswick (1); Quebec (3); Ontario (1); Manitoba (1); Alberta (2); British Columbia (15); Yukon Territory (35); Northwest Territories, Mainland (10); Northwest Territories, Arctic Archipelago (21). Details of background and standard for the 2 L and 5 L counters during the period from November 4, 1980 to October 31, 1981 are summarized in Tables 1 and 2; Table 3 gives the number of counts used to determine the average background and standard counting rates; and Table 4 lists the number of different background and standard gas preparations used for counting

  14. Radiocarbon dating of ancient Japanese documents

    International Nuclear Information System (INIS)

    History is a reconstruction of past human activity, evidence of which is remained in the form of documents or relics. For the reconstruction of historic period, the radiocarbon dating of ancient documents provides important information. Although radiocarbon age is converted into calendar age with the calibration curve, the calibrated radiocarbon age is still different from the historical age when the document was written. The difference is known as 'old wood effect' for wooden cultural property. The discrepancy becomes more serious problem for recent sample which requires more accurate age determination. Using Tandetron accelerator mass spectrometer at Nagoya University, we have measured radiocarbon ages of Japanese ancient documents, sutras and printed books written dates of which are clarified from the paleographic standpoint. The purpose is to clarify the relation between calibrated radiocarbon age and historical age of ancient Japanese document by AMS radiocarbon dating. This paper reports 23 radiocarbon ages of ancient Japanese documents, sutras and printed books. The calibrated radiocarbon ages are in good agreement with the corresponding historical ages. It was shown by radiocarbon dating of the ancient documents that Japanese paper has little gap by 'old wood effect'; accordingly, ancient Japanese paper is a suitable sample for radiocarbon dating of recent historic period. (author)

  15. Peat record reflecting Holocene climatic change in the Zoige Plateau and AMS radiocarbon dating

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Through the use of reliable AMS dating of high resolution (15-30 years) peat and the establishment of monsoon climate proxies sequence, we have been able to recognize several cold, dry events in the Tibetan Plateau during the Holocene. The more obvious ones occurred around 12800, 11300, 10200, 9580, 8900, 6400, 4400, 3700, 2800 and 1500 cal. aBP. These events correlate well with both ice rafting events recorded in high latitude North Atlantic Ocean sediment cores and cooling events in the low latitude SST. Spectral analysis indicates high frequency climate variation on centennial-millennial time scale during the Holocene. This further reflects Holocene climate instability and the existence of centennial-millenium scale rhythm in mid latitude areas as well.

  16. Radiocarbon dating of the silk fabrics laced with colored threads 'Ezo Nishiki' by AMS

    International Nuclear Information System (INIS)

    Ezo Nishiki are silk fabrics in which elegant designs of dragon or peony were laced with color threads. They were made originally in China and imported into Japan by way of the Amur Basin and Sakhalin. Although the foreign commerce flourished actively during Quing dynasty (1616-1912), a few ancient records suggests that the origin ascends to Yuan (1271-1368) or early Ming dynasty (1368-1644). We measured radiocarbon ages of 34 Ezo Nishiki samples. Although most of them showed the period of Quing dynasty, a sample indicated that the origin of the trade can be traced back to the middle 14th or the early 15th century. (author)

  17. Radiocarbon dating: use and abuse

    International Nuclear Information System (INIS)

    Some of the problems associated with radiocarbon dating are discussed with particular reference to the British neolithic site of Briar Hill, Northampton, England. The problems arise when co-ordinating the radiocarbon dates with observed stratigraphy. In particular, three dates are much earlier than expected and no explanation of the early dates can be given as they represent neither sequence nor context. Doubts as to the validity of the dating and, hence, interpretation are expressed. (U.K.)

  18. Chemical characterization and AMS radiocarbon dating of the binder of a prehistoric rock pictograph at Tadrart Acacus, southern west Libya

    Czech Academy of Sciences Publication Activity Database

    Mori, F.; Ponti, R.; Messina, A.; Flieger, Miroslav; Havlíček, Vladimír; Sinibaldi, M.

    2006-01-01

    Roč. 7, - (2006), s. 344-349. ISSN 1296-2074 Institutional research plan: CEZ:AV0Z50200510 Keywords : rock pictograph * libya n sahara * radiocarbon dating Subject RIV: EE - Microbiology, Virology Impact factor: 0.738, year: 2006

  19. Microscale radiocarbon dating of paintings

    Energy Technology Data Exchange (ETDEWEB)

    Hendriks, Laura; Hajdas, Irka; McIntyre, Cameron [ETH Zurich, Ion Beam Physics, Zurich (Switzerland); Kueffner, Markus; Ferreira, Ester S.B. [SIK-ISEA, Zurich, Zurich (Switzerland); Scherrer, Nadim C. [Bern University of Applied Sciences, HKB, Bern (Switzerland)

    2016-03-15

    In this paper, radiocarbon dating of paintings using minimal sample sizes has been investigated, in an effort to address the problem of limited access to sample material in paintings. {sup 14}C analyses were conducted on signed and dated paintings from two Swiss artists of the twentieth century. The selected paintings dated from the 1930s and 1960s, provided the opportunity to evaluate the dating accuracy on paintings realized before and after 1950 AD when the {sup 14}C bomb peak was created, as a result of the nuclear tests conducted in the 1950/1960s. The work focused on the one hand on minimizing the size of the canvas sample required for accelerator mass spectrometer radiocarbon measurement on the gas ion source of the MICADAS and, on the other hand, on testing the possibility of dating the organic binder of the paint. Following careful characterization of the paint composition by X-ray fluorescence spectroscopy, Fourier transformed infrared spectroscopy, and Raman spectroscopy, paints containing no other carbon source than the natural organic binder were identified and dated. (orig.)

  20. Radiocarbon dating with accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Radiocarbon dating by means of accelerator mass spectrometry (AMS) has two great advantages over conventional dating: 1) much smaller samples can be handled and 2) counting time is significantly shorter. Three examples are given for Holocene-age material from east-central Ellesmere Island. The results demonstrate the potential use of this technique as a powerful research tool in studies of Quaternary chronology. Individual fragments of marine shells as small as 0.1 g have been dated successfully at the IsoTrace Laboratory, University of Toronto. In the case of an aquatic moss from a lake sediment core, an increment 0.5 cm thick could be used instead of a 5 cm-thick slice, thus allowing a much more precise estimate of the onset of organic sedimentation

  1. Radiocarbon dating of medieval manuscripts from the University of Seville

    Energy Technology Data Exchange (ETDEWEB)

    Santos, F.J., E-mail: fsantos@us.e [Centro Nacional de Aceleradores (CNA), Avda. Thomas Alva Edison 7, Isla de la Cartuja, 41092 Seville (Spain); Gomez-Martinez, I.; Garcia-Leon, M. [Centro Nacional de Aceleradores (CNA), Avda. Thomas Alva Edison 7, Isla de la Cartuja, 41092 Seville (Spain)

    2010-04-15

    Eleven samples (parchment and paper) from different medieval manuscripts belonging to the cultural heritage of the University of Seville have been radiocarbon dated on the 1 MV AMS facility at the CNA in Seville (Spain). The objective of this study is double. First of all, these are the first real 'unknown' samples treated in the radiocarbon laboratory and dated on our AMS facility, SARA (Spanish Accelerator for Radionuclide Analysis). Besides, some useful information about the manuscripts can be obtained, either to corroborate the dates, or in some cases, to decide between possible dates. As expected, a general agreement is found between radiocarbon results and palaeographical data. Nevertheless, some interesting facts have been learned through this study. We present in this paper the procedure to prepare the samples and the ages obtained with a brief discussion of the results.

  2. Radiocarbon dating of medieval manuscripts from the University of Seville

    International Nuclear Information System (INIS)

    Eleven samples (parchment and paper) from different medieval manuscripts belonging to the cultural heritage of the University of Seville have been radiocarbon dated on the 1 MV AMS facility at the CNA in Seville (Spain). The objective of this study is double. First of all, these are the first real 'unknown' samples treated in the radiocarbon laboratory and dated on our AMS facility, SARA (Spanish Accelerator for Radionuclide Analysis). Besides, some useful information about the manuscripts can be obtained, either to corroborate the dates, or in some cases, to decide between possible dates. As expected, a general agreement is found between radiocarbon results and palaeographical data. Nevertheless, some interesting facts have been learned through this study. We present in this paper the procedure to prepare the samples and the ages obtained with a brief discussion of the results.

  3. NERC radiocarbon dating: 1975-1985

    International Nuclear Information System (INIS)

    The paper reviews the work of the Natural Environment Research Council Radiocarbon Dating Laboratory in connection with Quaternary research, over the last decade. A description is given of the development of the dating service and in-house research. Quaternary research investigations aided by radiocarbon dating are described under the topic headings: The late Devensian glacial maximum, late glacial, middle Devensian, palaeomagnetic secular variation in lake sediments, vegetational history, faunal history, palaeolimnology, ground water, volcanology, periglacial research, palaoeohydrology, geomorphology, quaternary events in low-latitudes, environmental archaeology, archaeology, deep sea sediments, continental shelf, coastal geomorphology, and radiocarbon dating in Antarctica. (U.K.)

  4. AMS radiocarbon dating at Oxford and its contribution to issues of the extinction of Neanderthals and the spread of Homo sapiens sapiens across Eurasia

    International Nuclear Information System (INIS)

    The Oxford Radiocarbon Accelerator Unit has participated in a number of projects central to the question of the evolutionary fate of the Neanderthals and the spread of our own species across Eurasia. This paper outlines some of the key issues in this field and reports on some dating projects which have refined our knowledge of these momentous events in human history

  5. AMS radiocarbon dating at Oxford and its contribution to issues of the extinction of Neanderthals and the spread of Homo sapiens sapiens across Eurasia

    CERN Document Server

    Pettitt, P B; Hedges, R E M; Hodgins, G W L

    2000-01-01

    The Oxford Radiocarbon Accelerator Unit has participated in a number of projects central to the question of the evolutionary fate of the Neanderthals and the spread of our own species across Eurasia. This paper outlines some of the key issues in this field and reports on some dating projects which have refined our knowledge of these momentous events in human history.

  6. Radiocarbon dating of ancient Japanese calligraphy sheets. Checks with ancient documents of known age and its application to kohitsugire calligraphies

    International Nuclear Information System (INIS)

    Radiocarbon ages of ancient documents, sutras and books of known age were measured by AMS. The calibrated radiocarbon ages corresponded to the years in which they were written. The result shows that Japanese paper is suitable for radiocarbon dating. Radiocarbon dating on ancient calligraphies of unknown age clarified their historical ages and academic value. (author)

  7. Mass spectrometric detection of radiocarbon for dating applications

    Energy Technology Data Exchange (ETDEWEB)

    Synal, H.-A., E-mail: synal@phys.ethz.ch [ETH Zurich, Laboratory of Ion Beam Physics, Building HPK, 8093 Zurich (Switzerland); Schulze-Koenig, T.; Seiler, M.; Suter, M.; Wacker, L. [ETH Zurich, Laboratory of Ion Beam Physics, Building HPK, 8093 Zurich (Switzerland)

    2013-01-15

    Radiocarbon is still the most important nuclide measured by accelerator mass spectrometry (AMS). The related capabilities for dating and tracer studies are eminent not only in archaeology but also drive important applications in the earth and environmental sciences as well as in biomedical research. So far, standard mass spectrometric systems have not been capable of radiocarbon dating because of interfering molecular isobars which, however, can be completely eliminated in charge changing processes at high ion beam energies (MeV) [1,2]. Here, we present a novel type mass spectrometry system for radiocarbon analyses. Radiocarbon dating was performed using 45 keV {sup 14}C ions from the ion source and a molecule dissociation unit kept at ground potential. This proof-of-principle experiment demonstrates for the first time the feasibility of mass spectrometric radiocarbon dating without an accelerator. The results obtained will be the basis of an optimized design for a radiocarbon dating instrument comparable in size, complexity and cost to standard mass spectrometers.

  8. Precision radiocarbon dating of a Late Holocene vegetation history

    International Nuclear Information System (INIS)

    The purpose of this research is to precisely date vegetation changes associated with early human presence in the Hawkes Bay region. A sequence of AMS radiocarbon ages was obtained using a new technique developed at Rafter Radiocarbon Laboratory. A density separation method was used to concentrate pollen and spores extracted from unconsolidated lake sediments from a small-enclosed lake in coastal foothills of southern Hawkes Bay. Radiocarbon measurements were made on fractions of concentrated pollen, separated from associated organic debris. These ages directly date vegetation communities used to reconstruct the vegetation history of the region. This technique results in more accurate dating of Late Holocene vegetation changes interpreted from palynological analyses than techniques formerly used. Precision dating of palynological studies of New Zealand prehistory and history is necessary for correlation of vegetation changes to cultural changes because of the short time span of human occupation of New Zealand. (author). 35 refs., 3 figs., 1 tab

  9. Radiocarbon dates to access the origin of the ice man

    Energy Technology Data Exchange (ETDEWEB)

    Niklaus, R. [Institute of Particle Physics, ETH Zurich, Hongerberg (Switzerland)]|[Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience; Bonani, G. [Institute of Particle Physics, ETH Zurich, Hongerberg (Switzerland); Prinoth-Fornwagner, R. [Innsbruck Univ. (Austria)

    1996-12-31

    Different samples from the Late and Final Neolithic in Northern Italy were radiocarbon dated at the AMS Facility in Zurich, Switzerland in order to determine the origin of the Ice Man from the Hauslabjoch. The cultural classification was obtained on the basis of topological studies of the cooper axe and of the flint dagger as well as studies of artefact materials (the flint or the wood of a composite arrow), while the chronological classification of the Ice Man was obtained with the help of new and old radiocarbon dates. 9 refs., 1 tab., 2 figs.

  10. Radiocarbon dates to access the origin of the ice man

    International Nuclear Information System (INIS)

    Different samples from the Late and Final Neolithic in Northern Italy were radiocarbon dated at the AMS Facility in Zurich, Switzerland in order to determine the origin of the Ice Man from the Hauslabjoch. The cultural classification was obtained on the basis of topological studies of the cooper axe and of the flint dagger as well as studies of artefact materials (the flint or the wood of a composite arrow), while the chronological classification of the Ice Man was obtained with the help of new and old radiocarbon dates. 9 refs., 1 tab., 2 figs

  11. Radiocarbon dating prehistoric pottery from Northern Europe

    DEFF Research Database (Denmark)

    Philippsen, Bente; Craig, Oliver; Heron, Carl;

    2012-01-01

    -depositional contamination with organic carbon, such as humic acids, may also be problematic. We present these data with radiocarbon datings of contemporaneous terrestrial and aquatic samples to find out the true age of the pottery and estimate the reservoir age. Lipid analysis and bulk carbon and nitrogen stable isotope......Direct dating of the pottery is an important goal in archaeological research and many attempts have been made using radiocarbon. One important goal has been to date the earliest pottery in a region to assess the origin and dispersal of ceramic technology. Also with the increasing application of...... organic residue analysis to study pottery use, it has become important to combine residue data with direct dates on the artefact being investigated. In this study we have radiocarbon dated different organic materials associated with archaeological potsherds from three Ertebølle sites in Northern Germany...

  12. Development of BASIC program for radiocarbon dating

    International Nuclear Information System (INIS)

    The continuous improvement of the system and the needs have produced the successful radiocarbon dating system of today to detect very low energy β-radioactivity. However, it still takes longer than 1,000 minutes for a sample counting. In a gas counting system, it is very difficult to keep the drift of impressed high voltage for a proportional counter less than 5 volts throughout the counting time. The temperature and the characteristics of gas itself also change during experiment. The accumulation of the above drift and errors are closely concerned with the accuracy and reliability of the radiocarbon date. The detection and reduction of the errors are only possible by using a ''fully automatic radiocarbon dating system'' linked to a personal computer system. In this paper, the author presents the BASIC (Beginners All-purpose Symbolic Instruction Code) program for a fully automatic radiocarbon dating system. In this paper, the outline of the system and software development are described. The details of the program include the description for gas-collection, gas-enclosing, plateau counting, β-ray counting, age calculation and data file maintenance. The author wrote numerous remark statements into the program so that it can be understood by users without detailed knowledge of the operation of a personal computer system or of the radiocarbon dating. Using this system, the author found that the radiocarbon dating has greatly progressed in speed and labour-saving, and that the accuracy and reliability of the date itself has also improved much than former manual systems. (Wakatsuki, Y.)

  13. The freshwater reservoir effect in radiocarbon dating

    DEFF Research Database (Denmark)

    Philippsen, Bente

    case studies will show the degree of variability of the freshwater reservoir effect over short and long timescales. Radiocarbon dating of recent water samples, aquatic plants and animals, shows that age differences of up to 2000 years can occur within one river. In the Limfjord, freshwater influence...... caused reservoir ages to vary between 250 and 700 years during the period 5400 BC - AD 700. Finally, I will discuss the implications of the freshwater reservoir effect for radiocarbon dating of Mesolithic pottery from inland sites of the Ertebølle culture in Northern Germany....

  14. The freshwater reservoir effect in radiocarbon dating

    DEFF Research Database (Denmark)

    Philippsen, Bente

    2013-01-01

    The freshwater reservoir effect can result in anomalously old radiocarbon ages of samples from lakes and rivers. This includes the bones of people whose subsistence was based on freshwater fish, and pottery in which fish was cooked. Water rich in dissolved ancient calcium carbonates, commonly known...... order of magnitude and degree of variability of the freshwater reservoir effect over short and long timescales. Radiocarbon dating of recent water samples, aquatic plants, and animals, shows that age differences of up to 2000 14C years can occur within one river. The freshwater reservoir effect has also...... implications for radiocarbon dating of Mesolithic pottery from inland sites of the Ertebølle culture in Northern Germany. The surprisingly old ages of the earliest pottery most probably are caused by a freshwater reservoir effect. In a sediment core from the Limfjord, northern Denmark, the impact of the...

  15. Use of radiocarbon technique for archaelogic dating

    International Nuclear Information System (INIS)

    The nuclear technique based on the beta radiation measurements emitted by the radiocarbon is applied an the geochronologycal dating of organic samples of prehistoric fires and sambaqui shells. This paper describes the origin of the method, the technique used and its applications, the analysis method, the equipments and the experiences performed. (Author)

  16. Radiocarbon dating of interlaboratory check samples

    International Nuclear Information System (INIS)

    This note presents the results of a series of interlaboratory age determinations in which the Geological Survey of Canada's Radiocarbon Dating Laboratory has been involved. There is good agreement between laboratories, although there may be other problems related to the interpretation of individual samples

  17. Accelerator mass spectrometry for radiocarbon dating

    OpenAIRE

    Bronk, Christopher Ramsey.; Hedges, Robert; Robert Hedges

    1987-01-01

    Accelerator mass spectrometry (AMS) has been used routinely for radiocarbon measurements for several years. During this period it has become evident neither the accuracy nor the range of the technique were as great as had originally been hoped. This thesis describes both theoretical work to understand the reasons for this and practical solutions to overcome some of the problems. The production and transport of the ions used in the measurements are found to be the most crucial stages in...

  18. Geological Survey of Canada radiocarbon dates XXIX

    International Nuclear Information System (INIS)

    This list presents 622 radiocarbon age determinations made by the Radiocarbon Dating Laboratory. All samples dated more than two years ago have now been reported in date lists. The total number (609) of samples from various areas are as follows: Offshore (43); Newfoundland (42); Labrador (11); Nova Scotia (39); New Brunswick (7); Champlain Sea (38); Quebec (54); Ontario (23); Manitoba (3); Saskatchewan (9); Alberta (6); British Columbia (92); Yukon Territory (71); Northwest Territories, mainland (33); Northwest Territories, Arctic Archipelago (126); U.S.A. - New York (6); Washington (1); Denmark Greenland (3). Tables 1 and 2 summarize the details of background and standard counts for the 2 L and 5 L counters during the period from December 6, 1988 to January 9, 1990. (author). Refs

  19. Accelerator mass spectrometry for radiocarbon dating

    International Nuclear Information System (INIS)

    Accelerator mass spectrometry (AMS) has been used routinely for radiocarbon measurements for several years. This thesis describes theoretical work to understand the reasons for low accuracy and range and offers practical solutions. The production and transport of the ions used in the measurements are found to be the most crucial stages in the process. The theories behind ion production by sputtering are discussed and applied to the specific case of carbon sputtered by caesium. Experimental evidence is also examined in relation to the theories. The phenomena of space charge and lens aberrations are discussed along with the interaction between ion beams and gas molecules in the vacuum. Computer programs for calculating phase space transformations are then described; these are designed to help investigations of the effects of space charge and aberrations on AMS measurements. Calculations using these programs are discussed in relation both to measured ion beam profiles in phase space and to the current dependent transmission of ions through the Oxford radiocarbon accelerator. Improvements have been made to this accelerator and these are discussed in the context of the calculations. C- ions are produced directly from carbon dioxide at the Middleton High Intensity Sputter Source. Experiments to evaluate the performance of such a source are described and detailed design criteria established. An ion source designed and built specifically for radiocarbon measurements using carbon dioxide is described. Experiments to evaluate its performance and investigate the underlying physical processes are discussed. (author)

  20. Radiocarbon dating development and practices at MINT

    International Nuclear Information System (INIS)

    The MINT radiocarbon dating technique was introduced and a very well-designed vacuum line was developed to generate benzene from samples containing carbon. A liquid scintillation counter provides a very good prerequisite for precise measurement of the C-14 activity in the benzene. From time to time, assessment on the status of the analytical capabilities of the system and advice on improvement and upgrading required was made. For routine analysis, standard sampling, pretreatment, carbon dioxide conversion and measurement procedures were adopted. Radiocarbon dating is now, one of the most important developments of the twenties century in the comprehension of the history of human development, a quick, easy, reliable and scientifically acceptable method to determine the age of historical artefacts and archaeological samples. (Author)

  1. Low energy cyclotron for radiocarbon dating

    International Nuclear Information System (INIS)

    The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity 14C measurements that are now done at accelerator facilities. We found that no significant background is present when the cyclotron is tuned to accelerate 14C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect 14C directly at modern concentrations. We show how a conventional carbon negative ion source, located outside the cyclotron magnet, would produce sufficient beam and provide for quick sampling to make radiocarbon dating milligram samples with a modest laboratory instrument feasible

  2. Low energy cyclotron for radiocarbon dating

    Energy Technology Data Exchange (ETDEWEB)

    Welch, J.J.

    1984-12-01

    The measurement of naturally occurring radioisotopes whose half lives are less than a few hundred million years but more than a few years provides information about the temporal behavior of geologic and climatic processes, the temporal history of meteoritic bodies as well as the production mechanisms of these radioisotopes. A new extremely sensitive technique for measuring these radioisotopes at tandem Van de Graaff and cyclotron facilities has been very successful though the high cost and limited availability have been discouraging. We have built and tested a low energy cyclotron for radiocarbon dating similar in size to a conventional mass spectrometer. These tests clearly show that with the addition of a conventional ion source, the low energy cyclotron can perform the extremely high sensitivity /sup 14/C measurements that are now done at accelerator facilities. We found that no significant background is present when the cyclotron is tuned to accelerate /sup 14/C negative ions and the transmission efficiency is adequate to perform radiocarbon dating on milligram samples of carbon. The internal ion source used did not produce sufficient current to detect /sup 14/C directly at modern concentrations. We show how a conventional carbon negative ion source, located outside the cyclotron magnet, would produce sufficient beam and provide for quick sampling to make radiocarbon dating milligram samples with a modest laboratory instrument feasible.

  3. Radiocarbon dating in groundwater systems. Chapter 4

    International Nuclear Information System (INIS)

    The radioactive isotope of carbon, radiocarbon (14C), was first produced artificially in 1940 by Martin Kamen and Sam Ruben, who bombarded graphite in a cyclotron at the Radiation Laboratory at Berkeley, CA, in an attempt to produce a radioactive isotope of carbon that could be used as a tracer in biological systems (Kamen (1963) [101]; Ruben and Kamen (1941) [102]). Carbon-14 of cosmogenic origin was discovered in atmospheric CO2 in 1946 by Willard F. Libby, who determined a half-life of 5568 a. Libby and his co-workers (anderson et al. (1947) [103]; Libby et al. (1949) [104]) developed radiocarbon dating of organic carbon of biological origin, which revolutionized research in a number of fields, including archaeology and quaternary geology/climatology, by establishing ages and chronologies of events that have occurred over the past approximately 45 ka.

  4. Using accelerator mass spectrometry for radiocarbon dating of textiles

    Energy Technology Data Exchange (ETDEWEB)

    Jull, A.J.T.

    1997-12-01

    Since 1981 we have operated an NSF Accelerator Mass Spectrometry (AMS) Facility at the University of Arizona. The AMS method allows us to use very small samples of carbon, <1 mg for radiocarbon dating in contrast to earlier counting techniques. This has opened a vast array of applications of radiocarbon dating that was difficult to do before AMS because of sample size limitations of decay counting. Some of the many applications of AMS include paleoclimatic studies, archaeological research and the age of first settlement of North America by man, dating of art works and artifacts, fall times and terrestrial residence ages of meteorites, production of {sup 14}C in lunar samples by galactic and solar cosmic rays, studies of in situ {sup 14}C produced by cosmic ray spallation in rocks and ice, and studies of {sup 14}C in groundwater dissolved inorganic carbon and dissolved organic carbon. At our laboratory, we have also successfully applied AMS {sup 14}C to dating of many types of textiles, including silks and linens, art works, documents and artifacts fabricated from wood, parchment, ivory, and bone. The results for many of these samples are often important in questions of the authenticity of these works of art and artifacts. Our studies have encompassed a wide range of art works ranging from the Dead Sea Scrolls, the Shroud of Turin, and the Chinese silk trade to the works of Raphael, Rembrandt, and Picasso. Recently, we also dated the Vinland Map, a controversial document that shows the eastern coast of North America apparently using information from Viking voyages.

  5. Radiocarbon Dating of Vertisols in China

    Institute of Scientific and Technical Information of China (English)

    LIULIANGWU

    1996-01-01

    Vertisols,which are mainly developed on fluvial and lacustrine deposits and basalt,are extensively distributed in China.66 samples of them for radiocarbon dating were collected across 5 porvinces and 1 autonomous region,ranging from warm-temperate to subtropical and tropical zones in China.The soil organic matter was dated via surface horizon,black soil horizon and dark-colour horizon of the vertisols,whereas carbonate through calcareous concretions and dispersed carbonate in soil profile using radiocarbon method.The present article elucidates the dates of genetic horizons,and of surface and buried vertisols as well.14C dating indicates that the surface vertisols were formed during the end of the late Pleistocene.ca.15600 years ageo.Correlation between depth of sampling and measured 14C age shows that age characteristics of the vertisols of China are close to those of West Germany,Italy,TUrnisia,Australia and Argentina,However,two buried vertisols developed on fluvial and lacustrine deposits were formed during different geological periods,The buried soils in warm-temperate zone were formed in the mid Holocene,while those in subtropics were buried at 12930 years B.P., and formed in the end of the late Pleistocene.

  6. Precision and reproducibility in AMS radiocarbon measurements.

    Energy Technology Data Exchange (ETDEWEB)

    Hotchkis, M.A.; Fink, D.; Hua, Q.; Jacobsen, G.E.; Lawson, E. M.; Smith, A.M.; Tuniz, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Accelerator Mass Spectrometry (AMS) is a technique by which rare radioisotopes such as {sup 14}C can be measured at environmental levels with high efficiency. Instead of detecting radioactivity, which is very weak for long-lived environmental radioisotopes, atoms are counted directly. The sample is placed in an ion source, from which a negative ion beam of the atoms of interest is extracted, mass analysed, and injected into a tandem accelerator. After stripping to positive charge states in the accelerator HV terminal, the ions are further accelerated, analysed with magnetic and electrostatic devices and counted in a detector. An isotopic ratio is derived from the number of radioisotope atoms counted in a given time and the beam current of a stable isotope of the same element, measured after the accelerator. For radiocarbon, {sup 14}C/{sup 13}C ratios are usually measured, and the ratio of an unknown sample is compared to that of a standard. The achievable precision for such ratio measurements is limited primarily by {sup 14}C counting statistics and also by a variety of factors related to accelerator and ion source stability. At the ANTARES AMS facility at Lucas Heights Research Laboratories we are currently able to measure {sup 14}C with 0.5% precision. In the two years since becoming operational, more than 1000 {sup 14}C samples have been measured. Recent improvements in precision for {sup 14}C have been achieved with the commissioning of a 59 sample ion source. The measurement system, from sample changing to data acquisition, is under common computer control. These developments have allowed a new regime of automated multi-sample processing which has impacted both on the system throughput and the measurement precision. We have developed data evaluation methods at ANTARES which cross-check the self-consistency of the statistical analysis of our data. Rigorous data evaluation is invaluable in assessing the true reproducibility of the measurement system and aids in

  7. Radiocarbon determinations for Chillagoe rock paintings: small sample AMS

    International Nuclear Information System (INIS)

    Indirect dating methods have been applied to the rock paintings of Chillagoe, north Queensland, revealing patterns of superimposition, depictions of items of known antiquity, the use of fragile paints such as mud, and in-situ pigment stratigraphies (David 1994). These patterns suggest that the Chillagoe rock paintings are relatively young, likely less than 3000 years old. A change in the geographical distribution of rock painting styles suggests a regionalization of the styles starting around 3000 years BP. Such regionalization implies that major cultural changes accompanied the changes in rock painting styles. This model of temporal change is now being investigated through a collaboration between the University of Queensland, ANSTO and the Department of Chemistry, Texas A and M University to directly analyze radiocarbon in the charcoal pigments in several of the Chillagoe rock paintings. Samples collected from fourteen separate charcoal rock drawings at five rock shelters in the Chillagoe region were submitted to plasma chemical treatment. Though unreactive, the excited and energetic argon atoms in the plasma remove surface-absorbed CO2 through inelastic collisions. Samples yielding less than 100 micrograms carbon required special handling for AMS analysis. An isotope dilution technique utilizing 14C-free carbon was chosen. Radiocarbon analysis were also performed and the results will be presented

  8. Radiocarbon determinations for Chillagoe rock paintings: small sample AMS

    Energy Technology Data Exchange (ETDEWEB)

    Armitage, R.A.; Hyman, M.; Rowe, M. W. [Texas A and M University, College Station, Texas (United States). Department of Chemistry; David, B. [Queensland Univ St. Lucia, QLD (Australia); Tuniz, C.; Lawson, E.; Jacobsen, G.; Hua, G. [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia)

    1997-12-31

    Indirect dating methods have been applied to the rock paintings of Chillagoe, north Queensland, revealing patterns of superimposition, depictions of items of known antiquity, the use of fragile paints such as mud, and in-situ pigment stratigraphies (David 1994). These patterns suggest that the Chillagoe rock paintings are relatively young, likely less than 3000 years old. A change in the geographical distribution of rock painting styles suggests a regionalization of the styles starting around 3000 years BP. Such regionalization implies that major cultural changes accompanied the changes in rock painting styles. This model of temporal change is now being investigated through a collaboration between the University of Queensland, ANSTO and the Department of Chemistry, Texas A and M University to directly analyze radiocarbon in the charcoal pigments in several of the Chillagoe rock paintings. Samples collected from fourteen separate charcoal rock drawings at five rock shelters in the Chillagoe region were submitted to plasma chemical treatment. Though unreactive, the excited and energetic argon atoms in the plasma remove surface-absorbed CO{sub 2} through inelastic collisions. Samples yielding less than 100 micrograms carbon required special handling for AMS analysis. An isotope dilution technique utilizing {sup 14}C-free carbon was chosen. Radiocarbon analysis were also performed and the results will be presented. Paper No. 25; 2 refs., 1 tab.

  9. Radiocarbon dating of late pleistocene marine shells from the southern north sea

    NARCIS (Netherlands)

    Busschers, F.S.; Wesselingh, F.P.; Kars, R.H.; Versluijs-Helder, M.; Wallinga, J.; Bosch, J.H.A.; Timmner, J.; Nierop, K.G.J.; Meijer, T.; Bunnik, F.P.M.; Wolf, De H.

    2014-01-01

    This article presents a set of Late Pleistocene marine mollusk radiocarbon (AMS) age estimates of 30-50 C-14 kyr BP, whereas a MIS5 age (>75 ka) is indicated by quartz and feldspar OSL dating, biostratigraphy, U-Th dating, and age-depth relationships with sea level. These results indicate that th

  10. Radiocarbon dating of late pleistocene marine shells from the southern North Sea

    NARCIS (Netherlands)

    Busschers, F.S.; Wesselingh, F.P.; Kars, R.H.; Versluijs-Helder, M.; Wallinga, J.; Bosch, J.H.A.; Timmner, J.; Nierop, K.G.J.; Meijer, T.; Bunnik, F.P.M.; Wolf, H. de

    2014-01-01

    This article presents a set of Late Pleistocene marine mollusk radiocarbon (AMS) age estimates of 30-50 14C kyr BP, whereas a MIS5 age (>75 ka) is indicated by quartz and feldspar OSL dating, biostratigraphy, U-Th dating, and age-depth relationships with sea level. These results indicate that the 14

  11. Assessing screening criteria for the radiocarbon dating of bone mineral

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Ricardo, E-mail: ldv1452@gmail.com [Leibniz Labor for Isotopic and Radiometric Dating, Max-Eyth-Str. 11-13, 24118 Kiel (Germany); Graduate School Human Development in Landscapes, Christian Albrecht University, Kiel (Germany); Huels, Matthias [Leibniz Labor for Isotopic and Radiometric Dating, Max-Eyth-Str. 11-13, 24118 Kiel (Germany); Nadeau, Marie-Josee; Grootes, Pieter M. [Leibniz Labor for Isotopic and Radiometric Dating, Max-Eyth-Str. 11-13, 24118 Kiel (Germany); Graduate School Human Development in Landscapes, Christian Albrecht University, Kiel (Germany); Garbe-Schoenberg, C.-Dieter [Institute of Geosciences, Marine Climate Research and ICPMS Lab, Kiel University, Ludewig-Meyn-Str. 10, D-24118 Kiel (Germany); Graduate School Human Development in Landscapes, Christian Albrecht University, Kiel (Germany); Hollund, Hege I. [Institute for Geo- and Bioarchaeology, The VU University, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Lotnyk, Andriy [Faculty of Engineering, Institute for Material Science, Synthesis and Real Structure, Kiel University, Kaiserstr. 2, D-24143 Kiel (Germany); Leibniz Institute of Surface Modification (IOM), Permoserstr. 15, D-04318 Leipzig (Germany); Kienle, Lorenz [Faculty of Engineering, Institute for Material Science, Synthesis and Real Structure, Kiel University, Kaiserstr. 2, D-24143 Kiel (Germany); Graduate School Human Development in Landscapes, Christian Albrecht University, Kiel (Germany)

    2013-01-15

    Radiocarbon dating of bone mineral (carbonate in the apatite lattice) has been the target of sporadic research for the last 40 years. Results obtained by different decontamination protocols have, however, failed to provide a consistent agreement with reference ages. In particular, quality criteria to assess bone mineral radiocarbon dating reliability are still lacking. Systematic research was undertaken to identify optimal preservation criteria for bone mineral in archeological bones. Six human long bones, originating from a single site, were radiocarbon-dated both for collagen and apatite, with the level of agreement between the dates providing an indication of exogenous carbon contamination. Several techniques (Histology, FTIR, TEM, LA-ICP-MS) were employed to determine the preservation status of each sample. Research results highlight the importance of a micro-scale approach in establishing bone preservation, in particular the use of trace element concentration profiles demonstrated its potential use as a viable sample selection criterion for bone carbonate radiocarbon dating.

  12. Assessing screening criteria for the radiocarbon dating of bone mineral

    International Nuclear Information System (INIS)

    Radiocarbon dating of bone mineral (carbonate in the apatite lattice) has been the target of sporadic research for the last 40 years. Results obtained by different decontamination protocols have, however, failed to provide a consistent agreement with reference ages. In particular, quality criteria to assess bone mineral radiocarbon dating reliability are still lacking. Systematic research was undertaken to identify optimal preservation criteria for bone mineral in archeological bones. Six human long bones, originating from a single site, were radiocarbon-dated both for collagen and apatite, with the level of agreement between the dates providing an indication of exogenous carbon contamination. Several techniques (Histology, FTIR, TEM, LA-ICP-MS) were employed to determine the preservation status of each sample. Research results highlight the importance of a micro-scale approach in establishing bone preservation, in particular the use of trace element concentration profiles demonstrated its potential use as a viable sample selection criterion for bone carbonate radiocarbon dating.

  13. Underground water dating and age corrections using radiocarbon

    International Nuclear Information System (INIS)

    This paper describe a method that correlate underground water dating using radiocarbon and other environmental isotopes in order to estimate recharge conditions of an aquifer located in Romania. Radiocarbon ages were corrected by six correction models. Obtained data conducted to a mean transit velocity of studied aquifer of 0.55 m/year, value which is specific for this type of aquifer. Although radiocarbon measurement method proposed in this paper is a classical one, optimizations to the preparation technique allow reduction of time and financial costs and can be successfully applied to a large number of samples, common in hydrological studies. (author)

  14. Radiocarbon dating of ancient bronze statues: Preliminary results from the Riace statues

    International Nuclear Information System (INIS)

    The low amount of material needed for the measurements makes AMS radiocarbon a technique suitable for the dating of ancient bronze artefacts through the analysis of the organic residues contained into the casting cores. We present the results of the AMS radiocarbon dating analyses carried out on the organic remains extracted from the casting cores of the Riace bronzes, among the most famous and well preserved sculptures of the Greek-Classical period. Although different dating hypotheses have been suggested on the base of stylistic considerations, no conclusive answers are, so far, available. The sample selection and preparation protocols of the different kind of organic materials (charred wood, vegetal remains and animal hairs) are described as well as the interpretation of the results in the frame of the current dating hypotheses and available analytical information about the casting technology.

  15. Radiocarbon dates from Wairau Bar and their implications for the prehistoric colonisation of New Zealand

    International Nuclear Information System (INIS)

    A set of thirteen moa eggshell samples from burial features at the Wairau Bar site were used for dating. The samples were obtained from the Canterbury Museum in Christchurch where they have been displayed as part of a permanent exhibition.Three marine shell samples were also analysed. Radiocarbon dating of the samples was carried out using conventional and AMS techniques. The results will be presented and the archaeological implications for the prehistoric colonization of New Zealand will be discussed

  16. The comparison of absolute dating (Radiocarbon dating) and relative dating of Pringapus and Gondosuli temples

    International Nuclear Information System (INIS)

    The absolute dating (radiocarbon, 14C dating) and relative dating of Pringapus and Gondosuli temples in Temanggung regency (district) of Central Java Province have been carried out. The field sampling was done especially with the purpose to obtain vertical data, so that excavation method was adopted in the case. The main data were the ecofacts of organic habitation such as bones, woods, charcoals, shells, and paper artefacts. The artefacts data were used as a comparison. The comparative data analysis were conducted at Yogyakarta archaeological Department Laboratory, thus included dating of artefacts which were performed according to archaeological analysis procedures, generally based on the attributes attached to the artefacts, whereas the absolute dating of charcoal samples were performed in the Radiocarbon Dating Laboratory at Yogyakarta Nuclear Research Centre. Based on the relative dating of epigraphy content on the andesit rock from Gondosuli Temple which showed the year of 754 Saka or 832 AD, the Pringapus Temple was estimated to be built in the 850 AD. According to the absolute dating (Radiocarbon Dating with delta 13C and tree ring corrections) the age for Gondosuli temple based on GDS/LU-2/Spit-7 samples is (384 -602) AD and from GDS/LU-2/Spit-8 = (452 - 652) AD. With these significant differences in the results obtained, it can be concluded that culture environment where the sample were collected already existed before the temple was built. Further investigation is still required

  17. Liquid scintillators for radiocarbon dating in archaeology

    International Nuclear Information System (INIS)

    A simple scintillator counter with one photomultiplier and no cooling is used for determining the absolute age of archaeological specimens by means of radiocarbon. Background is reduced by using a steel- and lead-laminated shield and amplitude pulse-height selection, and by making the detector from selected 'clean' materials. Ethyl benzene is synthesized from the carbon contained in the archaeological specimen. From 18 to 72 ml of liquid scintillator was used in the measurements, corresponding to the introduction of 3 - 12 g of carbon from the specimen. With 40 ml of scintillator the background-count speed and the contemporaneous carbon speed (without background) were respectively 23.5 and 37 counts/min and with 70 ml, 28 and 57 counts/ min. The statistical error of 48-h measurements of specimens 5500 yr old is respectively 65 and 35 yr with 40 and 70 ml of the scintillator. Archaeological specimens from various regions of the Soviet Union were measured. (author)

  18. Micadas: A versatile radiocarbon dating system in routine operation

    Energy Technology Data Exchange (ETDEWEB)

    Wacker, Lukas; Hajdas, Irena; Synal, Hans-Arno [Ion Beam Physics, ETH Zurich (Switzerland); Kromer, Bernd [Heidelberg Academy of Sciences (Germany); Nemec, Mojmir; Ruff, Matthias [Department of Chemistry and Biochemistry, University of Bern (Switzerland)

    2009-07-01

    The mini carbon dating system (Micadas) at ETH Zuerich was built 4 years ago. While it was mainly used for experimental development the first 3 years, we present our first experiences in routine operation for gaseous and solid radiocarbon samples. We show the prospects of the direct measurement of carbon dioxide with the gas ion source for either small samples or samples where low precision is required. Beyond that, we demonstrate the excellent stability and reproducibility of the Micadas system on high-precision measurements of solid samples. This ends in a discussion about the perspectives of our mini radiocarbon dating system.

  19. Radiocarbon dating of ancient rock paintings

    International Nuclear Information System (INIS)

    This report presents progress made on a technique for 14C dating pictographs. A low-temperature oxygen plasma is used coupled with high-vacuum technologies to selectively remove C-containing material in the paints without contamination from inorganic carbon from rock substrates or accretions

  20. Radiocarbon

    Science.gov (United States)

    Broecker, W. S.

    2003-12-01

    Willard Libby's invention of the radiocarbon dating method revolutionized the fields of archeology and Quaternary geology because it brought into being a means to correlate events that occurred during the past 3.5×104 years on a planet-wide scale (Libby et al., 1949). This contribution was recognized with the award of the Nobel Prize for Chemistry. In addition, radiocarbon measurements have been a boon to the quantification of many processes taking place in the environment, to name a few: the rate of "ventilation" of the deep ocean, the turnover time of humus in soils, the rate of growth of cave deposits, the source of carbon-bearing atmospheric particulates, the rates of gas exchange between the atmosphere and water bodies, the replacement time of carbon atoms in human tissue, and depths of bioturbation in marine sediment. Some of these applications have been greatly aided by the creation of excess 14C atoms as the result of nuclear tests conducted in the atmosphere. Since the 1960s, this so-called bomb radiocarbon has made its way into all of the Earth's active carbon reservoirs. To date, tens of thousands of radiocarbon measurements have been made in laboratories throughout the world.

  1. Uses of radiocarbon dating in archaeology

    International Nuclear Information System (INIS)

    Carbon dating is one of the mist effective tools in the archaeologist's kit. It has provided illumination where none was once thought possible. The historians of one hundred years ago could only dream of such a wonderful, albeit frightening atomic clock ticking away, helping to mark the passing of the years and the ages of man. It is a vital part in the investigation and preservation of our past and a lovely bit of analysis to compliment digital records of monuments. It places the plants, animals, and people of yore into an understandable and verifiable context

  2. Luminescence and radiocarbon dating of raised beach sediments, Bunger Hills, East Antarctica

    International Nuclear Information System (INIS)

    Luminescence and radiocarbon dating of raised marine sediments from the Bunger Hills, East Antarctica, demonstrates that luminescence methods can be applied to such poorly bleached sediments as long as the luminescence behaviour of the sediments is understood. This is essential as the complete zeroing of the luminescence signal due to light exposure is required to allow an accurate age for the sediment accumulation. Unfortunately, independent checks on the luminescence ages are rare. In the present study, some independent age control is provided by AMS radiocarbon ages from shell obtained from and adjacent to the luminescence dated horizons, although the radiocarbon ages may suffer to some degree from variability in the marine reservoir effect. Application of the single aliquot luminescence technique to feldspar grains from the marine sediments demonstrated that the luminescence behaviour of the sediments was complex. For each sample, 18 replicate paleodose estimates were used to demonstrate whether the sediments were well bleached before deposition. Optically, well-bleached samples give younger luminescence ages, whilst poorly bleached samples often give excessively old ages compared to the associated radiocarbon-dated material. (author)

  3. Molecular sieve sampling of CO2 from decomposition of soil organic matter for AMS radiocarbon measurements

    International Nuclear Information System (INIS)

    A molecular sieve based procedure has been established for sampling CO2 of decomposing soil organic matter for AMS radiocarbon measurements. The sampling and desorption lines are capable to produce well measurable (>1 mg) AMS targets.

  4. Radiocarbon dating of Mesolithic pottery from Northern Germany

    DEFF Research Database (Denmark)

    Philippsen, Bente

    2013-01-01

    The earliest pottery in Schleswig-Holstein, Northern Germany, was produced by the Final Mesolithic Ertebølle culture. Radiocarbon dating of food crusts on Ertebølle pottery indicated that ceramics from inland sites were substantially older than those from the coast. Therefore, a freshwater...... reservoir effect was suspected. For assessing the risk of a reservoir effect in the food crust, the presence of aquatic products such as fish has to be identified. It was tested whether stable carbon and nitrogen isotopes can be used for this purpose. In the study presented here I measured the order of...... magnitude and the degree of variability of the freshwater reservoir effect in Schleswig-Holstein. Experiments with copies of Ertebølle vessels yielded reference material for radiocarbon dating and stable isotope analysis. Food crusts, terrestrial samples and fishbones from two Ertebølle inland sites were...

  5. The interpretation of archaeological dates from an AMS perspective

    International Nuclear Information System (INIS)

    The XVII century saw the establishment of the scientific method and scholars such as Galileo were giving excellent contributions to a variety of fields ranging from the natural sciences to the humanities. At the dawn of the new millenium, after a period of excessive specialization, the scientific climate is once again encouraging broad collaborations across different disciplines. For projects involving AMS measurements in general and radiocarbon dating in particular, the benefits of this new trend are numerous. For example, the full potential of the radiocarbon dating method can be exploited only through the mutual understanding of the problems related to sample selection, chemical preparation, AMS measurement, data analysis and interpretation. This paper is intended to enhance the exchange of information by reporting to our current and potential collaborators about the latest technical developments undertaken at the ANTARES AMS facility at ANSTO. Furthermore, we will present two splendid examples of collaborative research: the radiocarbon dating of a replica of a famous chesspiece and the archaeological investigations at the ancient settlement of Sos Hoyuk (north-eastern Anatolia, Turkey) where the multidisciplinary approach was the key to a better understanding of the social structure, settlement patterns, land use and cultural contact, especially with the lands of Trans-Caucasus. (author). 12 refs., 4 figs

  6. Radiocarbon dates on bones of extinct birds from Hawaii.

    OpenAIRE

    James, H.F.; Stafford, T.W.; Steadman, D W; Olson, S.L.; Martin, P. S.; Jull, A J; McCoy, P C

    1987-01-01

    Bones from a stratified sedimentary deposit in the Puu Naio Cave site on Maui, Hawaiian Islands, reveal the late Holocene extinction of 19 species of birds. The age of the sediment and associated fauna was determined by direct radiocarbon dating (tandem particle accelerator-mass spectrometer; TAMS) of amino acids extracted from bones weighing as little as 450 mg. The 14C dates indicate that sediment has been accumulating in the lava tube for at least the last 7750 years, a suitable time frame...

  7. Year of Birth Determination Using Radiocarbon Dating of Dental Enamel

    Energy Technology Data Exchange (ETDEWEB)

    Buchholz, B A; Spalding, K L

    2009-03-10

    Radiocarbon dating is typically an archaeological tool rather than a forensic one. Recently however, we have shown that the amount of radiocarbon present in tooth enamel, as a result of nuclear bomb testing during the cold war, is a remarkably accurate indicator of when a person is born. Enamel isolated from human teeth is processed to form graphite and carbon-14 ({sup 14}C) levels are measured using accelerator mass spectrometry. Since there is no turnover of enamel after it is formed, {sup 14}C levels in the enamel represent {sup 14}C levels in the atmosphere at the time of its formation. In this paper we describe the strategy used to determine the date of birth of an individual based on radiocarbon levels in tooth enamel, focusing on the methodology of this strategy. Year of birth information can significantly assist police investigators when the identity of a deceased individual is unknown. In such cases police will try to match particulars of the unidentified individual (which is often only gender and/or an estimate of age), with particulars from missing persons lists.

  8. Year of Birth Determination Using Radiocarbon Dating of Dental Enamel

    International Nuclear Information System (INIS)

    Radiocarbon dating is typically an archaeological tool rather than a forensic one. Recently however, we have shown that the amount of radiocarbon present in tooth enamel, as a result of nuclear bomb testing during the cold war, is a remarkably accurate indicator of when a person is born. Enamel isolated from human teeth is processed to form graphite and carbon-14 (14C) levels are measured using accelerator mass spectrometry. Since there is no turnover of enamel after it is formed, 14C levels in the enamel represent 14C levels in the atmosphere at the time of its formation. In this paper we describe the strategy used to determine the date of birth of an individual based on radiocarbon levels in tooth enamel, focusing on the methodology of this strategy. Year of birth information can significantly assist police investigators when the identity of a deceased individual is unknown. In such cases police will try to match particulars of the unidentified individual (which is often only gender and/or an estimate of age), with particulars from missing persons lists.

  9. A radiocarbon dated Weichselian sequence from Sejeroe, Denmark

    International Nuclear Information System (INIS)

    Kineto-stratigraphic studies through a cliff section on the island of Sejeroe, Denmark, have revealed the presence of three till beds (interbedded with stratified meltwater deposits) related to the Main-, the East-Jutland-, and Belt Sea advances respectively. Below the tills there is a stratified deposit of clayey sand and silt with and admixture of organic material. The pollen in the organic part contains high percentages of Cyperaceae and Gramineae; radiocarbon dates of 36900 +- 460 B.P. and 36710 +- 460 B.P. from the deposit suggest a correlation with the Hengelo Interstadial in the Netherlands. (auhtor)

  10. Radiocarbon dating of the Goti-Finiglacial boundary of the Swedish Time Scale

    International Nuclear Information System (INIS)

    Wile working with the revision of the Swedish Time Scale, based on clay-varve chronology, mollusc shell of Portlandia arctica were found in the clay at Ekensberg, Stockholm, Sweden, deposited at the beginning of the Finiglacial epoch. The clay-varves have been connected with the revised Swedish Time Scale and the time for deposition is 10370 clay-varve years cal BP. Shells of bivalves, shell fragments and periostracum have been AMS radiocarbon-dated at the Svedberg Laboratory in Uppsala. The 11 radiometric datings are grouped in two assemblages, one between 10500 and 11600 BP and one between 8200 and 9100 BP. These results are compared with the radiocarbon age obtained for a fish skeleton found in varved clay close to Ekensberg during the geological mapping of the area. The age of the fish is 8600 BP, which is in agreement with the periostracum datings. Reservoir effects and calibration of the radiocarbon ages to sidereal years are discussed. 32 refs., 4 figs., 1 tab

  11. Accelerator radiocarbon dating of evidence for prehistoric horticulture in Illinois

    Science.gov (United States)

    Conard, N.; Asch, D.L.; Asch, N.B.; Elmore, D.; Gove, H.; Rubin, M.; Brown, J.A.; Wiant, M.D.; Farnsworth, K.B.; Cook, T.G.

    1984-01-01

    With the development of direct detection radiocarbon dating, which uses an accelerator as part of a highly selective mass spectrometer, it is now possible to determine the age of milligram samples of organic materials1-5. One application of accelerator dating is in evaluating scanty, sometimes controversial evidence for early horticulture throughout the world. We have now used the technique to date small samples of carbonized, cultivated plant remains from archaeological sites in Illinois. The results, reported here, establish (1) that squash was introduced by 7,000 yr ago, 2,500 yr before eastern North American records previously reported; (2) that horticulture involving indigenous plants had begun by 4,000 BP in eastern North America with domestication of Iva annua, a small-seeded annual; (3) that anomalous discoveries of Archaic period maize represent contaminants; and (4) that introduction of maize by initial Middle Woodland times (???2,000 BP) is questionable. ?? 1984 Nature Publishing Group.

  12. New radiocarbon dates for Milu (Elaphurus davidianus) sub-fossils from southeast China

    Energy Technology Data Exchange (ETDEWEB)

    Ding, X.F. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); Shen, C.D., E-mail: cdshen@gig.ac.cn [State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); Ding, P.; Yi, W.X. [State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou (China); Fu, D.P.; Liu, K.X. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China)

    2013-01-15

    Milu (Elaphurus davidianus, Pere David's deer) is one of the few species of large mammals that became extinct in the wild, but survived domestically. A good understanding of expansion and habitat is required if the reintroduction of Milu into the wild is to be implemented. Among the widely reported findings of Milu sub-fossils, only a small fraction have been dated. Here we report new AMS radiocarbon dates on Milu sub-fossil samples unearthed from two sites at Qingdun, Jiangsu and Fujiashan, Zhejiang in southeast China. These AMS {sup 14}C ages of Milu sub-fossils provide new evidence for the presence of Milu expansion in the lower reaches of the Yangtze River during the Holocene Optimum interval from 5000 yr BC to 3000 yr BC. These new ages also have important implications for the reconstruction of the paleoclimate and paleogeography during the Neolithic Period in southeast China.

  13. Forest soil disturbance intervals inferred from soil charcoal radiocarbon dates

    International Nuclear Information System (INIS)

    Forest soil disturbance intervals are usually too long to measure using plot-based studies, and thus they are poorly understood. The mean soil disturbance interval (MSDI) in an old-growth forest on the west coast of Vancouver Island was estimated from radiocarbon dates of charcoal from organic and mineral soil horizons. Two assumptions are required to estimate the MSDI: charcoal from forest fires is deposited within the organic horizon and eventually mixed into deeper mineral horizons by soil disturbances, and the probability of soil disturbance is spatially homogeneous and affected only by the time since the last fire or the last soil disturbance. The MSDI is then estimated by the rate at which the proportion of undisturbed sample sites (determined by the proportion of sites with charcoal from the most recent fire in the organic horizon) decreases with increasing time since the last fire. Soil charcoal evidence of time since fire was determined at 83 sites using 141 radiocarbon dates. The estimated MSDI was greater on slopes (ca. 2010 years) than on terraces (ca. 920 years). The long periods between soil disturbances, especially on slopes, are consistent with other evidence from the study area that suggests infrequent tree uprooting is the predominant mode of soil disturbance. (author)

  14. Accelerator radiocarbon dating of evidence for prehistoric horticulture in Illinois

    International Nuclear Information System (INIS)

    The authors have now used direct detection radiocarbon dating (which uses an accelerator as part of a highly selective mass spectrometer) to date small samples of carbonized, cultivated plant remains from archaeological sites in Illinois. The results, reported here, establish (1) that squash was introduced by 7,000 yr ago, 2,500 yr before eastern North American records previously reported; (2) that horticulture involving indigenous plants had begun by 4,000 BP in eastern North American with domestication of Iva annua, a small-seeded annual; (3) that anomalous discoveries of Archaic period maize represent contaminants; and (4) that introduction of maize by initial Middle Woodland times (approx. 2,000 BP) is questionable. (author)

  15. The impact on archaeology of radiocarbon dating by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Radiocarbon dating by accelerator mass spectrometry (AMS) is based on direct determination of the ratio of 14C: 12C atoms rather than on counting the radioactivity of 14C. It is therefore possible to measure much lower levels of 14C in a sample much more rapidly than the conventional technique allows. Consequently, minimum sample size is reduced approximately 1000-fold and the datable time span of the method can, theoretically, be doubled. Greater selectivity, in the field and the laboratory, is the most important archaeological attribute of AMS 14C dating. It allows on-site chronological consistency to be tested by multiple sampling; archaeological materials to be dated that contain too little C, or are too rare or valuable, to be dated by the conventional method; and the validity of a date to be tested by isolating and independently dating particular fractions in chemically complex samples. In this paper, recent archaeological applications of the new technique are reviewed under these two headings: verification dating applied to the origin and spread of anatomically modern humans in Europe and the Americas, to putative evidence for early (pre-Neolithic) agriculture in Israel and Egypt, and to the dating of rare Palaeolithic and later artefacts; and the building of new and more-detailed chronologies illustrated by reference to Upper Palaeolithic sequences in Europe, Mesolithic-Neolithic sequences in Southwest Asia, and Neolithic-Bronze Age chronologies in Britain. (author)

  16. Radiocarbon dating of VIRI bone samples using ultrafiltration

    Science.gov (United States)

    Minami, Masayo; Yamazaki, Kana; Omori, Takayuki; Nakamura, Toshio

    2013-01-01

    Ultrafiltration can effectively remove low-molecular-weight (LMW) contaminants from bone gelatin to extract high-molecular-weight (HMW) proteins that are derived from original bone collagen, though it cannot remove HMW collagen crosslinked with humic acids. Therefore, ultrafiltration is often used to obtain more accurate 14C dates of bones. However, ultrafiltration may introduce new contaminants to bone gelatins, mainly from ultrafilters used. To study the effects of ultrafiltration on 14C age, we analyzed the C/N ratio, δ13CPDB and δ15NAIR values, and 14C ages of acid-soluble bone collagen obtained by decalcification, gelatin extracted from acid-insoluble bone collagen, and the HMW gelatin and LMW fractions produced during ultrafiltration of the extracted gelatin. Bone samples from the Fifth International Radiocarbon Intercomparison (VIRI) were used: VIRI-E (mammoth), -F (horse), -G (human), and -I (whale). In this study, carbon and nitrogen content and gelatin yields were used to evaluate collagen preservation in the VIRI bone samples. Radiocarbon ages, δ13CPDB and δ15NAIR values of unfiltered and HMW gelatins were obtained and compared with the published consensus values. The LMW fraction was found to exhibit different values from those of the other fractions, indicating the possible presence of extraneous contamination. The Vivaspin™ 6 ultrafilters used in this study were analyzed and radiocarbon dated both before and after cleaning. We present evidence to suggest that LMW fraction contaminants could be derived from the ultrafilters rather than humic substances. Excessively long ultrafiltration time was suspected to have contaminated the bone samples with material from the ultrafilter, because those samples exhibited older 14C ages than did those filtered for shorter durations. The results in this study indicate that 14C ages of unfiltered gelatin extracted from well-preserved bones can be sufficiently accurate, and that care should be taken not to

  17. Radiocarbon dating of VIRI bone samples using ultrafiltration

    Energy Technology Data Exchange (ETDEWEB)

    Minami, Masayo, E-mail: minami@nendai.nagoya-u.ac.jp [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan); Yamazaki, Kana [Faculty of Science, Nagoya University, Nagoya 464-8602 (Japan); Omori, Takayuki [University Museum, University of Tokyo, Tokyo 113-0033 (Japan); Nakamura, Toshio [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan)

    2013-01-15

    Ultrafiltration can effectively remove low-molecular-weight (LMW) contaminants from bone gelatin to extract high-molecular-weight (HMW) proteins that are derived from original bone collagen, though it cannot remove HMW collagen crosslinked with humic acids. Therefore, ultrafiltration is often used to obtain more accurate {sup 14}C dates of bones. However, ultrafiltration may introduce new contaminants to bone gelatins, mainly from ultrafilters used. To study the effects of ultrafiltration on {sup 14}C age, we analyzed the C/N ratio, {delta}{sup 13}C{sub PDB} and {delta}{sup 15}N{sub AIR} values, and {sup 14}C ages of acid-soluble bone collagen obtained by decalcification, gelatin extracted from acid-insoluble bone collagen, and the HMW gelatin and LMW fractions produced during ultrafiltration of the extracted gelatin. Bone samples from the Fifth International Radiocarbon Intercomparison (VIRI) were used: VIRI-E (mammoth), -F (horse), -G (human), and -I (whale). In this study, carbon and nitrogen content and gelatin yields were used to evaluate collagen preservation in the VIRI bone samples. Radiocarbon ages, {delta}{sup 13}C{sub PDB} and {delta}{sup 15}N{sub AIR} values of unfiltered and HMW gelatins were obtained and compared with the published consensus values. The LMW fraction was found to exhibit different values from those of the other fractions, indicating the possible presence of extraneous contamination. The Vivaspin Trade-Mark-Sign 6 ultrafilters used in this study were analyzed and radiocarbon dated both before and after cleaning. We present evidence to suggest that LMW fraction contaminants could be derived from the ultrafilters rather than humic substances. Excessively long ultrafiltration time was suspected to have contaminated the bone samples with material from the ultrafilter, because those samples exhibited older {sup 14}C ages than did those filtered for shorter durations. The results in this study indicate that {sup 14}C ages of unfiltered

  18. Radiocarbon dating of VIRI bone samples using ultrafiltration

    International Nuclear Information System (INIS)

    Ultrafiltration can effectively remove low-molecular-weight (LMW) contaminants from bone gelatin to extract high-molecular-weight (HMW) proteins that are derived from original bone collagen, though it cannot remove HMW collagen crosslinked with humic acids. Therefore, ultrafiltration is often used to obtain more accurate 14C dates of bones. However, ultrafiltration may introduce new contaminants to bone gelatins, mainly from ultrafilters used. To study the effects of ultrafiltration on 14C age, we analyzed the C/N ratio, δ13CPDB and δ15NAIR values, and 14C ages of acid-soluble bone collagen obtained by decalcification, gelatin extracted from acid-insoluble bone collagen, and the HMW gelatin and LMW fractions produced during ultrafiltration of the extracted gelatin. Bone samples from the Fifth International Radiocarbon Intercomparison (VIRI) were used: VIRI-E (mammoth), -F (horse), -G (human), and -I (whale). In this study, carbon and nitrogen content and gelatin yields were used to evaluate collagen preservation in the VIRI bone samples. Radiocarbon ages, δ13CPDB and δ15NAIR values of unfiltered and HMW gelatins were obtained and compared with the published consensus values. The LMW fraction was found to exhibit different values from those of the other fractions, indicating the possible presence of extraneous contamination. The Vivaspin™ 6 ultrafilters used in this study were analyzed and radiocarbon dated both before and after cleaning. We present evidence to suggest that LMW fraction contaminants could be derived from the ultrafilters rather than humic substances. Excessively long ultrafiltration time was suspected to have contaminated the bone samples with material from the ultrafilter, because those samples exhibited older 14C ages than did those filtered for shorter durations. The results in this study indicate that 14C ages of unfiltered gelatin extracted from well-preserved bones can be sufficiently accurate, and that care should be taken not to

  19. Radiocarbon and thermoluminescence dates from iron age dwelling places in Isokylae, Salo, South-West Finland

    International Nuclear Information System (INIS)

    In connection with the excavations at Isokylae in Salo a number of samples have been dated using the radiocarbon and thermoluminescence dating methods. In TL dating the quartz inclusion method was applied to samples of pottery and burnt clay. In radiocarbon dating charcoal samples were used. The results from the two dating methods are in good agrement and these physical dates also agree with the archaeological chronology. (author)

  20. The Geological Survey of Canada Radiocarbon Dating Laboratory

    International Nuclear Information System (INIS)

    The Radiocarbon Dating Laboratory of the Geological Survey of Canada began routine 14C age determinations in 1961 using a 2 litre copper, proportional counter and CO2 as the counting gas. This counter is operated routinely at a pressure of 2 atmospheres where the maximum dating limit is approximately 40 000 years using the 4σ criterion. In 1964 a 5 litre counter was put into operation. Routinely this counter is operated at a pressure of 1 atmosphere where its dating limit is approximately 40 000 years. When operated at 4 atmospheres its age limit increases to about 54 000 years. Organic samples are burned in a stream of oxygen and the CO2 released is purified on passage through a series of chemicals and traps. Inorganic samples are dissolved in phosphoric acid. Up to the end of 1983 more than 3700 age determinations have been carried out on various types of sample material. Since 1963 twenty-three Geological Survey of Canada Date Lists have been published. The Laboratory also carries out a program of 14C determinations of samples of known age for the purpose of assessing the accuracy of the method and learning more about the natural and man-made 14C distribution and circulation in nature

  1. Radiocarbon dating and compositional analysis of pre-Columbian human bones

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, E., E-mail: andrade@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México D.F. (Mexico); Solís, C.; Canto, C.E.; Lucio, O.G. de [Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México D.F. (Mexico); Chavez, E. [ESIME-Z, Instituto Politécnico Nacional, ALM Zacatenco, 07738 México D.F. (Mexico); Rocha, M.F.; Villanueva, O.; Torreblanca, C.A. [Centro INAH Zacatecas, Miguel Auza No. 205, Col. Centro, Zacatecas/Zacatecas CP 98000 (Mexico)

    2014-08-01

    Analysis of ancient human bones found in “El Cóporo”, an archaeological site in Guanajuato, Mexico; were performed using a multi techniques scheme: {sup 14}C radiocarbon dating, IBA (Ion Beam Analysis), SEM-EDS (Scanning Electron Microscope Energy Dispersive X-ray Spectroscopy). We measured the elemental composition of the bones, especially some with a superficial black pigmentation. Soil samples collected from the burial place were also analyzed. The {sup 14}C dating was performed with a new High Voltage Europe 1 MV Tandentron Accelerator Mass Spectrometer (AMS) recently installed in the IFUNAM (Instituto de Física, Universidad Nacional Autónoma de México). The radiocarbon dating allowed us to determine the date of death of the individual in a period between the year 890 and 975 AD, which is consistent with the late period of the Cóporo civilization. The element sample analysis of bones with the surface black pigmentation show higher levels of Fe, Mn and Ba compared when bone’s black surface was mechanically removed. These three elements were found in soil samples from the skeleton burial place. These results indicate more likely that the bone black coloration is due to a postmortem alteration occurring in the burial environment.

  2. Radiocarbon dating and compositional analysis of pre-Columbian human bones

    International Nuclear Information System (INIS)

    Analysis of ancient human bones found in “El Cóporo”, an archaeological site in Guanajuato, Mexico; were performed using a multi techniques scheme: 14C radiocarbon dating, IBA (Ion Beam Analysis), SEM-EDS (Scanning Electron Microscope Energy Dispersive X-ray Spectroscopy). We measured the elemental composition of the bones, especially some with a superficial black pigmentation. Soil samples collected from the burial place were also analyzed. The 14C dating was performed with a new High Voltage Europe 1 MV Tandentron Accelerator Mass Spectrometer (AMS) recently installed in the IFUNAM (Instituto de Física, Universidad Nacional Autónoma de México). The radiocarbon dating allowed us to determine the date of death of the individual in a period between the year 890 and 975 AD, which is consistent with the late period of the Cóporo civilization. The element sample analysis of bones with the surface black pigmentation show higher levels of Fe, Mn and Ba compared when bone’s black surface was mechanically removed. These three elements were found in soil samples from the skeleton burial place. These results indicate more likely that the bone black coloration is due to a postmortem alteration occurring in the burial environment

  3. Testing the effectiveness of AMS radiocarbon pretreatment and preparation on archaeological textiles

    International Nuclear Information System (INIS)

    Archaeological textiles are prepared and radiocarbon dated by two different methods and the results compared to demonstrate the effective removal of contaminating carbon. The distributions of ages of textiles measured at the Rafter Radiocarbon Lab fall into two categories and are not the result of random mixing between sample and contaminant

  4. Some remarks on radiocarbon dated archaeological samples from Finland

    International Nuclear Information System (INIS)

    A comparison between radiocarbon ages and archaeologically estimated ages for samples from Finland indicates that the radiocarbon ages in many cases are much younger than the estimated ages. The distribution of the samples in an estimated age/radiocarbon age diagram shows that a contamination of younger material can hardly have made many of the ages younger. The samples must therefore consist of young material into the cultural layers. (author)

  5. Dating the time of birth: A radiocarbon calibration curve for human eye-lens crystallines

    International Nuclear Information System (INIS)

    Radiocarbon bomb-pulse dating has been used to measure the formation age of human eye-lens crystallines. Lens crystallines are special proteins in the eye-lens that consist of virtually inert tissue. The experimental data show that the radiocarbon ages to a large extent reflect the time of birth, in accordance with expectations. Moreover, it has been possible to develop an age model for the formation of the eye-lens crystallines. From this model a radiocarbon calibration curve for lens crystallines has been calculated. As a consequence, the time of birth of humans can be determined with an accuracy of a few years by radiocarbon dating.

  6. Radiocarbon and thermoluminescence dating of the Old Alluvium from a coastal site in Perak, Malaysia

    Science.gov (United States)

    Kamaludin, bin Hassan; Nakamura, Toshio; Price, David M.; Woodroffe, Colin D.; Fujii, Shoji

    1993-03-01

    Exposures of the 'Old Alluvium' in Pantai Mine and Sinar Manjung Mine in Perak, Peninsular Malaysia, reveal woody peat layers interbedded with angular sands and gravels. Eight samples from peat within the Pantai Mine were dated using accelerator mass spectrometry (AMS) radiocarbon dating, together with a near-surface shell sample. Five samples of quartz sand from the Pantai Mine and three samples of similar sand from Sinar Manjung Mine were dated by thermoluminescence (TL) dating. While for several samples both dating techniques were at the limits of their detection, results from the upper strata of the northwestern face of the Pantai Mine indicate agreement between the two independent dating techniques. The age of the Old Alluvium, known as the Simpang Formation in Perak, is confirmed as Late Pleistocene at this site. The measured ages range from 28,000 years B.P. to 67,000 years B.P., but the lower units are older than this and appear at this site to be beyond the range of both dating techniques.

  7. Radiocarbon dates on desiccated moa (Dinornithiformes) flesh from inland Otago, New Zealand

    International Nuclear Information System (INIS)

    Remains of soft tissues from extinct moa (Dinornithiformes), mainly desiccated sinew, muscle, skin, and feathers have been recovered rather seldom but their distribution is distinctive. Of 22 records of such finds accumulated between 1864 and 1987, 15 came from inland Otago, west of Dunedin in the southern South Island. Most were found in the late nineteenth century in rockshelters, clefts or alluvial sediments and were regarded at the time as ev dence of the survival of moa up to about AD 1800. Improbable as this latter point is, it has not been tested by radiocarbon dating until now. Our particular impetus to do so, however, arises in another way. It is from research, again largely within inland Otago, on Maori artefacts which have also been made from various other kinds of soft tissues (flax, grasses, dog skin, bird skin, feathers etc.). A series of accelerator mass spectrometry (AMS) radiocarbon dates on these shows that they are exclusively late, post-AD 1650, which begs the question of why the age range does not extend across the full prehistoric period, beginning about AD 1300. (author). 6 refs., 2 figs., 1 tab.

  8. Study of a metallurgical site in Tuscany (Italy) by radiocarbon dating

    Energy Technology Data Exchange (ETDEWEB)

    Cartocci, A. [Dipartimento di Fisica dell' Universita e I.N.F.N. Sezione di Firenze, via Sansone 1, 50019 Sesto Fiorentino, Florence (Italy); Fedi, M.E. [Dipartimento di Fisica dell' Universita e I.N.F.N. Sezione di Firenze, via Sansone 1, 50019 Sesto Fiorentino, Florence (Italy)]. E-mail: fedi@fi.infn.it; Taccetti, F. [Dipartimento di Fisica dell' Universita e I.N.F.N. Sezione di Firenze, via Sansone 1, 50019 Sesto Fiorentino, Florence (Italy); Benvenuti, M. [Dipartimento di Scienze della Terra dell' Universita di Firenze, via La Pira 4, 50121 Florence (Italy); Chiarantini, L. [Dipartimento di Scienze della Terra dell' Universita di Firenze, via La Pira 4, 50121 Florence (Italy); Guideri, S. [Societa Parchi Val di Cornia S.p.a., via G. Lerario, Piombino, Livorno (Italy)

    2007-06-15

    Tuscany represents one of the most important ancient mining districts of Italy. Metalworking activities have been present in the area since ancient times and several mining centres have been active in the region since the Etruscan period. Two of the more notable mining locations are the island of Elba and the towns of Populonia and Massa Marittima. In order to reconstruct the development of metallurgical techniques in the past, a multi-disciplinary approach is required, involving both archaeological study and archaeometric analysis of the sites of interest. One of the most complex problems is establishing the chronological history of metallurgical exploitation in ancient sites: archaeological remains are sometimes incomplete and the stratigraphy of archaeological horizons might have been deeply altered. Thus, direct dating of metallurgical slags and other remains of mining and metalworking activities using radiocarbon measurements is particularly useful for developing site chronologies. Charcoal samples from a recent excavation in Populonia were dated by AMS radiocarbon in order to reconstruct the chronological evolution of ancient metallurgical production; results reported here are consistent with archaeological observations.

  9. Are the ‘new’ AMS Varna dates older?

    Directory of Open Access Journals (Sweden)

    Tanya Dzhanfezova

    2013-06-01

    Full Text Available The paper elaborates on the AMS dating results obtained for the Chalcolithic cemetery near Varna, located on the western Black Sea coast in northeastern Bulgaria. The focus here is not on the comparison between absolute dates acquired for various sites from the middle and late Chalcolithic period in the region. It is rather on the examination of the main approaches towards suggested chronological frameworks. Divided into three parts, the text reviews regional methods for proceeding conventional radiocarbon dates (II A and such, related to the later AMS measurement of bone collagen (II B. Both approaches are considered as deserving more attention with regard to the problematic aspects that may affect the acquisition of reliable results. The 19 new AMS Varna dates are found important for chronological revisions. However, at this stage they alone are not considered sufficient for inarguable modifications of the schemes (III. Along with identification of major factors that should be taken into account when dealing with the chronological debates in the specified region, strategies for solving some of the issues are also suggested.

  10. Dating the time of birth: A radiocarbon calibration curve for human eye-lens crystallines

    DEFF Research Database (Denmark)

    Kjeldsen, Henrik; Heinemeier, Jan; Heegaard, Steffen;

    2010-01-01

    Radiocarbon bomb-pulse dating has been used to measure the formation age of human eye-lens crystallines. Lens crystallines are special proteins in the eye-lens that consist of virtually inert tissue. The experimental data show that the radiocarbon ages to a large extent reflect the time of birth...

  11. Sedimentary lake records of Northern Amazon: the radiocarbon dating as a tool for paleoenvironmental assessment

    International Nuclear Information System (INIS)

    The present work focused the radiocarbon technique for calculating fluxes of tracers in core sediments, which are used to point out paleoenviromental changes. This study was developed in a lake watershed located in one of the most northen portions in the Brazilian Amazon (Caracarana Lake)covering a wide boundary region, where the tropical rain forest changes suddenly to savanna. The sediment cores were taken bya avibrational-corer device placed at the top of aluminium tubes and samples in 1cm-section, considering the sedimentary facies. The samples for radiocarbon dating were analysed by radiometric technique, measuring the 14 C content in a liquid scintillation spectrometer for extended countings , or by AMs (accelerator-mass-spectrometer) measurements for poor-carbon samples. The total organic carbon (TOC) was analysed by a CHN analyser and the minerals (Kaolinite, Quartz, Calcite and Silice Amorphous) were quantified by FTIR spectrometry (Fourier Transformed Infra-Red). The Caracarana Lake core (RR94-9), considered for this study, was the most clear and continous lacustrine record amd showed a good agreement with the results obtained for the other studies in Amazonia and South America, regarding to the optimum holocenic climatic phase. We conclude, supported by the correlation between the silice amorphous and TOC and among the three detrial minerals, that the rise to Caracarana Lake as well as other ones situated in this region was hapenned in very modern times, during the mid and early Holocene, comprising the last few millennia. (author). 16 refs., 3 figs., 1 tab

  12. ‘Old wood’ effect in radiocarbon dating of prehistoric cremated bones?

    OpenAIRE

    Olsen, Jesper; Heinemeier, Jan; Hornstrup, Karen Margrethe; Bennike, Pia; Thrane, Henrik

    2013-01-01

    Numerous reports of successful radiocarbon dating of cremated bones have emerged during the last decade. The success of radiocarbon dating cremated bones depends on the temperature during burning and the degree of recrystallisation of the inorganic bone matrix. During cremation bones undergo major morphological and mineralogical changes which have raised some interesting questions and discussion on the origin of the carbon source in archaeologically cremated bones. Recent laboratory experimen...

  13. Relevance of medieval, Egyptian and American dates to the study of climatic and radiocarbon variability

    International Nuclear Information System (INIS)

    Basic radiocarbon dating and dendrochronology have been combined to yield calibrated dates that are more accurate than conventional radiocarbon dates. This has been shown to be true for medieval and Egyptian dynastic dating. Because radiocarbon is a cosmogenically produced radioisotope, heliomagnetic and geomagnetic fields play a major role in its synthesis in the Earth's upper atmosphere. Inasmuch as a calibrated radiocarbon record exists for nearly 10 000 years, we now seem to possess in the short-time variations of the production rate a history of solar activity expressed via heliomagnetic fields carried by the solar wind. In turn, solar activity has a controlling effect on climate on Earth within modifications provided by the complex interactions of the atmosphere-Earth-ocean system. Both radiocarbon measurements and other empirical research methods agree on variations of climate during historically more recent periods on Earth. This leads to the suggestion that the radiocarbon calibration curve may be also a significant indicator or tracer for climatic changes for the Holocene or the Neolithic-Mesolithic. (author)

  14. Radiocarbon dating of Fugendake Volcano in Unzen, SW Japan

    OpenAIRE

    Xu, Sheng; Hoshizumi, Hideo; Uto, Kozo; Freeman, Stewart P. H. T.

    2013-01-01

    This article presents new radiocarbon ages for the lavas, pyroclastic flow, and lahar deposits that originated from the Fugendake and Mayuyama volcanoes of the Younger Unzen Volcano, SW Japan. Nine charcoal samples were collected from the lavas and pyroclastic flow deposits, and 17 soil samples from the underlying volcanic-related products. This data set, together with previously published ages (thermoluminescence, K-Ar, fission track, and 14C), yielded new information about the timing of Lat...

  15. Radiocarbon dating of archaeological geological and groundwater samples

    International Nuclear Information System (INIS)

    In the context of the project VIE/8/003 sponsored by the IAEA, a regular and complete C14 laboratory was installed at the Centre of the Nuclear Techniques in 1986. In this paper the authors present the procedure of sample treatment and saple activity measurement of the radiocarbon method and some preliminary results obtained after more than one year of operation of the laboratory

  16. Radiocarbon dating of the last volcanic eruption of the Ciomadul volcano, Southest Carpathians

    International Nuclear Information System (INIS)

    Complete text of publication follows. The last volcanic eruption in the Carpathian-Pannonian Region occurred within the Ciomadul volcano, Southeast Carpathians. It is a lava dome complex active for about 900 ka. Following the effusive activity, at least two major explosive volcanic eruptions occurred forming two craters (Mohos and St. Anna). These eruptions resulted in pumiceous pyroclastic fall and flow deposits. In order to understand the behavior of this volcano and evaluate the possible renewal of the volcanic eruption, it is crucial to constrain the length of the active and repose periods and know the date of the last eruption. The former K/Ar and radiocarbon data are controversial and give only a rough estimate for the active phases. The age data for the last eruption is in the range from 10000 and 40000. In this study, we focus on the time of the last volcanic eruptions. We analyzed charcoal fragments found in pumiceous pyroclastic flow deposits from two localities. C-14 dating from the first locality (Bx) was executed by GPC technique in the ATOMKI, and the following five dating (one repeated dating of the ATOMKI sample, with excellent match; one resampled charcoal from the first locality, and one sample from a second locality (Tf), and dating of NaOH-soluble fractions coming from sample prep for all the three charcoal samples) in NSF Lab in Tucson, AZ by AMS technique. The new radiocarbon data provided valuable information on the behaviour of the Ciomadul volcano and help to constrain the time of the last eruption of the volcano. The main conclusions are the following: 1. The last volcanic eruption occurred at about 27000 BP. 2. The product of the youngest eruption is exposed at the southern margin of the volcano (Bx locality) and not at west (Tf locality) as was previously thought. 3. A striking new result is that there were at least two major explosive eruptions, not a single one, related to the formation of the St. Anna crater. The youngest one followed

  17. High-precision radiocarbon dating and historical biblical archaeology in southern Jordan

    OpenAIRE

    Levy, Thomas E.; Higham, Thomas; Bronk Ramsey, Christopher; Smith, Neil G.; Ben-Yosef, Erez; Robinson, Mark; Münger, Stefan; Knabb, Kyle; Schulze, Jürgen P.; Najjar, Mohammad; Tauxe, Lisa

    2008-01-01

    Recent excavations and high-precision radiocarbon dating from the largest Iron Age (IA, ca. 1200–500 BCE) copper production center in the southern Levant demonstrate major smelting activities in the region of biblical Edom (southern Jordan) during the 10th and 9th centuries BCE. Stratified radiocarbon samples and artifacts were recorded with precise digital surveying tools linked to a geographic information system developed to control on-site spatial analyses of archaeological finds and model...

  18. Establishing the date of Maori environmental impact in New Zealand through pollen analysis and radiocarbon dating

    International Nuclear Information System (INIS)

    Full text: Over the last decade there has been an intense debate about whether New Zealand prehistory is long ( > 1500 years) or short ( < 800 years). Pollen and charcoal analyses have played a key role in this debate by helping to pinpoint the transition from relatively undisturbed environments to those deforested by anthropogenic fires. Problems with in situ contamination, reworking of sediments, confusion of natural with anthropogenic impacts, and different theoretical expectations of growth, spread and impact of early Maori populations have led to disparate conclusions. We review pollen based studies carried out on a variety of fossil sites, including peat bogs, swamps, estuaries and lakes, and contribute new results. Different sedimentary environments show varying susceptibilities to contamination and have resulted in a wide spread of ages for initial Maori impact. Datable materials least susceptible to contamination by old or young carbon are pure peat and macrofossils, whereas lake, swamp and silty sediments are most susceptible. Analysis of the radiocarbon ages obtained for the start of Maori deforestation show that ages falling in the 'long' prehistory period are exclusively derived from lake sediments and swamps. In contrast, the bulk of the ages falling in the 'short' prehistory period are from pure peat and selected plant fragments. We conclude from our analysis of radiocarbon ages for pollen based deforestation that the first evidence of Maori environmental impact began about 700-550 calendar years BP (1250-1400 AD). Finer age resolution is limited by dating techniques, site limitations and the uncertainty associated with identifying the first signs of human impact. The period we have identified corresponds with the oldest dated archaeological sites and supports the short prehistory hypothesis. We discuss how to distinguish reliable fossil sites from those that have a high risk of giving misleading results

  19. Radiocarbon dating and 13 C/12 C ratio of soils under tropical and subtropical climates

    International Nuclear Information System (INIS)

    It was used an association radiocarbon dates with the carbon isotopic composition of soil organic matter, where 14 C dating gives elements of chronology, and δ13 C is used as indicator of the vegetation types in the environment. The total soil organic matter was dried, floated and sieved. The humin fraction was extracted from the 0,250 mm fraction. Radiocarbon datings were performed by a liquid scintillation method. The carbon of the soil organic matter and humin fraction are transformed into benzene, that was analyzed in low level liquid scintillation spectrometer. Based on results of carbon isotope analysis and Radiocarbon dating of soil samples of Londrina, Piracicaba and Altamira, it is concluded that probable changes of vegetation and climate occurred in the South and Southeast regions of Brazil in the mid-Holocene. (author). 81 refs., 16 figs., 7 tabs

  20. Thermoluminescence dates for the Lake Mungo aboriginal fireplaces and the implications for radiocarbon dating

    International Nuclear Information System (INIS)

    During the Quaternary period in Australia large areas of western New South Wales and northern Victoria were covered by hundreds of lakes, both large and small. Nearly all are dry today but some may still be recognized by the long low dunes that follow the eastern shorelines. Many traces of early human occupation have been found along the shorelines of nearly all the major lakes and some of the best exposures have occurred on the lunette along the eastern shore of Lake Mungo. This lunette, has suffered massive erosion in recent times and this has uncovered the sites of many ancient fireplaces. Charcoal from some of these fireplaces has been dated by Barbetti and Polach (1973) using the radiocarbon method and the ages place the lakeside dwellers at Mungo in an area of Australian prehistory around 30 000 years ago. The baked sediment from below the fireplaces appears to have been heated to a temperature in excess of 400oC according to archaeomagnetic studies carried out by Barbetti (1973) and this indicated that the fireplaces might lend themselves to the technique of thermoluminescence (TL) dating. The results of the TL dating programme are described elsewhere. (author)

  1. Accelerator and radiometric radiocarbon dates on a range of materials from colluvial deposits at Holywell Coombe, Folkestone

    International Nuclear Information System (INIS)

    This paper reports preliminary results of a radiocarbon dating study, involving both conventional and accelerator mass spectrometry (AMS) techniques, on a range of materials recovered from colluvial deposits at Holywell Coombe, Folkestone. Materials dated by conventional means include wood, hazel-nuts, organic detritus and tufa. The tufa dates were measured at Harwell and at Gliwice, Poland; all other conventional dates were determined at the Godwin Laboratory (Cambridge). Accelerator dates have been obtained from seeds, charcoal, bone and shells of the land snail Arianta arbustorum, and were all measured at the Oxford Laboratory. The results shed light on the following issues: (1) the reproducibility of dates from adjacent sections; (2) comparisons of shell and charcoal dates from the same stratigraphical horizons; (3) comparisons of tufa dates with others based on organic material from the same profiles; (4) assessment of multiple dates from different components of the same material or replicate dates on the same object; and (5) stratigraphical conformity of dates from different laboratories. A replicate biostratigraphical and dating study of two adjacent profiles, reassuringly, gave comparable results. Shell and charcoal samples from a Lateglacial palaeosol likewise produced paired dates that were statistically indistinguishable. All the dates based on organic materials, whether conventional or AMS, were stratigraphically consistent. However, the determinations from all the tufa samples from Holywell Coombe gave apparent ages that were anomalously old. This is thought to be due to contamination from the Chalk bedrock. A parallel study of another tufa in Kent, this time on Atherfield Clay, produced dates very close to expected values. (Author)

  2. Analysis of Artificial Radiocarbon in Different Skeletal and Dental Tissue Types to Evaluate Date of Death

    Energy Technology Data Exchange (ETDEWEB)

    Ubelaker, D H; Buchholz, B A; Stewart, J

    2005-07-19

    Radiocarbon dating, with special reference to the modern bomb-curve, can provide useful information to elucidate the date of death of skeletonized human remains. Interpretation can be enhanced with analysis of different types of tissues within a single skeleton because of the known variability of formation times and remodeling rates. Analysis of radiocarbon content of teeth, especially the enamel in tooth crowns provides information about the date of formation in the childhood years and in consideration of the known timing of tooth formation can be used to estimate the birth date after 1950 A.D. Radiocarbon analysis of modern cortical and trabecular bone samples from the same skeleton may allow proper placement on the pre-1963 or post-1963 sides of the bomb-curve since most trabecular bone generally undergoes more rapid remodeling than does most cortical bone. Pre-1963 bone formation would produce higher radiocarbon values for most trabecular bone than for most cortical bone. This relationship is reversed for formation after 1963. Radiocarbon analysis was conducted in this study on dental, cortical and trabecular bone samples from two adult individuals of known birth (1925 and 1926) and death dates (1995 and 1959). As expected, the dental results correspond to pre-bomb bomb-curve values reflecting conditions during the childhoods of the individuals. The curve radiocarbon content of most bone samples reflected the higher modern bomb-curve values. Within the bone sample analyses, the values of the trabecular bone were higher than those of cortical bone and supported the known placement on the pre-1963 side of the bomb-curve.

  3. Radiocarbon Dating of Soil Organic Matter Fractions in Andosols in Northern Ecuador

    OpenAIRE

    Tonneijck, Femke H.; Van der Plicht, Johannes; Jansen, Boris; Verstraten, Jacobus M.; Hooghiemstra, Henry

    2006-01-01

    Volcanic ash soils (Andosols) may offer great opportunities for paleoecological studies, as suggested by their characteristic accumulation of organic matter (OM). However, understanding of the chronostratigraphy of soil organic matter (SOM) is required. Therefore, radiocarbon dating of SOM is necessary, but unfortunately not straightforward. Dating of fractions of SOM obtained by alkali-acid extraction is promising, but which fraction (humic acid or humin) renders the most accurate 14C dates ...

  4. Radiocarbon dating of old groundwater - History, potential, limits and future

    International Nuclear Information System (INIS)

    Full text: The principles of groundwater dating up to about 40 000 yr by means of 14C were elaborated about fifty years ago. Prior this time hydrologic estimates of the recharge rate and flow velocities of groundwater were poor. Already the first 14C dates proved that any elderly water budget or geohydraulic concept had to be substantially revised especially in arid zones. Groundwater is usually considerably older than expected before the introduction of the 14C method. During one decade of gathering experience with groundwater dating it was recognized that absolute dates of groundwater require a so-called reservoir correction either based on the carbon isotope or hydrochemical compositions of the inorganic carbon species or both. A variety of simple to complex correction models for conventional 14C dates was elaborated besides more easily applicable empirical correction methods. Attempts to date groundwater with 14C in the dissolved organic constituents elucidated other kinds of hydrological problems. The requirement of absolute dates is primarily restricted, however, to scientific-relevant paleohydrological studies. In applied hydrology geohydraulic estimates of the budget of fresh groundwater directly profit from easily determinable relative groundwater ages. Such 14C dates allow estimates of regional geohydraulic parameters of the aquifer and its over and underlain aquitards, monitoring of the groundwater movement and detection of overexploitation. In any case the interpretation of groundwater ages requires a good understanding of the hydrodynamics of the system to be dated beside that of the hydrochemical composition. In arid and semi-arid zones, these dates allow to differentiate between renewable and non-renewable groundwater resources. This information is indispensable for numerical modeling as neglecting of non-stationary recharge conditions results in overestimated recharge rates. The difficulty to determine absolute 14C dates of groundwater has supported

  5. Holocene Fire History of an Eastern Oregon Forest Based on Soil Charcoal Radiocarbon Dates

    Science.gov (United States)

    Carson, R. J.; Malkemus, D.; Clifton, C. F.

    2006-12-01

    Limited research has been done on long-term forest fire histories in northeastern Oregon. As part of an investigation to determine the minimum age of a 300 ha landslide in the Blue Mountains, a pit was excavated near the toe of the slide. The pit, located in a depression between the landslide and a ridge, contains massive clays and silts, and an 8000-year sequence of forest fires recorded in 7 buried charcoal layers. Eight- thousand-year-old Mazama Ash (Crater Lake, Oregon) is common in the area, but no tephra was found in the excavation. The upper 17 cm is organic rich soil. Seven horizons of charcoal are present; the upper six are subhorizontal and occur at depths of 17, 36, 41, 46, 52, and 57 cm. The lowest charcoal horizon follows a disconformity that cuts diagonally across the pit from 85 to 125 cm below the surface; oxidation in the form of orange mottling occurs above this disconformity (interpreted to be a paleoslope) and is prominent below it. The charcoal horizons provide evidence of large-scale forest fires in the vicinity, with differing intensities represented by the amount of charcoal in each horizon. The layers vary in thickness from 2 to 6 cm. Five charcoal horizons were radiocarbon dated (AMS) and calendar calibrated. The charcoal at the base of the soil (at 17 cm) provided an age of AD 1670 to 1960; this horizon correlates with widespread fires in the Blue Mountains in AD 1855. The horizon second closest to the surface (at 36 cm) provided an age of 1310 ± 40 B.P. The thickest horizon (at 46 cm) yielded an age of 2420 ± 40 B.P. The lowest horizontal horizon (at 57 cm) provided an age of 3460 ± 40 B.P. The lowest charcoal (at the disconformity) yielded an age of 7990 ± 40 B.P. Based on radiocarbon dates, the mean rate of sedimentation in the closed depression is approximately 1.2 cm/century. Fire episodes (which correspond remarkably well with a lake core site approximately 150 km south), indicate relatively long periods (from 400 to over 4000

  6. 14C AMS dating Yongcheon cave

    International Nuclear Information System (INIS)

    The biggest island in South Korea is Jeju Island, which lies 80 km south of the mainland and has one shield volcano, Mt. Halla. The volcanic island and its lava tubes were added to the world heritage list by UNESCO in 2007. Among the many lava tubes on the island, a unique cave had been accidentally found in 2005 while some workers were replacing a telephone pole. Until the discovery, it had been completely isolated from the outside by naturally-built sand blocks. Yongcheon cave is a lime-decorated lava tube showing both the properties of a volcanic lava tube and a limestone cave. This cave, about 3 km in length, is acknowledged to be the best of this type in the world and includes a large clean-water lake, lava falls, and richly developed speleothems inside it. Even though there is archaeological evidence from well preserved pottery that ancient people entered this place, the preservation of artifacts was ensured by a geological change that made later entrance difficult. We have collected charcoal samples scattered around the cave and dated them using AMS. Ages were in the range of ca. 1570-1260 BP (A.D. 340–880) and this corresponds to the Ancient Three Kingdoms and the Unified Silla era in Korean history. The 14C AMS measurement results presented in this paper on wood charcoal provide precise dates which will be very useful not only to clarify the nature of human activities in this cave but also to provide reference dates when comparing other dating methods.

  7. {sup 14}C AMS dating Yongcheon cave

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.H., E-mail: jefflee@snu.ac.kr [AMS Lab., NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Choe, K. [AMS Lab., NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, J.C. [Dept. of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Choi, S.H.; Kang, J.; Song, S.; Song, Y.M. [AMS Lab., NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Jang, J.G. [Jeju National Museum, Jeju 690-782 (Korea, Republic of)

    2013-01-15

    The biggest island in South Korea is Jeju Island, which lies 80 km south of the mainland and has one shield volcano, Mt. Halla. The volcanic island and its lava tubes were added to the world heritage list by UNESCO in 2007. Among the many lava tubes on the island, a unique cave had been accidentally found in 2005 while some workers were replacing a telephone pole. Until the discovery, it had been completely isolated from the outside by naturally-built sand blocks. Yongcheon cave is a lime-decorated lava tube showing both the properties of a volcanic lava tube and a limestone cave. This cave, about 3 km in length, is acknowledged to be the best of this type in the world and includes a large clean-water lake, lava falls, and richly developed speleothems inside it. Even though there is archaeological evidence from well preserved pottery that ancient people entered this place, the preservation of artifacts was ensured by a geological change that made later entrance difficult. We have collected charcoal samples scattered around the cave and dated them using AMS. Ages were in the range of ca. 1570-1260 BP (A.D. 340-880) and this corresponds to the Ancient Three Kingdoms and the Unified Silla era in Korean history. The {sup 14}C AMS measurement results presented in this paper on wood charcoal provide precise dates which will be very useful not only to clarify the nature of human activities in this cave but also to provide reference dates when comparing other dating methods.

  8. Radiocarbon dating of holocene eruptions of the Elbrus volcano (North Caucasus, Russia)

    International Nuclear Information System (INIS)

    Carbon-containing materials formed as a result of the Elbrus volcano eruptions during the recent 10 thousand years are studied the radiocarbon dating method. Three differing in age episodes of the Elbrus volcano eruptions in holocene: the oldest (7200-7500 years ago), the middle (4600-5500 years ago) and the youngest (at the start of our era) ones were identified

  9. Compound-specific radiocarbon dating of the varved Holocene sedimentary record of Saanich Inlet, Canada

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Smittenberg, R.H.; Hopmans, E.C.; Schouten, S.; Hayes, J.M.; Eglinton, T.I.

    2004-01-01

    The radiocarbon contents of various biomarkers extracted from the varve-counted sediments of Saanich Inlet, Canada, were determined to assess their applicability for dating purposes. Calibrated ages obtained from the marine planktonic archaeal biomarker crenarchaeol compared favorably with varve-cou

  10. Radiocarbon dating of fluvial organic matter reveals land-use impacts in boreal peatlands

    DEFF Research Database (Denmark)

    Hulatt, Chris J.; Kaartokallio, Hermanni; Oinonen, Markku;

    2014-01-01

    This study measured the effects of land use on organic matter released to surface waters in a boreal peat catchment using radiocarbon dating of particulate and dissolved organic carbon (POC and DOC), DOC concentration, stable carbon and nitrogen isotope composition, and optical measurements...

  11. Radiocarbon Dating and age Inversions in Lake Chapala Late Holocene Sediments, Western Mexico.

    Science.gov (United States)

    Zarate-Del Valle, P.; Israde-Alcantara, I.; Ramírez-Sánchez, H.; Gómez-Salazar, S.; Ríos-Donato, N.

    2006-12-01

    Neotectonic Lake Chapala, the major Mexican freshwater reservoir lies at the north and northeast of the Citala Rift and is linked to history of the active Plio-Quaternary Transmexican Volcanic Belt geological province. Eight radiocarbon 14C dates were obtained on shallow sediment samples from a gravity corer (T46) of 5 cm in diameter and 1.7 m long. The core was collected from the western sector of Lake Chapala (103° 15.43' W, 20° 14.45' N) at water depth of 3.7 m (june 2000). In general, shallow sediments (Lake Chapala are dark and silty with granulometric median ranging from 10 to 50 μm. Major oxides in sediments are: SiO2 (54.05%), Al2O3 (18.94%), Fe2O3 (6.75%) and CaO (2.57%). The major mineralogical composition of sediments is as follows: plagioclases (25.86%), quartz (20.92%), clays (38.5%), carbonates (2.99%) and TiO2 (1.05%). Radiocarbon ages were measured by accelerator mass spectrometry (AMS) and were obtained through the organic carbon fraction extracted from the bulk sediment samples sliced every 20 cm taken from the whole core. Stratigraphically ordered from highest to lowest, the eight ages reported are: 1) 2,000 ±40 yr on sediments at 30 cm deep; 2) 1,920 ±35 yr on sediments at 50 cm deep; 3) 1,900 ±35 yr on sediments at 70 cm deep; 4) 2,080 ±35 yr on sediments at 90 cm deep; 5) 2,090 ±50 yr on sediments at 110 cm deep; 6) 2,190 ±35 yr on sediments at 130 cm deep; 7) 2,050 ±35 yr on sediments at 150 cm deep and, 8) 1,500 ±35 yr on sediments at 170 cm deep. From the top until 70 cm and from 130 to bottom we observe two age inversions; the interval apparently with no age inversions is from 70cm to 130cm. As it is known the age inversions observed may be due to a) ancient carbon being incorporated into the sediment during deposition; b) unrecognized bioturbation, c) Postdepositional alteration and, d) variations in the apparent geological ages of the different chemical phases comprising the total sediment. Basically, the factors probably

  12. Radiocarbon microanalysis on ice impurities for dating of Alpine glaciers

    OpenAIRE

    May, Barbara Luise

    2009-01-01

    The main objective of this thesis is the deployment of radiometric dating on Alpine ice archives, where conventional, stratigraphical dating techniques fail. To this end a 14C analysis of particulate and, in a novel attempt, also of dissolved organic carbon contained in the ice matrix is developed. Aimed at minimizing the required ice sample size, the designed ice processing line allows for handling of up to 700 g ice and is shown to involve blank levels small enough to ensure reliable 14C an...

  13. Collagen Fingerprinting: A New Screening Technique for Radiocarbon Dating Ancient Bone.

    Directory of Open Access Journals (Sweden)

    Virginia L Harvey

    Full Text Available Collagen is the dominant organic component of bone and is intimately locked within the hydroxyapatite structure of this ubiquitous biomaterial that dominates archaeological and palaeontological assemblages. Radiocarbon analysis of extracted collagen is one of the most common approaches to dating bone from late Pleistocene or Holocene deposits, but dating is relatively expensive compared to other biochemical techniques. Numerous analytical methods have previously been investigated for the purpose of screening out samples that are unlikely to yield reliable dates including histological analysis, UV-stimulated fluorescence and, most commonly, the measurement of percentage nitrogen (%N and ratio of carbon to nitrogen (C:N. Here we propose the use of collagen fingerprinting (also known as Zooarchaeology by Mass Spectrometry, or ZooMS, when applied to species identification as an alternative screening method for radiocarbon dating, due to its ability to provide information on collagen presence and quality, alongside species identification. The method was tested on a series of sub-fossil bone specimens from cave systems on Cayman Brac (Cayman Islands, chosen due to the observable range in diagenetic alteration, and in particular, the extent of mineralisation. Six (14C dates, of 18 initial attempts, were obtained from remains of extinct hutia, Capromys sp. (Rodentia; Capromyidae, recovered from five distinct caves on Cayman Brac, and ranging from 393 ± 25 to 1588 ± 26 radiocarbon years before present (yr BP. All of the bone samples that yielded radiocarbon dates generated excellent collagen fingerprints, and conversely those that gave poor fingerprints also failed dating. Additionally, two successfully fingerprinted bone samples were screened out from a set of 81. Both subsequently generated (14C dates, demonstrating successful utilisation of ZooMS as an alternative screening mechanism to identify bone samples that are suitable for 1(4C analysis.

  14. Radiocarbon AMS determination of the biogenic component in CO{sub 2} emitted from waste incineration

    Energy Technology Data Exchange (ETDEWEB)

    Calcagnile, L., E-mail: lucio.calcagnile@unisalento.it [CEDAD-Department of Innovation Engineering, University of Salento, via per Monteroni, 73100 Lecce (Italy); Quarta, G., E-mail: gianluca.quarta@unisalento.it [CEDAD-Department of Innovation Engineering, University of Salento, via per Monteroni, 73100 Lecce (Italy); D' Elia, M., E-mail: marisa.delia@unisalento.it [CEDAD-Department of Innovation Engineering, University of Salento, via per Monteroni, 73100 Lecce (Italy); Ciceri, G., E-mail: giovanni.ciceri@erse-web.it [Ricerca sul Sistema Energetico-RSE spa, Dipartimento Ambiente e Sviluppo Sostenibile, Via R. Rubattino, 54, 20134 Milano (Italy); Martinotti, V., E-mail: valter.Martinotti@erse-web.it [Ricerca sul Sistema Energetico-RSE spa, Dipartimento Ambiente e Sviluppo Sostenibile, Via R. Rubattino, 54, 20134 Milano (Italy)

    2011-12-15

    The thermal utilization of waste for energy production is gaining importance in European countries. Nevertheless, the combustion of waste leads to significant CO{sub 2} emissions in the atmosphere which, depending on the fraction of biogenic and fossil materials, have to be only partially accounted for the national greenhouse gas inventory. For this reason the development of proper methodologies for the measurement of the biogenic fraction in the combusted waste is an active research field. In fact the determination of the radiocarbon concentration in the carbon dioxide stack emissions allows to have a direct indication of the biogenic component in the burned fuel. We present the results of the AMS radiocarbon analyses carried out on carbon dioxide sampled at the stack of three power plants located in Northern Italy burning natural gas, landfill biogas and SRF (Solid Recovered Fuel) derived from MSW (Municipal Solid Waste). The sampling apparatus and the applied processing protocols are described together with the calculation procedures used to determine, from the measured radiocarbon concentrations, the proportion of biogenic and fossil component in the flue gas and in the combusted fuel. The results confirm the high potentialities of this approach in the analysis of industrial CO{sub 2} emissions.

  15. Radiocarbon AMS determination of the biogenic component in CO 2 emitted from waste incineration

    Science.gov (United States)

    Calcagnile, L.; Quarta, G.; D'Elia, M.; Ciceri, G.; Martinotti, V.

    2011-12-01

    The thermal utilization of waste for energy production is gaining importance in European countries. Nevertheless, the combustion of waste leads to significant CO 2 emissions in the atmosphere which, depending on the fraction of biogenic and fossil materials, have to be only partially accounted for the national greenhouse gas inventory. For this reason the development of proper methodologies for the measurement of the biogenic fraction in the combusted waste is an active research field. In fact the determination of the radiocarbon concentration in the carbon dioxide stack emissions allows to have a direct indication of the biogenic component in the burned fuel. We present the results of the AMS radiocarbon analyses carried out on carbon dioxide sampled at the stack of three power plants located in Northern Italy burning natural gas, landfill biogas and SRF (Solid Recovered Fuel) derived from MSW (Municipal Solid Waste). The sampling apparatus and the applied processing protocols are described together with the calculation procedures used to determine, from the measured radiocarbon concentrations, the proportion of biogenic and fossil component in the flue gas and in the combusted fuel. The results confirm the high potentialities of this approach in the analysis of industrial CO 2 emissions.

  16. Pushing the limits of high-precision radiocarbon measurements

    International Nuclear Information System (INIS)

    Accelerator Mass Spectrometry (AMS) is mostly used for radiocarbon dating, because it allows determining efficiently 14C without isobaric or molecular background. While for many years these measurements were performed on large tandem accelerators (3 - 6 MV), this has changed over the last 10 years and compact AMS systems (2 and allows for the first time precise routine radiocarbon dating of micro-gram samples. The impact of the new-generation compact radiocarbon dating systems is discussed.

  17. Radiocarbon dating programme at the Birbal Sahni Institute of Paleobotany

    International Nuclear Information System (INIS)

    Sample combustion is described in a pure oxygen stream to obtain CO2, and the subsequent conversion to CH4 proceeding for 8 to 12 hours. A low-background proportional counter with an in-built anticoincidence counter was used in measurement. The shielding box consisted of 10 cm lead layers and of a 2 cm mercury layer with a 10 cm paraffine wax layer in between. The circuit diagram is shown. The detector background was 1.4 imp/min. The Laboratory is involved in Quaternary research applied to paleobotany and palynology. The application is described of 14C dating in determining the vegetation, climatic and agricultural history and geomorphological future. 14C dating applications in archeology and in determining the post-growth factor are shown. (J.P.)

  18. The radiocarbon dating project at Aboriginal Affairs, Victoria

    International Nuclear Information System (INIS)

    The purpose of this project has been to publish a complete list of the age estimates relating to the archaeological sites in the State of Victoria from 1951 to 1995, and to assess the value and the limitations of this information for interpreting the prehistory of this region. This project has recorded 476 dates coming from 14 laboratories, and ranging in age from the time of European settlement to the limit of the technique at around 40,000 years BP. However, the available evidence indicates that large discrepancies may exist in these results, and this has lead to the recommendation that this data should not be used in research projects requiring dating accuracies of less than a few hundred years

  19. The first radiocarbon dating of pollen from syngenetic ice-wadge

    International Nuclear Information System (INIS)

    The methodology for extracting the pollen concentrate from the syngenetic ice-wadge for the pollen radiocarbon dating with application of the acceleration mass-spectrometry is described. The results of the radiocarbon dating of pollen and spores (the extracted spore-pollen concentrate) sampled directly from the syngenetic ice-wadge, are obtained for the first time through this methodology. It is established, that the sample from the upper ice-wadge at the height of 20.2 m has the oldest date of 25200 years; the lower sample, positioned at the height of 17.2 m, is aged 21170 years; and the lowest sample, located at the height of 10.0 m, is aged 22400 years

  20. High-resolution AMS 14C dating of post-bomb peat archives of atmospheric pollutants

    DEFF Research Database (Denmark)

    Goodsite, Michael E.; Rom, Werner; Heinemeier, Jan; Lange, Todd; Ooi, Suat; Appleby, Peter G.; Shotyk, William; Van Der Knaap, W. O.; Lohse, Christian; Hansen, Torben S.

    Peat deposits in Greenland and Denmark were investigated to show that high-resolution dating of these archives of atmospheric deposition can be provided for the last 50 years by radiocarbon dating using the atmospheric bomb pulse. 14C was determined in macrofossils from sequential one cm slices...... using accelerator mass spectrometry (AMS). Values were calibrated with a general-purpose curve derived from annually averaged atmospheric 14CO2 values in the northernmost northern hemisphere (NNH, 30°-90°N). We present a thorough review of 14C bomb-pulse data from the NNH including our own measurements...... range of the bomb-pulse (from the mid-1950s on). Comparing the 14C AMS results with the customary dating method for recent peat profiles by 210Pb, we show that the use of 137Cs to validate and correct 210Pb dates proves to be more problematic than previously supposed. As a unique example of our...

  1. Radiocarbon dating in near-Eastern contexts: Confusion and quality control

    OpenAIRE

    van der Plicht, J.; Bruins, HJ; Bruins, Hendrik J.; Boaretto, E; Carmi, I.

    2001-01-01

    Near-Eastern archaeology has long remained oblivious to radiocarbon dating as unique historical calendars brought about a perception that C-14 dating is superfluous. Circular chronological reasoning may occur as a result. There is now strong C-14 evidence that the early part of Egyptian history seems older than age assessments currently in vogue among scholars. It is vital to apply systematic and high-quality C-14 dating to each and every excavation in the Near East to measure time with the s...

  2. Radiocarbon dating the end of moa-hunting in New Zealand prehistory

    International Nuclear Information System (INIS)

    For over 150 years, New Zealand scientists and prehistorians have investigated and debated when the last moa (Aves : Dinornithiformes) was hunted and killed by humans (see Anderson 1989). Prior to the introduction of radiocarbon dating into New Zealand archaeology in the mid-1950s, theories on when moa predation ended were based on Maori oral tradition, dubious eye witness accounts, moa bones found on the surface of the ground and arbitrary archaeological excavations of large culling sites. Radiocarbon dating provided an absolute chronological tool for determining when the remains of moa found in prehistoric context were deposited, meaning the activity of moa-hunting could be more easily attributed to a particular period in New Zealand prehistory. (author)

  3. From 14C/12C measurements towards radiocarbon dating of ice

    NARCIS (Netherlands)

    Oerlemans, J.; Wal, R.S.W. van de; Roijen, J.J. van; Raynaud, D.; Borg, K. van der; Jong, A.F.M. de; Lipenkov, V.; Huybrechts, P.

    1994-01-01

    A dry extraction method of CO2 included in glacier ice adds a contamination equivalent to 1.8 μg modern carbon for a 35 μg C sample. This enables radiocarbon dating by accelerator mass spectrometry of 35 μg C samples to about 25 000 BP. Measured 14C/12C ratios are presented for a part of the Vostok

  4. New radiocarbon dates for the transition from middle to upper palaeolithic at El Castillo (Cantabria)

    International Nuclear Information System (INIS)

    The stratigraphic sequence at the El Castillo cave in Cantabria, Spain, extends from Lower to Upper Palaeolithic. The transition from Middle to Upper Palaeolithic is represented by levels assigned to Quina Mousterian and Early Aurignacian. Accelerator Mass Spectrometry Radiocarbon dates put the archaic Aurignacian industries at ca. 40,000 years ago and indicate that in northern Spain the Upper Palaeolithic began several millennia earlier than in other parts of western Europe. (authors). 16 refs., 1 tab

  5. From 14C/12C measurements towards radiocarbon dating of ice

    International Nuclear Information System (INIS)

    A dry extraction method of CO2 included in glacier ice adds a contamination equivalent to 1.8 μg modern carbon for a 35 μg C sample. This enables radiocarbon dating by accelerator mass spectrometry of 35 μg C samples to about 25 000 BP. Measured 14C/12C ratios are presented for a part of the Vostok ice core, and for some surface samples; high 14C/12C values ranging between 65 and 105 pm C indicate in-situ 14C production during the ablation. The reproducibility of radiocarbon dating of ice is demonstrated by results for some parts of the Caroline core, yielding an age versus depth profile, in which the age does not simply increases with depth. The results indicate that the accuracy of radiocarbon dating of ice is not limited by the statistical error arising in the accelerator measurements, but by the uncertainty in the contamination background of the samples and by the in-situ production of 14C. 12 refs, 4 figs, 2 tabs

  6. Rewriting the Central European Early Bronze Age Chronology: Evidence from Large-Scale Radiocarbon Dating.

    Directory of Open Access Journals (Sweden)

    Philipp W Stockhammer

    Full Text Available The transition from the Neolithic to the Early Bronze Age in Central Europe has often been considered as a supra-regional uniform process, which led to the growing mastery of the new bronze technology. Since the 1920s, archaeologists have divided the Early Bronze Age into two chronological phases (Bronze A1 and A2, which were also seen as stages of technical progress. On the basis of the early radiocarbon dates from the cemetery of Singen, southern Germany, the beginning of the Early Bronze Age in Central Europe was originally dated around 2300/2200 BC and the transition to more complex casting techniques (i.e., Bronze A2 around 2000 BC. On the basis of 140 newly radiocarbon dated human remains from Final Neolithic, Early and Middle Bronze Age cemeteries south of Augsburg (Bavaria and a re-dating of ten graves from the cemetery of Singen, we propose a significantly different dating range, which forces us to re-think the traditional relative and absolute chronologies as well as the narrative of technical development. We are now able to date the beginning of the Early Bronze Age to around 2150 BC and its end to around 1700 BC. Moreover, there is no transition between Bronze (Bz A1 and Bronze (Bz A2, but a complete overlap between the type objects of the two phases from 1900-1700 BC. We thus present a revised chronology of the assumed diagnostic type objects of the Early Bronze Age and recommend a radiocarbon-based view on the development of the material culture. Finally, we propose that the traditional phases Bz A1 and Bz A2 do not represent a chronological sequence, but regionally different social phenomena connected to the willingness of local actors to appropriate the new bronze technology.

  7. Radiocarbon dating of the Early Natufian at el-Wad Terrace, Mount Carmel, Israel

    Science.gov (United States)

    Eckmeier, E.; Yeshurun, R.; Weinstein-Evron, M.; Mintz, E.; Boaretto, E.

    2012-04-01

    The Natufian culture (15-11.5 kyr BP) of the Levant played an integral role in the transition from nomadic hunter-gatherers to the establishment of sedentism and, finally, to food producing societies of the Neolithic. The Natufian sites in the Southern Levant are characterised by a lack of macrobotanical remains, including charcoal, and a poor preservation of bone collagen. A result of the scarcity of radiocarbon dateable material is that only about 30 reliable radiocarbon dates from the Natufian are available for constructing a chronology of this period, which would enable a better synchronisation of archaeological and environmental data. A key question of Natufian research is if and to what extent past climate changes influenced the lifestyle of the Natufian communities, but the prerequisite for the correlation of cultural and environmental events in time are accurate chronologies. Therefore, a chronological framework with dates from well-defined contexts and samples of good quality is essential for the investigation of the Natufian. We present new C-14 data from the site of el-Wad Terrace, one of the major Natufian hamlets of the 'core area' of this culture. The samples (12 charcoals and 34 bones, of which 6 charcoals and 5 bones were suitable for dating) were derived from Early Natufian (15-13 kyr BP) living surfaces, dwellings and burials. Using FTIR, we investigated the environmental factors that influenced the preservation of material for radiocarbon dating of the site, and we tested a modified pre-treatment method for poorly preserved charcoal samples. We found that the usual pre-treatment protocol for C-14 samples (W-ABA) removed more charcoal material than the method modified by Rebollo et al. (2008) which omits the first acid treatment (W-BA). This first acid step enhanced the extraction of humic substances during the subsequent base step. The modified W-BA method is a promising tool for dating poorly preserved charcoals which needs further testing with

  8. Radiocarbon dating of fluvial organic matter reveals land-use impacts in boreal peatlands.

    Science.gov (United States)

    Hulatt, Chris J; Kaartokallio, Hermanni; Oinonen, Markku; Sonninen, Eloni; Stedmon, Colin A; Thomas, David N

    2014-11-01

    This study measured the effects of land use on organic matter released to surface waters in a boreal peat catchment using radiocarbon dating of particulate and dissolved organic carbon (POC and DOC), DOC concentration, stable carbon and nitrogen isotope composition, and optical measurements. Undisturbed sites invariably released modern DOC and POC (agricultural and drained sites, and was consistently observed at agricultural and peat extraction areas throughout the seasons. Conventional mean DOC ages reached 3,100 (±122) years before collection. On average, DOC concentrations were up to 38% higher at impacted sites compared to natural areas, but there was no significant effect of land use on surface water DOC concentrations. The study indicates that the true extent of land use impacts is not necessarily detectible through changes in DOC concentration alone: Radiocarbon dating was essential to show that leaching of old soil organic matter at modified sites had replaced, rather than supplemented, the modern DOM that is usually released from pristine peatlands. Relationships between the specific fluorescence intensity of DOM and its radiocarbon age were identified, indicating that optical techniques may provide a method for the detection of changes in DOM age. PMID:25260159

  9. Radiocarbon and thermoluminescence dating of quaternary sediments in Deception Bay, southeast Queensland: some problems encountered

    International Nuclear Information System (INIS)

    Full text: Radiocarbon and Thermoluminescence dating of sediment facies were utilised to develop a chronometric framework for the quaternary coastal evolution of Deception Bay southeast Queensland (Cotter 1996). This chronometric framework was developed in the context of a broader geoarchaeological and palaeogeographical investigation of the indigenous cultural landscape of the area. The TL analysis confirmed the presence of previously undated Pleistocene sands within the study area. However in the course of dating one sedimentary sequence, conventional radiocarbon analysis of Notispisula sheldls produced an age of 5190± 90 years BP (Beta-85415) whilst an overlying sandy unit (shown by particle size analysis and SEM surface textural analysis to be aeolian transported) subject to TL-dating produced an age of 14,900 ± 3300 years BP (W1942). This poster highlights the considerations made in order to reconcile this obvious anomaly. In effect, previously obtained radiometric data within the study area (Flood 1981; Hall 1996), in conjunction with an examination of the adequacy of the sampled materials for radiocarbon and TL age determinations point to the TL determination being in error. Similar anomalies have been shown to occur elsewhere in southeast Queensland (Tejan-Kella et al. 1990) explanations for which have been related to selective rather than total bleaching of Holocene sands (Prescott personal communication). Re-dating of the sand sequence using the selective bleach method is required to examine whether the dating anomaly shown for Deception Bay parallels selective bleaching effects determined for other sequences within southeast Queensland. Unfortunately this is beyond the scope and funds of this geoarchaeological study

  10. High-precision accelerator-mass-spectrometer radiocarbon dating of buried tidal-marsh soils - An approach to estimating the frequency and coastal extent of subduction zone earthquakes in Oregon and Washington

    International Nuclear Information System (INIS)

    Accurate and precise radiocarbon dating of buried tidal-marsh soils in estuarine stratigraphic sequences in the Pacific Northwest can help distinguish soils submerged during regional plate-boundary earthquakes from soils submerged during local upper-plate earthquakes or by non-tectonic processes. More precise ages than those resulting from conventional methods of radiocarbon analysis can be obtained by averaging multiple accelerator-mass-spectrometer (AMS) 14C ages of rigorously selected and pretreated plant macrofossils at the abrupt upper contacts of tidal-marsh soils. An initial test of this method in Coos Bay, Oregon, shows that standard deviations on AMS ages can be reduced to ± 25-40 radiocarbon years. But consideration of the total analytical errors in AMS analysis and age differences due to variations in the rate of 14C production in the atmosphere over time indicate that 95% confidence limits on calendar-corrected ages for submergence events range from 50 to 450 years

  11. Chemical pretreatments for improving the radiocarbon dates of peats and organic silts in a gley podzol environment : Grahams Terrace, north Westland

    International Nuclear Information System (INIS)

    Radiocarbon dates obtained for peats and organic silts from the high rainfall/leaching environment of North Westland have been shown to conflict with known stratigraphic evidence by yielding anomalously young dates. This study examines the effectiveness of 14 chemical pretreatment methods, including classical humus fractionation of soil organic matter, hydrolysis with mineral acids (6 M HCl and 70% HNO3), and extraction of lipids and cellulose, in removing young carbon contaminants from peat and organic silt samples prior to radiocarbon assay. The criterion chosen for judging the effectiveness of a treatment in removing young contaminants is an increase in 14C age, with the assumption that contamination is largely due to young carbon. Chemical pretreatments were undertaken on peat and organic silt samples taken immediately above (5-0 cm) and below (0-5 cm) a layer of Kawakawa Tephra found at Grahams Terrace in North Westland. Radiocarbon dates, obtained by accelerator mass spectrometer (AMS), showed that most of the pretreatments and their extracts improved the 14C ages compared with untreated samples. The hydrolysis of peat and organic silt samples with 70% HNO3 and dating the resultant residue produced significantly increased 14C dates (c. 6000 years) with respect to untreated samples. The major conclusion from this study is that existing radiocarbon dates of 12,000 yr B.P. and older, on peats and organic silts from gley podzol environments, are contaminated by younger, less stable, more mobile carbon, such as fulvic and humic acid fractions. (author). 20 refs., 1 fig., 1 tab

  12. Instrumental developments at the IBA-AMS dating facility at the University of Lecce

    International Nuclear Information System (INIS)

    The accelerator mass spectrometry (AMS) radiocarbon dating facility at the University of Lecce, Italy is now fully operational and in the first year of operation more than 500 samples both organic and inorganic have been measured for applications in archaeology, history of art, geology and environmental sciences. The experimental capabilities of the facility have been recently significantly improved by the installation of an in vacuum and in air ion beam analysis (IBA) beam line. Investigations are routinely carried out in material science and cultural heritage diagnostics

  13. Stratigraphic assignment of sample from quaternary age using radiocarbon dating method

    International Nuclear Information System (INIS)

    Radiocarbon dating for quaternary samples from Watuadeg, Kalasan, Sleman Yogyakarta has been carried out. The samples are taken from Tuffaceous sand layer (top sample) which overlies a paleosoil (bottom sample). After pretreatment, the weight of the samples was optimized in order to reach same or more than 20 inHg pressure from CO2 gas or 3 ml volume benzene. The result of the dating of the samples are expected to enable stratigraphic assignment of the layers where the samples were taken. The dating result of the Tuffaceous sand = 5835.69 ± 66.91 BP (3885.69 ± 66.91 BC) and Paleosoil sample = 6127.87± 66.12 BP (4177.87 ± 66.12 BC). From the stratigraphic aspect, the dating results show the two layers, are in conformable relation without any abnormality. (author)

  14. TL and radiocarbon dating of neolithic sepultures from Sudan: intercomparison of results

    International Nuclear Information System (INIS)

    Thermoluminescence dating of a set of 29 pottery sherds excavated at the neolithic sites of El Kadada and El Ghaba (near Shendi, Central Sudan) was carried out at Bordeaux University. The archaeological dose was measured using the fine grain technique. The annual dose was determined by analytical techniques (neutron activation analysis, ICP spectrometry, XRF, low background gamma spectrometry) and by ''on-site'' measurements of the environmental radioactivity (gammametry). The crystalline inclusions of the samples were characterized by optical microscopy and cathodoluminescence: the TL minerals mainly consist of quartz and K-feldspar crystals. In some cases, radioactive inclusions of zircons and monazites are observed. The TL and the radiocarbon dates show a good agreement, verifying the validity of the radiocarbon ages which were suspected to be too old because of the nature of the dated material (shells). Taking into account all the chronological data, it is shown that El Ghaba and El Ghaba necropolis were used respectively within the 4800-3300 B.C. and 4200-3000 B.C. date-ranges for neolithic cultures, the occupation of El Kadada starting five or six centuries later than El Ghaba. (Author)

  15. NON-DESTRUCTIVE RADIOCARBON DATING: NATURALLY MUMMIFIED INFANT BUNDLE FROM SW TEXAS

    Energy Technology Data Exchange (ETDEWEB)

    Steelman, K L; Rowe, M W; Turpin, S A; Guilderson, T P; Nightengale, L

    2004-09-07

    Plasma oxidation was used to obtain radiocarbon dates on six different materials from a naturally mummified baby bundle from the Lower Pecos River region of southwest Texas. This bundle was selected because it was thought to represent a single event and would illustrate the accuracy and precision of the plasma oxidation method. Five of the materials were clearly components of the original bundle with 13 dates combined to yield a weighted average of 2135 {+-} 11 B.P. Six dates from a wooden stick of Desert Ash averaged 939 {+-} 14 B.P., indicating that this artifact was not part of the original burial. Plasma oxidation is shown to be a virtually non-destructive alternative to combustion. Because only sub-milligram amounts of material are removed from an artifact over its exposed surface, no visible change in fragile materials has been observed, even under magnification. The method is best applied when natural organic contamination is unlikely and serious consideration of this issue is needed in all cases. If organic contamination is present, it will have to be removed before plasma oxidation to obtain accurate radiocarbon dates.

  16. Radiocarbon dating of lake sediments and peats by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    The small sample size requirement of accelerator mass spectrometry has allowed the measurement of the 14C/12C ratio for components of various lake sediment and peat samples, with a view to gaining greater understanding of sedimentary processes and to overcome some of the problems associated with conventional radiocarbon dating of sediments, where the 14C/12C ratio of the whole sample, less carbonate, is measured. Some of the fractions of sedimentary organic matter are amenable to analysis. Different molecules are specific to higher plants, algae and bacteria, so estimates of the major sources of input to the sediment can be made. The lipid fraction, though a small component (1%) of the total organic matter, yields most source information. Analyses of n-fatty acids and n-alkanes by capillary gas chromatography are used to interpret the radiocarbon result for the total crude lipid samples in the light of the environmental information so gained. Comparison of the various radiocarbon results for different components of the sediment has provided evidence for the importance of the amount of organic carbon in the samples, microbial attack during storage, the presence of mineral carbon, mixing, hard-water effects and the influence of terrestrial material on lake sediments. A regime has been proposed for the routine preparation of samples at an accelerator mass spectrometry facility in order to provide maximum useful information on a sediment sample. (author)

  17. Chemical treatment method for AMS-measurement of radiocarbon in seawater samples

    Energy Technology Data Exchange (ETDEWEB)

    Aramaki, Takafumi [Mutsu Establishment, Japan Atomic Energy Research Inst., Mutsu, Aomori (Japan)

    1999-02-01

    To reveal a migration behavior of radionuclides in the marine environment, it is necessary to make clear the seawater movement in the ocean. The dissolved inorganic radiocarbon ({sup 14}C) in seawater is supplied only from the air at the sea surface and flows with seawater. The absolute quantity of the {sup 14}C decreases with the passage of time. Therefore, it is used as `Tracer of seawater`. The accelerator mass spectrometer (AMS) was installed in JAERI Mutsu establishment at April, 1997. It can measure {sup 14}C/C (or {sup 129}I/I) extensively. To measure the {sup 14}C/C in seawater samples by AMS, two chemical processes are necessary in stripping carbon dioxde (CO{sub 2}) from the inorganic carbonic acid dissolved in seawater and making graphite from this CO{sub 2}. Present processing methods requires time (40 min/sample) and complicated procedures. In contrast with it, newly developed method of CO{sub 2} stripping accomplished to reduce the processing time to one half and increase the yield. On the other hand, the new method of graphite forming is simplified by the improvement of present method. (author)

  18. Radiocarbon dating of groundwater in tertiary sediments of the eastern Murray Basin

    International Nuclear Information System (INIS)

    The Tertiary sediments located in the eastern part of the Murray Basin contain one of the most important low salinity groundwater resources in New South Wales. It is imperative that the hydrogeological environment in which the groundwater occurs be thoroughly understood to allow adequate management of the resource. A radiocarbon dating project was carried out on 37 groundwater samples from bores screened in these unconsolidated sediments. The results indicate water ages in the range 'modern' to 15 800 years. Groundwater recharge areas are indicated and rates of groundwater recharge and movement determined. The latter shows close correlation with velocity values quantitatively determined by Darcy's law

  19. Comparative radiocarbon dating of lignite, pottery, and charcoal samples from Babeldaob Island, Republic of Palau

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, A.; Chappell, J.; Clark, G.; Phear, S. [Australian National University, Canberra, ACT (Australia)

    2005-07-01

    It is difficult to construct archaeological chronologies for Babeldaob, the main island of Palau (western Micronesia), because the saprolitic clays of the dominant terraced-hill sites and associated ceramic sherds often contain old carbon that originated in lignites. This has implications, as well, for chronologies of sedimentary sequences. Comparative analysis of the dating problem using lignite, pottery, and charcoal samples indicates that, in fact, there are both old and young sources of potential contamination. It is concluded that radiocarbon samples from Babeldaob need to be tested for appropriate carbon content rather than relying solely upon material identification.

  20. On the reliability of archaeological rat bone for radiocarbon dating in New Zealand

    International Nuclear Information System (INIS)

    Holdaway and Beavan (1999) discussed the radiocarbon dating of bone of various species from the site of Hukanui Pool, Hawkes Bay. We question their conclusion that two apparently reliable rat bone gelatin determinations from the Hukanui Pool site provide support for the entire suite of rat determinations from previously dated 'natural' sites. We present evidence that contradicts their conclusion that bone material from the broad range of archaeological midden sites is generally less well-preserved than bone from 'natural' caves in New Zealand such as Hukanui Pool. We show that when dates from archaeological bone from Pleasant River and Shag River Mouth are evaluated, the state of preservation is comparable with material from the 'natural' site of Hukanui Pool, and should provide accurate and reproducible radiocarbon determinations. Our conclusion has serious implications for the acceptance of the model proposed by Holdaway (1999), because if archaeological bone is well-preserved but yields unreliable and unreproducible results, it is likely that well-preserved 'natural' bone is similarly affected. (author)

  1. Radiocarbon Dating on Jabung Temple Sites one of the Temples in East Java

    International Nuclear Information System (INIS)

    Radiocarbon dating of organic materials (charcoal) around Jabung templein Jabung temple village, Paiton, Probolinggo district, East Java provincehas been carried out. Excavation archaeologically in different location incertain distance has been done which is considered relevant to the temple'sage and the location of the excavation boxes are the test holes (TH=LU) i.e :LU 1, LU 2, LU 3, LU 4, LU 5, LU 6, LU 7, and LU 8. From those test holes wecan find out that only LU 4 and LU 3 which contain significant charcoal. Thepretreatment (acid, base, acid washing) followed by continued preparationwith carbon contained charcoal burning process, burn to be acetylene gas (C2H2). 14C contained in acetylene is counted by gas proportional counter.After being processed charcoal from LU 3 is not qualified in volumerequirement which is needed for the next analysis. The result for 3000minutes, for background counting = 1.1 ± 0.21 cpm, counting of standard14.51 ± 0.52 cpm, while counting from charcoal sample only from LU 4location is 13.51 ± 0.12 cpm. From data of LU 4 charcoal counting above,we can count the date (age) of the sample that is 510 ± 80 BP. If we usetree ring correction for the data, result will be between 1306-1456 AD onlevel of confidence 68.3% while on level of confidence 95.4% result will bebetween 1281-1624 AD. Relative dating base on ancient inscription show 1354AD. From the data, relative dating is in the range of to absolute dating(radiocarbon dating). (author)

  2. Radiocarbon dating of prehistoric phytoliths: a preliminary study of archaeological sites in China

    Science.gov (United States)

    Zuo, Xinxin; Lu, Houyuan; Zhang, Jianping; Wang, Can; Sun, Guoping; Zheng, Yunfei

    2016-05-01

    Phytoliths can occlude some organic carbon during their deposition in plants. This carbon fraction is recognised as an ideal dating material because of its high resistance to decomposition and post-deposition contamination at the time of phytolith formation. However, the reliability of phytolith radiocarbon dating has recently been questioned. The development of a new extraction protocol for phytoliths, with paired dating between phytoliths and other materials from the same sediment, may provide further evidence for the reliability of phytolith dating. We present an improved method for extracting phytoliths from soils. We compared the dating of phytoliths and other materials (e.g., charcoal and plant seeds) recovered at the same depth from seven pits at six archaeological sites in China. The estimated ages of the phytoliths and other materials were generally consistent, except for one outlier. We attribute this inconsistency to the post-depositional processes of phytoliths in soil, rather than to the uptake of old carbon from the soil. Our results clearly show the potential for phytolith carbon dating at archaeological sites in the absence of other dating materials.

  3. Radiocarbon dating of prehistoric phytoliths: a preliminary study of archaeological sites in China.

    Science.gov (United States)

    Zuo, Xinxin; Lu, Houyuan; Zhang, Jianping; Wang, Can; Sun, Guoping; Zheng, Yunfei

    2016-01-01

    Phytoliths can occlude some organic carbon during their deposition in plants. This carbon fraction is recognised as an ideal dating material because of its high resistance to decomposition and post-deposition contamination at the time of phytolith formation. However, the reliability of phytolith radiocarbon dating has recently been questioned. The development of a new extraction protocol for phytoliths, with paired dating between phytoliths and other materials from the same sediment, may provide further evidence for the reliability of phytolith dating. We present an improved method for extracting phytoliths from soils. We compared the dating of phytoliths and other materials (e.g., charcoal and plant seeds) recovered at the same depth from seven pits at six archaeological sites in China. The estimated ages of the phytoliths and other materials were generally consistent, except for one outlier. We attribute this inconsistency to the post-depositional processes of phytoliths in soil, rather than to the uptake of old carbon from the soil. Our results clearly show the potential for phytolith carbon dating at archaeological sites in the absence of other dating materials. PMID:27225903

  4. Isotopes, diet and aquatic reservoir corrections in radiocarbon Dating – selected developments and examples from Greenland and Northern Europe

    International Nuclear Information System (INIS)

    The last four decades have seen enormous development in awareness of the risk of reservoir effects corrupting radiocarbon dates on organisms from mixed atmospheric/aquatic environments. Consequently, methods have been developed to detect, quantify and correct for these effects. At the Aarhus Dating Centre, we have had the privilege of being inspired by and having had the opportunity to follow in the footsteps of pioneers in the field, such as Henrik Tauber of the Copenhagen Radiocarbon Laboratory. Rather than attempting to give a global review, I will try to pass on how we at the Aarhus Dating Centre experienced and tried to apply a fruitful combination of radiocarbon dating, stable isotope analysis, dietary studies, and reservoir correction models through collaboration with inspiring researchers from different user communities. (author)

  5. Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

    Science.gov (United States)

    Schindler, Matthias; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

    2016-05-01

    Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO2 and reduced to graphite to determine 14C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

  6. Radiocarbon dating of silica sinter deposits in shallow drill cores from the Upper Geyser Basin, Yellowstone National Park

    Science.gov (United States)

    Lowenstern, Jacob B.; Hurwitz, Shaul; McGeehin, John P.

    2016-01-01

    To explore the timing of hydrothermal activity at the Upper Geyser Basin (UGB) in Yellowstone National Park, we obtained seven new accelerator mass spectrometry (AMS) radiocarbon 14C ages of carbonaceous material trapped within siliceous sinter. Five samples came from depths of 15-152 cm within the Y-1 well, and two samples were from well Y-7 (depths of 24 cm and 122 cm). These two wells, at Black Sand and Biscuit Basins, respectively, were drilled in 1967 as part of a scientific drilling program by the U.S. Geological Survey (White et al., 1975). Even with samples as small as 15 g, we obtained sufficient carbonaceous material (a mixture of thermophilic mats, pollen, and charcoal) for the 14C analyses. Apparent time of deposition ranged from 3775 ± 25 and 2910 ± 30 14C years BP at the top of the cores to about 8000 years BP at the bottom. The dates are consistent with variable rates of sinter formation at individual sites within the UGB over the Holocene. On a basin-wide scale, though, these and other existing 14C dates hint that hydrothermal activity at the UGB may have been continuous throughout the Holocene.

  7. Radiocarbon dating of the human eye lens crystallines reveal proteins without carbon turnover throughout life

    DEFF Research Database (Denmark)

    Lynnerup, Niels; Kjeldsen, Henrik; Heegaard, Steffen;

    2008-01-01

    subsequent remodelling of these fibers, nor removal of degraded lens fibers. Human tissue ultimately derives its (14)C content from the atmospheric carbon dioxide. The (14)C content of the lens proteins thus reflects the atmospheric content of (14)C when the lens crystallines were formed. Precise radiocarbon...... dating is made possible by comparing the (14)C content of the lens crystallines to the so-called bomb pulse, i.e. a plot of the atmospheric (14)C content since the Second World War, when there was a significant increase due to nuclear-bomb testing. Since the change in concentration is significant even on...... a yearly basis this allows very accurate dating. METHODOLOGY/PRINCIPAL FINDINGS: Our results allow us to conclude that the crystalline formation in the lens nucleus almost entirely takes place around the time of birth, with a very small, and decreasing, continuous formation throughout life. The...

  8. Rapidly Melting Ice Caps of Northern Baffin Island: Insights From Cosmogenic and Conventional Radiocarbon Dating

    Science.gov (United States)

    Anderson, R. K.; Miller, G. H.; Briner, J. P.; Lifton, N.; Devogel, S. B.

    2006-12-01

    The interior plateau of northern Baffin Island in the eastern Canadian Arctic is home to several small (lichen trimlines across much of the plateau. These trimlines represent previous multi-year snow or ice cover and their aerial extent can be measured via satellite imagery. Based on these measurements, modern ice caps represent only ~3% of ice-cap extent during the Little Ice Age. Radiocarbon dating of moss, preserved beneath the ice caps due to their cold-based nature, suggests a sudden expansion of ice cover around 520 calendar years before present (cal BP), indicated by a mode of 7 dates of approximately this age. This coincides with a pulse of global volcanic activity; predicted cooling from increased aerosol loading may have triggered rapid ice-cap growth. However, dead moss emerging at three sites is more than 1000 years old, with a maximum age of 1326±15 cal BP, indicating that portions of the remaining ice caps have remained intact from more than 1000 years Further constraints on ice cap size are provided by 14C cosmogenic exposure dating. 14C concentrations in rocks at the modern ice margin are too low to be the result of continuous exposure since deglaciation followed by shielding for 500-1000 years by ice cover. Exposure history modeling indicates at least one additional prior period of ice cover of approximately 1000 years. This cold interval most likely occurred sometime since 4 ka, after the Holocene Thermal Maximum in the Arctic and coeval with the onset of Neoglaciation. Radiocarbon dating reveals that some plateau ice caps have been continuously present for more than 1000 years, whereas others formed early in the Little Ice Age (~520 cal BP). Even without additional warming, continuation of current climatic conditions on northern Baffin Island will result in the demise of all ice on the plateau, a condition that has not occurred for more than 1300 years.

  9. AMS radiocarbon age for fossil bone by XAD-2 chromatography method

    International Nuclear Information System (INIS)

    The XAD-2 chromatography method was examined for its ability to efficiently eliminate exogenous organic matter from fossil bones and to improve the accuracy of radiocarbon (14C) dating and stable isotope determinations on bone proteins. The fossil bones used in the experiment were animal fossil bones collected from the Awazu submarine archaeological site, Shiga, Japan. For comparison, the gelatin-extraction method was also applied to the same samples. It was found that the gelatin-extraction method is sufficient for 14C dating on well-preserved bones, but insufficient on poorly preserved bones, containing less than 1% extractable gelatin. The XAD-2 resin is useful for the clean up of proteins especially from poorly preserved bones. The carbon stable isotope fractionation of around 0.1percent by XAD-2 treatment on modern collagen standards was larger than reported previously. The isotopic variation by sequential extraction of bones probably originates from changes in the amino acid composition and seems to be less sensitive to the indication of the removal of organic contamination

  10. Direct radiocarbon dates for prehistoric paintings at the Altamira, El Castillo and Niaux caves

    International Nuclear Information System (INIS)

    Among things that most strikingly distinguish modern humans from other hominids and the rest of the animal kingdom is the ability to represent things and events pictorially. Complex paintings of the type discovered in the Altamira, El Castillo, Niaux and Lascaux caves represent an important stepping stone in the cultural evolution of humankind. Until now dates were derived from style or dated remains left by prehistoric visitors and could be biased by prolonged occupation or visits unrelated to painting activity. Here we report the first radiocarbon dates for the charcoal used to draw stylistically similar bisons in these caves: 14,000 ± 400 yr BP in the Spanish caves of Altamira, 12,990 ± 200 yr BP in El Castillo, and 12,890 ± 160 yr BP for a bison of different style in the French Pyrenean cave of Niaux. Our results demonstrate the imprecise nature of stylistic dating and show that painting dates derived from remains of human activities should be used with caution. (Author)

  11. Effects of sample mass and macrofossil type on radiocarbon dating of arctic and boreal lake sediments

    Energy Technology Data Exchange (ETDEWEB)

    Oswald, W W; Anderson, P M; Brown, T A; Brubaker, L B; Hu, F S; Lozhkin, A V; Tinner, W; Kaltenrieder, P

    2006-05-29

    Dating lake sediments by accelerator mass spectrometry (AMS) {sup 14}C analysis of plant macrofossils overcomes one of the main problems associated with dating bulk sediment samples, the presence of old organic matter. Even so, many AMS dates from arctic and boreal sites appear to misrepresent the age of the sediment. To understand the nature of these apparent dating anomalies better, we conducted a series of {sup 14}C dating experiments using samples from Alaskan and Siberian lake-sediment cores. First, to test whether our analytical procedures introduced a sample-mass bias, we obtained {sup 14}C dates for different-sized pieces of single woody macrofossils. In these sample-mass experiments, sized statistically equivalent ages were found for samples as small as 0.05 mg C. Second, to assess whether macrofossil type influenced dating results, we conducted sample-type experiments in which {sup 14}C dates were obtained for different macrofossil types sieved from the same depth in the sediment. We dated materials from multiple levels in sediment cores from Upper Capsule Lake (North Slope, northern Alaska) and Grizzly Lake (Copper River Basin, southern Alaska), and from single depths in other records from northern Alaska. In several of the experiments there were significant discrepancies between dates for different plant tissues, and in most cases wood and charcoal were older than other macrofossil types, usually by several hundred years. This pattern suggests that {sup 14}C dates for woody macrofossils may misrepresent the age of the sediment by centuries, perhaps due to their longer terrestrial residence time and the potential in-built age of long-lived plants. This study identifies why some {sup 14}C dates appear to be inconsistent with the overall age-depth trend of a lake-sediment record, and it may guide the selection of {sup 14}C samples in future studies.

  12. Lithostratigraphy and radiocarbon dates of the Akunoura-oki core from Nagasaki bay, western Japan

    International Nuclear Information System (INIS)

    The latest Pleistocene to Holocene deposits are distributed in Nagasaki Bay and its surrounding area. In this study, sedimentary facies and radiocarbon dates of the Akunoura-oki core were analyzed for clarifying lithostratigraphy and depositional environments of Nagasaki Bay in the Holocene. The depositional environments inferred from the core succession are as follows: The lower sandy silt and clay (Unit 1), 3.55 m thick, are estuary deposits showing rapid deposition (about 19 mm/yr); the middle gravelly sand and sand (Unit 2), 0.60 m thick, are sandy tidal-sandbar deposits, and deposited extremely slowly (about 0.1 mm/yr) during rapid rising stage of sea-level; the upper clay and silt (Unit 3), 5.32 m thick, are inner bay deposits of slow deposition (about 1.3 mm/yr) during a persistent highstand in sea-level. (author)

  13. Collection of radiocarbon dates on the mammoths ( Mammuthus primigenius) and other genera of Wrangel Island, northeast Siberia, Russia

    Science.gov (United States)

    Vartanyan, Sergey L.; Arslanov, Khikmat A.; Karhu, Juha A.; Possnert, Göran; Sulerzhitsky, Leopold D.

    2008-07-01

    We present and discuss a full list of radiocarbon dates for woolly mammoth and other species of the Mammoth fauna available from Wrangel Island, northeast Siberia, Russia. Most of the radiocarbon dates are published here for the first time. Of the124 radiocarbon dates on mammoth bone, 106 fall between 3700 and 9000 yr ago. We believe these dates bracket the period of mammoth isolation on Wrangel Island and their ultimate extinction, which we attribute to natural causes. The absence of dates between 9-12 ka probably indicates a period when mammoths were absent from Wrangel Island. Long bone dimensions of Holocene mammoths from Wrangel Island indicate that these animals were comparable in size to those on the mainland; although they were not large animals, neither can they be classified as dwarfs. Occurrence of mammoth Holocene refugia on the mainland is suggested. Based on other species of the Mammoth fauna that have also been radiocarbon on Wrangel Island, including horse, bison, musk ox and woolly rhinoceros, it appears that the mammoth was the only species of that fauna that inhabited Wrangel Island in the mid-Holocene.

  14. Sun, Ocean, Nuclear Bombs, and Fossil Fuels: Radiocarbon Variations and Implications for High-Resolution Dating

    Science.gov (United States)

    Dutta, Koushik

    2016-06-01

    Radiocarbon, or 14C, is a radiometric dating method ideally suited for providing a chronological framework in archaeology and geosciences for timescales spanning the last 50,000 years. 14C is easily detectable in most common natural organic materials and has a half-life (5,730±40 years) relevant to these timescales. 14C produced from large-scale detonations of nuclear bombs between the 1950s and the early 1960s can be used for dating modern organic materials formed after the 1950s. Often these studies demand high-resolution chronology to resolve ages within a few decades to less than a few years. Despite developments in modern, high-precision 14C analytical methods, the applicability of 14C in high-resolution chronology is limited by short-term variations in atmospheric 14C in the past. This article reviews the roles of the principal natural drivers (e.g., solar magnetic activity and ocean circulation) and the anthropogenic perturbations (e.g., fossil fuel CO2 and 14C from nuclear and thermonuclear bombs) that are responsible for short-term 14C variations in the environment. Methods and challenges of high-resolution 14C dating are discussed.

  15. 14C-AMS at the Leibniz-Labor: radiometric dating and isotope research

    International Nuclear Information System (INIS)

    The Leibniz-Labor was founded to provide radiometric dating services using AMS and measured over 15 000 samples and 26 800 targets up to September 2002. Research and development have primarily been directed at improving the efficiency and reliability of AMS measurements, optimising existing sample preparation procedures for AMS and developing new ones. The standard chemical pre-treatment of organic radiocarbon samples produces often two fractions: one from which contaminants have been removed, and one in which they have been enriched. Dating both fractions reveals the degree of sample contamination. This provides a useful indication of the reliability of the sample age obtained and of the environmental conditions where the sample was taken. Upgrades to reduce maintenance include replacing four cryo- by turbo pumps, installing a deionizer loop, which keeps conductivity between 100 and 150 μS/cm to control corrosion, in the closed cooling water circuit, and developing a new sample wheel, which holds target holders with a groove and spring clip. Long term stability is demonstrated by the results obtained for IAEA reference materials, measured routinely and regularly over the years. Tests made as part of the FIRI project demonstrate that reliable measurements down to <0.1 mg C can be made

  16. Radiocarbon dating of kohitsugire calligraphies attributed to Fujiwara Shunzei: Akihiro-gire, Oie-gire, and Ryosa-gire

    International Nuclear Information System (INIS)

    Kohitsugire are ancient paper sheets containing graceful calligraphy. They were originally the pages of rare ancient manuscripts; therefore, they contain valuable historical information. However, among the kohitsugire attributed to famous calligraphists, many copies and counterfeits written several centuries later are also in circulation. We measured the radiocarbon ages of three kohitsugire (Akihiro-gire, Oie-gire, and Ryosa-gire) attributed to Fujiwara Shunzei. Among paleographers, it had been commonly accepted that Akihiro-gire was written by Shunzei in his youth. However, radiocarbon dating showed that Akihiro-gire is not Shunzei's work. Therefore, it is probably a page from an anonymous manuscript.

  17. 14C AMS dating of fires in the central Amazon rain forest

    International Nuclear Information System (INIS)

    Soil samples were collected in tierra firme upland and lowland areas of the Km 41 reserve near Manaus (20 deg. 30'S and 60 deg. W), in Central Brazilian Amazon, within a 1700 m transect, at eight different depth ranges, from surface to 100 cm. The highest charcoal concentrations were found at the depth range of 20-50 cm. AMS radiocarbon dating of 31 samples were performed at the ANU. The ages of the charcoals were found to vary within the 130 to 2400 years BP range, mostly between 1200 and 1400 years BP, one of the known Holocene dry periods of the Amazon region. The results show that the fires have regional dimensions and are associated with climate regional changes

  18. Direct radiocarbon dating and stable isotopes of the neandertal femur from Les Rochers-de-Villeneuve (Lussac-les-Châteaux, Vienne)

    OpenAIRE

    Beauval, C.; Lacrampe-Cuyaubère, F.; B. Maureille; Trinkaus, E

    2010-01-01

    Direct radiocarbon dating of the Neandertal femoral diaphysis from the Rochers-de-Villeneuve (Lussac-les-Châteaux, Vienne) has yielded an age of 45,200 ± 1,100 14C years B.P. (OxA-15257) [48,455 ± 1,878 cal. years B.P.], and stable isotope values of δ13C = - 19.0‰ and δ15N = 11.6‰. The direct radiocarbon date makes it the oldest directly dated European Neandertal specimen, even though others have securely associated radiocarbon dates in the same time range. The stable isotopes are similar to ...

  19. Co-development of Conceptual Understanding and Critical Attitude: Analyzing texts on radiocarbon dating

    Science.gov (United States)

    Décamp, N.; Viennot, L.

    2015-08-01

    This research documents the impact of a teaching interview aimed at developing a critical attitude in students, and focused on a particular topic: radiocarbon dating. This teaching interview is designed to observe students' reaction to limited written explanations of the phenomenon under study, and their possible frustration or intellectual satisfaction in relation to these texts. We aim to document the possible link between students' developing conceptual understanding of a topic and their ability to express their frustration when presented with very incomplete explanations, or their intellectual satisfaction when presented with complete explanation. As a side product, we intend to observe some of their a priori ideas concerning this topic. Ten teaching interviews conducted with fourth-year University students were recorded, transcribed and coded. Beyond a series of results concerning students' a priori understanding of the domain, the analysis of the interviews suggests that, when students are presented with texts of increasing completeness and discuss these with the interviewer, their critical reactions evolve in time in a very specific way. We propose a tentative model for this co-evolution of student conceptual command and critical stance. The discussion bears on possible interpretations for the 'anesthesia of judgment' observed in most students at the beginning of the interview, and for a few of them throughout the discussion. Keeping in mind the 'competence vs concepts' current alternative, the conditions that seem to free students' critical potential are analyzed in relation to their evolving command of the topic and their degree of intellectual satisfaction.

  20. Radiocarbon dating of the Peruvian Chachapoya/Inca site at the Laguna de los Condores

    International Nuclear Information System (INIS)

    Full text: An archaeological site with several funerary houses built in the cliffs of the Laguna de los Condores by the Chachapoya people was discovered in 1997 in the cloud forest at a sea level of 2500 m in the Amazonas/San Martin area in Peru. The Chachapoya people and their culture is not fully understood until now and some myths entwine around the origin of that South American ancient civilisation. The Chachapoya are described as people of warriors, which were finally subdued by the Incas. A typical characteristic of their culture is the special burial of their dead in funeral bundles containing the remains of the bodies. At the Laguna de los Condores more that 200 mummies have been found and transferred to Leymebamba. During the rescue work of the mummies, which were in danger to be destroyed by looters, it turned out that two different burial patterns could be detected. It is assumed, that after conquering of the Chachapoyas, the Inca people took over also the burial cliff houses and used it for their own burials. The Incas themselves were subdued by the Spanish Conquistadors in 1532 AD. In order to shed light on the transition from the Chachapoya to the Inka dominance, which is connected with the history of the Laguna de los Condores funeral site, a multidisciplinary project between archaeologists, anthropologists and physicists has been started. VERA contributes to this project with several radiocarbon dates of archaeological objects and of the mummies from this Chachapoya/Inca site. (author)

  1. Preceramic, Aceramic or Early Ceramic? The radiocarbon dated beginning of the Neolithic in the Aegean

    Directory of Open Access Journals (Sweden)

    Agathe Reingruber

    2015-12-01

    Full Text Available The Pre-Pottery-Neolithic refers to a period in the Eastern Mediterranean when ceramic containers were not yet in use (although small objects made of clay were already being created. This concept, which reflects a specific and quite unique stage in the development of human history, was introduced to Aegean prehistory under the term of Preceramic during the 1950’s (e.g., in Argissa Magoula and Sesklo. Shortly thereafter, a different term, the Aceramic, was applied in the Aegean (e.g., in Knossos for levels devoid of pottery, although ceramic products were supposedly used in the wider region. In some cases, the thin levels interpreted as Preceramic or as Aceramic contained sherds that were regarded as being intrusive from above (e.g., Argissa-Magoula, Franchthi Cave. The new sequences of radiocarbon dates allow a more precise description of this early period and thereby contribute, not least, also to the clarification of terminological issues.

  2. Radiocarbon dating of plant macro-remains from the palaeochannel and its implication for the reconstruction of sediment deposition processes

    Czech Academy of Sciences Publication Activity Database

    Barta, P.; Hajnalová, M.; Látková, Michaela

    Brno: The Institute of Archaeology of the Academy of Sciences of the Czech Republic, Brno, 2014 - (Poláček, L.), s. 113-116. (Spisy archeologického ústavu AV ČR Brno. 51). ISBN 978-80-86023-60-1 R&D Projects: GA ČR(CZ) GAP405/11/2258 Keywords : radiocarbon dating * Mikulčice * Early Middle Ages * chronology * plant macro-remains Subject RIV: AC - Archeology, Anthropology, Ethnology

  3. AMS dating of early shellmounds of the Southeastern Brazilian coast

    Energy Technology Data Exchange (ETDEWEB)

    Lima, T. A. [Universidade Federal, Rio de Janeiro (UFRJ), RJ (Brazil). Museu Nacional. Dept. de Antropologia; Macario, K.D.; Anjos, R.M.; Gomes, P.R.S. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Fisica; Coimbra, M.M. [Universidade Estadual de Londrina, PR (Brazil). Dept. de Fisica; Elmore, D. [Purdue Univ., IN (United States). Purdue Rare Isotopes Measurement Lab.

    2003-06-01

    This paper discusses the chronology of prehistoric settlements of the central-south Brazilian coast. A charcoal sample from a coastal shell mound of Rio de Janeiro State was dated by {sup 14} C-AMS to 7, 860+- 80 years B P as part of an interdisciplinary project between physicists and archaeologists. This is an unexpected result that reinforces two similar previous early dates for the same region, which were questioned by Brazilian archaeologists because they implied in pulling back by some two thousand years the antiquity consensually accepted for the settlement of that region. (author)

  4. AMS dating of early shellmounds of the Southeastern Brazilian coast

    International Nuclear Information System (INIS)

    This paper discusses the chronology of prehistoric settlements of the central-south Brazilian coast. A charcoal sample from a coastal shell mound of Rio de Janeiro State was dated by 14 C-AMS to 7, 860+- 80 years B P as part of an interdisciplinary project between physicists and archaeologists. This is an unexpected result that reinforces two similar previous early dates for the same region, which were questioned by Brazilian archaeologists because they implied in pulling back by some two thousand years the antiquity consensually accepted for the settlement of that region. (author)

  5. Timescales for carbon cycling in terrestrial ecosystems - what have we learned from AMS Radiocarbon measurements?

    International Nuclear Information System (INIS)

    Radiocarbon can be used to study carbon dynamics in terrestrial ecosystems on timescales ranging from years to decades (for 'bomb' 14C) to millennia (for cosmogenic 14C). This talk will provide examples of recent advances in understanding sources and stabilization mechanisms for soil organic matter, as well as controls on the age of CO2 respired from ecosystems. I will focus on results from Amazonia, including the implications for a global carbon sink in intact tropical forests. (author)

  6. Correlation of Radiocarbon Dating on Surowono Temple to Other Temples in Central Java and East of Java

    International Nuclear Information System (INIS)

    Radiocarbon dating on charcoal sample have been carried out from Surowono Temple sites, Canggu village, Pare district, Kediri East Java Province. Sampling carried out by excavation on a few location with 5 test holes, that is LU1, LU2, LU3. LU4, LU5. Laboratorium analysis on significant charcoal sample only gained from LU3 test hole. After being processed and prepared to be benzene by using Benzene Synthesizer and counted by Liquid Scintillation Counter Packard 2000CA/LL, was found that age of radiocarbon dating is 885 ± 51.46 BP or 1052.61 ± 51.46 BP. Correction result tree ring correction resulting confidence level 68.3 % : 1052 - 1245 AD while confidence level on 95.4 % : 1038 - 1262 AD. Compare to recent research shows that radiocarbon dating result on Surowono temple and other temples in East of Java around 13th - 15th century and other temples in Southern of Central Java around 10th century, while other temples in Northern of Central Java around 8'th century. (author)

  7. New insights into the radiocarbon calibration based on 14C and U-Th dating of corals drilled offshore Tahiti (IODP Expedition #310)

    Science.gov (United States)

    Durand, Nicolas; Deschamps, Pierre; Bard, Edouard; Hamelin, Bruno; Camoin, Gilbert; Thomas, Alexander L.; Henderson, Gideon M.; Yokoyama, Yusuke

    2010-05-01

    Beyond the high-precision tree-ring calibration, the fossil corals are the most reliable archive that can be used to calibrate the radiocarbon time scale. In this contribution, we present a new radiocarbon dataset based on paired 14C and U-Th dating of fossil shallow-water tropical corals drilled offshore Tahiti during the IODP Expedition 310 'Tahiti Sea-Level'. Before 14C and U-Th analyses, rigorous screening criteria have been applied in order to select pristine aragonitic coral skeletons and avoid those displaying any post-mortem diagenesis that alters original ages. In particular, we made a significant effort to improve detection and quantification of very small amount of secondary calcite in the aragonitic coral lattice using X-ray diffraction measurements [1]. In addition, we apply a strict screening criterion based on δ234U. However, the new Tahiti dataset allow to refine the previous tolerance ranges previously adopted. More than 60 radiocarbon dates were processed at the Laboratoire de Mesure du Carbone 14 (Saclay, France) with the ARTEMIS AMS facility. This new Tahiti record provides new data to the radiocarbon calibration for two distinct time windows: for the interval between 29,200 and 36,200 years BP and for the last deglaciation period, with especially, a higher resolution (40 data) for the 14,000 - 16,000 years BP time interval. These new data extend the previous Tahiti record beyond 13,900 years BP which was the oldest U-Th age obtained on cores drilled onshore in the modern Tahiti barrier reef [2, 3]. These new results are compared with 14C chronologies from other corals, those of Barbados [4, 5] and those from other Pacific islands (Mururoa, Vanuatu, Marquesas, Christmas), and from the Cariaco Basin sediment [6, 7], the Iberian Margin sediment [8, 9] and the Bahamian speleothem [10] records. The new 14C dataset from the corals drilled offshore Tahiti allows to validate the precision and accuracy of other records either directly dated by U-Th or

  8. Radiocarbon dating of the human eye lens crystallines reveal proteins without carbon turnover throughout life.

    Directory of Open Access Journals (Sweden)

    Niels Lynnerup

    Full Text Available BACKGROUND: Lens crystallines are special proteins in the eye lens. Because the epithelial basement membrane (lens capsule completely encloses the lens, desquamation of aging cells is impossible, and due to the complete absence of blood vessels or transport of metabolites in this area, there is no subsequent remodelling of these fibers, nor removal of degraded lens fibers. Human tissue ultimately derives its (14C content from the atmospheric carbon dioxide. The (14C content of the lens proteins thus reflects the atmospheric content of (14C when the lens crystallines were formed. Precise radiocarbon dating is made possible by comparing the (14C content of the lens crystallines to the so-called bomb pulse, i.e. a plot of the atmospheric (14C content since the Second World War, when there was a significant increase due to nuclear-bomb testing. Since the change in concentration is significant even on a yearly basis this allows very accurate dating. METHODOLOGY/PRINCIPAL FINDINGS: Our results allow us to conclude that the crystalline formation in the lens nucleus almost entirely takes place around the time of birth, with a very small, and decreasing, continuous formation throughout life. The close relationship may be further expressed as a mathematical model, which takes into account the timing of the crystalline formation. CONCLUSIONS/SIGNIFICANCE: Such a life-long permanence of human tissue has hitherto only been described for dental enamel. In confront to dental enamel it must be held in mind that the eye lens is a soft structure, subjected to almost continuous deformation, due to lens accommodation, yet its most important constituent, the lens crystalline, is never subject to turnover or remodelling once formed. The determination of the (14C content of various tissues may be used to assess turnover rates and degree of substitution (for example for brain cell DNA. Potential targets may be nervous tissues in terms of senile or pre

  9. Radiocarbon dating of the first Turkish bridge over the River Tisza

    International Nuclear Information System (INIS)

    Complete text of publication follows. Situated at the junction of the Tisza and Zagyva rivers, the territory of the presentday Szolnok town has been nearly continuously inhabited since the beginning of the Neolithic age. Gravures and other written documents attested the presence of bridge(s) over the River Tisza during the centuries. The first bridges were mentioned in 1526 as temporary pontoon bridges used for the needs of the Turkish army. The remainings of an old bridge on the River Tisza were discovered last summer in excavations of the river bank at Szolnok. It was supposed that the remainings found were probably part of the bridge built in 1562, the first wooden bridge over the River Tisza mentioned in the letter of bishop of town Eger [1] but could also been parts of a bridge built much later. Although the mineral water and sodium silicate have penetrated the wood logs resulting in though blackish-brown and hardened by petrifaction samples, the original character of the pylons was still evident. Six timbers (7 samples) have been radiocarbon dated. Samples were physically and chemically pre-treated to remove contamination before they were converted to CO2. In order to avoid the 'old wood' effect, in which the inner tree rings may be tenths of years older than the outer ring of sapwood deposited just before the tree died the exterior was removed. Physical treatments consisted of cleaning, sorting, grinding and sieving. Chemical treatment included the standard A/A/A method. The pre-treated samples were combusted to CO2 in a controlled oxygen stream. The purified CO2 was trapped and measured by gas proportional counting [2]. Correction for fractionation was done by measuring the δ13CPDB value. Calibration of 14C dates to calendar years was performed using the Calib 4.4.2 program [3]. The results showed the wood sample prepared by A/A/A contained contaminants of more recent carbon material which gave it a more recent date and spread the results over four

  10. Revised radiocarbon dates for Mwanihuki, Makira : a c. 3000 BP aceramic site4 in the southeast Solomon Islands

    International Nuclear Information System (INIS)

    Excavation of three middens on Mwanihuki, located on the north coast of Makira in the southeast Solomon Islands has returned radiocarbon dates that show an initial occupation bracket between 3351 ± 42 BP and 2975 ± 21 BP (uncalibrated). The material culture of this phase consisted of a small amount of subsistence shell and worked chert, and an absence of any ceramics. This date range, along with the absence of the distinctive Lapita type dentate stamped pottery has aligned phasing of this site with the contemporaneous aceramic Vatuluma Posovi cave site in central Guadalcanal. (author)

  11. A graphical method to evaluate predominant geochemical processes occurring in groundwater systems for radiocarbon dating

    Science.gov (United States)

    Han, Liang-Feng; Plummer, L. Niel; Aggarwal, Pradeep

    2012-01-01

    A graphical method is described for identifying geochemical reactions needed in the interpretation of radiocarbon age in groundwater systems. Graphs are constructed by plotting the measured 14C, δ13C, and concentration of dissolved inorganic carbon and are interpreted according to specific criteria to recognize water samples that are consistent with a wide range of processes, including geochemical reactions, carbon isotopic exchange, 14C decay, and mixing of waters. The graphs are used to provide a qualitative estimate of radiocarbon age, to deduce the hydrochemical complexity of a groundwater system, and to compare samples from different groundwater systems. Graphs of chemical and isotopic data from a series of previously-published groundwater studies are used to demonstrate the utility of the approach. Ultimately, the information derived from the graphs is used to improve geochemical models for adjustment of radiocarbon ages in groundwater systems.

  12. Molecular Radiocarbon Dating of Tropical Lake Sediments: Insights into the Chronology of Leaf Wax Stable Isotope Records

    Science.gov (United States)

    Douglas, P. M.; Pagani, M.; Eglinton, T. I.; Brenner, M.; Curtis, J. H.; Hodell, D. A.

    2010-12-01

    Leaf wax δD and δ13C measurements in marine and lacustrine sediment cores are promising proxies for past climatic and environmental change. However, a number of studies of marine sediments indicate centennial to millennial scale offsets between the radiocarbon ages of leaf waxes and the age of surrounding sediments due to long-term storage of these lipids in soils. These offsets present a complication for the interpretation of leaf wax stable isotope records that has not been thoroughly addressed. We present leaf wax δD, δ13C and Δ14C values for a sediment core from Lake Chichancanab in southeastern Mexico. This lake was previously studied using mineralogical (gypsum) and carbonate isotopic (δ18O) climate proxies, which indicated a sequence of severe droughts from 750 to 1000 AD, coincident with the collapse of the Classic Maya civilization. A suite of leaf wax δD values was plotted against the original sediment core chronology, which was developed using radiocarbon dates on terrestrial macrofossils. The leaf wax results also indicated major hydrological variability over the past 3000 years, but were not temporally coherent with the other climate proxy records. Leaf wax radiocarbon ages are 400 to 1200 years older than terrestrial macrofossil radiocarbon ages from the same depths, suggesting that leaf waxes are retained in the watershed for extended periods prior to deposition in the lake. We fit a 2nd-order polynomial equation to the depth profile of leaf wax radiocarbon ages (r2 =0.99) and refit the leaf wax δD profile to this “leaf wax age model”. This approach yielded much greater coherence with mineralogical and carbonate isotopic proxy records, including evidence for a period of severe drought (35‰ D-enrichment) from 750 to 1000 A.D. Our results indicate that long-term storage of leaf waxes in drainage basin soils can lead to temporal inaccuracies in leaf wax stable isotope records. These inaccuracies, however, can be corrected using a

  13. Youngest reported radiocarbon age of a moa (Aves : Dinornithiformes) dated from a natural site in New Zealand

    International Nuclear Information System (INIS)

    The extinction date of the giant flightless New Zealand ratite bird, the crested moa (Pachyornis australis), is of considerable interest because the youngest verified remains are dated to the Pleistocene–Holocene transition c. 10,000 yr BP, which was characterised by severe climatic and habitat change, and are considerably earlier than the late Holocene extinctions of the other eight moa species. Analysis of a partial crested moa skeleton (NMNZ S23569) from Castle Keep Entrance, Bulmer Cave System, Mount Owen, South Island, generated a radiocarbon date of 564±26 yr BP (544-508 cal yr BP; 95.4% AD 1396-1442). As a result the Bulmer Cave specimen represents the youngest moa yet found from a natural site in New Zealand. Combined with additional crested moa remains dated to the late Holocene from Cheops Cave (Mount Arthur) and Magnesite Quarry (Cobb Valley), this indicates that crested moa did not go extinct during the Pleistocene–Holocene transition but survived until after Polynesian colonisation in c. AD 1280. The new radiocarbon dates reported here have important implications for the timing of moa extinction and the late survival of moa in alpine areas of New Zealand. (author). 47 refs., 2 figs., 1 tab.

  14. Towards an absolute chronology for the Aegean iron age: new radiocarbon dates from Lefkandi, Kalapodi and Corinth.

    Directory of Open Access Journals (Sweden)

    Michael B Toffolo

    Full Text Available The relative chronology of the Aegean Iron Age is robust. It is based on minute stylistic changes in the Submycenaean, Protogeometric and Geometric styles and their sub-phases. Yet, the absolute chronology of the time-span between the final stages of Late Helladic IIIC in the late second millennium BCE and the archaic colonization of Italy and Sicily toward the end of the 8(th century BCE lacks archaeological contexts that can be directly related to events carrying absolute dates mentioned in Egyptian/Near Eastern historical sources, or to well-dated Egyptian/Near Eastern rulers. The small number of radiocarbon dates available for this time span is not sufficient to establish an absolute chronological sequence. Here we present a new set of short-lived radiocarbon dates from the sites of Lefkandi, Kalapodi and Corinth in Greece. We focus on the crucial transition from the Submycenaean to the Protogeometric periods. This transition is placed in the late 11(th century BCE according to the Conventional Aegean Chronology and in the late 12(th century BCE according to the High Aegean Chronology. Our results place it in the second half of the 11(th century BCE.

  15. Towards an absolute chronology for the Aegean iron age: new radiocarbon dates from Lefkandi, Kalapodi and Corinth.

    Science.gov (United States)

    Toffolo, Michael B; Fantalkin, Alexander; Lemos, Irene S; Felsch, Rainer C S; Niemeier, Wolf-Dietrich; Sanders, Guy D R; Finkelstein, Israel; Boaretto, Elisabetta

    2013-01-01

    The relative chronology of the Aegean Iron Age is robust. It is based on minute stylistic changes in the Submycenaean, Protogeometric and Geometric styles and their sub-phases. Yet, the absolute chronology of the time-span between the final stages of Late Helladic IIIC in the late second millennium BCE and the archaic colonization of Italy and Sicily toward the end of the 8(th) century BCE lacks archaeological contexts that can be directly related to events carrying absolute dates mentioned in Egyptian/Near Eastern historical sources, or to well-dated Egyptian/Near Eastern rulers. The small number of radiocarbon dates available for this time span is not sufficient to establish an absolute chronological sequence. Here we present a new set of short-lived radiocarbon dates from the sites of Lefkandi, Kalapodi and Corinth in Greece. We focus on the crucial transition from the Submycenaean to the Protogeometric periods. This transition is placed in the late 11(th) century BCE according to the Conventional Aegean Chronology and in the late 12(th) century BCE according to the High Aegean Chronology. Our results place it in the second half of the 11(th) century BCE. PMID:24386150

  16. Hard-water dynamics and their reservoir effects on radiocarbon dating of Lake Heihai sediments (NE Tibetan Plateau, Qinghai, China)

    Science.gov (United States)

    Lockot, Gregori; Hartmann, Kai; Wünnemann, Bernd; Ramisch, Arne; Diekmann, Bernhard

    2014-05-01

    Age determination of lake sediments with radiocarbon dating can always entail a perturbation with hard water. Atmospheric carbon (expressing the "real" ages) can be mixed with older carbon from allochthonous input (e.g. marl or limestone), causing an overestimation of 14C ages. The usual approach to eliminate this effect is to date living plants or shells to determine the modern offset in age. Subsequently, this offset is subtracted from 14C ages of a sediment core to attain hard water corrected ages. However, this approach assumes a constant hard water effect over the entire period under consideration, which generally is unlikely. Here we present a highly variable hard water effect through time determined from a combined chronology of two long sediment cores from Lake Heihai (NE Tibetan Plateau). The chronology is based on 20 14C AMS dates of Potamogeton spec. Based on the relation between 14C ages and the input of allochthonous carbonates as well as calculated sedimentation rates, we developed an age-depth-model that estimates the actual ages of the sediments and allows the quantification of hard water effect through time. As a result this model suggests a fluctuating hard water effect varying between 102 to 103 ka. Ages in the lower 3 meter of the core, which corresponds to late glacial times, strongly correlate with the input of dolomite (CaMg(CO3)2). The correlation suggests a strong linkage between the allochthonous input of old carbon and the variations in dating results. In this section, the estimated hard water effect shows its highest values. Results of XRD, grain size and pollen data confirm a shallow lake with high rates of detrital input. The Late Glacial - Holocene transition to warmer and wetter conditions is marked by prominent changes in the mineralogy of lacustrine carbonates and the composition of pollen taxa. During this time the lake constantly rose and increasingly buffered the influence of allochthonous carbonates. The episode is

  17. Radiometric dating

    International Nuclear Information System (INIS)

    The paper on radiometric dating is a chapter in a handbook of Holocene Palaeoecology and Palaeohydrology. This chapter is part of a section on dating methods. Radiocarbon dating is discussed with respect to the apparent ages of lake sediments, seawater, sea creatures and plants. Isotope dating methods for the late Holocene deposits involving 210Pb, 137Cs, sup(239, 240)Pu, 241Am, 32Si and 39Ar are also described. (U.K.)

  18. Radiocarbon dating of charcoal fragments from the cave A5-3 in Arsanjan, Iran

    International Nuclear Information System (INIS)

    Modern humans (Homo-sapiens), who originated in East Africa about 200,000 years ago, migrated out of Africa about 130,000-60,000 years ago, dispersed in West Asia, and finally replaced Neanderthals in Europe and Asia. The region of West Asia, especially southern Iran, therefore, is very important to understand the evolution of modem humans. The Japan-Iran international research group, led by Professor Tsuneki of Tsukuba University, has investigated A5-3 cave in the Arsanjan archeological site in southern Iran since 2011. The sequence of layers in the cave is estimated to belong Middle Paleolithic to the Proto-Neolithic period, based on the type of lithic artifacts excavated. In this study, we measured AMS-14C dates of charcoal fragments collected from the layers to reveal the chronology of the Arsanjan site. Charcoal samples collected from surface layer to Layer 4 in Trench E5 (total 6 layers) and Layers 2 and 3 in Trench B3 (total 10 layers) in the A5-3 cave were used. In Trench E5, charcoal samples of surface layer were dated at modern, samples of Layer 1 at 300-115 BP, samples of Layer 2 at 26,750-26,370 BP, and one sample of Layer 3 and samples of Layer 4 were older than 14C-detection limit. In Trench B3, charcoal samples of Layer 2 were dated at 36,500-35,300 BP, and one sample of Layer 3 was dated at 36,890±190 BP. The layers in both Trenches E5 and B3 had been considered to correspond to each other base on the type of lithic artifacts, but the 14C results show that the layers of Trench B3 are about 10,000 BP older than those of Trench E5. Layers 2 and 3 in Trench B3 belong to the early Upper Paleolithic period, contemporary with the result reported for AH IV layer in Ghar-e Boof archeological site at Dasht-e Rostam region, southwestern Iran. This study is the second finding of use of these micro-blades at 37,000 BP in Iran, following the Ghar-e Boof site. Layer 4 in Trench B3 includes Middle Paleolithic artifacts, and so 37,000 BP obtained for Layer 3 in

  19. Radiocarbon dating of the late pleistocene syngenetic ice-wedges at the Bison sequence, lower Kolyma river

    International Nuclear Information System (INIS)

    Radiocarbon dating of organic microinclusions from syngenetic ice-wedges was made using the method of accelerating mass-spectrometry to determine the time of the ice wedges formation at the Bison sequence in the lower Kolyma river. It was ascertained that the ice was formed at least 33-26 thousand years gas, moreover, the ice vertical growth rate did not exceed 0.8 m per 1 thousand years. Isotopic data obtained confirmed vertical stratification of the ice in wedges so that younger ice is located above ancient ice

  20. Radiocarbon dating of milligram-size samples using gas proportional counters: an evaluation of precision and of design parameters

    International Nuclear Information System (INIS)

    Radiocarbon dating parameters, such as instrumental techniques used, dating precision achieved, sample size, cost and availability of equipment and, in more detail, the merit of small gas proportional counting systems are considered. It is shown that small counters capable of handling 10-100mg of carbon are a viable proposition in terms of achievable precision and in terms of sample turnover, if some 10 mini-counters are operated simultaneously within the same shield. After consideration of the factors affecting the performance of a small gas proportional system it is concluded that an automatic, labour saving, cost effective and efficient carbon dating system, based on some sixteen 10 ml-size counters operating in parallel, could be built using state-of-art knowledge and components

  1. Development of a method for fast and automatic radiocarbon measurement of aerosol samples by online coupling of an elemental analyzer with a MICADAS AMS

    Science.gov (United States)

    Salazar, G.; Zhang, Y. L.; Agrios, K.; Szidat, S.

    2015-10-01

    A fast and automatic method for radiocarbon analysis of aerosol samples is presented. This type of analysis requires high number of sample measurements of low carbon masses, but accepts precisions lower than for carbon dating analysis. The method is based on online Trapping CO2 and coupling an elemental analyzer with a MICADAS AMS by means of a gas interface. It gives similar results to a previously validated reference method for the same set of samples. This method is fast and automatic and typically provides uncertainties of 1.5-5% for representative aerosol samples. It proves to be robust and reliable and allows for overnight and unattended measurements. A constant and cross contamination correction is included, which indicates a constant contamination of 1.4 ± 0.2 μg C with 70 ± 7 pMC and a cross contamination of (0.2 ± 0.1)% from the previous sample. A Real-time online coupling version of the method was also investigated. It shows promising results for standard materials with slightly higher uncertainties than the Trapping online approach.

  2. Reliable 14-C AMS dates on bird and Pacific rat Rattus exulans bone gelatin, from a CaCO3-rich deposit

    International Nuclear Information System (INIS)

    We tested the reliability of accelerator mass spectrometry (AMS) radiocarbon dates on bone gelatin by dating samples whose maximum or minimum age was constrained by stratigraphic position relative to well-dated volcanic tephra layers. The tephra layers were not reworked, and were thick enough to preclude the possibility of redeposition resulting in specimens being found outside the age bounds set by the tephras. The damp, fossiliferous, carbonate-rich sediment was in a relatively constant, cool environment in a small cave at nearly 900 m altitude. Bones from four species of bird with different diets (a pigeon, a rail, an owlet-nightjar, and a large ratite) and one rodent, the Pacific rate Rattus exulans, were dated. The calibrated (calendar) AMS age of each bone was compared to ages predicted from their stratigraphic position and calculated sedimentation rates, inferred from the age of each tephra layer. Samples of moa (Aves: Dinornithiformes) eggshell were also dated by AMS, providing an independent dating material. None of the bone gelatin or eggshell dates displayed any significant in-built (reservoir) age relative to the marker horizons, nor were any AMS ages significantly younger than expected. Our results agree with previous studies in showing that 14C AMS dates on bone gelatin from deposits that have always had a relatively cool, and stable physical environment are likely to be reliable. For bones protected from weathering before burial, and then incorporated in a stable, carbonate-rich environment, the filtered bone gelatin procedure used in this study is adequate to give reliable AMS ages. Possible reasons for discrepancies in bone gelatin AMS dates relative to marine shell, or charcoal dates from archaeological sites in dune deposits, are also discussed. (author). 70 refs., 7 figs., 2 tabs

  3. The contribution of 14C AMS dating to the Greater Angkor archaeological project

    Science.gov (United States)

    Zoppi, U.; Barbetti, M.; Fletcher, R.; Hua, Q.; Chhem, R. K.; Pottier, C.; Watanasak, M.

    2004-08-01

    For well over five centuries, the Khmer kingdom ruled over a vast territory, including most of what is now known as Cambodia, Thailand, Vietnam and Laos. Between the 9th and 14th century AD, the Khmer Kings developed the Angkor area into a remarkable administrative and religious centre for their society. According to new estimates by the Greater Angkor Project, the entire urban complex of the capital city covered about 1000 square km making it probably the largest archaeological site in the world. Great stone temples and some other monumental structures and earthworks are the only visible remains of this fascinating civilisation. Thankfully, there is a substantial on-going multinational effort to preserve and restore what is left and in 1992 UNESCO (United Nations Educational Scientific and Cultural Organisation) declared Angkor a World Heritage Site. This paper presents two particular aspects of the Greater Angkor Project where radiocarbon dating by AMS specifically added to our knowledge of the history of this ancient capital city.

  4. The contribution of 14C AMS dating to the Greater Angkor archaeological project

    International Nuclear Information System (INIS)

    For well over five centuries, the Khmer kingdom ruled over a vast territory, including most of what is now known as Cambodia, Thailand, Vietnam and Laos. Between the 9th and 14th century AD, the Khmer Kings developed the Angkor area into a remarkable administrative and religious centre for their society. According to new estimates by the Greater Angkor Project, the entire urban complex of the capital city covered about 1000 square km making it probably the largest archaeological site in the world. Great stone temples and some other monumental structures and earthworks are the only visible remains of this fascinating civilisation. Thankfully, there is a substantial on-going multinational effort to preserve and restore what is left and in 1992 UNESCO (United Nations Educational Scientific and Cultural Organisation) declared Angkor a World Heritage Site. This paper presents two particular aspects of the Greater Angkor Project where radiocarbon dating by AMS specifically added to our knowledge of the history of this ancient capital city

  5. The use of AMS 14C dating to explore issues of occupation and demise at the medieval city of Angkor, Cambodia

    Science.gov (United States)

    Penny, Dan; Hua, Quan; Pottier, Christophe; Fletcher, Roland; Barbetti, Mike

    2007-06-01

    Angkorian temples are characterised by one or more encircling moats that are excavated into the alluvial substrate. As a key part of the overall design of the temple, the moats are important symbolically and are presumed to be contemporaneous with the associated temple. They also represent important depositional basins for sediment and other materials and can therefore yield vertical profiles of sediment that has accumulated since the moat was originally excavated. Unconformities in these moat profiles can be dated absolutely using small-sample, high-precision AMS radiocarbon techniques. These unconformities are likely to represent periodic re-excavation or maintenance of the moat and therefore indicate the presence of large, presumably centrally organised workforces. In some instances, presumed anthropogenic unconformities occur centuries after Angkor was supposedly abandoned. In this way, radiocarbon dates themselves are being used as a proxy indicator of cultural activity and are being used to challenge the historiography of Angkor's famous demise.

  6. The use of AMS 14C dating to explore issues of occupation and demise at the medieval city of Angkor, Cambodia

    International Nuclear Information System (INIS)

    Angkorian temples are characterised by one or more encircling moats that are excavated into the alluvial substrate. As a key part of the overall design of the temple, the moats are important symbolically and are presumed to be contemporaneous with the associated temple. They also represent important depositional basins for sediment and other materials and can therefore yield vertical profiles of sediment that has accumulated since the moat was originally excavated. Unconformities in these moat profiles can be dated absolutely using small-sample, high-precision AMS radiocarbon techniques. These unconformities are likely to represent periodic re-excavation or maintenance of the moat and therefore indicate the presence of large, presumably centrally organised workforces. In some instances, presumed anthropogenic unconformities occur centuries after Angkor was supposedly abandoned. In this way, radiocarbon dates themselves are being used as a proxy indicator of cultural activity and are being used to challenge the historiography of Angkor's famous demise

  7. Environmental changes in the western Amazonia: morphological framework, geochemistry, palynology and radiocarbon dating data

    Energy Technology Data Exchange (ETDEWEB)

    Horbe, Adriana M.C., E-mail: ahorbe@ufam.edu.b [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil). Dept. de Geociencias; Behling, Hermann [Georg August Universitaet Goettingen (Germany). Albrecht von Haller Institut fuer Pflanzenwissenschaften. Abteilung fuer Palynologie und Klimadynamik; Nogueira, Afonso C.R. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Inst. de Geociencias; Mapes, Russell [University of North Carolina, Chapel Hill, NC (United States). Dept. of Geological Science

    2011-09-15

    The sediments from the Coari lake, a 'terra firme' lake sculpted into Plio-Pleistocene deposits, and the Acara lake, a flooding-type lake developed on Quaternary sediments in the flood plain of the mid-Solimoes river, in the western Amazonia, Brazil, were studied to investigate the environmental condition of their developing. This study includes mineral composition, geochemistry, Pb isotope, palynology, radiocarbon-age and morphological framework of the lakes obtained from SRTM satellite images. The geological and the environmental conditions in the two lakes are highly variable and suggest that their evolution reflect autogenic processes under humid rain forest condition. Although kaolinite, quartz, muscovite, illite, and smectite are the main minerals in both lakes, the geochemistry indicates distinct source, the Acara lake sediments have higher concentrations of Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}, FeO, CaO, K{sub 2}O, MgO, Na{sub 2}O, P{sub 2}O{sub 5}, Ba, V, Cu, Ni, Zn, Pb, Sr, Li, Y and La and have more radiogenic Pb than the Coari lake sediments. The radiocarbon ages suggest that at 10160 yr BP the Coari lake started to be developed due to avulsion of the Solimoes river, and the Acara lake was formed by the meander abandonment of Solimoes river retaining its grass dominated shore at ca. 3710 yr BP. (author)

  8. Environmental changes in the western Amazonia: morphological framework, geochemistry, palynology and radiocarbon dating data

    International Nuclear Information System (INIS)

    The sediments from the Coari lake, a 'terra firme' lake sculpted into Plio-Pleistocene deposits, and the Acara lake, a flooding-type lake developed on Quaternary sediments in the flood plain of the mid-Solimoes river, in the western Amazonia, Brazil, were studied to investigate the environmental condition of their developing. This study includes mineral composition, geochemistry, Pb isotope, palinology, radiocarbon-age and morphological framework of the lakes obtained from SRTM satellite images. The geological and the environmental conditions in the two lakes are highly variable and suggest that their evolution reflect autogenic processes under humid rain forest condition. Although kaolinite, quartz, muscovite, illite, and smectite are the main minerals in both lakes, the geochemistry indicates distinct source, the Acara lake sediments have higher concentrations of Al2O3, Fe2O3, Fe O, Ca O, K2O, Mg O, Na2O, P2O5, Ba, V, Cu, Ni, Zn, Pb, Sr, Li, Y and La and have more radiogenic Pb than the Coari lake sediments. The radiocarbon ages suggest that at 10160 yr BP the Coari lake started to be developed due to avulsion of the Solimoes river, and the Acara lake was formed by the meander abandonment of Solimoes river retaining its grass dominated shore at ca. 3710 yr BP. (author)

  9. Environmental changes in the western Amazonia: morphological framework, geochemistry, palynology and radiocarbon dating data

    International Nuclear Information System (INIS)

    The sediments from the Coari lake, a 'terra firme' lake sculpted into Plio-Pleistocene deposits, and the Acara lake, a flooding-type lake developed on Quaternary sediments in the flood plain of the mid-Solimoes river, in the western Amazonia, Brazil, were studied to investigate the environmental condition of their developing. This study includes mineral composition, geochemistry, Pb isotope, palynology, radiocarbon-age and morphological framework of the lakes obtained from SRTM satellite images. The geological and the environmental conditions in the two lakes are highly variable and suggest that their evolution reflect autogenic processes under humid rain forest condition. Although kaolinite, quartz, muscovite, illite, and smectite are the main minerals in both lakes, the geochemistry indicates distinct source, the Acara lake sediments have higher concentrations of Al2O3, Fe2O3, FeO, CaO, K2O, MgO, Na2O, P2O5, Ba, V, Cu, Ni, Zn, Pb, Sr, Li, Y and La and have more radiogenic Pb than the Coari lake sediments. The radiocarbon ages suggest that at 10160 yr BP the Coari lake started to be developed due to avulsion of the Solimoes river, and the Acara lake was formed by the meander abandonment of Solimoes river retaining its grass dominated shore at ca. 3710 yr BP. (author)

  10. IBA analyses and lead concentration measurements of AMS-14C dated bones from two medieval sites in Italy

    International Nuclear Information System (INIS)

    AMS (accelerator mass spectrometry) radiocarbon dated human bone samples recovered in the deserted medieval village of Quattro Macine, Lecce, in Southern Italy, were analyzed by PIXE (particle induced X-ray emission) and PIGE (particle induced gamma ray emission). The optimization of the PIXE-PIGE experimental set-up in term of beam energy and detection geometry resulted in the possibility to obtain information about major, minor and trace elements of the samples. Unexpectedly, all the analyzed samples showed a Pb concentration higher than 50 ppm. Two possible explanations of the measured high Pb concentration are discussed in the paper: the pre-mortem intake associated with the use of Pb-rich glazed pottery and the post-mortem intake from soil as the result of diagenetic processes

  11. Preparing and measuring ultra-small radiocarbon samples with the ARTEMIS AMS facility in Saclay, France

    Energy Technology Data Exchange (ETDEWEB)

    Delque-Kolic, E., E-mail: emmanuelle.delque-kolic@cea.fr [LMC14, CEA Saclay, Batiment 450 Porte 4E, 91191 Gif sur Yvette (France); Comby-Zerbino, C.; Ferkane, S.; Moreau, C.; Dumoulin, J.P.; Caffy, I.; Souprayen, C.; Quiles, A.; Bavay, D.; Hain, S.; Setti, V. [LMC14, CEA Saclay, Batiment 450 Porte 4E, 91191 Gif sur Yvette (France)

    2013-01-15

    The ARTEMIS facility in Saclay France measures, on average, 4500 samples a year for French organizations working in an array of fields, including environmental sciences, archeology and hydrology. In response to an increasing demand for the isolation of specific soil compounds and organic water fractions, we were motivated to evaluate our ability to reduce microgram samples using our standard graphitization lines and to measure the graphite thus obtained with our 3MV NEC Pelletron AMS. Our reduction facility consists of two fully automated graphitization lines. Each line has 12 reduction reactors with a reduction volume of 18 ml for the first line and 12 ml for the second. Under routine conditions, we determined that we could reduce the samples down to 10 {mu}g of carbon, even if the graphitization yield is consequently affected by the lower sample mass. Our results when testing different Fe/C ratios suggest that an amount of 1.5 mg of Fe powder was ideal (instead of lower amounts of catalyst) to prevent the sample from deteriorating too quickly under the Cs+ beam, and to facilitate pressing procedures. Several sets of microsamples produced from HOxI standard, international references and backgrounds were measured. When measuring {sup 14}C-free wood charcoal and HOxI samples we determined that our modern and dead blanks, due to the various preparation steps, were of 1.1 {+-} 0.8 and 0.2 {+-} 0.1 {mu}g, respectively. The results presented here were obtained for IAEA-C1, {sup 14}C-free wood, IAEA-C6, IAEA-C2 and FIRI C.

  12. Age validation of canary rockfish (Sebastes pinniger) using two independent otolith techniques: lead-radium and bomb radiocarbon dating.

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, A H; Kerr, L A; Cailliet, G M; Brown, T A; Lundstrom, C C; Stanley, R D

    2007-11-04

    Canary rockfish (Sebastes pinniger) have long been an important part of recreational and commercial rockfish fishing from southeast Alaska to southern California, but localized stock abundances have declined considerably. Based on age estimates from otoliths and other structures, lifespan estimates vary from about 20 years to over 80 years. For the purpose of monitoring stocks, age composition is routinely estimated by counting growth zones in otoliths; however, age estimation procedures and lifespan estimates remain largely unvalidated. Typical age validation techniques have limited application for canary rockfish because they are deep dwelling and may be long lived. In this study, the unaged otolith of the pair from fish aged at the Department of Fisheries and Oceans Canada was used in one of two age validation techniques: (1) lead-radium dating and (2) bomb radiocarbon ({sup 14}C) dating. Age estimate accuracy and the validity of age estimation procedures were validated based on the results from each technique. Lead-radium dating proved successful in determining a minimum estimate of lifespan was 53 years and provided support for age estimation procedures up to about 50-60 years. These findings were further supported by {Delta}{sup 14}C data, which indicated a minimum estimate of lifespan was 44 {+-} 3 years. Both techniques validate, to differing degrees, age estimation procedures and provide support for inferring that canary rockfish can live more than 80 years.

  13. Radiocarbon dating of organic compounds in sediments using preparative capillary gas chromatography (PCGC)

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, Masao [Japan Marine Science and Technology Center, Yokosuka, Kanagawa (Japan); Shibata, Yasuyuki; Yoneda, Minoru; Mukai, Hitoshi; Tanaka, Atsushi; Uehiro, Takashi; Morita, Masatoshi [National Inst. for Environmental Studies, Tsukuba, Ibaraki (Japan); Kawamura, Kimitaka [Hokkaido Univ., Sapporo (Japan); Hirota, Masashi [National Inst. for Environmental Studies, Tsukuba, Ibaraki (Japan)

    2001-02-01

    CG-AMS system, combining two-dimensional gas chromatography and accelerator mass spectroscopy, has been developed for compound-specific carbon 14 measurement. Samples from shallow sea sediments in Sanbanse, Tokyo bay ware collected, six typical fatty acids were separated therefrom. Ages were estimated from the carbon 14 measurement. Acids of carbon number 15 and 16 has nearly contemporary age, whereas acids of carbon number 22 has age of 17000 years. (A. Yamamoto)

  14. The effects of cultivation on the organic matter of total soil and in the different soil particle size separates using radiocarbon dating

    International Nuclear Information System (INIS)

    The effects of cultivation on the organic matter and nutrients in the total soil and in five particle size separates were studied through chemical analyses and radiocarbon dating. Samples were taken from the A and B horizons of an uncultivated field and of fields cultivated during 5,60 and 90 years which had never received treatment with fertilizers. (M.A.)

  15. Radiocarbon dating of palaeosol components in moraines in Lapland, northern Sweden

    Science.gov (United States)

    Hormes, Anne; Karlén, Wibjörn; Possnert, Göran

    2004-10-01

    Accurate geochronologies are the key for comparison of palaeoclimate records. In order to clarify problems concerning the geochronology of glacier fluctuations we dated palaeosols in moraines in the Kebnekaise mountain region of Swedish Lapland. These palaeosols already have been dated several years ago using bulk samples of the palaeosols and yielded ages of 6180-5790 and 2750-2100 cal yr BP. In an attempt to evaluate the sources of contamination associated with bulk samples these soils were re-dated by using Coleoptera fragments, Cenococcum geophilum spores, humic acids and woody plant tissues. The new dates reveal that the two palaeosols found within the moraines represent much longer periods of time than was previously assumed. Soil formation periods can be distinguished for periods 7800-7580, 6300-4080, 2450-2000 and 1170-740 cal yr BP. These age groups point to differentiated soil formation processes, resedimentation, bioturbation and/or cryoturbation. The results show that dated terrestrial macrofossils from glacial moraines indicate climate changes that are in accordance with other proxy records in northern and central Scandinavia and in certain times off-phase with glacier fluctuations in southern maritime Norway. This throws light on possible changing interaction of forcing factors during the Holocene.

  16. Radiocarbon datings and glacial striae from the innar part of Boknfjord area, South Norway

    International Nuclear Information System (INIS)

    Whale bones overlain by moraine at Borgoey island have been dated to 12,380+-150 B.P. At Tveit, further east, whale bones overlain by littoral material were dated to 11,970+-100 B.P. These datings, together with the glacial striae in the area, show that Borgoe was covered by ice during a glacial advance at about Older Dryas Chronozone, while Tveit was not, and that a calving bay existed in the inner part of the Boknfjord area at the same time. At the mouth of Vindafjord, east of Tveit, and 3-4 km outside terminal moraines of Younger Dryas age, shells overlain by ground moraine were dated to 11,630+-100 B.P. This shows that the ice front in an early phase of the Younger Dryas glacial advance was situated at least 3-4 km beyond the pronounced Ra moraines in Vindafjord. The main trend of the shore line displacement between 12,000 and 9,500 B.P., based upon the whale bones and earlier investigations, can be established. (Auth.)

  17. A chronology of the PY608E-PC sediment core (Lake Pumoyum Co, southern Tibetan Plateau) based on radiocarbon dating of total organic carbon

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Takahiro, E-mail: twatanabe@geo.kankyo.tohoku.ac.jp [Graduate School of Environmental Studies, Tohoku University, 6-6-20 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579 (Japan); Graduate School of Science, Tohoku University, 6-3 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8578 (Japan); Nakamura, Toshio [Center for Chronological Research, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601 (Japan); Matsunaka, Tetsuya [School of Marine Science and Technology, Tokai University, 3-20-1 Orido, Shimizu, Shizuoka 424-0902 (Japan); Nara, Fumiko Watanabe [Graduate School of Science, Tohoku University, 6-3 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8578 (Japan); Zhu Liping; Wang Junbo [Institute of Tibetan Plateau Research, Chinese Academy of Science, No. 18 Shuangqing Road, Haidian District, Beijing 100085 (China); Kakegawa, Takeshi [Graduate School of Science, Tohoku University, 6-3 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8578 (Japan); Nishimura, Mitsugu [School of Marine Science and Technology, Tokai University, 3-20-1 Orido, Shimizu, Shizuoka 424-0902 (Japan)

    2013-01-15

    Paleoclimatic records from the Tibetan Plateau provide important clues for understanding the Asian monsoon and Asian climate systems. To reconstruct climatic and environmental changes in the southern Tibetan Plateau, a 3.77-m-long sediment core (PY608E-PC) was taken from the southeastern part of Lake Pumoyum Co in August 2006. Because terrestrial plant residues are extremely rare in this core, we performed radiocarbon dating on the total organic carbon fraction. We also estimated the old carbon effect and radiocarbon reservoir age of the total organic carbon fraction. Using these estimates, we propose a new radiocarbon chronology for past climatic changes from ca. 12,500 to 700 cal BP. The linear sedimentation rate of the core was founded to be constant at 32.0 cm/kyr, indicating stable sedimentation conditions in Lake Pumoyum Co from the period of the Younger Dryas to the Holocene.

  18. Inland Ertebølle Culture: the importance of aquatic resources and the freshwater reservoir effect in radiocarbon dates from pottery food crusts

    Directory of Open Access Journals (Sweden)

    Bente Philippsen

    2014-11-01

    Full Text Available The Ertebølle culture is a late Mesolithic hunter-gatherer-fisher culture in southern Scandinavia, northern Germany and Poland. Archaeological finds as well as scientific analyses of humans and their artefacts indicate the great importance of aquatic resources, both marine and freshwater, to Ertebølle subsistence. In northern Germany, modern freshwater fish samples can have very high apparent radiocarbon ages (up to 3000 years. If such dramatic 'freshwater reservoir effects' also existed during the late Mesolithic, they could lead to artificially old radiocarbon dates for the bones of Ertebølle humans and domestic dogs, and for carbonised food crusts on cooking pots. Conversely, if we can demonstrate radiocarbon age 'offsets' in such samples, we can often attribute them to the exploitation of freshwater food resources. This article discusses methods of identifying freshwater resources in prehistoric pottery, including radiocarbon reservoir effects. We consider the results of radiocarbon, stable isotope and elemental analyses of food crusts on prehistoric pottery from four sites in the Alster and Trave valleys: Kayhude, Schlamersdorf, Bebensee and Seedorf.

  19. Qualitative application based on IR spectroscopy for bone sample quality control in radiocarbon dating

    International Nuclear Information System (INIS)

    Bone samples suffer from contamination and deterioration, depending on their conservation state and previous restoration and consolidation processes. The sample preparation laboratory of the CEDAD (Center for Dating and Diagnostics) of University of Lecce is developing a quality control protocol for bone samples based on Fourier transform infrared (FTIR) spectroscopy to identify the presence of collagen in bone samples and to assess its quality. FTIR measurements were carried out on collagen extracted from many ancient samples dated at CEDAD. Efforts to shift the FTIR quality control test from the filtration step to a check-in treatment are proceeding to optimize the time for preparation and to reduce the overall turnaround time. A standard fast demineralization treatment was set up and applied to a variety of ancient samples of different origin and age

  20. Qualitative application based on IR spectroscopy for bone sample quality control in radiocarbon dating

    Science.gov (United States)

    Gianfrate, G.; D'Elia, M.; Quarta, G.; Giotta, L.; Valli, L.; Calcagnile, L.

    2007-06-01

    Bone samples suffer from contamination and deterioration, depending on their conservation state and previous restoration and consolidation processes. The sample preparation laboratory of the CEDAD (Center for Dating and Diagnostics) of the University of Lecce is developing a quality control protocol for bone samples based on Fourier transform infrared (FTIR) spectroscopy to identify the presence of collagen in bone samples and to assess its quality. FTIR measurements were carried out on collagen extracted from many ancient samples dated at CEDAD. Efforts to shift the FTIR quality control test from the filtration step to a check-in treatment are proceeding to optimize the time for preparation and to reduce the overall turnaround time. A standard fast demineralization treatment was set up and applied to a variety of ancient samples of different origin and age.

  1. Radiocarbon dates of the medieval period stone anchors from Dabhol, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Sundaresh; Tripati, S.; Vora, K.H.

    dredging operation in Dabhol creek. the anchors are lying in front of the Cus- tom Office of Dabhol. One of the anchors had wooden fluke remains in the holes, which were removed and kept safely by an active social worker at Dabhol. These anchors.... The calibrated date of the first sam- ple ranged between 654 and 524 yrs BP, and the second sample ranged between 653 and 537 yrs BP (Table 2). Discussion The discovery of anchors from the Dab- hol creek is one of the significant find- ings to support...

  2. Investigations on alluvial deposits through borehole stratigraphy, radiocarbon dating and passive seismic technique (Carnic Alps, NE Italy)

    Science.gov (United States)

    Viero, Alessia; Marchi, Lorenzo; Cavalli, Marco; Crema, Stefano; Fontana, Alessandro; Mozzi, Paolo; Venturini, Corrado

    2016-04-01

    Alluvial sediment investigations provide fundamental tools to infer the processes that control geomorphological evolution of mountain environments. By analyzing sediment stratigraphy in depth, it is possible to retrieve the source, the geology, the time of deposition, the relative distance travelled by material as well as to distinguish among different type of transport (i.e., gravitational, fluvial or glacial). In this work, we present a combination of log stratigraphy, radiocarbon dating and geophysical surveys carried out on the valley floor of the But River (Carnic Alps, North East Italy). The But River basin drains an area of 326 km2 with a range in elevation from 2769 to 323 m a.s.l.; the bedrock mainly consists of carbonates and quartz arenites with minor inclusions of effusive rocks. After Pleistocene the gravitational deposits from mountain slopes have impounded the But River several times. In particular, we analyzed a sector of the upper portion of the But valley close to the confluence of the Moscardo Torrent, frequently affected by debris flows. A borehole was drilled in the But River floodplain, at the intersection with the Moscardo Torrent alluvial fan, down to a depth of 80 m. The analysis of the core samples allowed discerning three sedimentary levels rich in clay and organic materials, which testify the presence of small dam lakes, originated from the Moscardo debris-flow deposits. Three samples of wood and plant debris were collected from 13, 14 and 23 m of depth, respectively. They were analyzed through radiocarbon dating in order to determine the age of the lakes and, thus, to infer the activity of the debris flows building the Moscardo cone. The calibrated ages of the 3 samples are close to the younger limit of the radiocarbon method indicating a fast aggradation of the valley floor, starting from a period ranging between 1450 - 1632 AD. Historical maps and documents confirm the presence of the lakes until 19th century and they permit to assess

  3. Developments in radiocarbon calibration for archaeology

    NARCIS (Netherlands)

    Ramsey, Christopher Bronk; Buck, Caitlin E.; Manning, Sturt W.; Reimer, Paula; van der Plicht, Hans

    2006-01-01

    This update on radiocarbon calibration results from the 19th International Radiocarbon Conference at Oxford in April 2006, and is essential reading for all archaeologists. The way radiocarbon dates and absolute dates relate to each other differs in three periods: back to 12400 cal BR radiocarbon dat

  4. Ancient Mtdna Sequences And Radiocarbon Dating Of Human Bones From The Chalcolithic Caves Of Wadi El-Makkukh.

    Science.gov (United States)

    Salamon, M.; Tzur, S.; Arensburg, B.; Zias, J.; Nagar, Y.; Weiner, S.; Boaretto, E.

    DNA from fossil human bones can provide valuable information for understanding intra- and inter-population relationships. Using the DNA preserved inside crystal aggregates from human fossil bones containing relatively large amounts of collagen, we demonstrate the presence of reproducible mtDNA control region sequences. Radiocarbon dates from each bone show that the burial caves were used for up to 600 years during the Chalcolithic period (5th-4th millennium BP). A comparison of the ancient DNA sequences with modern mtDNA databases indicates that all samples can most likely be assigned to the R haplogroup sub-clades, which are common in West-Eurasia. In four cases more precise and confident haplogroup identifications could be achieved (H, U3a and H6). The H haplogroup is present in three out of the four assigned ancient samples. This haplogroup is prevalent today in West - Eurasia. The results reported here tend to genetically link this Chalcolithic group of individuals to the current West Eurasian populations.

  5. Chronology of cholelithiasis. Dating gallstones from atmospheric radiocarbon produced by nuclear bomb explosions

    International Nuclear Information System (INIS)

    We investigated the natural history of cholelithiasis in 59 samples of stones from the gallbladder or common bile duct in 15 patients, using as a tracer for the timing of stone formation the 14C released into the environment during nuclear weapons testing. The ages of the stones were correlated with the dates of onset of symptoms and with other clinical data. None of 11 symptomatic patients had symptoms or complications until at least two years (mean +/- SD, 8.0 +/- 5.1 years) after stone formation began. There was a lag time of 11.7 +/- 4.6 years between initial stone formation and cholecystectomy. The growth rates of stones from 11 symptomatic patients and 4 asymptomatic patients were similar (2.6 +/- 1.4 and 2.6 +/- 1.1 mm per year). Studies of two stones retrieved from the common bile duct showed that one had the same age as a cholecystic stone; the other, removed two years after cholecystectomy, apparently grew in the common bile duct. The long latency period between the formation of gallstones and the onset of symptoms indicates that interruption of the natural progression of gallstone disease is potentially possible with medical therapy

  6. AMS14C dating and stable isotope plots of Late Pleistocene ice-wedge ice

    International Nuclear Information System (INIS)

    Strategy for AMS14C dating of organic micro inclusions from syngenetic ice-wedge ice is considered. AMS14C dates are interpreted in terms of fictitious aging of ice-wedge and permafrost sediments due to high concentration of allochthonous organic material. The dating of organic material from small sample, gives the reliable 14C age. The 14C dates from syngenetic ice-wedges are compared with the dates of the host sediments surrounding syngenetic ice wedges. AMS14C dating of small samples of ice-wedge ice yields to set δ18O plots from ice-wedges to the time scale and to correlate them with ice core δ18O record

  7. THE EFFECTS OF POSSIBLE CONTAMINATION ON THE RADIOCARBON DATING OF THE DEAD SEA SCROLLS II: EMPIRICAL METHODS TO REMOVE CASTOR OIL AND SUGGESTIONS FOR REDATING

    OpenAIRE

    Rasmussen, Kaare Lund; Van der Plicht, Johannes; Doudna, Gregory; Nielsen, Frederik; Hojrup, Peter; Stenby, Erling Halfdan; Pedersen, Carl Th; Højrup, Peter

    2009-01-01

    While kept at the Rockefeller Museum in East Jerusalem, many Dead Sea Scroll fragments were exposed to castor oil by the original team of editors in the course of cleaning the parchments. Castor oil must be regarded as a serious contaminant in relation to radiocarbon dating. If modern castor oil is present and is not removed prior to dating, the (14)C dates will be skewed artificially towards modern values. In Rasmussen et al. (2001), it was shown that the standard AAA pretreatment procedure ...

  8. AMS-dating of Late Pleistocene and Holocene syngenetic ice-wedges

    International Nuclear Information System (INIS)

    We discuss the 14C dating (both conventional and AMS) of Siberian permafrost sediments and ice-wedge ice. Direct dating of Late Pleistocene and Holocene syngenetic ice-wedges was done on organic material included in the ice. The time of ice formation (in 14C years) is 21,000-14,000 BP for Seyaha, and 7100 BP for Shchuch'ya. The AMS dates show that the ice-wedges stratification is normal, i.e., the older ice is located below the younger. The 14C dates yield for the first time a timescale (in 14C years) for paleoclimatic indicators (oxygen and hydrogen isotope ratios from the ice)

  9. Carbon isotopes: variations of their natural abundance. Application to correction of radiocarbon dates, to the study of plant metabolism and to paleoclimate

    International Nuclear Information System (INIS)

    The radiocarbon activity of contemporaneous samples shows: i) variations in the specific activity of the atmospheric C14, which varies with time and locality. ii) variations due to isotope discrimination, or fractionation, of the carbon isotope ratio during the fixation of carbon by organic or inorganic matter. The variation in the atmospheric concentration of carbon 14 as observed in tree rings are synchronous and of the same amplitude for both hemispheres (southern and northern). A curve for correction of radiocarbon dates of the southern hemisphere is given for the last 500 years. The activity of atmospheric radiocarbon as measured in tree rings varies with latitude, showing a difference of (4.5+-1) per mille between the northern and southern hemispheres, the latter having lower concentration of radiocarbon, equivalent to an age difference of about 35 years. This variation can be explained by a larger exchange of carbon 14 between the atmosphere and the sea in the southern hemisphere to a larger free ocean surface (40%) and a higher agitation by winds. The main differences of the isotope fractionation by different types of plants are correlated to their photosynthetic pathways and thus to the enzyme which effects the primary fixation of carbon. The delta C13 values can be used as basis of a paleoclimate indicator

  10. Coastal rainforest boundary dynamics during the late Holocene in monsoonal Australia: evidence from radiocarbon dates of abandoned nests of Orange-footed Scrubfowl

    International Nuclear Information System (INIS)

    The late Holocene history of monsoon rainforest retreat was explored by radiocarbon dating abandoned Orange-footed Scrubfowl (Megapodius reinwardt Gaimard) nests in coastal savannas in the Northern Territory of Australia. Previous work has demonstrated that in savanna environments this rainforest bird can not build nor maintain the large heaps of soil and leaf litter that it uses for nests. Excavations of two earthen mounds in a savanna habitat verified that they were abandoned Scrubfowl nests, and not Aboriginal middens, given their lack of stratigraphy, non-sequential dating of charcoal in a vertical profile, and absence of archaeological material. Radiocarbon dates of material taken from the surface of abandoned nests were determined for three sites on the coast of the Northern Territory. These analyses revealed that for all three sites, rainforests have contracted within the last 1800 years BP. On Elcho Island an abandoned nest was found to contain the land snail Xanthomelon spheroidea Le Guillou (known to prefer rainforest habitat) with a modern radiocarbon age, suggesting recent contraction of rainforest. The results of this study further weaken the theory that Aboriginal burning was a major cause of rain forest fragmentation in the monsoon tropics, and possibly elsewhere in Australia

  11. Coastal rainforest boundary dynamics during the late Holocene in monsoonal Australia: evidence from radiocarbon dates of abandoned nests of Orange-footed Scrubfowl

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, D.M.J.S.; Panton, W.J. [Parks and Wildlife Commission of the Northern Territory, Darwin, NT (Australia); Head, J. [Australian National Univ, Canberra, ACT (Australia). Quaternary Dating Research Centre

    1997-12-31

    The late Holocene history of monsoon rainforest retreat was explored by radiocarbon dating abandoned Orange-footed Scrubfowl (Megapodius reinwardt Gaimard) nests in coastal savannas in the Northern Territory of Australia. Previous work has demonstrated that in savanna environments this rainforest bird can not build nor maintain the large heaps of soil and leaf litter that it uses for nests. Excavations of two earthen mounds in a savanna habitat verified that they were abandoned Scrubfowl nests, and not Aboriginal middens, given their lack of stratigraphy, non-sequential dating of charcoal in a vertical profile, and absence of archaeological material. Radiocarbon dates of material taken from the surface of abandoned nests were determined for three sites on the coast of the Northern Territory. These analyses revealed that for all three sites, rainforests have contracted within the last 1800 years BP. On Elcho Island an abandoned nest was found to contain the land snail Xanthomelon spheroidea Le Guillou (known to prefer rainforest habitat) with a modern radiocarbon age, suggesting recent contraction of rainforest. The results of this study further weaken the theory that Aboriginal burning was a major cause of rain forest fragmentation in the monsoon tropics, and possibly elsewhere in Australia.

  12. Groundwater dating with radiocarbon: application to an aquifer under semi-arid conditions in the south of Morocco (Guelmime).

    Science.gov (United States)

    Bouhlassa, S; Aiachi, A

    2002-04-01

    Radiocarbon dating is based on measuring the loss of the parent radionuclide (14C) in a given sample. This assumes two key features of the system. The first is that the initial concentration of the parent is known and has remained constant in the past. The second is that the system is closed to subsequent gains or losses of the parent, except through radioactive decay. But, the reaction and evolution of the carbonate system strongly dilute the initial 14C activity in dissolved inorganic carbon (DIC). The result is an artificial "aging" of groundwater by dilution of 14C. Unravelling the relevant processes and distinguishing 14C decay from 14C dilution is an engaging geochemical problem. Several attempts to overcome these problems have been made during the past 30 years and a number of possible correction procedures have been presented by different authors. Environmental isotopes study (13C, 14C) from the aquifers of the Guelmime under semi-arid conditions provides new information on recharge zones, mixing zones and the circulation routes of water. The combination of logP(CO2), the saturation index of dolomite and calcite, HCO3, delta13C, 14C and pH along flow paths can provide an indication of open- and closed-system conditions in the Oumlaachar and Seyyad sub-basins. This approach of geochemical analysis, when combined with correction procedures, allows us to understand age and recharge in the Guelmime aquifer. 14C groundwater ages range from modern to about 2700 years in this aquifer, and indicate recharge values of 0.55-15 mm/yr. PMID:11999164

  13. Groundwater dating with radiocarbon: application to an aquifer under semi-arid conditions in the south of Morocco (Guelmime)

    International Nuclear Information System (INIS)

    Radiocarbon dating is based on measuring the loss of the parent radionuclide (14C) in a given sample. This assumes two key features of the system. The first is that the initial concentration of the parent is known and has remained constant in the past. The second is that the system is closed to subsequent gains or losses of the parent, except through radioactive decay. But, the reaction and evolution of the carbonate system strongly dilute the initial 14C activity in dissolved inorganic carbon (DIC). The result is an artificial 'aging' of groundwater by dilution of 14C. Unravelling the relevant processes and distinguishing 14C decay from 14C dilution is an engaging geochemical problem. Several attempts to overcome these problems have been made during the past 30 years and a number of possible correction procedures have been presented by different authors. Environmental isotopes study (13C, 14C) from the aquifers of the Guelmime under semi-arid conditions provides new information on recharge zones, mixing zones and the circulation routes of water. The combination of logPCO2, the saturation index of dolomite and calcite, HCO3-, δ13C, 14C and pH along flow paths can provide an indication of open- and closed-system conditions in the Oumlaachar and Seyyad sub-basins. This approach of geochemical analysis, when combined with correction procedures, allows us to understand age and recharge in the Guelmime aquifer. 14C groundwater ages range from modern to about 2700 years in this aquifer, and indicate recharge values of 0.55-15 mm/yr

  14. Dating of Rattus exulans and bird bone from Pleasant River (Otago, New Zealand) : radiocarbon anomalies from diet

    International Nuclear Information System (INIS)

    Radiocarbon ages of Rattus exulans bone recovered from the Pleasant River, Otago, archaeological site were originally rejected on the basis of 14C variability allegedly caused by laboratory processing. Subsequent work revealed no burial contaminant that could have affected the results on bone protein as processed. We present the analysis of bone from seven bird species at the Pleasant River site, which showed that marshland fowl also had up to 300 yr radiocarbon variation in their ages, but maintained terrestrial-range δ13C and δ15N values. The apparent dietary effect that offsets marshland fowl 14C ages at Pleasant River suggested there was a similar, diet-based cause for the anomalous radiocarbon ages for some R. exulans at the site, rather than a laboratory contamination or processing effect. (author). 32 refs., 1 fig., 1 tab

  15. Radiocarbon dates of the Iron Age hillfort of O Achadizo (Boiro, A Coruña, NW Iberia: an approach to the dating of marine shells

    Directory of Open Access Journals (Sweden)

    Rubinos Pérez, Antonio

    1999-06-01

    Full Text Available The excavation of the hillfort of O Achadizo has brought to light several domestic structures intermingled with rubish heaps, belonging to the Iron Age Castro culture of NW Iberia. The abundant organic remains have constituted the basis for a systematic programme of radiocarbon dating of the different stratigraphic levels, which shows that the main occupation of the site took place between the VI and the II centuries cal. BC. Moreover, we have checked the 14C dates obtained from terrestrial samples (bones and charcoal against those made on marine shells coming from the same strata. As a result, we have found that the latter have an apparent age of 316±I9 years, caused by the reservoir effect. Therefore, we stress the need for taking into account -and correcting whenever possible- such a deviation before using samples of marine origin for chronological purposes.

    La excavación del castro de O Achadizo (Boiro, A Coruña puso al descubierto una serie de estructuras domésticas, así como varios basureros, encuadrables todos ellos dentro de la cultura castreña del Noroeste ibérico. El hecho de poder disponer de una gran cantidad de material orgánico procedente de los distintos niveles de habitación ha permitido llevar a cabo un programa sistemático de datación mediante el radiocarbono. Como resultado de los análisis radiométricos se deduce que la principal ocupación del yacimiento tuvo lugar entre los siglos VI al II cal BC. Por otra parte hemos cotejado las dataciones obtenidas sobre muestras con la misma procedencia estratigráfica, de origen terrestre (huesos y carbones y oceánico (conchas, a fin de evaluar el efecto de reserva marina. El valor medio de la edad aparente de las conchas de O Achadizo (316 ±19 es semejante al calculado para la costa portuguesa y subraya la necesidad de efectuar una corrección de las dataciones hechas sobre material orgánico de origen marino.

  16. The necessity of sample quality assessment in 14C AMS dating: The case of Cova des Pas (Menorca - Spain)

    International Nuclear Information System (INIS)

    The Cova des Pas cave is a karstic cave in the cliffs of the Barranc (canyon) de Trebaluger. It is a small cave only 6.5 m deep, 4.5 m wide and 1.7 m high. Yet more than 70 burials, in foetal position, from the Early Iron Age were found in this small cave. The conservation of the archaeological remains was very unusual. Not only wood, ropes and other plant material was found, but also remains of body tissue, hair and leather. In spite of the remarkable preservation of the bodies and artefacts, the state of conservation of the bone material was very bad. The bones contained little and heavily deteriorated collagen and the organic plant material was very fragile. The special environmental conditions of the cave are the cause of these unusual preservation conditions. Although the cave is situated in a limestone cliff, the soil of the cave is very acid. Unexpectedly bad sample quality seemed to be the major drawback for AMS radiocarbon dating on hair, wood, ropes and bone collagen, as well as on bio-apatite.

  17. Radiocarbon dating of charred human bone remains preserved in urns excavated from medieval Buddhist cemetery in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Toshio, E-mail: nakamura@nendai.nagoya-u.ac.j [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Sagawa, Shinichi; Yamada, Tetsuya [Gangoji Institute for Research of Cultural Properties, Nakain, Nara 630-8392 (Japan); Kanehara, Masaaki [School of Science Education, Nara University of Education, Takabatake, Nara 630-8528 (Japan); Tsuchimoto, Norio [Ichinomiya City Museum, Yamato, Ichinomiya 491-0922 (Japan); Minami, Masayo [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Omori, Takayuki [Graduate School of Environmental Studies, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Okuno, Mitsuru [Faculty of Science, Fukuoka University, Jonan, Fukuoka 814-0180 (Japan); Ohta, Tomoko [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan)

    2010-04-15

    For a preliminary test of {sup 14}C dating of cremated human remains, we have collected charred bone and wood-charcoal fragments from cremated remains contained in cinerary urns that had been excavated from medieval Buddhist cemetery at the Hoenji temple in Aichi prefecture, central Japan. More than 230 urn vessels were discovered from the excavated area of ca. 14 m wide and 14 m long. The identification of charred bone or charcoal fragments among the remains was performed by observation of surface appearance, inspection of fine structures by a microscope, bubble formation during the HCl treatments in preparing target material for AMS {sup 14}C dating, carbon and nitrogen contents, delta{sup 13}C and delta{sup 15}N values of the fragments. All {sup 14}C ages obtained for the samples that were identified as charred bone remains were almost consistent with the archeological age estimated based on typological analysis of respective urns. On the other hand, some {sup 14}C ages for the remains identified as wood charcoal, which had been produced from firewood or a wooden coffin during the cremation, were not consistent with archeological estimation, shifting toward older {sup 14}C ages, most probably as the result of old wood effect.

  18. Radiocarbon dating of charred human bone remains preserved in urns excavated from medieval Buddhist cemetery in Japan

    International Nuclear Information System (INIS)

    For a preliminary test of 14C dating of cremated human remains, we have collected charred bone and wood-charcoal fragments from cremated remains contained in cinerary urns that had been excavated from medieval Buddhist cemetery at the Hoenji temple in Aichi prefecture, central Japan. More than 230 urn vessels were discovered from the excavated area of ca. 14 m wide and 14 m long. The identification of charred bone or charcoal fragments among the remains was performed by observation of surface appearance, inspection of fine structures by a microscope, bubble formation during the HCl treatments in preparing target material for AMS 14C dating, carbon and nitrogen contents, δ13C and δ15N values of the fragments. All 14C ages obtained for the samples that were identified as charred bone remains were almost consistent with the archeological age estimated based on typological analysis of respective urns. On the other hand, some 14C ages for the remains identified as wood charcoal, which had been produced from firewood or a wooden coffin during the cremation, were not consistent with archeological estimation, shifting toward older 14C ages, most probably as the result of old wood effect.

  19. Laser AMS 14C dating of rock surface accretions

    International Nuclear Information System (INIS)

    Full text: Equipment has been purchased using a large Earth Sciences and Engineering ARC grant and installed in the Department of Anthropology and Archaeology, James Cook University. A krypton-ion laser used initially at Laval University, Quebec to demonstrate the potential of focusing light energy to induce oxidation of carbon-bearing substances has been replaced by a carbon dioxide laser. This decision was based on reducing the startup cost at James Cook University, increasing options for a wide range of output power, considerations for future applications and the cost of gas refills. A disadvantage of using the carbon dioxide laser is that non-visible light optics are needed because of the infrared output wavelength from the carbon dioxide. This has required the replacement of the glass window of the vacuum-tight micro-combustion chamber with a sodium chloride window and placing the equipment in a dehumidifier room. Laser light power experiments have so far been conducted on optimising the output from the laser and minimising the focal waist of the beam by adjusting the focusing mirrors and lenses. The aim of developing a focused laser system is to enable the dating of carbon in finely laminated rock surface accretions, but before this can be achieved a series of tests is planned to ensure that the focused laser system totally converts all the carbon-bearing substances under the beam into carbon dioxide. This is essential in order that the isotopic values representative of the carbon in the accretions is converted into carbon dioxide. Known quantities of graphite, charcoal, wood cellulose and calcium oxalate salts are being subjected to focused laser combustion or decomposition and the volumes of gas produced at different light powers are being measured. Isotopic measurements are also being conducted on the resulting gases to ensure that fractionation of carbon isotopes is not a problem. The paper will describe the arrangement of equipment and explain the

  20. Redundant 230Th/ 234U/ 238U, 231Pa/ 235U and 14C dating of fossil corals for accurate radiocarbon age calibration

    Science.gov (United States)

    Chiu, Tzu-Chien; Fairbanks, Richard G.; Mortlock, Richard A.; Cao, Li; Fairbanks, Todd W.; Bloom, Arthur L.

    2006-09-01

    230Th/ 234U/ 238U dating of fossil corals by mass spectrometry is remarkably precise, but some samples exposed to freshwater over thousands of years may gain and/or lose uranium and/or thorium and consequently yield inaccurate ages. Although a δ 234U initial value equivalent to modern seawater and modern corals has been an effective quality control criterion, for samples exposed to freshwater but having δ 234U initial values indistinguishable from modern seawater and modern corals, there remains a need for additional age validation in the most demanding applications such as the 14C calibration (Fairbanks et al., 2005. Radiocarbon calibration curve spanning 0 to 50,000 years BP based on paired 230Th/ 234U/ 238U and 14C dates on pristine corals. Quaternary Science Reviews 24(16-17), 1781-1796). In this paper we enhance screening criteria for fossil corals older than 30,000 years BP in the Fairbanks0805 radiocarbon calibration data set (Fairbanks et al., 2005) by measuring redundant 230Th/ 234U/ 238U and 231Pa/ 235U dates via multi-collector magnetic sector inductively coupled plasma mass spectrometry (MC-MS-ICPMS) using techniques described in Mortlock et al. (2005. 230Th/ 234U/ 238U and 231Pa/ 235U ages from a single fossil coral fragment by multi-collector magnetic-sector inductively coupled plasma mass spectrometry. Geochimica et Cosmochimica Acta 69(3), 649-657.). In our present study, we regard paired 231Pa/ 235U and 230Th/ 234U/ 238U ages concordant when the 231Pa/ 235U age (±2 σ) overlaps with the associated 230Th/ 234U/ 238U age (±2 σ). Out of a representative set of 11 Fairbanks0805 (Fairbanks et al., 2005) radiocarbon calibration coral samples re-measured in this study, nine passed this rigorous check on the accuracy of their 230Th/ 234U/ 238U ages. The concordancy observed between 230Th/ 234U/ 238U and 231Pa/ 235U dates provides convincing evidence to support closed system behavior of these fossil corals and validation of their 230Th/ 234U/ 238U

  1. Atmospheric radiocarbon variations 11,000 years ago

    Energy Technology Data Exchange (ETDEWEB)

    Hajdas, I.; Bonani, G. [Eidgenoessische Technische Hochschule, Zurich (Switzerland); Peteet, D. [LDEO of Columbia Univ. (United States); Boden, P. [Stockholm Univ. (Sweden)

    1997-09-01

    Records of climate changes were {sup 14}C dated using AMS method. High resolution dating allowed reconstruction of the atmospheric {sup 14}C variations at the time of deglaciation. An abrupt rise of up to 100%o in the atmospheric {sup 14}C/{sup 12}C ratio was found at 11`000 BP (radiocarbon age) which coincides with the limit of an abrupt cooling and a decrease in ocean ventilation. (author) 1 fig., 6 refs.

  2. Radiocarbon dating of modern peat profiles: Pre- and post-bomb C-14 variations in the construction of age-depth models

    OpenAIRE

    Goslar, T.; van der Knaap, Pim; Hicks, S; Andric, M; Czernik, J; Goslar, E; Rasanen, S; Hyotyla, H

    2005-01-01

    We present studies of 9 modern (up to 400-yr-old) peat sections from Slovenia, Switzerland, Austria, Italy, and Finland. Precise radiocarbon dating of modern samples is possible due to the large bomb peak of atmospheric 14C concentration in 1963 and the following rapid decline in the 14C level. All the analyzed 14C profiles appeared concordant with the shape of the bomb peak of atmospheric 14C concentration, integrated over some time interval with a length specific to the peat section. In the...

  3. Numerical dating of a Late Quaternary spit-shoreline complex at the northern end of Silver Lake playa, Mojave Desert, California: A comparison of the applicability of radiocarbon, luminescence, terrestrial cosmogenic nuclide, electron spin resonance, U-series and amino acid racemization methods

    Science.gov (United States)

    Owen, L.A.; Bright, Jordon; Finkel, R.C.; Jaiswal, M.K.; Kaufman, D.S.; Mahan, S.; Radtke, U.; Schneider, J.S.; Sharp, W.; Singhvi, A.K.; Warren, C.N.

    2007-01-01

    A Late Quaternary spit-shoreline complex on the northern shore of Pleistocene Lake Mojave of southeastern California, USA was studied with the goal of comparing accelerator mass spectrometry (AMS) radiocarbon, luminescence, electron spin resonance (ESR), terrestrial cosmogenic radionuclide (TCN) surface exposure, amino acid racemization (AAR) and U-series dating methods. The pattern of ages obtained by the different methods illustrates the complexity of processes acting in the lakeshore environment and highlights the utility of a multi-method approach. TCN surface exposure ages (mostly ???20-30 ka) record the initial erosion of shoreline benches, whereas radiocarbon ages on shells (determined in this and previous studies) within the spit, supported by AAR data, record its construction at fluctuating lake levels from ???16 to 10 ka. Luminescence ages on spit sediment (???6-7 ka) and ESR ages on spit shells (???4 ka) are anomalously young relative to radiocarbon ages of shells within the same deposits. The significance of the surprisingly young luminescence ages is not clear. The younger ESR ages could be a consequence of post-mortem enrichment of U in the shells. High concentrations of detrital thorium in tufa coating spit gravels inhibited the use of single-sample U-series dating. Detailed comparisons such as this provide one of the few means of assessing the accuracy of Quaternary dating techniques. More such comparisons are needed. ?? 2007 Elsevier Ltd and INQUA.

  4. The neolithic demographic transition in Europe: correlation with juvenility index supports interpretation of the summed calibrated radiocarbon date probability distribution (SCDPD as a valid demographic proxy.

    Directory of Open Access Journals (Sweden)

    Sean S Downey

    Full Text Available Analysis of the proportion of immature skeletons recovered from European prehistoric cemeteries has shown that the transition to agriculture after 9000 BP triggered a long-term increase in human fertility. Here we compare the largest analysis of European cemeteries to date with an independent line of evidence, the summed calibrated date probability distribution of radiocarbon dates (SCDPD from archaeological sites. Our cemetery reanalysis confirms increased growth rates after the introduction of agriculture; the radiocarbon analysis also shows this pattern, and a significant correlation between both lines of evidence confirms the demographic validity of SCDPDs. We analyze the areal extent of Neolithic enclosures and demographic data from ethnographically known farming and foraging societies and we estimate differences in population levels at individual sites. We find little effect on the overall shape and precision of the SCDPD and we observe a small increase in the correlation with the cemetery trends. The SCDPD analysis supports the hypothesis that the transition to agriculture dramatically increased demographic growth, but it was followed within centuries by a general pattern of collapse even after accounting for higher settlement densities during the Neolithic. The study supports the unique contribution of SCDPDs as a valid demographic proxy for the demographic patterns associated with early agriculture.

  5. Radiocarbon and Indian archaeology

    International Nuclear Information System (INIS)

    The increasing use of radiocarbon (C14) dating techniques in Indian archaeology has been described in detail. Work done in Microlithic cultures, Neolithic period, Indus civilization and Iron age cultures have been reported. C14 dates of various archaeological sites are listed. (K.B.)

  6. Environmental changes in the western Amazônia: morphological framework, geochemistry, palynology and radiocarbon dating data.

    Science.gov (United States)

    Horbe, Adriana M C; Behling, Hermann; Nogueira, Afonso C R; Mapes, Russell

    2011-09-01

    The sediments from the Coari lake, a "terra firme" lake sculpted into Plio-Pleistocene deposits, and the Acará lake, a flooding-type lake developed on Quaternary sediments in the floodplain of the mid-Solimões river, in the western Amazônia, Brazil, were studied to investigate the environmental condition of their developing. This study includes mineral composition, geochemistry, Pb isotope, palinology, radiocarbon-age and morphological framework of the lakes obtained from SRTM satellite images. The geological and the environmental conditions in the two lakes are highly variable and suggest that their evolution reflect autogenic processes under humid rainforest condition. Although kaolinite, quartz, muscovite, illite, and smectite are the main minerals in both lakes, the geochemistry indicates distinct source, the Acará lake sediments have higher concentrations of Al(2)O(3), Fe(2)O(3), FeO, CaO, K(2)O, MgO, Na(2)O, P(2)O(5), Ba, V, Cu, Ni, Zn, Pb, Sr, Li, Y and La and have more radiogenic Pb than the Coari lake sediments. The radiocarbon ages suggest that at 10160 yr BP the Coari lake started to be developed due to avulsion of the Solimões river, and the Acará lake was formed by the meander abandonment of Solimões river retaining its grass dominated shore at ca. 3710 yr BP. PMID:21830005

  7. Radiocarbon dating of ancient Japanese calligraphy sheets and the discovery of 45 letters of a lost manuscript

    International Nuclear Information System (INIS)

    The Miidera-gire is an ancient paper sheet with different, elegant calligraphy on both sides. One side contains a part of a Buddhist scripture from around the ninth to the twelfth century and written in cursive hand, while the other side contains a part of Monzen (an anthology of Chinese literary works). The paleographical style of this Monzen seems to be older than that of the Buddhist scripture and is similar to some Chinese manuscripts written in the Tang Dynasty (AD 618-907). However, amid these elegant calligraphic writings, there exist many copies and counterfeits that were written several centuries later. We, therefore, measured the radiocarbon age of the Miidera-gire by using accelerator mass spectrometry. The calibrated radiocarbon age indicated 666-776 [cal AD] (2σ error), thus leading to the conclusion that the Monzen was first written on the obverse side, and long afterwards, the Buddhist scripture was written on the reverse side. Since only a few incomplete books of Monzen were written before the ninth century, this calligraphy is one of the oldest of the existing Monzen manuscripts. (orig.)

  8. Accelerator mass spectrometry dating at Catalhoeyuek

    International Nuclear Information System (INIS)

    Several charred plant and charcoal samples from various stratigraphic levels of the Neolithic Site, Catalhoeyuek - Turkey, were dated in the AMS facility of Purdue University (PRIME Lab). Radiocarbon dates reveal a complicated chronology, as was foreseen from archeological investigations. Our measurements suggest that this unique Neolithic town may have been initiated at the East mound around 8390 BP. (orig.)

  9. AMS 14C dating at CIRCE: The Major Temple in Cumae (NA - Italy)

    Science.gov (United States)

    Capano, M.; Rescigno, C.; Sirleto, R.; Passariello, I.; Marzaioli, F.; D'Onofrio, A.; Terrasi, F.

    2015-10-01

    We present here one recent CIRCE (Centre for Isotopic Research on Cultural and Environmental Heritage) - Caserta (Italy) project on cultural heritage field, analysing several mice bones, discovered in the Major Temple on the acropolis of Cumae (Napoli, Southern Italy). The bones were found in a vase linked to the holy context. In order to know their dating and formulate an hypothesis on their presence on the site, if it was an accidental rodent inclusion (believed on the base of archaeological context to have occurred during building abandonment periods (IV-V or XIII centuries AD)) or an intentional and ritual remain, the bones were 14C dated by AMS at CIRCE. The results indicate that the mice bones date to the IV century BC and are contemporaneous with building construction. This dating seems to exclude an accidental rodent presence and it supports the hypothesis of Apollo veneration in the temple, based on the already known link between mice and Apollo worship rituals.

  10. Development of a nanofiltration method for bone collagen 14C AMS dating

    Science.gov (United States)

    Boudin, Mathieu; Boeckx, Pascal; Buekenhoudt, Anita; Vandenabeele, Peter; Van Strydonck, Mark

    2013-01-01

    Radiocarbon dating of bones is usually performed on the collagen fraction. However, this collagen can contain exogenous molecules, including humic substances (HSs) and/or other soil components that may have a different age than the bone. Incomplete removal can result in biased 14C dates. Ultrafiltration of collagen, dissolved as gelatin (molecular weight (MW) ∼100,000 Dalton), has received considerable attention to obtain more reliable dates. Ultrafiltration is an effective method of removal of low-molecular weight contaminants from bone collagen but it does not remove high-molecular weight contaminants, such as cross-linked humic collagen complexes. However, comparative dating studies have raised the question whether this cleaning step itself may introduce contamination with carbon from the filters used. In this study, a nanofiltration method was developed using a ceramic filter to avoid a possible extraneous carbon contamination introduced by the filter. This method should be applicable to various protein materials e.g. collagen, silk, wool, leather and should be able to remove low-molecular and high molecular weight HSs. In this study bone collagen was hot acid hydrolyzed to amino acids and nanofiltrated. A filter with a molecular weight cutoff (MWCO) of 450 Dalton was chosen in order to collect the amino acids in the permeate and the HSs in the retentate. Two pilot studies were set up. Two nanofiltration types were tested in pilot study 1: dead end and cross flow filtration. Humic substance (HS)-solutions with fossil carbon and modern hydrolyzed collagen contaminated with HSs were filtrated and analyzed with spectrofluorescence to determine the HS removal. Cross flow nanofiltration showed the most efficient HS removal. A second pilot study based upon these results was set up wherein only cross flow filtration was performed. 14C measurements of the permeates of hydrolyzed modern collagen contaminated with fossil HSs demonstrate a significant but incomplete

  11. Development of a nanofiltration method for bone collagen {sup 14}C AMS dating

    Energy Technology Data Exchange (ETDEWEB)

    Boudin, Mathieu, E-mail: mathieu.boudin@ugent.be [Royal Institute for Cultural Heritage, Jubelpark 1, B-1000 Brussels (Belgium); Ghent University, Faculty of Bioscience Engineering, Laboratory of Applied Physical Chemistry, Coupure Links 653, B-9000 Ghent (Belgium); Boeckx, Pascal [Ghent University, Faculty of Bioscience Engineering, Laboratory of Applied Physical Chemistry, Coupure Links 653, B-9000 Ghent (Belgium); Buekenhoudt, Anita [Flemish Institute for Technological Research, Separation and Conversion Technology, Boeretang 200, B-2400 Mol (Belgium); Vandenabeele, Peter [Ghent University, Department of Archaeology, Sint-Pietersnieuwstraat 35, B-9000 Ghent (Belgium); Van Strydonck, Mark [Royal Institute for Cultural Heritage, Jubelpark 1, B-1000 Brussels (Belgium)

    2013-01-15

    Radiocarbon dating of bones is usually performed on the collagen fraction. However, this collagen can contain exogenous molecules, including humic substances (HSs) and/or other soil components that may have a different age than the bone. Incomplete removal can result in biased {sup 14}C dates. Ultrafiltration of collagen, dissolved as gelatin (molecular weight (MW) {approx}100,000 Dalton), has received considerable attention to obtain more reliable dates. Ultrafiltration is an effective method of removal of low-molecular weight contaminants from bone collagen but it does not remove high-molecular weight contaminants, such as cross-linked humic collagen complexes. However, comparative dating studies have raised the question whether this cleaning step itself may introduce contamination with carbon from the filters used. In this study, a nanofiltration method was developed using a ceramic filter to avoid a possible extraneous carbon contamination introduced by the filter. This method should be applicable to various protein materials e.g. collagen, silk, wool, leather and should be able to remove low-molecular and high molecular weight HSs. In this study bone collagen was hot acid hydrolyzed to amino acids and nanofiltrated. A filter with a molecular weight cutoff (MWCO) of 450 Dalton was chosen in order to collect the amino acids in the permeate and the HSs in the retentate. Two pilot studies were set up. Two nanofiltration types were tested in pilot study 1: dead end and cross flow filtration. Humic substance (HS)-solutions with fossil carbon and modern hydrolyzed collagen contaminated with HSs were filtrated and analyzed with spectrofluorescence to determine the HS removal. Cross flow nanofiltration showed the most efficient HS removal. A second pilot study based upon these results was set up wherein only cross flow filtration was performed. {sup 14}C measurements of the permeates of hydrolyzed modern collagen contaminated with fossil HSs demonstrate a significant

  12. Development of a nanofiltration method for bone collagen 14C AMS dating

    International Nuclear Information System (INIS)

    Radiocarbon dating of bones is usually performed on the collagen fraction. However, this collagen can contain exogenous molecules, including humic substances (HSs) and/or other soil components that may have a different age than the bone. Incomplete removal can result in biased 14C dates. Ultrafiltration of collagen, dissolved as gelatin (molecular weight (MW) ∼100,000 Dalton), has received considerable attention to obtain more reliable dates. Ultrafiltration is an effective method of removal of low-molecular weight contaminants from bone collagen but it does not remove high-molecular weight contaminants, such as cross-linked humic collagen complexes. However, comparative dating studies have raised the question whether this cleaning step itself may introduce contamination with carbon from the filters used. In this study, a nanofiltration method was developed using a ceramic filter to avoid a possible extraneous carbon contamination introduced by the filter. This method should be applicable to various protein materials e.g. collagen, silk, wool, leather and should be able to remove low-molecular and high molecular weight HSs. In this study bone collagen was hot acid hydrolyzed to amino acids and nanofiltrated. A filter with a molecular weight cutoff (MWCO) of 450 Dalton was chosen in order to collect the amino acids in the permeate and the HSs in the retentate. Two pilot studies were set up. Two nanofiltration types were tested in pilot study 1: dead end and cross flow filtration. Humic substance (HS)-solutions with fossil carbon and modern hydrolyzed collagen contaminated with HSs were filtrated and analyzed with spectrofluorescence to determine the HS removal. Cross flow nanofiltration showed the most efficient HS removal. A second pilot study based upon these results was set up wherein only cross flow filtration was performed. 14C measurements of the permeates of hydrolyzed modern collagen contaminated with fossil HSs demonstrate a significant but incomplete

  13. Using of the AMS - 14 C technique for dating of soil charcoals, from holocene period, in the amazon forest(Manaus-Brazil region)

    International Nuclear Information System (INIS)

    The Accelerator Mass Spectrometry (AMS) technique was used to determine the radiocarbon age of charcoal fragments of soil samples from the Amazon Region near Manaus. The radiocarbon ages are within the 130 - 2400 years range. The interpretation is that these results are evidences of important fire events that occurred mostly during the superior Holocene dry phase. These res had spread out more intensely at the high land areas than at shoals. In this paper there are descriptions of the processes of sample preparation and the procedures for the AMS analysis. (author)

  14. MESOLITHIC HUMAN BONES FROM THE UPPER VOLGA BASIN: RADIOCARBON AND TRACE ELEMENTS

    OpenAIRE

    Alexandrovskiy, A. L.; Alexandrovskaya, E. I.; Zhilin, M. I.; Van der Plicht, J

    2009-01-01

    Human bones from 3 Mesolithic sites in the Upper Volga basin were analyzed for trace elements, and dated by accelerator mass spectrometry (AMS). The radiocarbon dates of the bones correspond to the Mesolithic era. However, some dates differ from those obtained for the enclosing deposits and for the worked wood fragments in the cultural layer. The elemental composition of the bones is interpreted in terms of increased concentrations of some elements and their impact on human health and behavior.

  15. Towards a radiocarbon chronology of the Late-Glacial: Sample selection strategies

    OpenAIRE

    Walker, M.J.C.; Bryant, C.; Coope, G R; Harkness, D. D.; J. J. Lowe; Scott, E.M.

    2001-01-01

    This paper outlines a dating program designed to test the reproducibility of radiocarbon dates on different materials of Late-Glacial age (plant macrofossils, fossil beetle remains, and the "humic" and "humin" chemical fractions of limnic sediments) using a combination of radiometric (beta counting) and accelerator mass spectrometry (AMS) techniques. The results have implications for the design of sampling strategies and for the development of improved dating protocols, both of which are impo...

  16. Radiocarbon dating of archaeological samples (sambaqui) using CO2 absorption and liquid scintillation spectrometry of low background radiation

    International Nuclear Information System (INIS)

    Sambaqui means, in the Tupi language, a hill of shells. The sambaquis are archaeological sites with remains of pre-historical Brazilian occupation. Since the sambaqui sites in the Rio de Janeiro state region are older than 10,000 years, the applicability of CO2 absorption on Carbo-sorb[reg] and 14C determination by counting on a low background liquid scintillation counter was tested. In the present work, sambaqui shells were treated with H3PO4 in a closed vessel in order to generate CO2. The produced CO2 was absorbed on Carbo-sorb[reg]. On saturation about 0.6 g of carbon, as CO2, was mixed with commercial liquid scintillation cocktail (Permafluor[reg]), and the 14C activity determined by counting on a low background counter, Packard Tricarb 3170 TR/SL, for a period of 1000 mins to enable detection of a radiocarbon age of 22,400 BP. But only samples with ages up to 3500 BP were submitted to the method because the samples had been collected in the municipality of Guapimirim, in archaeological sambaqui-type sites belonging to this age range. The same samples were sent to the 14C Laboratory of the Centro de Energia Nuclear na Agricultura (CENA/USP) where similar results were obtained

  17. Environmental changes in the western Amazônia: morphological framework, geochemistry, palynology and radiocarbon dating data

    Directory of Open Access Journals (Sweden)

    Adriana M.C. Horbe

    2011-09-01

    Full Text Available The sediments from the Coari lake, a “terra firme” lake sculpted into Plio-Pleistocene deposits, and the Acará lake, a flooding-type lake developed on Quaternary sediments in the floodplain of the mid-Solimões river, in the western Amazônia, Brazil, were studied to investigate the environmental condition of their developing. This study includes mineral composition, geochemistry, Pb isotope, palinology, radiocarbon-age and morphological framework of the lakes obtained from SRTM satellite images. The geological and the environmental conditions in the two lakes are highly variable and suggest that their evolution reflect autogenic processes under humid rainforest condition. Although kaolinite, quartz, muscovite, illite, and smectite are the main minerals in both lakes, the geochemistry indicates distinct source, the Acará lake sediments have higher concentrations of Al2O3, Fe2O3, FeO, CaO, K2O, MgO, Na2O, P2O5, Ba, V, Cu, Ni, Zn, Pb, Sr, Li, Y and La and have more radiogenic Pb than the Coari lake sediments. The radiocarbon ages suggest that at 10160 yr BP the Coari lake started to be developed due to avulsion of the Solimões river, and the Acará lake was formed by the meander abandonment of Solimões river retaining its grass dominated shore at ca. 3710 yr BP.Os sedimentos do lago Coari, de ambiente de terra firme eesculpido nos depósitos do Plio-Pleistocenos, e o Acará, típico lago de várzea e ambos formados nos sedimentos quaternários da planície de inundação do médio Solimões, no oeste da Amazônia, Brasil, foram estudados para investigar as condições ambientais durante sua formação. Este estudo inclui dados da composição mineralógica, química, isótopos de Pb, palinologia, datações de radiocarbono e a configuração morfológica dos lagos obtida por imagens SRTM. As condições geológica e ambiental dos lagos variam e sugerem que suas evoluções refletem processos autogenéticos em condições de floresta úmida

  18. Late Quaternary floods and droughts in the Nile valley, Sudan: new evidence from optically stimulated luminescence and AMS radiocarbon dating

    Science.gov (United States)

    Williams, M. A. J.; Williams, F. M.; Duller, G. A. T.; Munro, R. N.; El Tom, O. A. M.; Barrows, T. T.; Macklin, M.; Woodward, J.; Talbot, M. R.; Haberlah, D.; Fluin, J.

    2010-05-01

    Our results show that the late Pleistocene Nile in northern Sudan was shifting position and actively aggrading at 145 ± 20 kyr, 83 ± 24 kyr, 32 ± 8 kyr and 20.7 ± 0.2 kyr and indicate, for the first time, a phase of high-energy flow in the White Nile at 27.8 ± 3.2 kyr, with still high but somewhat reduced flow in that river at 13.3 kyr, 10 kyr and 4.8-4.0 kyr. Beach ridges associated with a 386 m strandline of the White Nile have OSL ages of 27.5 ± 2.7 kyr and 14.5 ± 1.6 kyr. The Holocene terraces and former channels of the main Nile have ages of 11 kyr, 6.5-5.0 kyr and 4.8-4.0 kyr, after which there was a general decline in flood discharge. The now arid main Nile valley in northern Sudan was significantly wetter during the early to middle Holocene, with a lake up to 450 km 2 in area, fed by an overflow channel from the early Holocene Nile between 9.5 kyr and 7.5 kyr. Previously stable late Pleistocene dunes were reactivated at intervals during the Holocene, with five samples from the White Nile valley indicating brief phases of Holocene dune activity at 9.9 ± 2.0 kyr, 9.0 ± 2.8 kyr, 6.6 ± 0.9 kyr, 4.8 ± 0.9 kyr and 2.9 ± 0.5 kyr, the earliest of which occurred within periods of generally wetter climate and higher Nile flow. The youngest freshwater shells on the Khor Abu Habl alluvial fan west of the White Nile correspond to a time of regionally wetter climate between 1.7 and 1.0 kyr. Our results suggest that millennial scale climatic instability may have been characteristic of Holocene climates in this region.

  19. Further investigations at the Naigani Lapita site (VL 21/5), Fiji : excavation, radiocarbon dating and palaeofaunal extinction

    International Nuclear Information System (INIS)

    This paper brings up-to-date a report by S. Best of initial excavations at Naigani in 1981. The results of subsequent fieldwork in 2000 include the excavation and dating of Lapita-age ovens associated with early settlement and extinct palaeofauna. These include the giant megapode (Megavitiornis altirostris), a species of Ducula pigeon, the giant iguana (Lapitiguana impensa), and probably the endemic crocodile (Volia athollandersoni). The Lapita site of VL 21/5 dates from 900 BC and represents an initial colonising settlement within the Fiji Islands. The period of occupation ended around 750 BC. The significance of Naigani is considered in terms of chronology, ceramic history, economy, extinctions, origins and interactions. (author). 33 refs., 10 figs., 2 tabs.

  20. Dating stratified settlement sites at Kom K and Kom W: Fifth millennium BCE radiocarbon ages for the Fayum Neolithic

    Energy Technology Data Exchange (ETDEWEB)

    Wendrich, W. [Department of Near Eastern Languages and Cultures, University of California, Los Angeles, CA 92521 (United States); Cotsen Institute of Archaeology, University of California, Los Angeles, CA 92521 (United States); Taylor, R.E., E-mail: retaylor@ucr.ed [Department of Anthropology, University of California, Riverside, Riverside, CA 92521 (United States); Cotsen Institute of Archaeology, University of California, Los Angeles, CA 92521 (United States); Keck Carbon Cycle Accelerator Mass Spectrometry Laboratory, Department of Earth System Science, University of California, Irvine, CA 92697 (United States); Southon, J. [Keck Carbon Cycle Accelerator Mass Spectrometry Laboratory, Department of Earth System Science, University of California, Irvine, CA 92697 (United States)

    2010-04-15

    The earliest evidence of the use of domesticated plants, a traditional hallmark of Neolithic societies in the ancient Near East, first appears in Egypt in archaeological sites in the Fayum depression. Due to wind erosion often resulting in deflation of sediments in this region, stratified sites containing organic materials are rare and the depositional contexts of some earlier {sup 14}C measurements on Fayum Neolithic materials are not precisely documented. We report the results of 29 AMS-based {sup 14}C determinations on charcoal recovered from stratified contexts in two Fayum Neolithic village sites, Kom K and Kom W. These data assign a mid-5th millennium BCE age to these sites and permit an estimate of the length of their occupation to be approximately three centuries.

  1. Progress in AMS measurement of natural {sup 32}Si for glacier ice dating

    Energy Technology Data Exchange (ETDEWEB)

    Morgenstern, Uwe, E-mail: u.morgenstern@gns.cri.n [GNS Science, National Isotope Centre, P.O. Box 30368, Avalon, Lower Hutt (New Zealand); Keith Fifield, L.; Tims, Stephen G. [Department of Nuclear Physics, RSPhysSE, The Australian National University, ACT 0200 (Australia); Ditchburn, Robert G. [GNS Science, National Isotope Centre, P.O. Box 30368, Avalon, Lower Hutt (New Zealand)

    2010-04-15

    AMS measurement of {sup 32}Si can allow for ice core dating over the last thousand years. Technique developments are reported. Necessary negative-ion yields of 20-30% can now be consistently achieved, and permit an overall efficiency from ice sample to detector of approx1%. A {sup 30}Si-spike technique has overcome the problem of extremely low intrinsic silicon concentration, with the added benefit of allowing determination of ppb-level silicon via isotope dilution. Improvements have also been made to the ionization detector in the gas-filled magnet that separates the accelerated {sup 32}Si ions from the intense flux of {sup 32}S ions. Preliminary {sup 32}Si AMS results of snow and ice samples from Mt. Cook National Park, New Zealand, are reproducible, and with {sup 32}Si concentrations 1.2-7.2 mBq/m{sup 3} comparable to results from mid-latitude snow samples measured previously via the radiometric technique, demonstrating the feasibility of the method. With these developments, the potential of {sup 32}Si as ice core dating tool is close to being realized, and attempts to determine chronologies for both alpine and Antarctic glaciers are underway.

  2. Examining sources of bias in radiocarbon ages of New Zealand Kiore

    International Nuclear Information System (INIS)

    Recent AMS dates for the Pacific rat (Rattus exulans / Kiore) from natural and archaeological sites are significantly older than the generally accepted time for human arrival in New Zealand. Because Rattus exulans is recognized as a human commensal for Polynesian colonization in Oceania, radiocarbon ages for Kiore could be used as an indicator of earliest human contact with New Zealand. A strictly chronological interpretation of the radiocarbon ages assembled, though, raises serious questions about this arrival time. Therefore, factors that could affect the age determinations were also examined. A research programme in progress at the Rafter Radiocarbon Laboratory aims to identify the range and influence of natural bias and variance in radiocarbon ages in kiore bone samples. It was found that the main factors that could bias these ages were the incomplete removal of contaminants by the current bone preparation methods, and dietary carbon reservoir effects. Preliminary results of the various analytical techniques employed are presented

  3. Dating raised bogs : New aspects of AMS C-14 wiggle matching, a reservoir effect and climatic change

    NARCIS (Netherlands)

    Kilian, MR; VanDerPlicht, J; VanGeel, B; Geel, B. van

    1995-01-01

    High resolution AMS dating of Holocene raised bog deposits (Engbertsdijksvenen, The Netherlands) shows natural C-14 variations (wiggles) which can be matched with the dendrochronological calibration curve. Comparison of our results with other, conventionally dated peat cores and the Delta(14)C recor

  4. Analysis of past recurrent methane seep activity using radiocarbon dating of Calyptogena spp. shells in the eastern Nankai subduction zone, Japan

    Science.gov (United States)

    Yagasaki, Kazuhiro; Ashi, Juichiro; Yokoyama, Yusuke; Miyairi, Yosuke; Kuramoto, Shin'ichi

    2016-04-01

    analysis that show multiple shallow faults and chaotic sediment structure below the colony site, the Calyptogena spp. shells have a strong connection to the coseismic faulting activity and could show potential for radiocarbon dating to be applied on marine samples providing the necessary calibration tools are available.

  5. Causal links between Nile floods and eastern Mediterranean sapropel formation during the past 125 kyr confirmed by OSL and radiocarbon dating of Blue and White Nile sediments

    Science.gov (United States)

    Williams, M. A. J.; Duller, G. A. T.; Williams, F. M.; Woodward, J. C.; Macklin, M. G.; El Tom, O. A. M.; Munro, R. N.; El Hajaz, Y.; Barrows, T. T.

    2015-12-01

    It has long been hypothesised that beds of highly organic mud or sapropels seen in marine sediment cores retrieved from the floor of the eastern Mediterranean accumulated during times of high Nile fluvial discharge. Our recent fieldwork in the valleys of the Blue Nile, the White Nile and the main Nile has for the first time revealed a sequence of extreme flood episodes synchronous with sapropel units S5 (124 kyr), S4 (102 kyr), S3 (81 kyr), S2 (55 kyr) and S1 (13.5-6.5 kyr). There are more weakly defined links with Nile floods and sapropel units S9 (240 kyr), S8 (217 kyr), S7 (195 kyr), S6 (172 kyr), but the dating error terms are too large to allow us to be too definite. During times of extreme floods over the past 125 kyr, wide distributary channels of the Blue Nile flowed across the Gezira alluvial fan in central Sudan and transported a bed load of sand and gravel into the lower White Nile valley. The sands were reworked by wind to form source-bordering dunes, all of which contain heavy minerals of Ethiopian provenance. These source-bordering dunes were active at 115-105 kyr, 60 kyr and 12-7 kyr, all times of extreme Blue Nile floods. The flood and dune sediments were dated using a combination of optically stimulated luminescence (OSL) and radiocarbon analyses. The Quaternary record of Nile floods discussed here shows a precessional signal and reflects episodes of stronger summer monsoon and more northerly seasonal movement of the ITCZ, linked to times of higher insolation in northern tropical latitudes. Progressive aggradation of Holocene Nile channels in northern Sudan has had a profound influence upon human settlement in the last 8 kyr.

  6. Prospects for ''iodine-129 dating'' of marine organic matter using AMS

    International Nuclear Information System (INIS)

    Natural levels of iodine 129 have been overwhelmed by a build-up of ''new'' iodine-129, a product of our nuclear age. Much of this new iodine-129 has entered the ocean and is now found in its upper layers. During primary production, marine organic matter incorporates iodine, which then moves through the food chain. The 129I/127I ratio in marine organics therefore represents the value found in the ocean's photic zone when the organic matter formed. Because the 129I/127I ratio in any well-mixed marine basin has increased rapidly since the advent of the nuclear age, establishing the build up pattern of 129I in that basin's surface waters would allow us to ''date'' the time of formation of any organics formed there, provided that we can obtain an adequate amount of iodine from samples. Measurement of this ratio requires the use of AMS. (orig.)

  7. Time since death and decay rate constants of Norway spruce and European larch deadwood in subalpine forests determined using dendrochronology and radiocarbon dating

    Science.gov (United States)

    Petrillo, Marta; Cherubini, Paolo; Fravolini, Giulia; Marchetti, Marco; Ascher-Jenull, Judith; Schärer, Michael; Synal, Hans-Arno; Bertoldi, Daniela; Camin, Federica; Larcher, Roberto; Egli, Markus

    2016-03-01

    Due to the large size (e.g. sections of tree trunks) and highly heterogeneous spatial distribution of deadwood, the timescales involved in the coarse woody debris (CWD) decay of Picea abies (L.) Karst. and Larix decidua Mill. in Alpine forests are largely unknown. We investigated the CWD decay dynamics in an Alpine valley in Italy using the chronosequence approach and the five-decay class system that is based on a macromorphological assessment. For the decay classes 1-3, most of the dendrochronological samples were cross-dated to assess the time that had elapsed since tree death, but for decay classes 4 and 5 (poorly preserved tree rings) radiocarbon dating was used. In addition, density, cellulose, and lignin data were measured for the dated CWD. The decay rate constants for spruce and larch were estimated on the basis of the density loss using a single negative exponential model, a regression approach, and the stage-based matrix model. In the decay classes 1-3, the ages of the CWD were similar and varied between 1 and 54 years for spruce and 3 and 40 years for larch, with no significant differences between the classes; classes 1-3 are therefore not indicative of deadwood age. This seems to be due to a time lag between the death of a standing tree and its contact with the soil. We found distinct tree-species-specific differences in decay classes 4 and 5, with larch CWD reaching an average age of 210 years in class 5 and spruce only 77 years. The mean CWD rate constants were estimated to be in the range 0.018 to 0.022 y-1 for spruce and to about 0.012 y-1 for larch. Snapshot sampling (chronosequences) may overestimate the age and mean residence time of CWD. No sampling bias was, however, detectable using the stage-based matrix model. Cellulose and lignin time trends could be derived on the basis of the ages of the CWD. The half-lives for cellulose were 21 years for spruce and 50 years for larch. The half-life of lignin is considerably higher and may be more than

  8. Palaeoecological caracterisation of the mammoth steppe at Final Pleistocene in Central Ukraine from zooarchaeology, stable isotope analyses and direct radiocarbon dating

    Science.gov (United States)

    Péan, Stéphane; Drucker, Dorothée.; Bocherens, Hervé; Haesaerts, Paul; Valladas, Hélène; Stupak, Dmytro; Nuzhnyi, Dmytro

    2010-05-01

    that a modification of the regional plant and climatic context may have inferred a change of food resource for mammoths, which could have been put into food competition with horses. Mammoths from Central Ukraine at late OIS 2 may have formed an isolated local population, under the pressure of modified ecological conditions, compared to the period of maximal extension of the mammoth steppe. Thus, thanks to a combined approach of zooarchaeology, stable isotopes and radiocarbon dating, in the stratigraphic context, a better knowledge of the palaeoecological context of the last mammoths at late Pleniglacial in Central Ukraine is expected.

  9. RICH - A new AMS facility at the Royal Institute for Cultural Heritage, Brussels, Belgium

    Science.gov (United States)

    Boudin, Mathieu; Van Strydonck, Mark; van den Brande, Tess; Synal, Hans-Arno; Wacker, Luckas

    2015-10-01

    Since 1989 the radiocarbon dating lab has their own graphitization system for 14C AMS dating but RICH (Royal Institute for Cultural Heritage) did not possess their own AMS and measurements were carried out in collaboration with other AMS facilities. In April 2013 the Micadas (Mini Carbon Dating System) AMS was installed at RICH in Brussels and after 1.5 year operation the high stability and performance of the Micadas can be demonstrated by repeated analyses of primary standard OXA II and secondary standards. Results of unknown samples measured on the RICH-Micadas and on other AMS systems are in good agreement.

  10. Accuracy of radiocarbon analyses at ANTARES

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, E.M.; Fink, D.; Hotchkis, M.; Hua, Q.; Jacobsen, G.; Smith, A.M.; Tuniz, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Accuracy in Accelerator Mass Spectroscopy (AMS) measurements, as distinct from precision, requires the application of a number of corrections. Most of these are well known except in extreme circumstances and AMS can deliver radiocarbon results which are both precise and accurate in the 0.5 to 1.0% range. The corrections involved in obtaining final radiocarbon ages are discussed. 3 refs., 1 tab.

  11. New radiocarbon dates for the transition from middle to upper palaeolithic at El Castillo (Cantabria); La transition paleolithique moyen-paleolithique superieur a El Castillo (Cantabrie): nouvelles datations par le carbone-14

    Energy Technology Data Exchange (ETDEWEB)

    Valladas, H. [Centre National de la Recherche Scientifique (CNRS), 91 - Gif-sur-Yvette (France). Centre des Faibles Radioactivites; Gomez, M.H. [Consejo Superior de Investigaciones Cientificas, Madrid (Spain); Cabrera-Valdes, V.; De Quiros, F.B.

    1996-06-13

    The stratigraphic sequence at the El Castillo cave in Cantabria, Spain, extends from Lower to Upper Palaeolithic. The transition from Middle to Upper Palaeolithic is represented by levels assigned to Quina Mousterian and Early Aurignacian. Accelerator Mass Spectrometry Radiocarbon dates put the archaic Aurignacian industries at ca. 40,000 years ago and indicate that in northern Spain the Upper Palaeolithic began several millennia earlier than in other parts of western Europe. (authors). 16 refs., 1 tab.

  12. Evolution of chemical and isotopic composition of inorganic carbon in a complex semi-arid zone environment: Consequences for groundwater dating using radiocarbon

    Science.gov (United States)

    Meredith, K. T.; Han, L. F.; Hollins, S. E.; Cendón, D. I.; Jacobsen, G. E.; Baker, A.

    2016-09-01

    Estimating groundwater age is important for any groundwater resource assessment and radiocarbon (14C) dating of dissolved inorganic carbon (DIC) can provide this information. In semi-arid zone (i.e. water-limited environments), there are a multitude of reasons why 14C dating of groundwater and traditional correction models may not be directly transferable. Some include; (1) the complex hydrological responses of these systems that lead to a mixture of different ages in the aquifer(s), (2) the varied sources, origins and ages of organic matter in the unsaturated zone and (3) high evaporation rates. These all influence the evolution of DIC and are not easily accounted for in traditional correction models. In this study, we determined carbon isotope data for; DIC in water, carbonate minerals in the sediments, sediment organic matter, soil gas CO2 from the unsaturated zone, and vegetation samples. The samples were collected after an extended drought, and again after a flood event, to capture the evolution of DIC after varying hydrological regimes. A graphical method (Han et al., 2012) was applied for interpretation of the carbon geochemical and isotopic data. Simple forward mass-balance modelling was carried out on key geochemical processes involving carbon and agreed well with observed data. High values of DIC and δ13CDIC, and low 14CDIC could not be explained by a simple carbonate mineral-CO2 gas dissolution process. Instead it is suggested that during extended drought, water-sediment interaction leads to ion exchange processes within the top ∼10-20 m of the aquifer which promotes greater calcite dissolution in saline groundwater. This process was found to contribute more than half of the DIC, which is from a mostly 'dead' carbon source. DIC is also influenced by carbon exchange between DIC in water and carbonate minerals found in the top 2 m of the unsaturated zone. This process occurs because of repeated dissolution/precipitation of carbonate that is dependent on

  13. AMS 14C dating of deglacial events in the Irish Sea Basin and other sectors of the British Irish ice sheet

    Science.gov (United States)

    McCabe, A. M.; Clark, P. U.; Clark, J.

    2005-08-01

    Sedimentary sequences deposited by the decaying marine margin of the British-Irish Ice Sheet (BIIS) record isostatic depression and successive ice sheet retreat towards centres of ice dispersion. Radiocarbon dating by accelerator mass spectrometry (AMS) of in situ marine microfaunas that are commonly associated with these sequences constrain the timing of glacial and sea level fluctuations during the last deglaciation, enabling us to evaluate the dynamics of the BIIS and its response to North Atlantic climate change. Here we use our radiocarbon-dated stratigraphy to define six major glacial and sea level events since the Last Glacial Maximum. (1) Initial deglaciation may have occurred ⩾18.3 kyr 14C BP along the northwestern Irish coast, in agreement with a deglacial age of ˜22 36Cl kyr BP for southwestern Ireland. Ice retreated to inland centres and areas of transverse moraine began to form across the north Irish lowlands. (2) Channels cut into glaciomarine deglacial sediments along the western Irish Sea coast are graded to below present sea level, identifying a fall of relative sea level (RSL) in response to isostatic emergence of the coast. (3) Marine mud that rapidly infilled these channels records an abrupt rise in global sea level of 10-15 m ˜16.7 14C kyr BP that flooded the Irish Sea coast and may have triggered deglaciation of a marine-based margin in Donegal Bay. (4) Intertidal boulder pavements in Dundalk Bay indicate that RSL ˜15.0 14C kyr BP was similar to present. (5) A major readvance of all sectors of the BIIS occurred between 14 and 15 kyr 14C BP which overprinted subglacial transverse moraines and delivered a substantial sediment flux to tidewater ice sheet margins. This event, the Killard Point Stadial, indicates that the BIIS participated in Heinrich event 1. (6) Subsequent deposition of marine muds on drumlins 12.7 14C kyr BP indicates isostatic depression and attendant high RSL resulting from the Killard Point readvance. These events

  14. Mid- to Late-Holocene estuarine infilling processes studied by radiocarbon dates, high resolution seismic and biofacies at Vitoria Bay, Espirito Santo, Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Alex C. Bastos

    2010-09-01

    Full Text Available Vitoria Bay is a 20 km long estuary, morphologically narrow, with a microtidal regime and, as other modern estuaries, was formed during the last post-glacial transgression. The estuarine bed morphology is characterised by a main natural channel limited by tidal flats with developed mangroves. Original radiocarbon dates were obtained for the site. Five radiocarbon ages ranging from 1,010 to 7,240 years BP were obtained from two sedimentary cores, which represent a 5 m thick stratigraphic sequence. The results indicate that, until about 4,000 cal. yrs BP, environmental conditions in Vitoria Bay were still of an open bay, with a free and wide connection with marine waters. During the last 4,000 yrs, the bay has experienced a major regression phase, by becoming more restricted in terms of seawater circulation and probably increasing tidal energy. Three main stratigraphic surfaces were recognised, which limit trangressive, trangressive/highstand and regressive facies. The present channel morphology represents a tidal scouring surface or a tidal diastem, which erodes and truncates regressive facies bedding. Foraminiferal biofacies, which change from marine to brackish and mangrove tidal-flat environments, support the seismic stratigraphic interpretation. Absence of mangrove biofacies at one of the two cores is also an indication of modern tidal ravinement.A Baía de Vitória é um estuário com 20 km de comprimento, morfologicamente estreito, com um regime de micromaré e, como outros estuários modernos, formado durante a última transgressão pós-glacial. A morfologia de fundo do estrato estuarino é caracterizada por um canal natural principal limitado por planícies de maré com manguezais desenvolvidos. Datações de radiocarbono originais foram obtidas para a área. Cinco idades de radiocarbono estendendo-se de 1.010 a 7.240 anos AP foram obtidas através de dois testemunhos de sedimento, representando uma sequência estratigráfica de 5 m de

  15. Continuous-flow accelerator mass spectrometry for radiocarbon analysis

    International Nuclear Information System (INIS)

    Accelerator Mass Spectrometry (AMS) is a widely used technique for radiocarbon dating of archaeological or environmental samples that are very small or very old (up to 50,000 years before present). Because of the method's extreme sensitivity, AMS can also serve as an environmental tracer and supplements conventional nuclear counting techniques for monitoring 14C emissions from operating nuclear power plants and waste repositories. The utility of present AMS systems is limited by the complex sample preparation process required. Carbon from combusted artefacts must be incorporated into a solid metallic target from which a negative ion beam is produced and accelerated to MeV energies by an accelerator for subsequent analysis. This paper will describe a novel technique being developed by the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Laboratory at the Woods Hole Oceanographic Institution for the production of negative carbon ion beams directly from a continuously flowing sample gas stream, eliminating the requirement for a solid target. A key component of the new technique is a microwave-driven, gaseous-feed ion source originally developed at Chalk River Laboratories for the very different requirements of a high current proton linear accelerator. A version of this ion source is now being adapted to serve as an injector for a dedicated AMS accelerator facility at NOSAMS. The paper begins with a review of the fundamentals of radiocarbon dating. Experiments carried out at NOSAMS with a prototype of the microwave ion source are described, including measurements of sample utilization efficiency and sample 'memory' effect. A new version of the microwave ion source, optimized for AMS, is also described. The report concludes with some predictions of new research opportunities that will become accessible to the technique of continuous-flow AMS. (author)

  16. Adult Human Pancreatic Islet Beta-Cells Display Limited Turnover and Long Lifespan as Determined by In-Vivo Thymidine Analog Incorporation and Radiocarbon Dating

    International Nuclear Information System (INIS)

    Diabetes mellitus results from an absolute or relative deficiency of insulin producing pancreatic beta-cells. The adult human beta-cell's turnover rate remains unknown. We employed novel techniques to examine adult human islet beta-cell turnover and longevity in vivo. Subjects enrolled in NIH clinical trials received thymidine analogues [iododeoxyuridine (IdU) or bromodeoxyuridine (BrdU)] 8-days to 4-years prior to death. Archival autopsy samples from ten patients (aged 17-74 years) were employed to assess beta-cell turnover by scoring nuclear analog labeling within insulin staining cells. Human adult beta-cell longevity was determined by estimating the cells genomic DNA integration of atmospheric carbon-14 (14C). DNA was purified from pancreatic islets isolated from cadaveric donors; whole islet prep DNA was obtained from a 15 year old donor, and purified beta-cell DNA was obtained from two donors (age 48 and 80 years). 14C levels were then determined using accelerator mass spectrometry (AMS). Cellular 'birth date' was determined by comparing the subject's DNA 14C content relative to a well-established 14C atmospheric prevalence curve. In the two subjects less than age 20 years, 1-2% of the beta-cell nuclei co-stained for BrdU/IdU. No beta-cell nuclei co-stained in the eight patients more than 30 years old. Consistent with the BrdU/IdU turnover data, beta-cell DNA 14C content indicated the cells 'birth date' occurred within the subject's first 30 years of life. Under typical circumstances, adult human beta-cells and their cellular precursors are established by young adulthood.

  17. Adult Human Pancreatic Islet Beta-Cells Display Limited Turnover and Long Lifespan as Determined by In-Vivo Thymidine Analog Incorporation and Radiocarbon Dating

    Energy Technology Data Exchange (ETDEWEB)

    Perl, S; Kushner, J A; Buchholz, B A; Meeker, A K; Stein, G M; Hsieh, M; Kirby, M; Pechhold, S; Liu, E H; Harlan, D M; Tisdale, J F

    2010-03-15

    Diabetes mellitus results from an absolute or relative deficiency of insulin producing pancreatic beta-cells. The adult human beta-cell's turnover rate remains unknown. We employed novel techniques to examine adult human islet beta-cell turnover and longevity in vivo. Subjects enrolled in NIH clinical trials received thymidine analogues [iododeoxyuridine (IdU) or bromodeoxyuridine (BrdU)] 8-days to 4-years prior to death. Archival autopsy samples from ten patients (aged 17-74 years) were employed to assess beta-cell turnover by scoring nuclear analog labeling within insulin staining cells. Human adult beta-cell longevity was determined by estimating the cells genomic DNA integration of atmospheric carbon-14 ({sup 14}C). DNA was purified from pancreatic islets isolated from cadaveric donors; whole islet prep DNA was obtained from a 15 year old donor, and purified beta-cell DNA was obtained from two donors (age 48 and 80 years). {sup 14}C levels were then determined using accelerator mass spectrometry (AMS). Cellular 'birth date' was determined by comparing the subject's DNA {sup 14}C content relative to a well-established {sup 14}C atmospheric prevalence curve. In the two subjects less than age 20 years, 1-2% of the beta-cell nuclei co-stained for BrdU/IdU. No beta-cell nuclei co-stained in the eight patients more than 30 years old. Consistent with the BrdU/IdU turnover data, beta-cell DNA {sup 14}C content indicated the cells 'birth date' occurred within the subject's first 30 years of life. Under typical circumstances, adult human beta-cells and their cellular precursors are established by young adulthood.

  18. Bringing AMS radiocarbon into the Anthropocene: Potential and drawbacks in the determination of the bio-fraction in industrial emissions and in carbon-based products

    Science.gov (United States)

    Quarta, Gianluca; Ciceri, Giovanni; Martinotti, Valter; D'Elia, Marisa; Calcagnile, Lucio

    2015-10-01

    In the frame of the general efforts to reduce atmospheric CO2 emissions different efforts are being carried out to stimulate the use of non-fossil energy sources and raw materials. Among these a significant role is played by the use of waste in Waste to Energy (WTE) plants. In this case a relevant problem is related to the determination of the proportion between the bio and the fossil derived fraction in CO2 atmospheric emissions since only the share of energy derived from the bio-fraction combustion can be labelled as "renewable". We discuss the potential of radiocarbon in this field by presenting the results of different campaigns carried out by analysing CO2 sampled at the stack of different power plants in Italy with different expected bio-content of the released carbon dioxide. The still open issues related to the calculation procedures and the achievable precision and accuracy levels are discussed.

  19. Radiocarbon Values From Otoliths of Regional Bottomfishes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data set contains bomb radiocarbon dating of opakapaka (Pristipomoides filamentosus) otoliths from recent and archival collections (1978-2008). Specimens were...

  20. Dirt, dates and DNA: Single-grain OSL and radiocarbon chronologies of perennially-frozen sediments, and their implications for sedimentary ancient DNA studies

    Science.gov (United States)

    Arnold, Lee J.; Roberts, Richard G.; Demuro, Martina; Macphee, Ross D. E.; Froese, Duane G.; Brock, Fiona; Willerslev, Eske

    2010-05-01

    Recent studies using 'sedimentary' ancient DNA (sedaDNA) techniques have demonstrated that sequence-based taxonomic identifications can be reliably made from perennially-frozen bulk sediment samples that are up to several hundred thousand years old. Amongst other possible uses, this technique provides the opportunity to search for genetic traces of extinct fauna in contexts in which in situ macrofossils are exceedingly rare or absent. In well controlled circumstances, sedaDNA can provide a sensitive tool for investigating species evolution and extinction dynamics. The use of sedaDNA techniques for this purpose, however, is reliant on the provision of reliable numerical age control directly on the bulk sediments from which DNA is extracted for analysis. An implicit assumption of the sedaDNA approach is that the extracted DNA is autochthonous with the host deposit and that it has not been physically transported from older source deposits or reworked within the sedimentary profile by post-depositional mixing. In this paper we investigate whether these fundamental conditions are upheld for (i) a range of perennially-frozen wetland sites across the Taimyr Peninsula and adjacent coastal lowlands of north-central Siberia, and (ii) locally-derived, perennially-frozen, loess sediments exposed along a 14.5 m thick river bluff sequence at the Stevens Village site, interior Alaska. Single-grain optically stimulated luminescence (OSL) and radiocarbon (14C) dating are combined to constrain the ages of both the inorganic and organic fractions of perennially-frozen deposits from which sedaDNA of extinct and extant species have been recovered. In doing so, we aim to provide new insights into the physical processes that can affect perennially-frozen sedaDNA sequences in high-latitude regions. OSL and 14C age/depth profiles, as well as single-grain equivalent dose (De) distribution characteristics, are used to assess the stratigraphic integrity of these sedaDNA sequences by (i

  1. Microgram level radiocarbon (14C) determination on carbonaceous particles in ice

    DEFF Research Database (Denmark)

    Jenk, Theo Manuel; Szidat, S.; Schwikowski, M.;

    2007-01-01

    Accelerator mass spectrometry; Organic carbon; Elemental carbon; Radiocarbon dating; Ice cores; Paleo-record Udgivelsesdato: June......Accelerator mass spectrometry; Organic carbon; Elemental carbon; Radiocarbon dating; Ice cores; Paleo-record Udgivelsesdato: June...

  2. Erosion of soil organic carbon at high latitudes and its delivery to Arctic Ocean sediments: New source to sink insight from radiocarbon dating

    Science.gov (United States)

    Hilton, Robert; Galy, Valier; Gaillardet, Jerome; Dellinger, Mathieu; Bryant, Charlotte; O'Regan, Matt; Grocke, Darren; Coxall, Helen

    2016-04-01

    Soils of the northern high latitudes store carbon over thousands of years and contain almost double the carbon stock of the atmosphere. Erosion processes can mobilise this pre-aged soil organic carbon from the landscape and supply it to rivers. If it escapes degradation during river transport and is delivered to the coastal ocean, this carbon may be sequestered for much longer periods of time (>104 yr) as a geological CO2 sink. Despite this recognition, the erosional flux and fate of particulate organic carbon (POC) in large rivers draining the high latitudes remains poorly constrained. Using radiocarbon activity, we quantify POC source, flux and fate in the Mackenzie River, the main sediment supplier to the Arctic Ocean. When combined with stable carbon isotopes and element ratios, the radiocarbon activity of POC allows us to distinguish inputs of POC from sedimentary rocks and quantify the average age of biospheric POC (from vegetation and soil) transported through the river system. We find that the eroded biospheric POC has resided in the basin for millennia, with a mean radiocarbon age of 5800±800 years. This is much older than large tropical rivers where we have equivalent data (Amazon River, Ganges River), and likely reflects the longer residence time of organic matter in cold, wet, high latitude soils. Based on the measured biospheric POC content and annual sediment flux, we calculate a biospheric POC flux of 2.2 (+1.3/-0.9) TgC yr‑1 from the Mackenzie River. This is the largest input of aged organic carbon to the Arctic Ocean, more than the combined POC flux from the Eurasian Rivers. Offshore, we use a marine core to investigate organic carbon burial over the Holocene period. Radiocarbon measurements of bulk organic carbon reveal a significant offset from benthic foraminifera radiocarbon ages throughout the core, which is dependent upon the grain size of the sediments. Organic matter in sediments >63μm are offset from foraminifera by ˜ 6,000 14C years

  3. Chemical Principles Revisited: Archaeological Dating.

    Science.gov (United States)

    Rowe, M. W.

    1986-01-01

    Discusses methods used to date archaeological artifacts and other remains. They include: (1) nuclear dating techniques (radiocarbon dating, accelerator radiocarbon dating, thermoluminescence, and others); (2) chemical dating techniques (amino acid racemization, obsidian hydration dating, elemental content changes, and thermal analysis dating); and…

  4. Le programme ARTEMIS : nouvel outil pour la datation radiocarbone AMS (Spectromètre de Masse par Accélérateur et nouvelles problématiques

    Directory of Open Access Journals (Sweden)

    Cyrille Billard

    2012-04-01

    Full Text Available La mise en route du nouvel équipement ARTEMIS (Accélérateur pour la Recherche en sciences de la Terre, Environnement, Muséologie, Implanté à Saclay à partir de 2004 ouvre de nouvelles perspectives scientifiques et conduit à de nouvelles procédures de soumission des échantillons destinés à une datation 14C. Le MCC dispose aujourd’hui de droits alloués aux services régionaux de l'archéologie, services du ministère de la Culture, confrontés à ce type de demandes (musées, monuments historiques. Il impose désormais une nouvelle démarche de programmation scientifique des datations, associant une analyse critique des demandes.Since 2004, the availability at Saclay of a new ARTEMIS installation (Accélérateur pour la Recherche en sciences de la Terre, Environnement, Muséologie has opened new scientific perspectives and led to new procedures for submitting samples for carbon-14 dating. The French Ministry of Culture has the possibility of using this tool for radiocarbon dating at the request of its regional archaeological services or other services, such as museums and the historic monuments administration. This use now implies a new approach to the scientific planning for dating problems, associated with a critical analysis of the requests.

  5. Temporal limits to the archaeological record in arid western NSW, Australia : lessons from OSL and radiocarbon dating of hearths and sediments

    International Nuclear Information System (INIS)

    The Western NSW Archaeology Program (WNSWAP) has been investigating surface scatters of Aboriginal stone artefacts and associated heat-retainer hearths in arid northwestern NSW, Australia, since 1995. The research combines new methods for documenting and analysing stone artefact scatters with an understanding of geomorphic landscape dynamics to seek insights into spatial and temporal patterns of Aboriginal occupation of the arid margin of Australia during the Late Holocene. The temporal dimension is dealt with in two ways: by radiocarbon determinations on charcoal from the remains of heat-retainer hearths associated with the artefact scatters, and by using optically simulated luminescence (OSL) and radiocarbon determinations from valley fill sediments to develop a chronology of landscape evolution of the valleys in which the artefacts and hearths are found. The heat-retainer hearths produced a record of just less than 2000 years of activity within the valley of Stud Creek, a 30 square km catchment in Sturt National Park. However, the record is discontinuous, with a gap in heat-retainer hearth construction of 200-400 years occurring between about 800 and 1100 y BP. Examination of patterns of erosion and deposition at the places where the hearths were found, and Bayesian statistical analysis of the radiocarbon determinations, demonstrates that this gap is real and not an artefact of the survey protocol. A discontinuous record is also evident when the sediments that comprise the valley fill upon which the hearths and stone artefact scatters are currently lying are examined. Five major sedimentary units can be identified, providing a record of depositional episodes ranging from modern or post-European back to the Late Pleistocene (about 70,000 years). But, in contrast to the record from the remains of the heat-retainer hearths, erosion is the major determinant of the temporal pattern of landscape change that can be reconstructed from this record. Gaps of up to 10

  6. Identifying sources of dissolved organic carbon in agriculturally dominated rivers using radiocarbon age dating: Sacramento-San Joaquin River Basin, California

    Science.gov (United States)

    Sickman, James O.; DiGiorgio, Carol L.; Davisson, M. Lee; Lucero, Delores M.; Bergamaschi, Brian A.

    2010-01-01

    We used radiocarbon measurements of dissolved organic carbon (DOC) to resolve sources of riverine carbon within agriculturally dominated landscapes in California. During 2003 and 2004, average Δ14C for DOC was -254‰ in agricultural drains in the Sacramento-San Joaquin Delta, -218‰ in the San Joaquin River, -175‰ in the California State Water Project and -152‰ in the Sacramento River. The age of bulk DOC transiting the rivers of California's Central Valley is the oldest reported for large rivers and suggests wide-spread loss of soil organic matter caused by agriculture and urbanization. Using DAX 8 adsorbent, we isolated and measured 14C concentrations in hydrophobic acid fractions (HPOA); river samples showed evidence of bomb-pulse carbon with average Δ14C of 91 and 76‰ for the San Joaquin and Sacramento Rivers, respectively, with older HPOA, -204‰, observed in agricultural drains. An operationally defined non-HPOA fraction of DOC was observed in the San Joaquin River with seasonally computed Δ14C values of between -275 and -687‰; the source of this aged material was hypothesized to be physically protected organic-matter in high clay-content soils and agrochemicals (i.e., radiocarbon-dead material) applied to farmlands. Mixing models suggest that the Sacramento River contributes about 50% of the DOC load in the California State Water Project, and agricultural drains contribute approximately one-third of the load. In contrast to studies showing stabilization of soil carbon pools within one or two decades following land conversion, sustained loss of soil organic matter, occurring many decades after the initial agricultural-land conversion, was observed in California's Central Valley.

  7. AMS exposure dating: evolution of river valley profiles across Himalayas during late Quaternary-Holocene

    International Nuclear Information System (INIS)

    River valley profile is one geomorphic feature, which contain relict landforms inherited from past periods with changing intensities of tectonic and climatic parameters. This aspect has been a subject of current research interest, using exposure dating technique. The results of some recent studies from major river valleys across Himalayas are being discussed

  8. In situ determination of 241Am on Enewetak Atoll. Date of survey: July 1977-December 1979

    International Nuclear Information System (INIS)

    An in situ gamma ray spectrometer system was operated at Enewetak Atoll from July 1977 to December 1979 in support of the Enewetak Cleanup Project. The system employed a high purity germanium planar detector suspended at a height of 7.4 m above ground. Conversion factors were established to relate measured photopeak count rate data to source concentration in the soil. Data obtained for 241Am, together with plutonium-to-americium ratios obtained from soil sample analyses, were used to establish area-averaged surface (0 to 3 cm) transuranic concentration values. In areas which exceeded cleanup criteria, measurements were made in an iterative fashion to guide soil removal until levels were reduced below the cleanup criteria. Final measurements made after soil removal had been completed were used to document remaining surface transuranic concentration values and to establish external exposure rate levels due to 137Cs and 60Co

  9. Radiocarbon dating of organic matter fractions of peat sample and utility of 13C/12C ratios as a record of vegetation

    International Nuclear Information System (INIS)

    The purpose of the investigation is to make clear the informations given by the isotopic composition of the carbon in the peat sample taken from the late Quaternary deposits. The radiocarbon concentration in the peat or the peaty soil may give the time of sedimentation when the carbon in this layer is free from the contamination of young organic materials. A peaty soil sample gave the younger age of HA 2 than that of HA 1, suggesting that the secondary adsorbed younger organic materials were bound to the surface of clay minerals stronger than originally existed organic matters. This may be interpreted by a plausible hypothesis that the organic materials transported from the upper layer adsorbed on mineral surfaces which have been created continuously by wheathering after the deposition of soil. The difference between the ages given by HA 1 and HA 2 is useful for the estimation of the amount of younger contaminants of carbon in peaty soil samples. The delta 13C values of the organic matters in the late Quaternary deposit suggest the vegetation at the time of deposition. (Kobatake, H.)

  10. First direct dating of Late Pleistocene ice-wedges by AMS

    OpenAIRE

    Vasil'chuk, YK; Van Der Plicht, J.; Jungner, H.; Sonninen, E; Vasil'chuk, AC; Vasil'chuk, Yurij K.; Vasil'chuk, Alla C.

    2000-01-01

    We present the first direct dating by C-14-accelerator mass spectrometry of three Late Pleistocene syngenetic ice-wedges from the Seyaha cross-section. They are representative of permafrost with multistage ice-wedges from the North of Western Siberia. The most important result is the clear vertical age stratification of the ice, i.e. the old ice is located beneath the young. This shows that a timescale can be assigned to these ice-wedges penetrating down into the permafrost. The age of the ic...

  11. Bomb radiocarbon in metabolically inert tissues from terrestrial and marine mammals

    International Nuclear Information System (INIS)

    We report here radiocarbon measurements of monkey eye lens nucleus proteins and a narwhal tusk, biological tissues which have sampled the bomb radiocarbon signal in different ways. The results confirm the metabolic inertness of eye lens nucleus proteins and demonstrate the feasibility of measuring radiocarbon in small samples of biological tissue using accelerator mass spectrometry (AMS). The narwhal tusk provides a unique record of the radiocarbon activity in Arctic Ocean waters over most of the 20th century

  12. Radiocarbon (AMS) dating the Classic Aurignacian, Proto-Aurignacian and Vasconian Mousterian at Gatzarria Cave (Pyrénées-Atlantiques, France)

    OpenAIRE

    Barshay-Szmidt, Carolyn C.; Eizenberg, Laura; Deschamps, Marianne

    2013-01-01

    The site of Gatzarria (Pyrenean France) was excavated in the 1960s and 1970s by Georges Laplace. The importance of the site lies in the fact that it contains a stratified sequence of Aurignacian industries (Proto-Aurignacian — Classic Aurignacian — Late Aurignacian), a Châtelperronian layer, as well as a long sequence of Mousterian layers (including what has been termed the Vasconian Mousterian). It is thus a key site for assessing the Middle to Upper Palaeolithic transition as well as the te...

  13. New Zealand radiocarbon database for archaeology

    International Nuclear Information System (INIS)

    The first radiocarbon determinations from New Zealand archaeological sites were obtained about 50 years ago. Since that time, many hundreds of samples have been dated, and for the archaeologist interested in synthesising these various data into coherent regional and national chronologies, the problem of compiling results is a difficult one to overcome. Adequately assessing important radiocarbon-related variables such as the material dated, the context of the sample, the age, standard error, correction factors and a host of other variables, depends upon time consuming effort to compile and decipher past sample record forms at IGNS and Waikato Laboratories. (author)

  14. Applications of radiocarbon measurements in environmental studies at INFN-LABEC, Florence

    Directory of Open Access Journals (Sweden)

    Chiari M.

    2012-04-01

    Full Text Available Radiocarbon is one of the most widespread radionuclides in nature. Although it is probably best known for dating in archaeology, in the case of the general public, it represents a useful tracer to study our environment, both in the past and nowadays. For instance, carbonaceous particles, which are in many cases the most abundant among aerosols constituents, are believed to play a major role in both health and climatic effects of aerosols. In particular, measurement of radiocarbon concentration in particulate matter samples can give information on the contributions of the fossil fuels combustion and of natural sources to the carbonaceous fraction in aerosols. These measurements are especially effective when separately performed on different carbonaceous fractions, like elemental and organic carbon (EC and OC, respectively. Past climate is also studied thanks to old archives, as e.g. marine sediments can be. In this case, instead of radiocarbon dating the bulk sediment, a reliable method to fix chronological markers is represented by dating foraminifera tests of CaCO3 picked from different layers in the sediment. Both the aforementioned applications are characterized by the fact that the samples that can be collected for 14C measurements are typically very small, i.e. few mg or less (before any treatment. Accelerator Mass Spectrometry (AMS is thus the only technique that can be applied to measure radiocarbon in such samples. Anyway, measurements cannot be so straightforward. In the case of the measurement of radiocarbon concentration in aerosol samples, a preparation line especially dedicated to the extraction of only the carbonaceous fraction of interest is mandatory. Actually, this line should include a combustion oven, from which either total carbon or EC and OC can separately evolve, and a system of traps to purify and collect the CO2. In the case of foraminifera tests (inorganic carbon, special care must be taken in the pre-treatment phase

  15. The AMS 14C dating of Iron Age rice chaff ceramic temper from Ban Non Wat, Thailand: First results and its interpretation

    Science.gov (United States)

    Higham, Charles F. W.; Kuzmin, Yaroslav V.; Burr, G. S.

    2010-04-01

    Pottery tempered with rice chaff from the early Iron Age cemetery of Ban Non Wat site, northeast Thailand, has been subjected to direct AMS 14C dating, using low temperature combustion with oxygen as originally developed by authors. The carbon yield (0.2-0.5%) testifies the suitability of this pottery for dating. However, not all the results are in agreement with expected archaeological ages and other 14C dates from the studied site and neighboring site of Noen U-Loke. This calls for a thorough analysis and interpretation of pottery temper dates from the region.

  16. The AMS 14C dating of Iron Age rice chaff ceramic temper from Ban Non Wat, Thailand: First results and its interpretation

    International Nuclear Information System (INIS)

    Pottery tempered with rice chaff from the early Iron Age cemetery of Ban Non Wat site, northeast Thailand, has been subjected to direct AMS 14C dating, using low temperature combustion with oxygen as originally developed by authors. The carbon yield (0.2-0.5%) testifies the suitability of this pottery for dating. However, not all the results are in agreement with expected archaeological ages and other 14C dates from the studied site and neighboring site of Noen U-Loke. This calls for a thorough analysis and interpretation of pottery temper dates from the region.

  17. Changes in solar activity and Holocene climatic shifts derived from 14C wiggle-match dated peat deposits

    NARCIS (Netherlands)

    Mauquoy, Dmitri; Geel, Bas van; Blaauw, Maarten; Speranza, Alessandra; Plicht, Johannes van der

    2004-01-01

    Closely spaced sequences of accelerator mass spectrometer (AMS) 14C dates of peat deposits display century-scale wiggles which can be fitted to the radiocarbon calibration curve. By wiggle-matching such sequences, high-precision calendar age chronologies can be generated which show that changes in m

  18. Radiocarbon concentration of lake sediment cellulose from Lake Erhai in southwest China

    International Nuclear Information System (INIS)

    To improve age models for lake sediment cores without suitable 14C dating materials such as terrestrial plant fossils, we investigated the radiocarbon dating of lake sediment cellulose. The cellulose fraction in the sediments was obtained by a sequential decomposition of other organic matter, and subsequently dated by AMS. In general, 14C ages of the lake sediment cellulose obtained from a 10-m sediment core from Lake Erhai on the Yunnan-Guizhou Plateau are in agreement with 14C dates from terrestrial plant fossils. For the early Holocene, however, differences of up to 1000 14C years are observed between lake sediment cellulose and terrestrial plant fossils. This disagreement is probably caused by the contribution of 14C-depleted cellulose synthesized by aquatic plants/algae in the lake. To obtain a precise and accurate chronology based on 14C ages of lake sediment cellulose, the origin of lake sediment cellulose needs to be established

  19. AMS-dated mollusks in beach ridges and berms document Holocene sea-level and coastal changes in northeastern Kuwait Bay

    Science.gov (United States)

    Reinink-Smith, Linda M.

    2015-09-01

    In northeastern Kuwait, ancient beach ridges and associated berms are separated from the present shoreline by a 4-6 km-wide sabkha. A diverse mollusk fauna in the beach ridges attests to a former open marine environment. A total of 21 AMS dates were obtained in this study. Thirteen mollusk samples from beach ridges yielded AMS dates ranging from ~ 6990 cal yr BP in the southeast to ~ 3370 cal yr BP in the northwest, suggesting a southeast to northwest age progression during the Holocene transgression. In contrast, four samples from berms throughout the study area yielded AMS dates of 5195-3350 cal yr BP showing no age progression; these berms consist largely of Conomurex persicus gastropods that aggregated by storms during a highstand at ~ 5000-3500 cal yr BP. The berms are presently at ~ + 6 m above sea level, 2-3 m above the beach ridges. Human settlements were common on the ridge crests before and after the highstand. Regression to present-day sea level commenced after the highstand, which is when the sabkha began forming. A landward, marine-built terrace, which yielded AMS dates > 43,500 14C yr BP, probably formed during Marine Oxygen Isotope Stage 5e and hence is not genetically related to the beach ridges.

  20. 41 CFR 301-11.10 - Am I required to record departure/arrival dates and times on my travel claim?

    Science.gov (United States)

    2010-07-01

    ... departure/arrival dates and times on my travel claim? 301-11.10 Section 301-11.10 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES ALLOWABLE TRAVEL EXPENSES 11-PER DIEM EXPENSES General Rules § 301-11.10 Am I required to record...

  1. A decade of AMS at University of Georgia

    Energy Technology Data Exchange (ETDEWEB)

    Culp, Randy, E-mail: rculp@uga.edu [Center for Applied Isotope Studies, University of Georgia, Athens, GA (United States); Noakes, John; Cherkinsky, Alex; Ravi Prasad, G.V.; Dvoracek, Doug [Center for Applied Isotope Studies, University of Georgia, Athens, GA (United States)

    2013-01-15

    In a span of 10 years, University of Georgia's Center for Applied Isotope Studies (CAIS) has transformed itself from principally a liquid scintillation counting (LSC) laboratory to one conducting thousands of accelerator mass spectrometry (AMS) and stable isotope ratio analysis (SIRA) annually. After receiving the first of the NEC compact AMS units in the United States, the CAIS began to meet the demand for {sup 14}C analysis outside the normal realm of most radiocarbon dating laboratories. With industry's support, isotope research continued on an already developing natural products program to authenticate materials origin and process of formation. The CAIS's AMS allowed for the detection of synthetic materials in milligram quantities rather than gram quantities required by LSC and allowed new compound specific SIRA techniques to be directed toward compound specific {sup 14}C measurement. By 2005 the CAIS was one of only a few laboratories accredited to determine bio-base content in industrial fuels and products by both AMS and LSC following ASTM D6866-10 [1]. Since 2001, when our first sample was analyzed by AMS method, both radiocarbon and natural products sample numbers have increased steadily. The advantages of AMS analysis in overall efficiency, cost savings, accuracy, and precision, are detailed here in a review of analytical precision for radiocarbon and natural products analyzed over 10 years of AMS operation. Comparisons are made between natural products and bio-based materials analyzed by both AMS and LSC. Although high precision is not required to authenticate natural products, for the purpose of product comparison with regard to degree of naturalness accurate and precise {sup 14}C measurement is shown to be achievable by both methods.

  2. Dating Cactus: Annual and Sub-annual Variations of Oxygen-18, Carbon-13 and Radiocarbon in Spines of a Columnar Cactus, Carnegiea gigantea.

    Science.gov (United States)

    Dettman, D. L.; English, N. B.; Sandquist, D. R.; Williams, D. G.

    2006-12-01

    We measured δ18O, δ13C and F14C of spines from a long-lived columnar cactus, Carnegiea gigantea (saguaro), to resolve a record of plant physiological responses to annual and sub-annual climate variation in the eastern Sonoran Desert. Spines grow from the apex of the cactus and are arranged serially along the side of the cactus oldest at the base, youngest at the apex. To establish the age of the spine series, we measured F14C of spines collected at 8 different heights from the apex (3.77 m) to the base of a naturally occurring saguaro. These spines yielded fractions of modern carbon (F14C) from 0.9679 and 1.5537, indicating the presence of carbon in spine tissue derived from atmospheric nuclear testing. We used the F14C of spine tissue to calculate the year of spine emergence for each of the 11 spines, assuming minimal re-allocation of stored carbon to growing spines. At the same 8 heights, we interpolated the date of spine emergence from observed height measurements made between 1964 and 2002. A very strong positive correlation (linear regression, r2 = 0.99, P saguaro (between 1.77 and 3.50 m) and representing ~15 years of growth, yielded δ18O variations in spine bulk organic material from 38° to 50° (VSMOW) and in δ13C from ° to 11.5° (VPDB). The δ18O and δ13C values were positively correlated over the entire record (linear regression, r2 = 0.22, P saguaro 30 km distant. Temporal isotopic records from saguaro and potentially other long-lived succulent plants may provide useful high-frequency records of ecological responses to climate variation in desert environments where other such records are lacking.

  3. State of the Art of the all-Optical Radiocarbon Detection (Invited)

    Science.gov (United States)

    Cancio Pastor, P.; Mazzotti, D.; Galli, I.; Giusfredi, G.; Bartalini, S.; Cappelli, F.; De Natale, P.

    2013-12-01

    Radiocarbon (14C), the 'natural clock' for dating organic matter, is a very elusive atom. Its present concentration is about one part per trillion. For the past 30 years, accelerator mass spectrometry (AMS) has been adopted as the standard method for detecting such carbon isotope at concentrations well below its natural abundance (3 parts per quadrillion). AMS requires a smaller carbon mass and shorter measurement times than the old standard method of liquid scintillation counting. However, AMS requires huge, expensive and high-maintenance experimental facilities. We have developed a laser spectroscopy technique that is sensitive enough to detect the radiocarbon dioxide molecules at very low concentrations with an all-optical setup that is orders of magnitude more compact and less expensive than AMS [1]. The optical spectroscopy approach is based in the detection of very weak absorption of IR laser light by a 14C-containing molecule as 14C-Carbon Dioxide. Spectroscopic techniques as Cavity Ring Down (CRD) spectroscopy that uses the kilometric absorption paths provided by high-Finesse Fabry-Perot cavities have revolutionized the trace gas detection of molecular species in terms of ultimate sensitivity. Nevertheless CRD has been not capable to detect very elusive molecules as radiocarbon Dioxide. The new developed technique, named SCAR (saturated-absorption cavity ring-down), makes use of molecular absorption saturation to enhance resolution and sensitivity with respect to conventional CRD [2]. By combining SCAR with a frequency-comb-linked CW coherent source, which delivers tunable radiation (around 4.5-μm wavelength) [3], we could set an unprecedented limit in trace gas detection, accessing the part-per-quadrillion concentration range. Comparison between AMS and SCAR techniques to detect 14C by measuring the same carbon samples shows SCAR-based results are currently one order of magnitude shy of challenging AMS, but there is still room for improvement [4

  4. ESR and AMS-based 14C Dating of Mousterian Levels at Mujina Pećina, Dalmatia, Croatia

    NARCIS (Netherlands)

    Rink, W.J.; Karavanić, I.; Pettitt, P.B.; Plicht, J. van der; Smith, F.H.; Bartoll, J.; Karavanic, I.

    2002-01-01

    This paper presents the first chronometric dates for sediments that contain a Mousterian industry in Dalmatia (south Croatia). Electron spin resonance (ESR) dating was conducted on two teeth from the Mousterian level E1 at the site of Mujina Pećina. Additionally five bone and one charcoal sample fro

  5. 14C AMS dates on Rattus exulans bones from natural and archaeological contexts on Norfolk Island, south-west Pacific

    International Nuclear Information System (INIS)

    The Pacific rat (Rattus exulans) was transported throughout the western Pacific by migrant peoples in prehistory. Meredith et al (1985) reported a minimum date for the presence of Rattus exulans on Norfolk Island using dates on charcoal from an apparently enclosing layer (the upper part of their Unit C4) in Cemetery Bay. 8 refs., 3 tabs

  6. Changes in the radiocarbon reservoir age in Lake Xingyun, Southwestern China during the Holocene.

    Directory of Open Access Journals (Sweden)

    Aifeng Zhou

    Full Text Available Chronology is a necessary component of paleoclimatology. Radiocarbon dating plays a central role in determining the ages of geological samples younger than ca. 50 ka BP. However, there are many limitations for its application, including radiocarbon reservoir effects, which may cause incorrect chronology in many lakes. Here we demonstrate temporal changes in the radiocarbon reservoir age of Lake Xingyun, Southwestern China, where radiocarbon ages based on bulk organic matter have been reported in previous studies. Our new radiocarbon ages, determined from terrestrial plant macrofossils suggest that the radiocarbon reservoir age changed from 960 to 2200 years during the last 8500 cal a BP years. These changes to the reservoir effect were associated with inputs from either pre-aged organic carbon or 14C-depleted hard water in Lake Xingyun caused by hydrological change in the lake system. The radiocarbon reservoir age may in return be a good indicator for the carbon source in lake ecosystems and depositional environment.

  7. Bomb-curve radiocarbon measurement of recent biologic tissues and applications to wildlife forensics and stable isotope (paleo)ecology

    OpenAIRE

    Uno, Kevin T.; Quade, Jay; Fisher, Daniel C.; Wittemyer, George; Douglas-Hamilton, Iain; Andanje, Samuel; Omondi, Patrick; Litoroh, Moses; Cerling, Thure E.

    2013-01-01

    Above-ground thermonuclear weapons testing from 1952 through 1962 nearly doubled the concentration of radiocarbon (14C) in the atmosphere. As a result, organic material formed during or after this period may be radiocarbon-dated using the abrupt rise and steady fall of the atmospheric 14C concentration known as the bomb-curve. We test the accuracy of accelerator mass spectrometry radiocarbon dating of 29 herbivore and plant tissues collected on known dates between 1905 and 2008 in East Africa...

  8. Gas chromatographic isolation technique for compound-specific radiocarbon analysis

    International Nuclear Information System (INIS)

    Full text: We present here a gas chromatographic isolation technique for the compound-specific radiocarbon analysis of biomarkers from the marine sediments. The biomarkers of fatty acids, hydrocarbon and sterols were isolated with enough amount for radiocarbon analysis using a preparative capillary gas chromatograph (PCGC) system. The PCGC systems used here is composed of an HP 6890 GC with FID, a cooled injection system (CIS, Gerstel, Germany), a zero-dead-volume effluent splitter, and a cryogenic preparative collection device (PFC, Gerstel). For AMS analysis, we need to separate and recover sufficient quantity of target individual compounds (>50 μgC). Yields of target compounds from C14 n-alkanes to C40 to C30 n-alkanes and approximately that of 80% for higher molecular weights compounds more than C30 n-alkanes. Compound specific radiocarbon analysis of organic compounds, as well as compound-specific stable isotope analysis, provide valuable information on the origins and carbon cycling in marine system. Above PCGC conditions, we applied compound-specific radiocarbon analysis to the marine sediments from western north Pacific, which showed the possibility of a useful chronology tool for estimating the age of sediment using organic matter in paleoceanographic study, in the area where enough amounts of planktonic foraminifera for radiocarbon analysis by accelerator mass spectrometry (AMS) are difficult to obtain due to dissolution of calcium carbonate. (author)

  9. AMS and controversies in history: The Spanish conquest of Peru

    International Nuclear Information System (INIS)

    The quest for understanding the past often contains a subjective component. Legends, myths, traditions and personal beliefs can unconsciously influence the interpretation of the scientific outcomes or, in the worst instances, even lead to forgery. Fortunately, an increasing number of scientific tools are available nowadays and can be combined to discredit such detriments and offer more reliable foundations for an objective analysis. Radiocarbon dating by AMS is a relatively non-invasive method and is particularly useful when valuable historical artefacts are involved. In this paper, we will present controversial cases where AMS is playing an important role in understanding the past. In particular, we will discuss the use of AMS to authenticate historical documents revealing a new version of the conquest of Peru by Pizarro in the early 1530s

  10. AMS and controversies in history The Spanish conquest of Peru

    CERN Document Server

    Zoppi, U; Jacobsen, G; Laurencich-Minelli, L; Lawson, E M; Sarkisian, G; Tuniz, C

    2000-01-01

    The quest for understanding the past often contains a subjective component. Legends, myths, traditions and personal beliefs can unconsciously influence the interpretation of the scientific outcomes or, in the worst instances, even lead to forgery. Fortunately, an increasing number of scientific tools are available nowadays and can be combined to discredit such detriments and offer more reliable foundations for an objective analysis. Radiocarbon dating by AMS is a relatively non-invasive method and is particularly useful when valuable historical artefacts are involved. In this paper, we will present controversial cases where AMS is playing an important role in understanding the past. In particular, we will discuss the use of AMS to authenticate historical documents revealing a new version of the conquest of Peru by Pizarro in the early 1530s.

  11. Characterization of recent Lake Tahoe fault activity: Combining Sub-Meter Resolution Seismic Imagery with AMS C-14 Dated Submerged Paleo-Surfaces.

    Science.gov (United States)

    Dingler, J. A.; Kent, G. M.; Babcock, J. A.; Driscoll, N. W.; Harding, A. J.; Gayes, P. T.; Karlin, B.; Morgan, C. W.; Heyvaert, A.; Richards, B. C.

    2002-12-01

    Deformational strain within the Lake Tahoe Basin was mapped during previous campaigns using a combination of high resolution seismic CHIRP, multi-beam swath bathymetry, and airborne laser altimetry. These previous campaigns identified submerged paleo-shorelines of Pleistocene to early Holocene age, which act as a tectonic strain marker due to fault related disruptions of this once flat surface, as well as significantly offset fault scarps. Building upon this previous work, specific sites were selected for additional investigation with seismic CHIRP and AMS C-14 dated vibra and piston cores. The combination of these three techniques is ideally suited for quantifying recent fault activity through the correlation of paleo-surfaces and accurate age determinations. Initial analysis of seismic CHIRP and piston coring conducted in Emerald Bay shows a complex normal fault system with a sedimentation rate much higher than other parts of the lake. Seismic CHIRP conducted near Zephyr Cove was able to image multiple paleo-shorelines. Vibra coring of these same surfaces recovered sands of the same consistency as beach sand. Additional piston cores were collected at various lake locations below 400 m depth, including two cores taken across the Stateline Fault. Core analysis and AMS C-14 dating combined with site-specific seismic CHIRP, and previous mapping, will improve chronological control on the fault activity within the Lake Tahoe Basin.

  12. Comment on "Radiocarbon Calibration Curve Spanning 0 to 50,000 Years B.P. Based on Paired 230Th/234U/238U and 14C Dates on Pristine Corals" by R.G. Fairbanks, R. A. Mortlock, T.-C. Chiu, L. Cao, A. Kaplan, T. P. Guilderson, T. W. Fairbanks, A. L. Bloom, P

    Energy Technology Data Exchange (ETDEWEB)

    Reimer, P J; Baillie, M L; Bard, E; Beck, J W; Blackwell, P G; Buck, C E; Burr, G S; Edwards, R L; Friedrich, M; Guilderson, T P; Hogg, A G; Hughen, K A; Kromer, B; McCormac, G; Manning, S; Reimer, R W; Southon, J R; Stuiver, M; der Plicht, J v; Weyhenmeyer, C E

    2005-10-02

    Radiocarbon calibration curves are essential for converting radiocarbon dated chronologies to the calendar timescale. Prior to the 1980's numerous differently derived calibration curves based on radiocarbon ages of known age material were in use, resulting in ''apples and oranges'' comparisons between various records (Klein et al., 1982), further complicated by until then unappreciated inter-laboratory variations (International Study Group, 1982). The solution was to produce an internationally-agreed calibration curve based on carefully screened data with updates at 4-6 year intervals (Klein et al., 1982; Stuiver and Reimer, 1986; Stuiver and Reimer, 1993; Stuiver et al., 1998). The IntCal working group has continued this tradition with the active participation of researchers who produced the records that were considered for incorporation into the current, internationally-ratified calibration curves, IntCal04, SHCal04, and Marine04, for Northern Hemisphere terrestrial, Southern Hemisphere terrestrial, and marine samples, respectively (Reimer et al., 2004; Hughen et al., 2004; McCormac et al., 2004). Fairbanks et al. (2005), accompanied by a more technical paper, Chiu et al. (2005), and an introductory comment, Adkins (2005), recently published a ''calibration curve spanning 0-50,000 years''. Fairbanks et al. (2005) and Chiu et al. (2005) have made a significant contribution to the database on which the IntCal04 and Marine04 calibration curves are based. These authors have now taken the further step to derive their own radiocarbon calibration extending to 50,000 cal BP, which they claim is superior to that generated by the IntCal working group. In their papers, these authors are strongly critical of the IntCal calibration efforts for what they claim to be inadequate screening and sample pretreatment methods. While these criticisms may ultimately be helpful in identifying a better set of protocols, we feel that there are

  13. In situ determination of /sup 241/Am on Enewetak Atoll. Date of survey: July 1977-December 1979

    Energy Technology Data Exchange (ETDEWEB)

    Tipton, W.J.; Fritzsche, A.E.; Jaffe, R.J.; Villaire, A.E.

    1981-11-01

    An in situ gamma ray spectrometer system was operated at Enewetak Atoll from July 1977 to December 1979 in support of the Enewetak Cleanup Project. The system employed a high purity germanium planar detector suspended at a height of 7.4 m above ground. Conversion factors were established to relate measured photopeak count rate data to source concentration in the soil. Data obtained for /sup 241/Am, together with plutonium-to-americium ratios obtained from soil sample analyses, were used to establish area-averaged surface (0 to 3 cm) transuranic concentration values. In areas which exceeded cleanup criteria, measurements were made in an iterative fashion to guide soil removal until levels were reduced below the cleanup criteria. Final measurements made after soil removal had been completed were used to document remaining surface transuranic concentration values and to establish external exposure rate levels due to /sup 137/Cs and /sup 60/Co.

  14. Ancient Egypt measured by radio-carbon

    International Nuclear Information System (INIS)

    The authors recall how carbon dating has been used for decades in Egyptian archaeology, and how biases and errors have been solved. They also describe how this technique is now supported by accelerator mass spectrometry (AMS), and thus allowed a better chronological knowledge of the Egyptian history. AMS indeed allows the measuring of extremely small isotopic rates from very small archaeological samples

  15. AMS dating of a recently rediscovered juvenile human mandible from Solutré (Saône-et-Loire, France)

    OpenAIRE

    Pestle, William; Colvard, Michael; Pettitt, Paul

    2009-01-01

    Nearly 150 years of excavation at the Upper Paleolithic type-site of Solutré has yielded substantial evidence for Late Pleistocene human occupation, food procurement, and tool manufacture in the Mâconnais. To date, however, no human skeletal material from the Solutrean phase of this eponymous site has been discovered. Among the finds curated by the Field Museum of Natural History resulting from a relatively obscure and poorly documented excavation conducted at the heart of the site in 1896 is...

  16. Methodological study on exposure date of Tiankeng by AMS measurement of in situ produced cosmogenic {sup 36}Cl

    Energy Technology Data Exchange (ETDEWEB)

    Dong Kejun [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Li Shizhuo [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); CNNC China North Nuclear Fuel Company Ltd., Baotou 014035 (China); He Ming [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Sasa, Kimikazu [Tandem Accelerator Complex, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Matsushi, Yuki [Disaster Prevention Research Institute, Kyoto University (Japan); Huang Baojian [Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004 (China); Ruan Xiangdong; Guan Yongjing [College of Physics Science and Technology, Guangxi University, Nanning 530004 (China); Takahashi, Tsutomu [Tandem Accelerator Complex, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Sueki, Keisuke [Graduate School of Pure and Applied Sciences, University of Tsukuba (Japan); Li Chaoli; Wu Shaoyong [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Wang Xianggao [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004 (China); Shen Hongtao [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China); College of Physics and Technology, Guangxi Normal University, Guilin 541004 (China); Nagashima, Yasuo [Tandem Accelerator Complex, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Jiang Shan, E-mail: jiangs@ciae.ac.cn [China Institute of Atomic Energy, P.O. Box 275(50), Beijing 102413 (China)

    2013-01-15

    Tiankeng is a typical Karst relief of the late Quaternary Period. Studies on the exposure ages of Tiankeng are very important in geographical research to elucidate the formation condition, the developing process, and the features of biological species. {sup 36}Cl on the surface layer of the rupture cross-section of Tiankeng is largely produced by cosmogenic high-energy neutron induced reactions {sup 40}Ca(n, {alpha}p) and {sup 39}K(n, {alpha}), and has accumulated since the formation of the Tiankeng. Low-energy neutron reaction {sup 35}Cl(n, {gamma}) contributes a small portion of {sup 36}Cl. In this work, the concentration of the cosmogenic {sup 36}Cl in rock samples taken from Dashiwei Tiankeng, Leye County, Guangxi Zhuang Autonomous Region, China, was measured jointly by Accelerator Mass Spectrometry (AMS) laboratories of CIAE and University of Tsukuba in an effort to estimate the formation time (or exposure age) of the Tiankeng. The results show that the exposure time of Da Shiwei Tiankeng is about 26 {+-} 9.6 ka (without erosion correction). The sampling strategy and procedures, experimental set-up, and preliminary results will be presented in detail.

  17. Radiocarbon ages from the northern Great Barrier Reef

    International Nuclear Information System (INIS)

    Results are reported from the 1973 Great Barrier Reef Expedition's radiocarbon dating programme with respect to all ages determined to date. Field and laboratory methods used are described and the reliability of the ages in terms of (i) the actual materials dated and (ii) the geomorphic, ecological or stratigraphic units from which the samples were obtained are assessed. Seventy-nine determinations based on 74 samples are reported. No interpretation of the results is attempted. (U.K.)

  18. Holocene megathermal abrupt environmental changes derived from 14C dating of a coral reef at Leizhou Peninsula, South China Sea

    International Nuclear Information System (INIS)

    A depth profile of a Goniopora coral reef at Leizhou Peninsula, South China Sea, was radiocarbon dated using liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS). The time of formation, during 6600-7400 cal BP, can be divided into nine stages, each terminated by abrupt growth cessation of Goniopora and appearance of Ostrea shells. The results show that, during the Holocene megathermal (8.2-3.3 ka BP), large climatic changes have occurred in the South China Sea area

  19. Studies on the radiocarbon sample from the shroud of turin

    International Nuclear Information System (INIS)

    In 1988, radiocarbon laboratories at Arizona, Cambridge, and Zurich determined the age of a sample from the Shroud of Turin. They reported that the date of the cloth's production lay between A.D. 1260 and 1390 with 95% confidence. This came as a surprise in view of the technology used to produce the cloth, its chemical composition, and the lack of vanillin in its lignin. The results prompted questions about the validity of the sample. Preliminary estimates of the kinetics constants for the loss of vanillin from lignin indicate a much older age for the cloth than the radiocarbon analyses. The radiocarbon sampling area is uniquely coated with a yellow-brown plant gum containing dye lakes. Pyrolysis-mass-spectrometry results from the sample area coupled with microscopic and microchemical observations prove that the radiocarbon sample was not part of the original cloth of the Shroud of Turin. The radiocarbon date was thus not valid for determining the true age of the shroud

  20. Studies on the radiocarbon sample from the shroud of turin

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Raymond N. [Los Alamos National Laboratory, University of California, 1961 Cumbres Patio, Los Alamos, NM 87544 (United States)]. E-mail: rnrogers@att.net

    2005-01-20

    In 1988, radiocarbon laboratories at Arizona, Cambridge, and Zurich determined the age of a sample from the Shroud of Turin. They reported that the date of the cloth's production lay between A.D. 1260 and 1390 with 95% confidence. This came as a surprise in view of the technology used to produce the cloth, its chemical composition, and the lack of vanillin in its lignin. The results prompted questions about the validity of the sample. Preliminary estimates of the kinetics constants for the loss of vanillin from lignin indicate a much older age for the cloth than the radiocarbon analyses. The radiocarbon sampling area is uniquely coated with a yellow-brown plant gum containing dye lakes. Pyrolysis-mass-spectrometry results from the sample area coupled with microscopic and microchemical observations prove that the radiocarbon sample was not part of the original cloth of the Shroud of Turin. The radiocarbon date was thus not valid for determining the true age of the shroud.

  1. In search of in-situ radiocarbon in Law Dome ice and firn

    CERN Document Server

    Smith, A M; Etheridge, D M; Lowe, D C; Hua, Q; Trudinger, C M; Zoppi, U; El-Cheikh, A

    2000-01-01

    Results of AMS radiocarbon measurements on CO and CO sub 2 separated from firn air directly pumped from the ice sheet, and on CO sub 2 separated from air extracted from ice cores by a dry grating technique, are presented. The firn air samples and ice cores used in this study were collected from the region of Law Dome, Antarctica. No evidence of in-situ sup 1 sup 4 CO sub 2 was found in the firn air samples or the ice core air samples from one site although a slight enhancement of sup 1 sup 4 CO above expected polar atmospheric concentrations was observed for some firn air samples. A clear in-situ sup 1 sup 4 CO sub 2 signal for ice pre-dating the radiocarbon bomb pulse was found, however, in air samples extracted from an ice core from a second site. We compare these results and propose an hypothesis to explain this apparent contradiction. The degree to which in-situ sup 1 sup 4 C is released from the ice crystals during trapping and bubble formation is considered and discussed. The selectivity of the dry grat...

  2. In search of in-situ radiocarbon in Law Dome ice and firn

    International Nuclear Information System (INIS)

    Results of AMS radiocarbon measurements on CO and CO2 separated from firn air directly pumped from the ice sheet, and on CO2 separated from air extracted from ice cores by a dry grating technique, are presented. The firn air samples and ice cores used in this study were collected from the region of Law Dome, Antarctica. No evidence of in-situ 14CO2 was found in the firn air samples or the ice core air samples from one site although a slight enhancement of 14CO above expected polar atmospheric concentrations was observed for some firn air samples. A clear in-situ 14CO2 signal for ice pre-dating the radiocarbon bomb pulse was found, however, in air samples extracted from an ice core from a second site. We compare these results and propose an hypothesis to explain this apparent contradiction. The degree to which in-situ 14C is released from the ice crystals during trapping and bubble formation is considered and discussed. The selectivity of the dry grating technique for the extraction of trapped atmospheric gases from ice cores is also discussed and compared with other methods

  3. Radiocarbon application in environmental science and archaeology in Croatia

    Energy Technology Data Exchange (ETDEWEB)

    Krajcar Bronic, I., E-mail: krajcar@irb.h [Radiocarbon Laboratory, Department of Experimental Physics, Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia); Obelic, B.; Horvatincic, N.; Baresic, J.; Sironic, A. [Radiocarbon Laboratory, Department of Experimental Physics, Ruder Boskovic Institute, Bijenicka 54, 10000 Zagreb (Croatia); Minichreiter, K. [Institute of Archaeology, Ulica grada Vukovara 68, 10000 Zagreb (Croatia)

    2010-07-21

    Radiocarbon is a cosmogenic radioisotope equally distributed throughout the troposphere and biosphere. This fact enables its most common application-radiocarbon dating. Natural equilibrium of radiocarbon has been disturbed by diverse anthropogenic activities during the last {approx}150 years, enabling also the use of {sup 14}C in various environmental applications. Here we present three types of studies by using {sup 14}C that were performed in the Zagreb Radiocarbon Laboratory. {sup 14}C in atmospheric CO{sub 2} has been monitored at several sites with various anthropogenic influences and the difference between the clean-air sites, the industrial city and the vicinity of a nuclear power plant has been established. {sup 14}C has been applied in geochronology of karst areas, especially in dating of tufa, speleothems and lake sediments, as well as in studies of geochemical carbon cycle. {sup 14}C has been used in various archaeological studies, among which the dating of the early Neolithic settlements in Croatia is presented. In these studies {sup 14}C was measured by radiometric techniques, i.e., by gas proportional counting and more recently by liquid scintillation counting (LSC). Two sample preparation techniques for LSC measurement were used: benzene synthesis for archaeological dating and other applications that require better precision, and direct absorption of CO{sub 2} for monitoring purposes. The presented results show that various studies by using {sup 14}C can be successfully performed by the LSC technique, providing a large enough sample (>1 g of carbon).

  4. Bomb-spike dating of a mummified baboon in Ludwig Cave, Namibia

    OpenAIRE

    Hodgins Greg; Brook George A.; Marais Eugene

    2007-01-01

    In 1982 a mummified adult female baboon was discovered on a ledge in Ludwig Cave in Namibia. A toe bone was removed for dating in July 1995. AMS radiocarbon dating of bone collagen, tendon, and skin indicates a post-modern age. Application of the atomic bomb-spike calibration curve suggests death in late 1977 and an age at death of around 19 years. Baboons roost in the cave and the mummified female, along with a mummified juvenile male discovered in 2002 and three rotting corpses discovered i...

  5. New radiocarbon data to study the history of roman and medieval Florence

    Energy Technology Data Exchange (ETDEWEB)

    Arnoldus-Huyzendveld, A. [Dipartimento di Archeologia e Storia delle Arti, Universita di Siena, via Roma 56, 53100 Siena (Italy); Fedi, M.E., E-mail: fedi@fi.infn.i [INFN Sezione di Firenze, via Sansone 1, 50019 Sesto Fiorentino (Italy); Cantini, F.; Bruttini, J. [Dipartimento di Archeologia e Storia delle Arti, Universita di Siena, via Roma 56, 53100 Siena (Italy); Cartocci, A. [INFN Sezione di Firenze, via Sansone 1, 50019 Sesto Fiorentino (Italy); Dipartimento di Fisica dell' Universita di Firenze, via Sansone 1, 50019 Sesto Fiorentino (Italy); Calabrisotto, C. Scire [Dipartimento di Fisica dell' Universita di Firenze, via Sansone 1, 50019 Sesto Fiorentino (Italy)

    2010-04-15

    Florence is a town worldwide known for its Renaissance masterpieces. It is often forgotten that it was founded during Roman times and remained a small village until the end of the early Middle Ages, practically confined within the ancient Roman boundaries. Since 2003, an extended archaeological research executed by the University of Sienna has studied the most ancient layers in the centre of Florence with the aim to enhance both the archaeological and paleo-environmental reconstruction of this area. One of the peculiarities of these excavations is that the early medieval layers were poor in datable ceramics, thus charcoals were sampled from different stratigraphic layers in order to contribute to the dating. Several data have already been published; here we focus on the excavation site of Palazzo Vecchio, now the seat of the municipality of Florence. This area is located close to the Arno river, along the eastern margin of the slightly elevated height upon which the Roman town was founded; actually, in the layers beneath the surface, the Roman theatre is still preserved. Radiocarbon dating of charcoals was performed in the LABEC laboratory in Florence, at the AMS beam line of the AMS-IBA 3 MV Tandetron accelerator. Comparison of these new data with the former ones and with the archaeological and geological data adds new information especially on natural phenomena like floods and on the human occupation of this area in the past.

  6. New radiocarbon data to study the history of roman and medieval Florence

    International Nuclear Information System (INIS)

    Florence is a town worldwide known for its Renaissance masterpieces. It is often forgotten that it was founded during Roman times and remained a small village until the end of the early Middle Ages, practically confined within the ancient Roman boundaries. Since 2003, an extended archaeological research executed by the University of Sienna has studied the most ancient layers in the centre of Florence with the aim to enhance both the archaeological and paleo-environmental reconstruction of this area. One of the peculiarities of these excavations is that the early medieval layers were poor in datable ceramics, thus charcoals were sampled from different stratigraphic layers in order to contribute to the dating. Several data have already been published; here we focus on the excavation site of Palazzo Vecchio, now the seat of the municipality of Florence. This area is located close to the Arno river, along the eastern margin of the slightly elevated height upon which the Roman town was founded; actually, in the layers beneath the surface, the Roman theatre is still preserved. Radiocarbon dating of charcoals was performed in the LABEC laboratory in Florence, at the AMS beam line of the AMS-IBA 3 MV Tandetron accelerator. Comparison of these new data with the former ones and with the archaeological and geological data adds new information especially on natural phenomena like floods and on the human occupation of this area in the past.

  7. Youngest radiocarbon age for Jefferson's ground sloth, Megalonyx jeffersonii (Xenarthra, Megalonychidae)

    DEFF Research Database (Denmark)

    Gregory McDonald, H.; Stafford, Thomas W.; Gnidovec, Dale M.

    2015-01-01

    A partial skeleton of the extinct ground sloth, Megalonyx jeffersonii, recovered from a farm near Millersburg, Ohio in 1890, was radiocarbon dated for the first time. The ungual dated is part of a skeleton mounted for exhibit at the Orton Geological Museum at Ohio State University and was the first...... mounted skeleton of this animal. From its initial discovery the bones were treated with multiple organic compounds that had the potential to compromise the radiocarbon age and the specimen required special treatments in order to obtain a valid radiocarbon age. The 14C measurement on the ungual from this...

  8. Mass accumulation rates and fallout radionuclides 210Pb, 137Cs and 241Am inventories determined in radiometrically dated abyssal sediments of the Black Sea

    International Nuclear Information System (INIS)

    Five abyssal (deep-sea) sediment cores collected during the two international cruises on R/V 'Professor Vodyanitskiy' (RADEUX-1998 and RADEUX-2000) in the framework of the Regional Technical Co-operation Project RER/2/003 'Marine Environmental Assessment in the Black Sea Region' were subjected to detailed radiometric analysis. The sediments were dated using the radionuclides 210Pb, 137Cs and 241Am and the results used to calculate a number of key parameters, e.g. radionuclide inventories, fluxes and sediment accumulation rates. The sediment cores were collected using a MARK II-400 multi-corer (Bowers and Connelly) in both Western and Eastern sub-basins of the Black Sea. The cores were sliced on board with a resolution of 0.2-0.4 cm for the top 5 cm and 1-5 cm downward using an extruder that was specially designed to prevent loss of the uppermost fluff-layer, possible down-smearing and interlayer cross-contamination of the sediment. Dry bulk density (DBD) and cumulative dry mass (CDM) were calculated on a salt-free basis using direct determination of the salt contribution to the dry mass of the sediment. Calculations showed that in the near surface sediments, and particularly in the top fluff-layer, the salt dissolved in pore-water contributed up to 30-60% of the mass of dried sediments. Neglecting this correction could cause an erroneous interpretation of the 210Pb activity profile, resulting in overestimation of both the average sedimentation rate and its recent temporal changes. Sediment samples were analysed for 210Pb, 226Ra, 137Cs and 241Am by direct gamma assay in UHMI after 3 weeks equilibration in hermetically sealed plastic holders, using an EG and G Ortec (Ametek) HPGe GWL series well-type coaxial low background intrinsic germanium detector. Correction was made for the effect of self-absorption of low energy γ-rays within the sample using attenuation parameters determined in. Chronostratigraphical analysis of the data and sediment age calculation have

  9. A new system for the simultaneous measurement of δ13C and δ15N by IRMS and radiocarbon by AMS on gaseous samples: Design features and performances of the gas handling interface

    Science.gov (United States)

    Braione, Eugenia; Maruccio, Lucio; Quarta, Gianluca; D'Elia, Marisa; Calcagnile, Lucio

    2015-10-01

    We present the general design features and preliminary performances of a new system for the simultaneous AMS-14C and IRMS δ13C and δ15N measurements on samples with masses in the μg range. The system consists of an elemental analyzer (EA), a gas splitting unit (GSU), a IRMS system, a gas handling interface (GHI) and a sputtering ion source capable of accepting gaseous samples. A detailed description of the system and of the control software supporting unattended operation are presented together with the first performance tests carried out by analyzing samples with masses ranging from 8 μgC to 2.4 mgC. The performances of the system were tested in term of stability of the ion beam extracted from the ion source, precision and accuracy of the results by comparing the measured isotopic ratios with those expected for reference materials.

  10. Tree rings and radiocarbon calibration

    International Nuclear Information System (INIS)

    Only a few kinds of trees in Australia and Southeast Asia are known to have growth rings that are both distinct and annual. Those that do are therefore extremely important to climatic and isotope studies. In western Tasmania, extensive work with Huon pine (Lagarostrobos franklinii) has shown that many living trees are more than 1,000 years old, and that their ring widths are sensitive to temperature, rainfall and cloud cover (Buckley et al. 1997). At the Stanley River there is a forest of living (and recently felled) trees which we have sampled and measured. There are also thousands of subfossil Huon pine logs, buried at depths less than 5 metres in an area of floodplain extending over a distance of more than a kilometre with a width of tens of metres. Some of these logs have been buried for 50,000 years or more, but most of them belong to the period between 15,000 years and the present. In previous expeditions in the 1980s and 1990s, we excavated and sampled about 350 logs (Barbetti et al. 1995; Nanson et al. 1995). By measuring the ring-width patterns, and matching them between logs and living trees, we have constructed a tree-ring dated chronology from 571 BC to AD 1992. We have also built a 4254-ring floating chronology (placed by radiocarbon at ca. 3580 to 7830 years ago), and an earlier 1268-ring chronology (ca. 7,580 to 8,850 years ago). There are many individuals, or pairs of logs which match and together span several centuries, at 9,000 years ago and beyond

  11. The impact of varying depositional processes on the preservation of lignin from the Mississippi and Amazon Rivers: A dual application of compound-specific and ramped pyrolysis radiocarbon dating

    Science.gov (United States)

    Williams, E. K.; Rosenheim, B. E.; McNichol, A. P.; Roberts, M.; Xu, L.

    2012-12-01

    The establishment of reliable terrestrial-marine particulate organic carbon (POC) fluxes is important to understanding biogeochemical cycling of carbon, reconstructing environmental and depositional processes, and organic carbon (OC) storage in continental margins. Marine preservation of riverine POC differs between river systems and depositional settings, determined by a combination of fluvial and marine processes. In this study, we compare the preservation of terrestrial OC in two depositional sediments related to major river systems - the Amazon and the Mississippi - using a combination of compound class extraction and radiocarbon determination and ramped pyrolysis radiocarbon determination that targets the bulk POC by separating it along lines of thermochemical stability. Submarine mudbanks emanating from the Amazon are continuously re-oxygenated on decadal timescales and have high iron and marine sulfate content. Conversely, subaerial marshes dominate the Mississippi delta, marked by low oxygen, iron, and sulfate content. These factors potentially result in a higher degree of selective preservation of terrestrial OC and different molecular components (Canfield, 1994; Zonneveld et al., 2010; Hedges et al., 1995) in Mississippi deltaic sediments than in the Amazon mudbank deposits. Because of these differing depositional conditions, we anticipate that more degradation-resistant terrestrial compounds, such as lignin, will be greater preserved in deltaic Mississippi River sediments versus in Amazon mudbank sediments. Preliminary results show that the Mississippi deltaic sediments have higher concentrations of lignin phenols (0.632 mg/mgOC) compared to the Amazon (Guianas mudbanks) sediments (0.176 mg/mgOC), consistent with rapid burial and less post-depositional marine processing in the wetlands. For both rivers, lignin phenol concentrations in the deposited sediment were higher than reported (Hedges et al., 1986; Onsted et al., 2000) suspended sediment lignin

  12. Dating of pollen samples from the sediment core of Lake St Anne in the East Carpathian Mountains, Romania

    Science.gov (United States)

    Hubay, Katalin; Katalin Magyari, Enikö; Braun, Mihály; Schabitz, Frank; Molnár, Mihály

    2016-04-01

    Lake St Anne (950 m a.s.l.) is situated in the Ciomadul volcano crater, the youngest volcano in the Carpathians. Aims driving forward the studies there are twofold, one is dating the latest eruption of the Ciomadul volcano and the other is the multi-proxy palaeoenvironmental reconstruction of this region. The sediment of Lake St Anne was sampled several times already, but never reached the bottom of the lake before. During the winter of 2013 at a new core location drilling started at 600 cm water depth and finally reached the bottom of the lake sediment at approximately 2300 cm including water depth. As for all multi-proxy studies essential requirement was to build a reliable chronology. Sediments were dated by radiocarbon method. Previous radiocarbon dates were measured on plant macrofossils, charcoal, Cladocera eggs, chironomid head capsules and bulk lake sediments. Lake St Anne has volcanic origin and there is intensive upwelling of CO2it is important to study and take into consideration, whether there is any local reservoir effect at the case of samples where it could be problematic. Furthermore the late part of the sediment section (between 15,000 and 30,000 cal. yr BP) has low organic matter content (less than 2-4%) with scarcity of datable plant macrofossil material. In this review a different fraction of pollen samples with terrestrial origin was tested and studied as a novel sample type for the radiocarbon dating. Pollen samples were extracted from the lake sediment cores. This type of organic material could be an ideal candidate for radiocarbon based chronological studies as it has terrestrial source and is present in the whole core in contrast with the terrestrial macrofossils. Although the pollen remains were present in the whole core, in many cases their amount give a challenge even for the AMS technic. Samples were measured with EnvironMICADAS AMS and its gas ion source in the HEKAL laboratory (Debrecen, Hungary). We examine the reliability the

  13. AMS 14 C dating controlled records of monsoon and Indonesian throughflow variability from the eastern Indian Ocean of the past 32,000 years

    Science.gov (United States)

    Li, Z. Y.; Chen, M. T.; Shi, X.; Liu, S.; Wang, H.

    2015-12-01

    Zi-Ye Li a, Min-Te Chen b, Hou-Jie Wang a, Sheng-Fa Liu c, Xue-Fa Shi ca College of Marine Geosciences, Ocean University of China, Qingdao 266100, P.R. Chinab Institute of Applied Geosciences, National Taiwan Ocean University, Keelung, Taiwan 20224, ROCc First Institute of Oceanography, SOA, Qingdao 266100, P.R. China Indonesian throughflow (ITF) is one of the most important currents responsible for transporting heat and moisture from the western Pacific to the Indian Oceans. The ITF is also well-known as effectively in modulating the global climate change with the interactions among ENSO and Asian monsoons. Here we present an AMS 14C dating controlled sea surface temperature (SST) record from core SO184-10043 (07°18.57'S, 105°03.53'E), which was retrieved from 2171m water depth at a north-south depression located at the southeastern offshore area of Sumatera in the eastern Indian Ocean. Based on our high-resolution SST using Mg/Ca analyses based on planktonic foraminifera shells of Globigerinoides ruber and alkenone index, U k'37-SST, oxygen isotope stratigraphy, and AMC 14C age-controls, our records show that, during the past 32,000 years, the SSTs were decreased which imply weaker ITF during Marine Isotope Stage (MIS) 2 and 3. The weaker UTF may respond to strengthened northeast monsoon during the boreal winter. During 21 to 15ka, the southeast monsoon had been stronger and the northeast monsoon was relatively weaker. During 15 to 8ka, rapid sea level rising may allow the opening of the gateways in the Makassar Strait and Lombok Strait that may have further strengthened the ITF. During the early Holocene, the northeast and southeast monsoons seem to be both strengthened. We will discuss the implications of the hydrographic variability and their age uncertainties in this paper during the meeting.

  14. Radiocarbon ages of pedogenic calcic nodules formed within vertisols, Coimbatore region, Tamil Nadu, India

    International Nuclear Information System (INIS)

    In this paper we discuss the limitation of radiocarbon dates on the pedogenic calcic nodules formed in situ within the vertisols in the upland region of Coimbatore, Tamil Nadu. The radiocarbon ages were obtained using low level scintillation counters and the ages range from ∼24 Ka to ∼31 Ka. The ages correlate well with the marine isotope stage of Late MIS3. Since the calcic nodules are pedogenised and formed in a terrestrial open system we express caution in the interpretation of the radiocarbon ages obtained on pedogenic carbonate nodules. The radiocarbon dates represent maximum ages and hence the ages measured should only be considered as age estimates and not absolute geologic ages. Multiple sub-mm size subsamples could provide more reliable estimates of soil chronology. (author)

  15. Holocene sea-level determination relative to the Australian continent: U/Th (TIMS) and 14C (AMS) dating of coral cores from the Abrolhos Islands

    Science.gov (United States)

    Eisenhauer, A.; Wasserburg, G. J.; Chen, J. H.; Bonani, G.; Collins, L. B.; Zhu, Z. R.; Wyrwoll, K. H.

    1993-02-01

    U/Th (TIMS) and 14C (AMS) measurements are presented from two coral cores from the Easter group of the Houtman Abrolhos Islands between 28°S and 29°S on the western continental margin of Australia. The U/Th measurements on the Morley core from Morley Island cover a depth interval from 0.2 m above present sea level to 24.4 m below present sea level and comprise eleven samples. The ages vary between 6320 ± 50 a, at 0.2 m above sea level, and 9809 ± 95 a, at 24.4 m below sea level (all errors are 2σ). The mean growth rate is 7.1 ± 0.9 m/ka. The 14C dates of selected Morley core corals show that the 14C ages are ˜ 1000 a younger than their corresponding U/Th ages, which agrees with previous results. The main purpose of our 14C measurements is to be able to compare them precisely with other coral cores where no U/Th measurements are available. The U/Th measurements of the Suomi core from Suomi Island cover a depth interval from 0.05 m to 14.2 m below present sea level and consist of four samples. The ages vary between 4671 ± 40 a, at 0.05 m below sea level, and 7102 ± 82 a, at 14.2 m below sea level, with a mean growth rate of 5.8 ± 0.2 m/ka. The growth history of both cores is explained by a simple model in which the growth rates of the Morley core can be interpreted as reflecting local rates of sea level rise, whereas the Suomi core is interpreted as reflecting lateral growth during the past ˜ 6000 a. Our results indicate that sea level relative to the western margins of the Australian continent was about 24 m lower than present at about 9800 a B.P. ( 14C gives a date of 8500 a B.P.). Sea level then rose and reached a highstand, slightly higher than the present position at about 6300 a B.P ( 14C date: 5500 a). This highstand declined but was still higher than present at 4600 a B.P. This is in agreement with previous observations along the Australian coastal margins and with observations from the Huon peninsula (Papua New Guinea). Our results are very

  16. On-line combustion of samples for AMS and ion source developments at ORAU

    International Nuclear Information System (INIS)

    Each stage in the handling of radiocarbon samples provides an additional opportunity for contamination and increased cost. For large samples, graphitization is worthwhile since it allows precise AMS measurements to be made in a short time. Some samples, however, do not require high precision. These include small samples, for which high precision is impossible, and samples for which only an approximate date is required. In these cases, there is an advantage in burning the samples and then introducing the CO2 directly into a gas ion source. ORAU has developed a system for performing on-line combustion, which is being tested for routine use. This paper presents the performance characteristics and explains the main design features. Such systems are expected to be useful for small samples in radiocarbon dating, the pre-screening of radiocarbon ages and in biomedical applications. The hybrid (graphite and CO2) ion source at Oxford has also been upgraded to incorporate a 40-target sample changing mechanism. This can be used both for graphite samples and for the targets required for measurements on CO2

  17. Millennium scale radiocarbon variations in Eastern North Atlantic thermocline waters: 0-7000 years

    International Nuclear Information System (INIS)

    Complete text of publication follows: Deep water corals are exceptional archives of modern and past ocean circulation as combined U-series and radiocarbon dating allows to reconstruct seawater radiocarbon. Here we present thermocline water radiocarbon concentrations that have been reconstructed for the past ∼ 7000 years for the eastern north Atlantic, based on deep-water corals from Rockall Bank and Porcupine Seabight. We find that thermocline water radiocarbon values follow overall the mean atmospheric long term trend with an average offset of Δ14C between intermediate water and atmosphere of -55±5 per thousand until 1960 AD. Residual variations are strong (±25 per thousand) over the past 7000 years and there is first evidence that those are synchronous to millennium scale climate variability. Over the past 60 years thermocline water radiocarbon values increase due to the penetration of bomb-radiocarbon into the upper intermediate ocean. Radiocarbon increases by Δ14C of +95 per thousand compared to +210 per thousand for eastern North Atlantic surface waters. Moreover, bomb-radiocarbon penetration to thermocline depth occurs with a delay of ∼ 10-15 years. Based on high resolution ocean circulation models we suggest that radiocarbon changes at upper intermediate depth are today barely affected by vertical mixing and represent more likely variable advection and mixing of water masses from the Labrador Sea and the temperate Atlantic (including Mediterranean outflow water). Consequently, we assume that residual radiocarbon variations over the past 7000 years reflect millennium scale variability of the Atlantic sub-polar and sub-tropical gyres

  18. Carbon 14 dating method

    International Nuclear Information System (INIS)

    This document gives a first introduction to 14C dating as it is put into practice at the radiocarbon dating centre of Claude-Bernard university (Lyon-1 univ., Villeurbanne, France): general considerations and recalls of nuclear physics; the 14C dating method; the initial standard activity; the isotopic fractioning; the measurement of samples activity; the liquid-scintillation counters; the calibration and correction of 14C dates; the preparation of samples; the benzene synthesis; the current applications of the method. (J.S.)

  19. Increase of radiocarbon concentration in tree rings from Kujawy (SE Poland) around AD 774-775

    Science.gov (United States)

    Rakowski, Andrzej Z.; Krąpiec, Marek; Huels, Mathias; Pawlyta, Jacek; Dreves, Alexander; Meadows, John

    2015-10-01

    Evidence of a rapid increase in atmospheric radiocarbon (14C) content in AD 774-775 was presented by Miyake et al. (2012), who observed an increase of about 12‰ in the 14C content in annual tree rings from Japanese cedar. Usoskin et al. (2013) report a similar 14C spike in German oak, and attribute it to exceptional solar activity. If this phenomenon is global in character, such rapid changes in 14C concentration may affect the accuracy of calibrated dates, as the existing calibration curve is composed mainly of decadal samples. Single-year samples of dendro-chronologically dated tree rings of deciduous oak (Quercus robur) from Kujawy, a village near Krakow (SE Poland), spanning the years AD 765-796, were collected and their 14C content was measured using the AMS system in the Leibniz Laboratory. The results clearly show a rapid increase of 9.2 ± 2.1‰ in the 14C concentration in tree rings between AD 774 and AD 775, with maximum Δ14C = 4.1 ± 2.3‰ noted in AD 776.

  20. Age models for peat deposits on the basis of coupled lead-210 and radiocarbon data.

    Science.gov (United States)

    Piotrowska, Natalia; de Vleeschouwer, François; Sikorski, Jarosław; Sensuła, Barbara; Michczyński, Adam; Fiałkiewicz-Kozieł, Barbara; Palowski, Bernard

    2010-05-01

    The study presents three examples of age-model construction based on the results of 210Pb and 14C dating methods applied to peat deposits. The three sites are ombrotrophic peat bogs: the Misten (Belgium), Slowinskie Bloto (N Poland) and Puscizna Mala (S Poland). All sites have been subjected to multiproxy studies aimed at reconstructing paleoenvironment and human activity, covering the last 1500, 1300 and 1800 years, respectively (De Vleeschouwer et al. 2009A, 2009B, in prep., Fialkiewicz-Koziel, ongoing PhD). A detailed comparison between 210Pb and post-bomb 14C results in the Misten bog has also been carried out by Piotrowska et al. (2009). In all cores, the 210Pb activity was calculated using 210Po and 208Po activities after acid-extraction from bulk samples, subsequent deposition on silver discs and measurements by alpha spectrometry. Unsupported 210Pb was detected until 35cm in Slowinskie Bloto, 15cm in the Misten and 19cm in Puscizna Mala. Constant Rate of Supply (CRS) model was then applied to compute ages of each 1-cm core interval. For the Misten and Slowinskie Bloto, radiocarbon measurements were performed on selected aboveground plant macrofossils, mainly Sphagnum spp. or Calluna vulgaris, Erica tetralix, and Andromeda polyfolia. Radiocarbon ages were determined using accelerator mass spectrometry (AMS) after acid-alkali-acid wash, combustion, purification of carbon dioxide and graphitisation. For Puscizna Mala bulk samples were dated after chemical preparation of benzene for liquid scintillation counting (LSC) or CO2 for gas proportional counting (GPC). Radiocarbon calibration was undertaken using the Intcal04 calibration curve and OxCal 4 software. As a priori information the 210Pb-derived ages were used in a P_Sequence model (Bronk Ramsey, 2008). A number of dates characterized by low agreement with stratigraphical order had to be considered as outliers and rejected from the final age model. For building a continuous age models a non-linear approach

  1. Dating the Bibong-ri Neolithic site in Korea: Excavating the oldest ancient boat

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gyujun, E-mail: danielp@kigam.re.k [Geochemical Analysis Center, Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources 305-350 (Korea, Republic of); Kim, Jong-Chan [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Youn, Minyoung; Yun, Chongcheol; Kang, Jin; Song, Yong-Mi; Song, Su-Jin; Noh, Hye-Jin [Electrostatic Accelerator Research Center, NCIRF, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Do-Kyun [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Im, Hack-Jong [Gimhae National Museum, Gimhae, Gyeongsangnam-do 621-060 (Korea, Republic of)

    2010-04-15

    The remains of an ancient wooden boat were unearthed at the Bibong-ri shell mound site. The site was located at Bibong-ri, Bugog-myeon, Changnyeong-gun, Gyeongsangnam-do in South Korea. A substantial fragment of the vessel was discovered in the lowest layer of the site. We collected 17 samples of charcoal and wood from pebble, sand, and shell layers. Sample preparation extracted the carbon from each sample material and converted it into graphite for AMS radiocarbon dating. Radiocarbon dates of the samples indicate that they belong to the Neolithic period and that the boat dates from ca. 5700 BC. To this point, the oldest known boat in the world has been a wooden boat dating from ca. 5500 BC in China. Other ancient boats from around the world include a logboat dating from ca. 3600 BC in Japan and a fleet of wooden boats dating from ca. 3000 BC in Egypt. The Bibong-ri boat is the first boat from the Neolithic period ever found in South Korea and must represent one of the world's oldest known boats.

  2. Dating the Bibong-ri Neolithic site in Korea: Excavating the oldest ancient boat

    International Nuclear Information System (INIS)

    The remains of an ancient wooden boat were unearthed at the Bibong-ri shell mound site. The site was located at Bibong-ri, Bugog-myeon, Changnyeong-gun, Gyeongsangnam-do in South Korea. A substantial fragment of the vessel was discovered in the lowest layer of the site. We collected 17 samples of charcoal and wood from pebble, sand, and shell layers. Sample preparation extracted the carbon from each sample material and converted it into graphite for AMS radiocarbon dating. Radiocarbon dates of the samples indicate that they belong to the Neolithic period and that the boat dates from ca. 5700 BC. To this point, the oldest known boat in the world has been a wooden boat dating from ca. 5500 BC in China. Other ancient boats from around the world include a logboat dating from ca. 3600 BC in Japan and a fleet of wooden boats dating from ca. 3000 BC in Egypt. The Bibong-ri boat is the first boat from the Neolithic period ever found in South Korea and must represent one of the world's oldest known boats.

  3. Determination of radiocarbon in stratospheric CO2, obtained through AirCore sampling.

    Science.gov (United States)

    Paul, Dipayan; Chen, Huilin; Been, Henk A.; Kivi, Rigel; Meijer, Harro A. J.

    2016-04-01

    The concentration of Greenhouse Gases (GHG), with carbon dioxide as the most prominent example, has been and still is increasing, predominantly due to emissions from fossil fuel combustion. CO2 is also the most important component of the global carbon cycle. Among other tracers, radiocarbon (Carbon-14) is a unique and an important atmospheric tracer used in the understanding of the global carbon cycle. Radiocarbon is a naturally occurring isotope (radioactive, t 1/2 = 5730 ± 40 years) of carbon produced through the interaction of thermalized neutrons and nitrogen in the upper atmosphere. Generally, for performing atmospheric radiocarbon measurements in the higher atmosphere, large samples (few liters of air) were collected using aircrafts and balloons. However, collecting stratospheric samples on a regular basis for radiocarbon analysis is extremely expensive. Here we describe the determination of radiocarbon concentrations in stratospheric CO2, collected using AirCore sampling. AirCore is an innovative sampling technique for obtaining vertical atmospheric profiles and, in Europe, is done on a regular basis at Sodankylä, Finland for CO2, CH4 and CO. The stratospheric parts of two such AirCore profiles were used in this study as a proof-of-principle. CO2 from the stratospheric air samples were extracted and converted to elemental carbon, which were then measured at the Accelerator Mass Spectrometric (AMS) facility of the Centre for Isotope Research (CIO) at the University of Groningen. The stratospheric part of the AirCore profile was divided into six sections, each contained approximately 10 μg C. A detailed description of the extraction, graphitization, AMS analysis and the derivation of the stratospheric radiocarbon profile will be the main focus. Through our results, we will show that AirCore is a viable sampling method for performing high-precision radiocarbon measurements of stratospheric CO2 with reasonably good spatial resolution on a regular basis

  4. L’apport des analyses 14C à l’étude de la nécropole de l’âge du Bronze de“ La Croix de la Mission ” à Marolles-sur-Seine The contribution of radiocarbon dating in the study of the Bronze Age cemetery of Marolles-sur-Seine “ La Croix de la Mission ”

    Directory of Open Access Journals (Sweden)

    Rebecca Peake

    2006-12-01

    Full Text Available Quatorze des 41 sépultures de la nécropole de “ la Croix de la Mission ” à Marolles-sur-Seine ont récemment fait l’objet d’une datation par le radiocarbone aux laboratoires de Groningen (Pays-Bas et de Lyon (France. Les résultats obtenus mettent en évidence l'utilisation en continu de la nécropole pendant plus d’un millénaire entre 2000 et 800 av. n. è. La corrélation entre ces nouvelles dates et les données archéologiques permet de cerner, avec plus de précision, l’éventail des différentes étapes chrono-culturelles représentées à travers les sépultures de la nécropole. [Les analyses 14C ont été effectuées par les laboratoires de Groningen (Centrum voor Isotopen Onderzoek Rijksuniversiteit Groningen Nijenborgh 4 NL-9747 AG Groningen et Lyon (Centre de Datation par le Radiocarbone Université Claude Bernard Lyon 1, 43, bd du 11 Novembre 1918 F-69622 Villeurbanne Cedex.]Fourteen of the 41 burials of the “ la Croix de la Mission ” Bronze Age cemetery at Marolles-sur-Seine have recently been carbon dated by the Lyon (France and Groningen (Netherlands laboratories. These new dates confirm the site’s occupation for more than 1000 years from 2000 BC to 800 BC and determine more precisely the different cultural and chronological phases of the cemetery illustrated by the great range of its burials.

  5. The role of inter-comparisons in radiocarbon quality assurance

    Science.gov (United States)

    Scott, Marian; Cook, Gordon; Naysmith, Philip

    2016-04-01

    Radiocarbon dating is used widely in many geochronology projects as a basis for the creation and testing of chronological constructs. Radiocarbon measurements are by their nature complex and the degree of sample pre-treatment varies considerably depending on the material. Within the UK and Europe, there are a number of well-established laboratories and increasingly, scientists are not just commissioning new dates, but also using statistical modelling of assemblages of dates, perhaps measured in different laboratories, to provide formal date estimates for their investigations. The issue of comparability of measurements (and thus bias, accuracy and precision of measurement) from the diverse laboratories is one which has been the focus of some attention both within the 14C community and the wider user communities for some time. As a result of this but also as part of laboratory benchmarking and quality assurance, the 14C community has undertaken a wide-scale, far-reaching and evolving programme of inter-comparisons, to the benefit of laboratories and users alike. This paper presents the results from the most recent exercise SIRI. The objectives of SIRI included, through choice of material, to contribute to the discussion concerning laboratory offsets and error multipliers in the context of IntCal (the International Calibration Programme) and to gain a better understanding of differences in background derived from a range of infinite age material types.

  6. Youngest radiocarbon age for Jefferson's ground sloth, Megalonyx jeffersonii (Xenarthra, Megalonychidae)

    Science.gov (United States)

    Gregory McDonald, H.; Stafford, Thomas W.; Gnidovec, Dale M.

    2015-03-01

    A partial skeleton of the extinct ground sloth, Megalonyx jeffersonii, recovered from a farm near Millersburg, Ohio in 1890, was radiocarbon dated for the first time. The ungual dated is part of a skeleton mounted for exhibit at the Orton Geological Museum at Ohio State University and was the first mounted skeleton of this animal. From its initial discovery the bones were treated with multiple organic compounds that had the potential to compromise the radiocarbon age and the specimen required special treatments in order to obtain a valid radiocarbon age. The 14C measurement on the ungual from this skeleton (11,235 ± 40 14C yr BP = 13,180-13,034 cal yr BP) is the youngest 14C age presently determined for M. jeffersonii.

  7. Radiocarbon ages of pedogenic carbonate nodules from Coimbatore region, Tamil Nadu

    International Nuclear Information System (INIS)

    In this paper we discuss the limitation of radiocarbon dates on the pedogenic calcic nodules formed in situ within the vertisols in the upland region of Coimbatore, Tamil Nadu. The radiocarbon ages were obtained using low-level scintillation counters and the dates range from ∼ 24 to 31 14C Kyrs BP. The ages correlate with the marine isotope stage of Late MIS3. However, since the calcic nodules are pedogenised and formed in an open system, the 14C ages should only be considered as estimates and not absolute ages because of the possibility of open-system behaviour with respect to carbon. Thus, we express caution in the interpretation of these and other radiocarbon ages obtained on pedogenic carbonate nodules. Multiple sub-mm size subsamples could provide more reliable age estimates. (author)

  8. The remarkable metrological history of 14C dating: from ancient Egyptian artifacts to particles of soot and grains of pollen

    International Nuclear Information System (INIS)

    Radiocarbon dating would not have been possible if 14C had not had the 'wrong' half-life, a fact that delayed its discovery. Following the discovery of this 5730 year radionuclide in laboratory experiments by Ruben and Kamen, it became clear to Willard Libby that 14C should exist in nature, and that it could serve as a quantitative means for dating artifacts and events marking the history of civilization. The search for natural radiocarbon was a metrological challenge; the level in the living biosphere [ca. 230 Bq/kg] lay far beyond the then current state of the measurement art. The metrological history of radiocarbon was traced from the initial breakthrough devised by Libby, to minor (evolutionary) and major (revolutionary) advances that brought 14C measurement from a crude, bulk [8 g carbon] dating tool, to a refined probe for dating tiny amounts of precious artifacts, and for 'molecular dating' at the 10-100 μg level. The first metrological revolution resulted from a combination of a major improvement in the 14C beta particle detection efficiency and consequent improvement in precision, and the new science of dendrochronology which extended the radiocarbon dating calibration curve to some 8000 years before present (BP). The fine structure of the calibration function revealed natural and anthropogenic variations in the 14C content of living matter, contrary to one of the basic assumptions of radiocarbon dating. This 'failure' of radiocarbon dating, however, spawned new multidisciplinary areas of environmental and geoscience. The most notable of the anthropogenic variations was that induced by atmospheric nuclear testing. The 'bomb pulse' of the mid-1960s gave rise to a global atmospheric and marine tracer experiment, and its by-product was an additional, short-term 14C 'decay curve' that has allowed the dating of late 20th Century artifacts to the nearest year or two. The second major advance came in 1977-78 when 'atom counting' of 14C was developed. Sensitivity

  9. Performance report for the low energy compact radiocarbon accelerator mass spectrometer at Uppsala University

    Science.gov (United States)

    Salehpour, M.; Håkansson, K.; Possnert, G.; Wacker, L.; Synal, H.-A.

    2016-03-01

    A range of ion beam analysis activities are ongoing at Uppsala University, including Accelerator Mass Spectrometry (AMS). Various isotopes are used for AMS but the isotope with the widest variety of applications is radiocarbon. Up until recently, only the 5 MV Pelletron tandem accelerator had been used at our site for radiocarbon AMS, ordinarily using 12 MeV 14,13,12C3+ ions. Recently a new radiocarbon AMS system, the Green-MICADAS, developed at the ion physics group at ETH Zurich, was installed. The system has a number of outstanding features which will be described. The system operates at a terminal voltage of 175 kV and uses helium stripper gas, extracting singly charged carbon ions. The low- and high energy mass spectrometers in the system are stigmatic dipole permanent magnets (0.42 and 0.97 T) requiring no electrical power nor cooling water. The system measures both the 14C/12C and the 13C/12C ratios on-line. Performance of the system is presented for both standard mg samples as well as μg-sized samples.

  10. Marine reservoir corrections for bowhead whale radiocarbon age determinations

    International Nuclear Information System (INIS)

    Twenty-two pairs of radiocarbon dates on driftwood and bowhead whale (Balaena mysticetus) bones from raised beaches, dates on whale bone and terrestrial plant detritus from a stratigraphic section, and 25 additional dates on whale bones from the lowest (≤ 1 ka BP) raised beaches in the eastern Canadian Arctic suggest that a marine reservoir correction of about -200 years is appropriate for normalized age determinations on bone collagen from the bowhead whale in this region. This is less than the correction (-400 years) normally applied to carbonate shells of marine molluscs from this region. The carbon in bowhead collagen appears to be derived from the whales' zooplankton food rather than from marine bicarbonate. (author). 39 refs., 1 tab., 3 figs

  11. Thermoluminescence dating of late-glacial sand sediments

    International Nuclear Information System (INIS)

    Ten Late-Glacial sediments were dated by the regeneration method combined with the plateau criteria. The thermoluminescence (TL) dates were compared with independent dates assessed indirectly by radiocarbon dating or varve chronology. For comparison, the 14C dates were calibrated by adding 1000 yr to the conventional results. Eight TL dates agreed with the 14C dates within the uncertainty of the TL dates (± 1 ka), one was overestimated and one underestimated. (author)

  12. Quaternary dating methods

    International Nuclear Information System (INIS)

    The papers in this book cover absolute, relative and multiple dating methods, and have been written by specialists from a number of different earth sciences disciplines - their common interest being the dating of geological materials within the Quaternary. Papers on absolute dating methods discuss radiocarbon, uranium-series, potassium argon, 40Ar/39Ar, paleomagnetic, obsidian hydration, thermoluminescence, amino acid racemization, tree rings, and lichenometric techniques. Those on relative dating include discussions on various geomorphic relative age indicators such as drainage density changes, hypsometric integrals, bifurcation ratios, stream junction angles, spur morphology, hillslope geometry, and till sheet characteristics. The papers on multiple dating cite examples from the Rocky Mountains, Australia, Lake Agassiz Basin, and the Southern Andes. Also included is the panel discussion which reviews and assesses the information presented, and a field trip guide which discusses the sequences of Wisconian tills and interlayered lacustrine and fluvial sediments. (orig.)

  13. TELL SABI ABYAD, SYRIA : RADIOCARBON CHRONOLOGY, CULTURAL CHANGE, AND THE 8.2 KA EVENT

    NARCIS (Netherlands)

    van der Plicht, J.; Akkermans, P. M. M. G.; Nieuwenhuyse, O.; Kaneda, A.; Russell, A.

    2011-01-01

    At Tell Sabi Abyad, Syria, we obtained a robust chronology for the 7th to early 6th millennium BC, the Late Neolithic. The chronology was obtained using a large set of radiocarbon dates, analyzed by Bayesian statistics. Cultural changes observed at similar to 6200 BC are coeval with the 8.2 ka clima

  14. Enhancing sample preparation capabilities for accelerator mass spectrometry radiocarbon and radiocalcium studies

    International Nuclear Information System (INIS)

    With support provided by the LLNL Accelerator Mass Spectrometry Laboratory, the UCR Radiocarbon Laboratory continued its studies involving sample pretreatment and target preparation for both AMS radiocarbon (14C) and radiocalcium (41Ca) involving applications to archaeologically -- and paleoanthropologically- related samples. With regard to AMS 14C-related studies, we have extended the development of a series of procedures which have, as their initial goal, the capability to combust several hundred microgram amounts of a chemically-pretreated organic sample and convert the resultant CO2 to graphitic carbon which will consistently yield relatively high 13C- ion currents and blanks which will yield, on a consistent basis, 14C count rates at or below 0.20% modern, giving an 2 sigma age limit of >50,000 yr BP

  15. Palaeo-poo: date from rat scats

    International Nuclear Information System (INIS)

    AMS dating has allowed a detailed study of the stratigraphy of stick-nest rat (Leporillus spp.) middens. The results of multiple dates on apparently the same layers of the middens show that the taphonomy of the midden is complex. Nevertheless, the information recovered from this source is an exciting addition to understanding arid ecosystems. Information about the local and regional vegetation, possible CO2-induced changes in stomata, distribution of mammals and their predator-prey relations has been recovered from the middens. Palaeoecological information coming from the arid zone has been limited but this source provides a breakthrough in providing direct and detailed ecological information. This helps contextualise the late Holocene increase in arid zone archaeological site visibility. It emphasises the pattern of arid zone mammal losses. It provides important corroborating evidence to other palaeoecological records. It is emphasised that the deposits containing pollen and macrofossils are datable using radiocarbon but there are some serious problems in providing ecological information from stick-nest rat middens

  16. Radiocarbon evidence for a smaller oceanic carbon dioxide sink than previously believed

    International Nuclear Information System (INIS)

    Radiocarbon produced naturally in the upper atmosphere or artificially during nuclear weapons testing is the main tracer used to validate models of oceanic carbon cycling, in particular the exchange of carbon dioxide with the atmosphere and the mixing parameters within the ocean itself. Here we test the overall consistency of exchange fluxes between all relevant compartments in a simple model of the global carbon cycle, using measurements of the long-term tropospheric CO2 concentration and radiocarbon composition, the bomb 14C inventory in the stratosphere and a compilation of bomb detonation dates and strengths. (author)

  17. Marine04 Marine radiocarbon age calibration, 26 ? 0 ka BP

    Energy Technology Data Exchange (ETDEWEB)

    Hughen, K; Baille, M; Bard, E; Beck, J; Bertrand, C; Blackwell, P; Buck, C; Burr, G; Cutler, K; Damon, P; Edwards, R; Fairbanks, R; Friedrich, M; Guilderson, T; Kromer, B; McCormac, F; Manning, S; Bronk-Ramsey, C; Reimer, P; Reimer, R; Remmele, S; Southon, J; Stuiver, M; Talamo, S; Taylor, F; der Plicht, J v; Weyhenmeyer, C

    2004-11-01

    New radiocarbon calibration curves, IntCal04 and Marine04, have been constructed and internationally ratified to replace the terrestrial and marine components of IntCal98. The new calibration datasets extend an additional 2000 years, from 0-26 ka cal BP (Before Present, 0 cal BP = AD 1950), and provide much higher resolution, greater precision and more detailed structure than IntCal98. For the Marine04 curve, dendrochronologically dated tree-ring samples, converted with a box-diffusion model to marine mixed-layer ages, cover the period from 0-10.5 ka cal BP. Beyond 10.5 ka cal BP, high-resolution marine data become available from foraminifera in varved sediments and U/Th-dated corals. The marine records are corrected with site-specific {sup 14}C reservoir age information to provide a single global marine mixed-layer calibration from 10.5-26.0 ka cal BP. A substantial enhancement relative to IntCal98 is the introduction of a random walk model, which takes into account the uncertainty in both the calendar age and the radiocarbon age to calculate the underlying calibration curve. The marine datasets and calibration curve for marine samples from the surface mixed layer (Marine04) are discussed here. The tree-ring datasets, sources of uncertainty, and regional offsets are presented in detail in a companion paper by Reimer et al.

  18. Dating megafaunal extinction on the Pleistocene Darling Downs, eastern Australia: the promise and pitfalls of dating as a test of extinction hypotheses

    Science.gov (United States)

    Price, Gilbert J.; Webb, Gregory E.; Zhao, Jian-xin; Feng, Yue-xing; Murray, Andrew S.; Cooke, Bernard N.; Hocknull, Scott A.; Sobbe, Ian H.

    2011-04-01

    OSL and U/Th (teeth) dating provide complimentary results and demonstrate that the faunal sequences actually span ˜120-83 ka, thus occurring beyond the AMS 14C dating window. Importantly, the dates suggest that the local decline in biological diversity was initiated ˜75,000 years before the colonisation of humans on the continent. Collectively, the data are most parsimoniously consistent with a pre-human climate change model for local habitat change and megafauna extinction, but not with a nearly simultaneous extinction of megafauna as required by the human-induced blitzkrieg extinction hypothesis. This study demonstrates the problems inherent in dating deposits that lie near the chronological limits of the radiocarbon dating technique, and highlights the need to cross-check previously-dated archaeological and megafauna deposits within the timeframe of earliest human colonisation and latest megafaunal survival.

  19. Methods of dating

    International Nuclear Information System (INIS)

    Scientific methods of dating, born less than thirty years ago, have recently improved tremendously. First the dating principles will be given; then it will be explained how, through natural radioactivity, we can have access to the age of an event or an object; the case of radiocarbon will be especially emphasized. The principle of relative methods such as thermoluminescence or paleomagnetism will also be shortly given. What is the use for dating. The fields of its application are numerous; through these methods, relatively precise ages can be given to the major events which have been keys in the history of universe, life and man; thus, dating is a useful scientific tool in astrophysics, geology, biology, anthropology and archeology. Even if certain ages are still subject to controversies, we can say that these methods have confirmed evolution's continuity, be it on a cosmic, biologic or human scale, where ages are measured in billions, millions or thousands of years respectively

  20. Radiocarbon age variation in bone and tissue from variable dietary effects

    International Nuclear Information System (INIS)

    Radiocarbon dates of >2000 yrs BP have been reported for bones of the Polynesian rat Rattus exulans in avian predator deposits in New Zealand. Because R. exulans is a human commensal introduced to New Zealand, the oldest dates for this species would be a proxy for earliest human contact with these islands, as well as for the timing of the introduction of mammalian predators. The reliability of the oldest ages for R. exulans bone is thus important in both archaeology and palaeobiology. Our research has shown that contamination of samples is not a likely cause of the dates returned for some R. exulans, and that this species do produce reliable 14C ages as shown by agreement of rat bone and associated materials in various sites. There is evidence, however, for diet-derived radiocarbon anomalies, as supported by work on modern populations and archaeological samples of R. exulans and other species, which can cause minimal to extreme variation in the radiocarbon isotopic content of bone and other tissue. As these anomalous radiocarbon ages can actually offer important information about palaeoenvironments such as inter-species relationships, we would caution those who would 'cleanse' chronologies or otherwise exclude such data from the general interpretation of sites. (author). 42 refs., 4 figs., 2 tabs

  1. Complexities in the Use of Bomb-Curve Radiocarbon to Determine Time Since Death of Human Skeletal Remains

    Energy Technology Data Exchange (ETDEWEB)

    Ubelaker, D H; Buchholz, B A

    2005-04-26

    Atmospheric testing of nuclear weapons during the 1950s and early 1960s doubled the level of radiocarbon ({sup 14}C) in the atmosphere. From the peak in 1963, the level of {sup 14}CO{sub 2} has decreased exponentially with a mean life of about 16 years, not due to radioactive decay, but due to mixing with large marine and terrestrial carbon reservoirs. Since radiocarbon is incorporated into all living things, the bomb-pulse is an isotopic chronometer of the past half century. The absence of bomb radiocarbon in skeletonized human remains generally indicates a date of death before 1950. Comparison of the radiocarbon values with the post 1950 bomb-curve may also help elucidate when in the post 1950 era, the individual was still alive. Such interpretation however, must consider the age at death of the individual and the type of tissue sampled.

  2. Age estimation in forensic sciences: Application of combined aspartic acid racemization and radiocarbon analysis

    Energy Technology Data Exchange (ETDEWEB)

    Alkass, K; Buchholz, B A; Ohtani, S; Yamamoto, T; Druid, H; Spalding, S L

    2009-11-02

    Age determination of unknown human bodies is important in the setting of a crime investigation or a mass disaster, since the age at death, birth date and year of death, as well as gender, can guide investigators to the correct identity among a large number of possible matches. Traditional morphological methods used by anthropologists to determine age are often imprecise, whereas chemical analysis of tooth dentin, such as aspartic acid racemization has shown reproducible and more precise results. In this paper we analyze teeth from Swedish individuals using both aspartic acid racemization and radiocarbon methodologies. The rationale behind using radiocarbon analysis is that above-ground testing of nuclear weapons during the cold war (1955-1963) caused an extreme increase in global levels of carbon-14 ({sup 14}C) which have been carefully recorded over time. Forty-four teeth from 41 individuals were analyzed using aspartic acid racemization analysis of tooth crown dentin or radiocarbon analysis of enamel and ten of these were split and subjected to both radiocarbon and racemization analysis. Combined analysis showed that the two methods correlated well (R2=0.66, p < 0.05). Radiocarbon analysis showed an excellent precision with an overall absolute error of 0.6 {+-} 04 years. Aspartic acid racemization also showed a good precision with an overall absolute error of 5.4 {+-} 4.2 years. Whereas radiocarbon analysis gives an estimated year of birth, racemization analysis indicates the chronological age of the individual at the time of death. We show how these methods in combination can also assist in the estimation of date of death of an unidentified victim. This strategy can be of significant assistance in forensic casework involving dead victim identification.

  3. Future directions of the AMS program at Lucas Heights

    Energy Technology Data Exchange (ETDEWEB)

    Tuniz, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1998-12-31

    The research program based on the ANTARES AMS spectrometer involves applications of the long-lived radionuclides {sup 14}C, {sup 10}Be, {sup 26}Al, {sup 36}Cl and {sup 129}I in earth sciences and archaeology. Examples of environmental applications of AMS at Lucas Heights include: use of the {sup 14}C bomb pulse to determine the age and age-spread of air trapped in Antarctic ice bubbles, key parameters to study the variability of CO{sub 2} and other greenhouse gases in the past; analyses of {sup 14}C bomb-pulse curves in tree rings from tropical regions and the southern hemisphere to improve our understanding of the carbon cycle and air-sea interactions, important processes for the global climate; analyses of {sup 10}Be and {sup 36}Cl produced in-situ in polished glacial bedrock and moraine boulders from Tasmania, New Zealand and Antarctica, as part of a major national project to unravel the timing of glacial cycles in the southern hemisphere. A recent archaeological application has been the radiocarbon dating of charcoal fragments from the rock shelter at Jinmium in the Northern Territory demonstrating that this site was occupied by Aboriginal people only during the late Holocene. In environmental monitoring, the analysis of {sup 129}I, {sup 14}C and {sup 36}Cl in water specimens from Mururoa and Fangatauga contributed to an IAEA study regarding residual radioactivity in the Pacific after the French nuclear program Extended abstract. 5 refs.

  4. Future directions of the AMS program at Lucas Heights

    International Nuclear Information System (INIS)

    The research program based on the ANTARES AMS spectrometer involves applications of the long-lived radionuclides 14C, 10Be, 26Al, 36Cl and 129I in earth sciences and archaeology. Examples of environmental applications of AMS at Lucas Heights include: use of the 14C bomb pulse to determine the age and age-spread of air trapped in Antarctic ice bubbles, key parameters to study the variability of CO2 and other greenhouse gases in the past; analyses of 14C bomb-pulse curves in tree rings from tropical regions and the southern hemisphere to improve our understanding of the carbon cycle and air-sea interactions, important processes for the global climate; analyses of 10Be and 36Cl produced in-situ in polished glacial bedrock and moraine boulders from Tasmania, New Zealand and Antarctica, as part of a major national project to unravel the timing of glacial cycles in the southern hemisphere. A recent archaeological application has been the radiocarbon dating of charcoal fragments from the rock shelter at Jinmium in the Northern Territory demonstrating that this site was occupied by Aboriginal people only during the late Holocene. In environmental monitoring, the analysis of 129I, 14C and 36Cl in water specimens from Mururoa and Fangatauga contributed to an IAEA study regarding residual radioactivity in the Pacific after the French nuclear program

  5. Rarotonga Radiocarbon (delta 14C) for 1950 to 1997

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Rarotonga coral radiocarbon (14C) timeseries. Coral radiocarbon (Delta-14C) on untreated, low-speed drilled samples. Precision is +/- 4 per mil as documented by an...

  6. Nauru Island Radiocarbon Data for 1994 to 1995

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Nauru-2 coral radiocarbon (14C) timeseries. (166E, 0.5S, 14m bottom depth). Coral radiocarbon (Delta-14C) on untreated, low-speed drilled samples. Precision is +/-...

  7. Growth rate determinations from radiocarbon in bamboo corals (genus Keratoisis)

    Science.gov (United States)

    Farmer, Jesse R.; Robinson, Laura F.; Hönisch, Bärbel

    2015-11-01

    Radiocarbon (14C) measurements are an important tool for determining growth rates of bamboo corals, a cosmopolitan group of calcitic deep-sea corals. Published growth rate estimates for bamboo corals are highly variable, with potential environmental or ecological drivers of this variability poorly constrained. Here we systematically investigate the application of 14C for growth rate determinations in bamboo corals using 55 14C dates on the calcite and organic fractions of six bamboo corals (identified as Keratoisis sp.) from the western North Atlantic Ocean. Calcite 14C measurements on the distal surface of these corals and five previously published bamboo corals exhibit a strong one-to-one relationship with the 14C of dissolved inorganic carbon (DI14C) in ambient seawater (r2=0.98), confirming the use of Keratoisis sp. calcite 14C as a proxy for seawater 14C activity. Radial growth rates determined from 14C age-depth regressions, 14C plateau tuning and bomb 14C reference chronologies range from 12 to 78 μm y-1, in general agreement with previously published radiometric growth rates. We document potential biases to 14C growth rate determinations resulting from water mass variability, bomb radiocarbon, secondary infilling (ontogeny), and growth rate nonlinearity. Radial growth rates for Keratoisis sp. specimens do not correlate with ambient temperature, suggesting that additional biological and/or environmental factors may influence bamboo coral growth rates.

  8. The role of radiometric dating method in field of the archaeology and geology

    International Nuclear Information System (INIS)

    The role of radiocarbon dating method in the field of geology and archaeology and 210Pb dating in the field of geology has been done. Radiocarbon dating method is a dating method with a maximum age restriction is 45,000 years old. This study is to review dating methods by using synthesis process that uses radioactive carbon (14C) in the sample which is converted to benzene (14C6H6) and counted by liquid scintillation counter, while 210Pb dating method is that dating based on the measurement of 210Pb activity. This dating is special for sediments sample, with the maximum age of 150 years old. Some samples in the environment around the archaeological research and the geological site have been successfully carried out by radiocarbon dating analysis. Radiocarbon dating can also provide data as a contribution to support research on paleotsunami, so it can be used to estimate probability of the occurrence of tsunami in the future, while for 210Pb method dating has done research on the sedimentation rate as well as research on the existence of harmful algal (harmful algal bloom, HAB) sample in the sediments which is very dangerous to the environment and has been examined in certain areas. From the results of the study indicate that radiocarbon dating which based on the counting of the activity of 14C, in the future experts of radiocarbon dating is prefer to use of “modern” radiocarbon dating or radiocarbon dating by using mass spectrometry based on cyclotron method, because samples needed and standard deviation of the results relatively much smaller. (author)

  9. Thermoluminescence dating of Indian archaeological sites

    International Nuclear Information System (INIS)

    In an attempt to provide a chronology for Indian archaeological sites, an extensive pottery dating programme was initiated during 1978-1979. So far we have provided a chronology for seven important Indian archaeological sites. The dated cultures include: 1) the Ochre Colour Ware culture, 2) the Pre-Harappan culture, 3) the megalithic culture and 4) the Painted Grey Ware culture. A complete survey of recently measured TL dates are presented in a model format similar to that used in Radiocarbon. (author)

  10. Dating the introduction of cereal cultivation to the British Isles: early palaeoecological evidence from the Isle of Man

    Science.gov (United States)

    Innes, James B.; Blackford, Jeffrey J.; Davey, Peter J.

    2003-10-01

    The adoption of cereal cultivation is a key benchmark in the transition from Mesolithic hunter-gatherer foraging to Neolithic farming economies, but the nature, timing and ecological-cultural context of the earliest cereal use in the British Isles and northwest Europe is still uncertain. We present AMS radiocarbon dating and fine-resolution pollen evidence from the Isle of Man for cereal growing in the latter stages of a distinct episode of forest disturbance at almost 6000 yr BP (uncalibrated). The coherent ecological structure of this phase at the fine resolution level suggests that it records cereal cultivation well before the Ulmus decline, rather than wild grass pollen grains. This example is one of a cluster of early dates for cereal-type pollen near the start of the sixth millenium BP, including several around the Irish Sea, which indicate that the introduction of cereal agriculture probably occurred as early in the central British Isles as in the northern European plain. This early cereal phase is followed later by a probable phase of pre-Ulmus decline pastoral activity. We also report Mesolithic age woodland disturbance around 7000 yr BP (uncalibrated) and the first radiocarbon dates for mid-Holocene forest history of the Isle of Man. Copyright

  11. Offsets of atmospheric radiocarbon concentration from IntCal09 in East Asia appeared in human bones excavated at Imdangdong tombs, Jingshan, Korea

    International Nuclear Information System (INIS)

    Radiocarbon dating of human bones excavated from Imdangdong toms, Korea, was carried out. The preservation of bone collagen was poor, and even though the measurement was successful, their calibrated ages were not in good agreement with archaeological observations as well. However, in comparing to the radiocarbon offsets appeared in Japanese tree rings, the calibration age shifted to the proper age. This might show that the regional effects on calibration curve were coincident between Japanese archipelagos and Korean peninsula. (author)

  12. 14C dating with the bomb peak: An application to forensic medicine

    International Nuclear Information System (INIS)

    Samples originating from the time period after 1950 can be radiocarbon dated utilising the 14C bomb peak as a calibration curve. The applicability of 'radiocarbon dating' of recent organic human material for the determination of the time of death of humans was tested. The radiocarbon results from hair and lipid samples from individuals with known date of death were compared with the results from two individuals with unknown time of death. An estimate of the year of death for the unknowns could be derived by this way. Due to the long turnover time of collagen in human bones it is not possible to use the radiocarbon content of bone collagen for a reliable estimate. In order to study the time dependence of the collagen turnover we tested 'soft' chemical methods for the isolation of collagen from the bone matrix. First radiocarbon results of this investigation are presented

  13. Hydropyrolysis: implications for radiocarbon pre-treatment and characterization of Black Carbon

    OpenAIRE

    Ascough, P.; M. I. Bird; Meredith, W.; Wood, R. E.; Snape, C.E.; Brock, F.; Higham, T.F.; Large, D.J.; Apperley, D. C.

    2010-01-01

    Charcoal is the result of natural and anthropogenic burning events, when biomass is exposed to elevated temperatures under conditions of restricted oxygen. This process produces a range of materials, collectively known as pyrogenic carbon, the most inert fraction of which is known as Black Carbon (BC). BC degrades extremely slowly, and is resistant to diagenetic alteration involving the addition of exogenous carbon making it a useful target substance for radiocarbon dating particularly of ...

  14. Application of the bomb radiocarbon chronometer to the validation of redfish Centroberyx affinis age

    International Nuclear Information System (INIS)

    Validation of methods used to estimate fish age is a critical element of the fish stock assessment process. Despite the importance of validation, few procedures are available that provide unbiased estimates of true fish age and those methods that are available are seldom used. The majority of these methods are unlikely to provide an indication of the true age of individual fish, data that are best suited to the validation process. Accelerator mass spectrometry analyses of radiocarbon in selected regions of Centroberyx affinis otoliths were used to validate the age estimation method for this species. Radiocarbon data from the otoliths of C. affinis with presumed birth dates between 1955 and 1985 described the increase in ocean radiocarbon attributable to the atmospheric detonation of nuclear weapons in the 1950s and 1960s. The results confirm the longevity of C. affinis and demonstrate the effectiveness of the bomb radiocarbon chronometer for the validation of age-estimation methods. (author). 31 refs., 2 tabs., 1 fig

  15. Uranium series dating of diprotodon teeth from archaeological sites on the Liverpool plains

    International Nuclear Information System (INIS)

    In an attempt to test unexpected Holocene radiocarbon dates for archaeological deposits containing tooth fragments of Diprotodon (and other megafauna), uranium series dates were obtained for the teeth. All proved 2 to 4 times older than radiocarbon ages for the deposits. This apparently excess age included dates on control species still extant and found associated with the megafauna. The causes of apparent contamination are discussed

  16. Aeolian stratigraphy and thermoluminescence dating of sediments of late Holocene age from Sola, southwest Norway

    International Nuclear Information System (INIS)

    Thermoluminescence age determinations were performed on four aeolian sand samples of late Holocene sediments from Stavanger airport, Sola, in southwest Norway. The locality is well suited for testing thermoluminescence dating because of a good agreement between radiocarbon ages and age information based on archaeological typology and sea level changes. The conclusion from a comparison of thermoluminescence and radiocarbon dates is that it is possible to date well bleached sediments as young as 1600 years with thermoluminescence. 57 refs., 7 figs., 6 tabs

  17. Radiocarbon enrichment of soil organic fractions

    International Nuclear Information System (INIS)

    Fractions of soil organic matter were extracted by classical procedures and their relative carbon content, radiocarbon content, and 13C/12C ratios determined. Three kinds of soil were examined; an experimental soil formed from a former subsoil low in organic carbon; two moderately productive pasture soils; and a pumice soil under native tussock and introduced grasses of low productivity. The degree of radiocarbon enrichment of the different fractions in both topsoil and subsoil samples was examined in relation to differences in soil type and soil and vegetation history. No consistent pattern of distribution of organic carbon in fractions was recorded and no individual fractions appeared to provide a more reliable guide to enrichment of soil organic matter than the whole soil carbon. (author)

  18. Application of Bomb Radiocarbon Chronologies to Shortfin Mako (Isurus oxyrinchus)

    Energy Technology Data Exchange (ETDEWEB)

    Ardizzone, D; Cailliet, G M; Natanson, L J; Andrews, A H; Kerr, L A; Brown, T A

    2007-07-16

    and the number of samples for MIA analysis was insufficient for some months. Hence, unequivocal validation of shortfin mako age estimates has yet to be accomplished. Atmospheric testing of thermonuclear devices in the 1950s and 1960s effectively doubled the natural atmospheric radiocarbon ({sup 14}C). The elevated {sup 14}C levels were first recorded in 1957-58, with a peak around 1963. As a consequence, {sup 14}C entered the ocean through gas exchange with the atmosphere at the ocean surface and in terrestrial runoff. Despite variable oceanographic conditions, a worldwide rise of the bomb {sup 14}C signal entered the ocean mixed layer as dissolved inorganic carbon (DIC) in 1957-58. The large amounts of {sup 14}C released from the bomb tests produced a signature that can be followed through time, throughout the marine food web, and into deeper waters. The marked increase of radiocarbon levels was first measured in the DIC of seawater and in biogenic marine carbonates of hermatypic corals in Florida. Subsequently, this record was documented in corals from other regions and in the thallus of rhodoliths. The accumulation of radiocarbon in the hard parts of most marine organisms in the mixed layer (such as fish otoliths and bivalves) was synchronous with the coral time-series. This technique has been used to validate age estimates and longevity of numerous bony fishes to date, as well as to establish bomb radiocarbon chronologies from different oceans. In the first application of this technique to lamnoid sharks, validated annual band-pair deposition in vertebral growth bands for the porbeagle (Lamna nasus) aged up to 26 years. Radiocarbon values from samples obtained from 15 porbeagle caught in the western North Atlantic Ocean (some of which were known-age) produced a chronology similar in magnitude to the reference carbonate chronology for that region. The observed phase shift of about 3 years was attributed to different sources of carbon between vertebrae and those for

  19. Dating of two paleolithic human fossils from Romania by accelerator mass spectrometry

    International Nuclear Information System (INIS)

    In this study, we have dated two human fossil remains from Romania by the method of radiocarbon using the technique of the accelerator mass spectrometry at the Pelletron system of Lund University, Sweden. Two fossil remains appear to be the most ancient human remains ever dated in our country: 1. A skull, a scapula and a tibia found in Baia de Fier in the Women's Cave, in Gorj county in the province Oltenia, by Constantin Nicolaescu-Plopsor in 1952; 2. A skull found in Cioclovina cave, near commune Bosorod, Hunedoara county in Transilvania by a worker at the exploitation of phosphate deposits in the year 1941. The skull was examined by Francisc Rainer, anthropologist, and Ioan Simionescu, geologist, who published a study. The lack of stratigraphic observations made very difficult the cultural and chronological assignments of this skull. These authors advanced the hypothesis that the skull belongs to the man of the type Homo sapiens fossilis. At the same time, a number of archaeologists believed that the skull might belong to a modern man, but there have been doubts about this matter. Under this circumstance, dating of the two skulls by physical analysis methods appears to be decisive. Samples of bone were taken from the scapula and tibia from Woman's cave, Baia de Fier and from the skull from Cioclovina cave. The content of Carbon 14 have been determined in the two samples by using the technique of accelerator mass spectrometry (AMS), performed at the AMS system of Lund University, in Sweden. Usually, the collagen amount sufficient for AMS measurements can be extracted from bone fragments with masses of 1 g or more (what provides 5 to 10% of the original collagen content). But, in the situation of the present studied fossil remains, because of the small quantity of bone samples and because the bones were very old, the determination of radiocarbon in the skulls was not so simple. For the preparation of the bone samples, we have essentially applied the Longin method

  20. Tritium AMS for biomedical applications

    International Nuclear Information System (INIS)

    The authors are developing 3H accelerator mass spectrometry (AMS) at LLNL for work in the biological sciences. Their group has applied 14C AMS to a variety of problems (such as low-level dosimetry of genotoxic materials) and the development and demonstration of 3H AMS would greatly complement these studies. In conjunction with their present AMS capacity, the ability to perform 3H AMS measurements at equivalent sensitivities will allow them to perform unique double labeling experiments in which they learn the fate, distribution, and metabolism of separate fractions of xenobiotics and biologicals. Also, the large number of commercially available 3H-tagged compounds will allow them to perform experiments using compounds that are simply unavailable in 14C-tagged form. The authors anticipate being able to measure 3H/1H concentrations as low as 1 part in 1014 from sample masses as low as 2 μgs. Progress to date and future plans are discussed

  1. Extracting growth rates from the non-laminated coralline sponge Astrosclera willeyana using "bomb" radiocarbon

    Energy Technology Data Exchange (ETDEWEB)

    Fallon, S; Guilderson, T

    2004-06-30

    Coralline sponges have the potential to fill in gaps in our understanding of subsurface oceanographic variability. However, one disadvantage they have compared to hermatypic reef building coral proxies is that they do not have annual density bands and need to be radiometrically dated for an age determination. To elucidate growth rate variability we have measured radiocarbon in 1 mm increments from Astrosclera willeyana sponges collected off the Central and Northern Great Barrier Reef (GBR) and from Truk in the Caroline Islands and compared these radiocarbon profiles to independently dated coral radiocarbon records. Growth rates of the GBR sponges average 1.2 {+-} 0.3 and 1.0 {+-} 0.3 mm yr{sup -1}, north and central respectively but can vary by a factor of two. The growth rate of the Truk sponge averages 1.2 {+-} 0.1 mm yr{sup -1}. These growth rates are significantly faster to those measured for other GBR Astrosclera willeyana sponges (0.2 mm yr{sup -1}) by Calcein staining (Woerheide 1988).

  2. Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus).

    Science.gov (United States)

    Nielsen, Julius; Hedeholm, Rasmus B; Heinemeier, Jan; Bushnell, Peter G; Christiansen, Jørgen S; Olsen, Jesper; Ramsey, Christopher Bronk; Brill, Richard W; Simon, Malene; Steffensen, Kirstine F; Steffensen, John F

    2016-08-12

    The Greenland shark (Somniosus microcephalus), an iconic species of the Arctic Seas, grows slowly and reaches >500 centimeters (cm) in total length, suggesting a life span well beyond those of other vertebrates. Radiocarbon dating of eye lens nuclei from 28 female Greenland sharks (81 to 502 cm in total length) revealed a life span of at least 272 years. Only the smallest sharks (220 cm or less) showed signs of the radiocarbon bomb pulse, a time marker of the early 1960s. The age ranges of prebomb sharks (reported as midpoint and extent of the 95.4% probability range) revealed the age at sexual maturity to be at least 156 ± 22 years, and the largest animal (502 cm) to be 392 ± 120 years old. Our results show that the Greenland shark is the longest-lived vertebrate known, and they raise concerns about species conservation. PMID:27516602

  3. Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus)

    DEFF Research Database (Denmark)

    Nielsen, Julius; Hedeholm, Rasmus B; Heinemeier, Jan;

    2016-01-01

    The Greenland shark (Somniosus microcephalus), an iconic species of the Arctic Seas, grows slowly and reaches >500 centimeters (cm) in total length, suggesting a life span well beyond those of other vertebrates. Radiocarbon dating of eye lens nuclei from 28 female Greenland sharks (81 to 502 cm in...... total length) revealed a life span of at least 272 years. Only the smallest sharks (220 cm or less) showed signs of the radiocarbon bomb pulse, a time marker of the early 1960s. The age ranges of prebomb sharks (reported as midpoint and extent of the 95.4% probability range) revealed the age at sexual...... maturity to be at least 156 ± 22 years, and the largest animal (502 cm) to be 392 ± 120 years old. Our results show that the Greenland shark is the longest-lived vertebrate known, and they raise concerns about species conservation....

  4. Application of combined nuclear methods for dating of geological and archaeological objects

    International Nuclear Information System (INIS)

    Paper presents some results in dating of geological and archaeological objects using thermoluminescence and radiocarbon methods. The results were evaluated comparatively to each other and to foreign laboratories. (NHA)

  5. C-14 bomb peak dating of human DNA samples at the microgram level

    International Nuclear Information System (INIS)

    Radiocarbon (14C, t1/2 = 5700 ± 30 years) is probably the radionuclide with the most versatile applications, spanning from archaeology to geoscience and medicine. Many of these applications are finally limited by the minimum amount of carbon in which the isotopic ratio 14C/12C can be measured. The required carbon sample size has dramatically decreased with the development of Accelerator Mass Spectrometry (AMS), typically from gram amounts for the classical beta counting method to about 1 milligram for AMS. The current work presents a further reduction into the few-μg carbon range. This means a decrease by a factor of one million compared to classical beta counting and is essential for the field of retrospective birth dating of human cells by means of radiocarbon from above-ground nuclear weapons testing between 1955 and 1963. The determination of 14C levels in genomic DNA can be used to retrospectively establish the birth date of cells in the human body. The main motive of the current work was to reduce the amount of carbon required for reliable 14C measurements to such an extent that investigations of neurons of particularly interesting small sections of the human brain (e.g. the olfactory bulb, bulbus olfactorius) were possible. In-depth investigations and development of 14C AMS sample preparation and measurement methods for μg-size DNA samples were carried out in close collaboration with the Department of Cell and Molecular Biology of the Karolinska Institute in Stockholm. As the most significant result, 14C measurements of 4.6 μg carbon DNA samples were performed with an overall precision of 2.3%. This allowed to study neurogenesis in the human olfactory bulb, which turned out to take place primarily at birth. Assuming throughout life a constant annual renewal rate of neurons in the human olfactory bulb, an upper limit of 0.34% for the renewal rate (95% confidence) was determined. At the Vienna Environmental Research Accelerator (VERA) the μg carbon

  6. Constraining the Late Pleistocene history of the Laurentide Ice Sheet by dating the Missinaibi Formation, Hudson Bay Lowlands, Canada

    Science.gov (United States)

    Dalton, April S.; Finkelstein, Sarah A.; Barnett, Peter J.; Forman, Steven L.

    2016-08-01

    Well-dated paleorecords from periods prior to the Last Glacial Maximum (LGM) are important for validating models of ice sheet build-up and growth. However, owing to glacial erosion, most Late Pleistocene records lie outside of the previously glaciated region, which limits their ability to inform about the dynamics of paleo-ice sheets. Here, we evaluate new and previously published chronology data from the Missinaibi Formation, a Pleistocene-aged deposit in the Hudson Bay Lowlands (HBL), Canada, located near the geographic center of the Laurentide Ice Sheet (LIS). Available radiocarbon (AMS = 44, conventional = 36), amino acid (n = 13), uranium-thorium (U-Th, n = 14), thermoluminescence (TL, n = 15) and optically stimulated luminescence (OSL, n = 5) data suggest that an ice-free HBL may have been possible during parts of Marine Isotope Stage 7 (MIS 7; ca. 243,000 to ca. 190,000 yr BP), MIS 5 (ca. 130,000 to ca. 71,000 yr BP) and MIS 3 (ca. 29,000 to ca. 57,000). While MIS 7 and MIS 5 are well-documented interglacial periods, the development of peat, forest bed and fluvial deposits dating to MIS 3 (n = 20 radiocarbon dates; 4 TL dates, 3 OSL dates), suggests that the LIS retreated and remained beyond, or somewhere within, the boundaries of the HBL during this interstadial. Ice sheet models approximate the margin of the LIS to Southern Ontario during this time, which is 700 km south of the HBL. Therefore, if correct, our data help constrain a significantly different configuration and dynamicity for the LIS than previously modelled. We can find no chronological basis to discount the MIS 3 age assignments. However, since most data originate from radiocarbon dates lying close to the reliable limit of this geochronometer, future work on dating the Missinaibi Formation using other geochronological methods (e.g. U-Th, OSL) is necessary in order to confirm the age estimates and strengthen the boundaries of the LIS during this period.

  7. Why date old bones?

    International Nuclear Information System (INIS)

    The methods for pretreatment and purification of bone have not been accorded the same standard protocols that are applied to other sample materials. Many users lack confidence in bone dates, with some justification, and it is not clear how to proceed. With the advent of AMS dating, it is becoming easy to date very small amounts of highly purified samples such as single amino acids from bone collagen. This note serves a warning that there are dangers in the uncritical application of powerful separation and measurement techniques to uncharacterized material. (orig.)

  8. High-resolution chronology for the Mesoamerican urban center of Teotihuacan derived from Bayesian statistics of radiocarbon and archaeological data

    Science.gov (United States)

    Beramendi-Orosco, Laura E.; Gonzalez-Hernandez, Galia; Urrutia-Fucugauchi, Jaime; Manzanilla, Linda R.; Soler-Arechalde, Ana M.; Goguitchaishvili, Avto; Jarboe, Nick

    2009-03-01

    A high-resolution 14C chronology for the Teopancazco archaeological site in the Teotihuacan urban center of Mesoamerica was generated by Bayesian analysis of 33 radiocarbon dates and detailed archaeological information related to occupation stratigraphy, pottery and archaeomagnetic dates. The calibrated intervals obtained using the Bayesian model are up to ca. 70% shorter than those obtained with individual calibrations. For some samples, this is a consequence of plateaus in the part of the calibration curve covered by the sample dates (2500 to 1450 14C yr BP). Effects of outliers are explored by comparing the results from a Bayesian model that incorporates radiocarbon data for two outlier samples with the same model excluding them. The effect of outliers was more significant than expected. Inclusion of radiocarbon dates from two altered contexts, 500 14C yr earlier than those for the first occupational phase, results in ages calculated by the model earlier than the archaeological records. The Bayesian chronology excluding these outliers separates the first two Teopancazco occupational phases and suggests that ending of the Xolalpan phase was around cal AD 550, 100 yr earlier than previously estimated and in accordance with previously reported archaeomagnetic dates from lime plasters for the same site.

  9. C-14 dates from a profile of Arroyo Tapalque, Buenos Aires Province, Argentina. Contribution to the chronology of faunal and environmental events

    International Nuclear Information System (INIS)

    Eleven radiocarbon dates were obtained from different materials in a stratigraphic section spanning the last 30,000 years. These new dates allow to calibrate different faunal and environmental events occurring in the area. (author)

  10. Pre- and post-bomb radiocarbon in fish otoliths

    Science.gov (United States)

    Kalish, John M.

    1993-02-01

    Measurements of radiocarbon in seawater dissolved inorganic carbon (DIC), or suitable proxies such as hermatypic corals, are a valuable source of information on carbon flux and ocean circulation. However, knowledge of the global distribution of both pre- and post-bomb radiocarbon is limited due to the sources of these data. Suitable hermatypic corals are restricted to shallow tropical and subtropical waters and oceanographic collections of seawater are prohibitively expensive. What is needed is a proxy for ocean radiocarbon that can be collected at most latitudes and depths, and which can be reliably aged. Here I report accelerator mass spectrometry analyses of radiocarbon from selected regions of fish otoliths and show that such measurements are suitable for determining both pre- and post-bomb radiocarbon in all oceans and at most depths. Radiocarbon data obtained from otoliths can extend our knowledge of carbon flux in the oceans and atmosphere and help to develop further understanding of the fate of atmospheric CO 2 and ocean circulation. The data presented here represent the first pre- and post-bomb time series of radiocarbon levels from temperate waters. Furthermore, I demonstrate that the dramatic increase in radiocarbon in the atmosphere and oceans, attributable to the atmospheric testing of thermonuclear bombs during the 1950's and 1960's, provides a chemical mark on fish otoliths that is suitable for the validation of age in fishes.

  11. New radiocarbon chronology of a late Holocene landslide event in the Mont Blanc massif, Italy

    Science.gov (United States)

    Hajdas, Irka; Sojc, Ursula; Ivy-Ochs, Susan; Akçar, Naki; Deline, Philip

    2016-04-01

    The Ferret valley Arp Nouva peat bog located in the Mont Blanc massif was critically evaluated since previously published radiocarbon dates have led to controversial conclusions on the formation of the swamp. Radiocarbon dating of roots from three pits of up to 1 m depth was applied to discuss the question whether the historical documented rock avalanche occurring in AD 1717 overran the peat bog or formed it at a later stage. Our results indicate that the rock avalanche formed the Arp Nouva peat bog by downstream blockage of the Bellecombe torrent. Furthermore, careful sample preparation with consequent separation of roots from the bulk peat sample provides possible explanation for the too old 14C ages of bulk peat samples dated previously (Deline and Kirkbride, 2009 and references therein). This work demonstrates that a combined geomorphological and geochronological approach is the most reliable way to reconstruct landscape evolution, especially in light of apparent chronological problems. The key to successful 14C dating is a careful sample selection and the identification of material that might be not ideal for chronological reconstructions. References Deline, Philip, and Martin P. Kirkbride. "Rock avalanches on a glacier and morainic complex in Haut Val Ferret (Mont Blanc Massif, Italy)".Geomorphology 103 (2009): 80-92.

  12. Date Rape

    Science.gov (United States)

    ... Can I Help a Friend Who Cuts? Date Rape KidsHealth > For Teens > Date Rape Print A A ... en español Violaciones durante citas What Is Date Rape? When people think of rape , they might picture ...

  13. Radiocarbon analyses along the EDML ice core in Antarctica

    International Nuclear Information System (INIS)

    Samples, 17 in total, from the EDML core drilled at Kohnen station Antarctica are analysed for 14CO and 14CO2 with a dry-extraction technique in combination with accelerator mass spectrometry. Results of the in situ produced 14CO fraction show a very low concentration of in situ produced 14CO. Despite these low levels in carbon monoxide, a significant in situ production is observed in the carbon dioxide fraction. For the first time we found background values for the ice samples which are equal to line blanks. The data set is used to test a model for the production of 14C in the ice matrix, in combination with a degassing as 14CO2 and possibly as 14CO into the air bubbles. Application of the model, for which no independent validation is yet possible, offers the opportunity to use radiocarbon analysis as dating technique for the air bubbles in the ice. Assigning an arbitrary error of 25% to the calculation of the in situ production leads to age estimates, after correction for the in situ production, which are in agreement with age estimates based on a volcanic layer match of EDML to the Dome C timescale in combination with a correction for firn diffusion

  14. Integrated Tree-Ring-Radiocarbon High-Resolution Timeframe to Resolve Earlier Second Millennium BCE Mesopotamian Chronology

    Science.gov (United States)

    Griggs, Carol B.; Lorentzen, Brita; Barjamovic, Gojko; Ramsey, Christopher Bronk; Kromer, Bernd; Wild, Eva Maria

    2016-01-01

    500 years of ancient Near Eastern history from the earlier second millennium BCE, including such pivotal figures as Hammurabi of Babylon, Šamši-Adad I (who conquered Aššur) and Zimrilim of Mari, has long floated in calendar time subject to rival chronological schemes up to 150+ years apart. Texts preserved on clay tablets provide much information, including some astronomical references, but despite 100+ years of scholarly effort, chronological resolution has proved impossible. Documents linked with specific Assyrian officials and rulers have been found and associated with archaeological wood samples at Kültepe and Acemhöyük in Turkey, and offer the potential to resolve this long-running problem. Here we show that previous work using tree-ring dating to place these timbers in absolute time has fundamental problems with key dendrochronological crossdates due to small sample numbers in overlapping years and insufficient critical assessment. To address, we have integrated secure dendrochronological sequences directly with radiocarbon (14C) measurements to achieve tightly resolved absolute (calendar) chronological associations and identify the secure links of this tree-ring chronology with the archaeological-historical evidence. The revised tree-ring-sequenced 14C time-series for Kültepe and Acemhöyük is compatible only with the so-called Middle Chronology and not with the rival High, Low or New Chronologies. This finding provides a robust resolution to a century of uncertainty in Mesopotamian chronology and scholarship, and a secure basis for construction of a coherent timeframe and history across the Near East and East Mediterranean in the earlier second millennium BCE. Our re-dating also affects an unusual tree-ring growth anomaly in wood from Porsuk, Turkey, previously tentatively associated with the Minoan eruption of the Santorini volcano. This tree-ring growth anomaly is now directly dated ~1681–1673 BCE (68.2% highest posterior density range), ~20

  15. Marine04 marine radiocarbon age calibration, 0-26 cal kyr BP

    OpenAIRE

    Hughen, Konrad A.; Baillie, Mike G.L.; Bard, Edouard; Beck, J. Warren; Bertrand, Chanda J.H.; Blackwell, Paul G.; Caitlin E. Buck; Burr, George S; Cutler, Kirsten B.; Damon, Paul E.; Edwards, Richard L.; Fairbanks, Richard G.; Friedrich, Michael; Guilderson, Thomas P; Kromer, Bernd

    2004-01-01

    New radiocarbon calibration curves, IntCal04 and Marine04, have been constructed and internationally ratified to replace the terrestrial and marine components of IntCal98. The new calibration data sets extend an additional 2000 yr, from 0–26 cal kyr BP (Before Present, 0 cal BP = AD 1950), and provide much higher resolution, greater precision, and more detailed structure than IntCal98. For the Marine04 curve, dendrochronologically-dated tree-ring samples, converted with a box diffusion model ...

  16. Stable lead (Pb) isotopes and concentrations - A useful independent dating tool for Baltic Sea sediments

    NARCIS (Netherlands)

    Zillén, L.; Lenz, C.; Jilbert, T.

    2012-01-01

    The prehistory of the Baltic Sea has for a long time suffered from imprecise dating, due to the large uncertainties associated with bulk radiocarbon dating of Baltic Seasediments. To constrain the timing of environmental changes in the Baltic Sea it is critical to apply new dating approaches. This s

  17. Radiocarbon ages of upper quaternary deposit in central Nepal and their geomorphological significance

    International Nuclear Information System (INIS)

    The author visited Nepal from October, 1980, to February, 1981, investigated the geomorphology and upper Quaternary geology in Central Nepal, and collected a number of samples for radiocarbon dating. After returning to his university, he dated ten samples by himself. In Nepal, radiocarbon age has been scarcely reported as yet, besides in Kathmandu valley. Therefore, the author's ten data of the age are very important for the late Quaternary chronological study of Nepal Himalayas. In this paper, the author describes sampling localities and horizons, dating results and their geomorphological significance. These ten samples included Pokhara valley, Marsyandi Kohla, Modi Khola, Madi Khola and Muktinath samples. Some conclusion was derived as for the geomorphological development in central Nepal: The last Himalayan glacial age had already ended before 9,000 yr BP (years before A.D. 1950); In the Midland region, from 4,300 to 600 yr BP, some large-scale mudflows broke out nearly contemporaneously in the upper valleys, and they flowed down torrentially and catastrophically to deposit in the middle course of rivers. But the cause of vast quantity of material suddenly brought down from the Great Himalayas has been still left unexplained. The conclusion like this also was able to be applied to the middle Marsyandi Khola and the Pokhara valley. The wide-spread schema that the river was aggraded in the glacial age and degraded in the interglacial age may not be applicable to the rivers in the Midland region of Nepal Himalayas. (Wakatsuki, Y.)

  18. Pego do Diabo (Loures, Portugal: dating the emergence of anatomical modernity in westernmost Eurasia.

    Directory of Open Access Journals (Sweden)

    João Zilhão

    Full Text Available BACKGROUND: Neandertals and the Middle Paleolithic persisted in the Iberian Peninsula south of the Ebro drainage system for several millennia beyond their assimilation/replacement elsewhere in Europe. As only modern humans are associated with the later stages of the Aurignacian, the duration of this persistence pattern can be assessed via the dating of diagnostic occurrences of such stages. METHODOLOGY/PRINCIPAL FINDINGS: Using AMS radiocarbon and advanced pretreatment techniques, we dated a set of stratigraphically associated faunal samples from an Aurignacian III-IV context excavated at the Portuguese cave site of Pego do Diabo. Our results establish a secure terminus ante quem of ca. 34,500 calendar years ago for the assimilation/replacement process in westernmost Eurasia. Combined with the chronology of the regional Late Mousterian and with less precise dating evidence for the Aurignacian II, they place the denouement of that process in the 37th millennium before present. CONCLUSIONS/SIGNIFICANCE: These findings have implications for the understanding of the emergence of anatomical modernity in the Old World as a whole, support explanations of the archaic features of the Lagar Velho child's anatomy that invoke evolutionarily significant Neandertal/modern admixture at the time of contact, and counter suggestions that Neandertals could have survived in southwest Iberia until as late as the Last Glacial Maximum.

  19. Svobodné Dvory near Hradec Králové: an Upper Palaeolithic hunting site and its dating

    Czech Academy of Sciences Publication Activity Database

    Šída, P.; Nývltová Fišáková, Miriam; Verpoorte, A.

    2006-01-01

    Roč. 58, č. 4 (2006), s. 772-780. ISSN 0323-1267 Institutional research plan: CEZ:AV0Z80010507 Keywords : Gravettien * Upper Palaeolithic * Mammoth * Radiocarbon dating Subject RIV: AC - Archeology, Anthropology, Ethnology

  20. Radiocarbon determinations using a minicyclotron: Applications in archaeology

    International Nuclear Information System (INIS)

    The first international minicyclotron AMS facility has been brought into routine operation after many years of effort. The mass resolution of this device is greater than 3000, and the precision of isotopic ratio measurements is 1%. The age limit for 14C dating is about 42,000 yr BP. We have used the International Oxalic Acid Standards together with geological and archaeological samples of known age as cross-checks, to evaluate the precision and accuracy of the machine. All of the cross-check results agree within two standard deviations. The performance of the machine has achieved the level of routine dating normally achieved by Tandem accelerators. The authors have used this new technique to provide a chronology for metallurgical relics in Ruichang, Janxi province. The results obtained provide significant proof for the existence of an extensive copper mining and refining industry which was 500 years earlier than previously thought

  1. Bomb-curve radiocarbon measurement of recent biologic tissues and applications to wildlife forensics and stable isotope (paleo)ecology

    Science.gov (United States)

    Uno, Kevin T.; Quade, Jay; Fisher, Daniel C.; Wittemyer, George; Douglas-Hamilton, Iain; Andanje, Samuel; Omondi, Patrick; Litoroh, Moses; Cerling, Thure E.

    2013-07-01

    Above-ground thermonuclear weapons testing from 1952 through 1962 nearly doubled the concentration of radiocarbon (14C) in the atmosphere. As a result, organic material formed during or after this period may be radiocarbon-dated using the abrupt rise and steady fall of the atmospheric 14C concentration known as the bomb-curve. We test the accuracy of accelerator mass spectrometry radiocarbon dating of 29 herbivore and plant tissues collected on known dates between 1905 and 2008 in East Africa. Herbivore samples include teeth, tusks, soft tissue, hair, and horn. Tissues formed after 1955 are dated to within 0.3-1.3 y of formation, depending on the tissue type, whereas tissues older than ca. 1955 have high age uncertainties (>17 y) due to the Suess effect. 14C dating of tissues has applications to stable isotope (paleo)ecology and wildlife forensics. We use data from 41 additional samples to determine growth rates of tusks, molars, and hair, which improve interpretations of serial stable isotope data for (paleo)ecological studies. 14C dating can also be used to calculate the time interval represented in periodic histological structures in dental tissues (i.e., perikymata), which in turn may be used as chronometers in fossil teeth. Bomb-curve 14C dating of confiscated animal tissues (e.g., ivory statues) can be used to determine whether trade of the item is legal, because many Convention of International Trade of Endangered Species restrictions are based on the age of the tissue, and thus can serve as a powerful forensic tool to combat illegal trade in animal parts.

  2. Bomb-curve radiocarbon measurement of recent biologic tissues and applications to wildlife forensics and stable isotope (paleo)ecology.

    Science.gov (United States)

    Uno, Kevin T; Quade, Jay; Fisher, Daniel C; Wittemyer, George; Douglas-Hamilton, Iain; Andanje, Samuel; Omondi, Patrick; Litoroh, Moses; Cerling, Thure E

    2013-07-16

    Above-ground thermonuclear weapons testing from 1952 through 1962 nearly doubled the concentration of radiocarbon ((14)C) in the atmosphere. As a result, organic material formed during or after this period may be radiocarbon-dated using the abrupt rise and steady fall of the atmospheric (14)C concentration known as the bomb-curve. We test the accuracy of accelerator mass spectrometry radiocarbon dating of 29 herbivore and plant tissues collected on known dates between 1905 and 2008 in East Africa. Herbivore samples include teeth, tusks, soft tissue, hair, and horn. Tissues formed after 1955 are dated to within 0.3-1.3 y of formation, depending on the tissue type, whereas tissues older than ca. 1955 have high age uncertainties (>17 y) due to the Suess effect. (14)C dating of tissues has applications to stable isotope (paleo)ecology and wildlife forensics. We use data from 41 additional samples to determine growth rates of tusks, molars, and hair, which improve interpretations of serial stable isotope data for (paleo)ecological studies. (14)C dating can also be used to calculate the time interval represented in periodic histological structures in dental tissues (i.e., perikymata), which in turn may be used as chronometers in fossil teeth. Bomb-curve (14)C dating of confiscated animal tissues (e.g., ivory statues) can be used to determine whether trade of the item is legal, because many Convention of International Trade of Endangered Species restrictions are based on the age of the tissue, and thus can serve as a powerful forensic tool to combat illegal trade in animal parts. PMID:23818577

  3. Optimization of simultaneous tritium-radiocarbon internal gas proportional counting

    Science.gov (United States)

    Bonicalzi, R. M.; Aalseth, C. E.; Day, A. R.; Hoppe, E. W.; Mace, E. K.; Moran, J. J.; Overman, C. T.; Panisko, M. E.; Seifert, A.

    2016-03-01

    Specific environmental applications can benefit from dual tritium and radiocarbon measurements in a single compound. Assuming typical environmental levels, it is often the low tritium activity relative to the higher radiocarbon activity that limits the dual measurement. In this paper, we explore the parameter space for a combined tritium and radiocarbon measurement using a natural methane sample mixed with an argon fill gas in low-background proportional counters of a specific design. We present an optimized methane percentage, detector fill pressure, and analysis energy windows to maximize measurement sensitivity while minimizing count time. The final optimized method uses a 9-atm fill of P35 (35% methane, 65% argon), and a tritium analysis window from 1.5 to 10.3 keV, which stops short of the tritium beta decay endpoint energy of 18.6 keV. This method optimizes tritium-counting efficiency while minimizing radiocarbon beta-decay interference.

  4. Optimization of Simultaneous Tritium-Radiocarbon Internal Gas Proportional Counting

    Energy Technology Data Exchange (ETDEWEB)

    Bonicalzi, Ricco; Aalseth, Craig E.; Day, Anthony R.; Hoppe, Eric W.; Mace, Emily K.; Moran, James J.; Overman, Cory T.; Panisko, Mark E.; Seifert, Allen

    2016-01-07

    Abstract Specific environmental applications can benefit from dual tritium and radiocarbon measurements in a single compound. Assuming typical environmental levels, it is often the low tritium activity relative to the higher radiocarbon activity that limits the dual measurement. In this paper, we explore the parameter space for a combined tritium and radiocarbon measurement using a methane sample mixed with an argon fill gas in low-background proportional counters of a specific design. We present an optimized methane percentage, detector fill pressure, and analysis energy windows to maximize measurement sensitivity while minimizing count time. The final optimized method uses a 9-atm fill of P35 (35% methane, 65% argon), and a tritium analysis window from 1.5 to 10.3 keV, which stops short of the tritium beta decay endpoint energy of 18.6 keV. This method optimizes tritium counting efficiency while minimizing radiocarbon beta decay interference.

  5. Rapid graphite target preparation with sealed tube zinc reduction method for C-14 dating by MICADAS

    International Nuclear Information System (INIS)

    Complete text of publication follows. In most cases the last step of the sample preparation for 14C dating by AMS is to produce graphite from the pure CO2 gas samples. Catalytic reaction is generally used to produce graphite for which stabilized temperature reaction cells are developed in certain laboratories. The properties (e.g. purity, conductivity) of the produced graphite vitally influence the quality of the AMS measurement. Although the internationally validated hydrogen reduction graphitization line of Hertelendi Laboratory of ATOMKI is able to produce high quality graphite for AMS C-14 analyses, the throughput of the prepared targets is highly limited. In this study we were looking for a rapid production and low cost graphitization method, whereby we are capable to handle numerous biomedical and environmental samples per day. The sealed tube zinc reduction method mostly suits to these criteria (Figure 1). We have adapted the method in ATOMKI and the goal of our study was to find out the proper conditions of the graphitization process. We have analyzed how does the graphitization time (240 - 3720 min) and the amount of zinc (30, 50 and 80 mg) and titanium hydride (7, 10 and 12 mg) reagents influence the value of the 12C ion current and the measured radiocarbon content of the sample and how big the caused isotope fractionation. Important task was to reach the achievable minimum background level and decrease the δ13C shift as minimal as possible. We have also investigated the reproducibility of graphitization process and examined the radiocarbon content of graphite targets made of oxalic acid standard (NIST-SRM-4990c). All of the graphite targets were prepared in ATOMKI laboratory and the AMS measurements were carried out on the MICADAS type accelerator mass spectrometer, developed and hosted in ETHZ, Zuerich. The amount of TiH2 we have examined does not have any kind of influence on the important features of the produced graphite. On the other hand the

  6. The 14C-AMS Laboratory at IF-UFF

    International Nuclear Information System (INIS)

    Full text: In 2009 a radiocarbon sample preparation laboratory dedicated to Accelerator Mass Spectrometry was installed at the Physics Institute of the Fluminense Federal University. At the Radiocarbon Laboratory samples of several kinds of materials such as charcoal, sediments, wood and shells go through specific chemical treatment and conversion to carbon dioxide. Graphite reduction is performed in sealed Pyrex tubes, using Zinc, Titanium Hydrate, and iron catalyst within an inner tube. Samples have been successfully produced yielding fluffy homogeneous graphite leading to high and stable currents in the ion source. For sample measurement an accelerator system produced by the National Electrostatics Corporation (NEC), was installed in the Physics Institute. The machine, specially developed to carbon analysis, is the State of the Art in 14C - AMS studies and its acquisition represent a very important step for Brazil towards the development of science and technology regarding radiocarbon studies. The system includes an open air deck 250 kV single stage electrostatic accelerator with magnetic and electrostatic analyzers that enable isotope separation and detection. Radiocarbon concentrations are measured to 1 part in 1015 with precision of 0.3 The Nuclear Applied Physics group on Chronological Studies is now performing multidisciplinary research in collaboration with Brazilian and foreign groups from several fields of science such as Archaeology, Geophysics, Oceanography and Biology, in studies on the evolution of marine, terrestrial and Antarctic ecosystems. (author)

  7. Investigating bomb radiocarbon transport in the southern Pacific Ocean with otolith radiocarbon

    Science.gov (United States)

    Grammer, G. L.; Fallon, S. J.; Izzo, C.; Wood, R.; Gillanders, B. M.

    2015-08-01

    To explore the transport of carbon into water masses from the surface ocean to depths of ∼ 1000 m in the southwest Pacific Ocean, we generated time series of radiocarbon (Δ14C) from fish otoliths. Otoliths (carbonate earstones) from long-lived fish provide an indirect method to examine the "bomb pulse" of radiocarbon that originated in the 1950s and 1960s, allowing identification of changes to distributions of 14C that has entered and mixed within the ocean. We micro-sampled ocean perch (Helicolenus barathri) otoliths, collected at ∼ 400- 500 m in the Tasman Sea, to obtain measurements of Δ14C for those depths. We compared our ocean perch Δ14C series to published otolith-based marine surface water Δ14C values (Australasian snapper (Chrysophrys auratus) and nannygai (Centroberyx affinis)) and to published deep-water values (800-1000 m; orange roughy (Hoplostethus atlanticus)) from the southwest Pacific to establish a mid-water Δ14C series. The otolith bomb 14C results from these different depths were consistent with previous water mass results in the upper 1500 m of the southwest Pacific Ocean (e.g. World Ocean Circulation Experiment and Geochemical Ocean Sections Study). A comparison between the initial Δ14C bomb pulse rise at 400-500 m suggested a ventilation lag of 5 to 10 yr, whereas a comparison of the surface and depths of 800-1000 m detailed a 10 to 20 yr lag in the time history of radiocarbon invasion at this depth. Pre-bomb reservoir ages derived from otolith 14C located in Tasman Sea thermocline waters were ∼ 530 yr, while reservoir ages estimated for Tasman Antarctic intermediate water were ∼ 730 yr.

  8. Investigating global change and fish biology with fish otolith radiocarbon

    Science.gov (United States)

    Kalish, John M.

    1994-06-01

    Fish otoliths, calcium carbonate gravity and auditory receptors in the membranous labyrinths of teleost fish, can provide radiocarbon data that are valuable to a wide range of disciplines. For example, the first pre- and post-bomb time series of radiocarbon levels from northern or southern hemisphere temperate oceans was obtained by carrying out accelerator mass spectrometry analyses on selected regions of fish otoliths. These data can provide powerful constraints on both carbon cycle models and ocean general circulation models. Because fish otoliths can serve as a proxy of radiocarbon in seawater dissolved inorganic carbon in all oceans and at most depths, there is considerable scope for further investigations of otolith radiocarbon in relation to both oceanography and global change. In addition to applications relevant to global change, fish otoliths are also valuable sources of information on the age, growth, and ecology of fishes, with age being among the most important parameters in population modelling and fisheries management. Use of the bomb radiocarbon chronometer to validate fish age determination methods offers considerable advantages over traditional forms of age validation and promises to become a standard tool in fish biology and fisheries management. Radiocarbon data from otoliths can also provide valuable information on the ecology of fishes and has already provided surprising information relevant to the ecology of some deep-sea fishes.

  9. Thermoluminescence dating

    International Nuclear Information System (INIS)

    The method of dating archaeological pottery specimens by thermoluminescence is described. Techniques for measuring the radiation dose within the pottery fabric and from the surrounding burial medium are discussed. Examples are given of dating projects. (U.K.)

  10. Considerations on the modelling of environmental radiocarbon

    International Nuclear Information System (INIS)

    Modelling radionuclide transfer within the natural environment involves three general steps: model formulation, its fitting using appropriate experimental data and model validation. The last process typically involves a sensitivity analysis and is used to modify model formulation and to direct future experimental effort. A wide variety of models exists appropriate to a number of different applications. Recently, attention has been directed to the development of principles for establishing local, regional and global upper bounds to doses. Here important considerations in model choice are the spatial detail required within the model, the links between models of differing resolution and the availability of suitable experimental data. We illustrate the model-building stages and discuss the above considerations in transfer modelling using radiocarbon which is produced and released as part of the nuclear fuel cycle. Its long half life of 5730 years, its mobility in the environment and its incorporation into man via the food chain make it of some considerable radiological significance. We consider local modelling of 14C transfer using a Gaussian plume model, while its global dispersal is modelled using a large globally-averaged compartmental model. The global analysis is used to make short term predictions of 14C specific activities to 2050 and longer-term predictions over a period of 10,000 years. We discuss the validation of these models and attempt to quantify the sources and magnitudes of the uncertainties in the model predictions. (26 refs., 2 figs.)

  11. Refining 14C dating of bone >30,000 BP : establishing an accurate chronology for the Middle to Upper Palaeolithic transition in France.

    NARCIS (Netherlands)

    Talamo, Sahra

    2012-01-01

    This thesis aims to improve the chronology of the transition from the Middle to Upper Palaeolithic in France through the radiocarbon dating of bone collagen samples. This requires accurate calibration of the radiocarbon time scale for this time interval, reliable extraction of collagen from prehisto

  12. Dating Violence

    Science.gov (United States)

    Stader, David L.

    2011-01-01

    Dating violence is a form of student-on-student victimization and is a serious school safety issue. Research indicates that at a minimum, 10 percent of high school students are victims of dating violence in one form or another. Among female high school students that date, some data indicate that as many as 30 percent may be victims of dating…

  13. Searching for the oldest baobab of Madagascar: radiocarbon investigation of large Adansonia rubrostipa trees.

    Directory of Open Access Journals (Sweden)

    Adrian Patrut

    Full Text Available We extended our research on the architecture, growth and age of trees belonging to the genus Adansonia, by starting to investigate large individuals of the most widespread Malagasy species. Our research also intends to identify the oldest baobabs of Madagascar. Here we present results of the radiocarbon investigation of the two most representative Adansonia rubrostipa (fony baobab specimens, which are located in south-western Madagascar, in the Tsimanampetsotse National Park. We found that the fony baobab called "Grandmother" consists of 3 perfectly fused stems of different ages. The radiocarbon date of the oldest sample was found to be 1136 ± 16 BP. We estimated that the oldest part of this tree, which is mainly hollow, has an age close to 1,600 yr. This value is comparable to the age of the oldest Adansonia digitata (African baobab specimens. By its age, the Grandmother is a major candidate for the oldest baobab of Madagascar. The second investigated specimen, called the "polygamous baobab", consists of 6 partially fused stems of different ages. According to dating results, this fony baobab is 1,000 yr old. This research is the first investigation of the structure and age of Malagasy baobabs.

  14. Southern Appalachian hillslope erosion rates measured by soil and detrital radiocarbon in hollows

    Science.gov (United States)

    Hales, T.C.; Scharer, K.M.; Wooten, R.M.

    2012-01-01

    Understanding the dynamics of sediment generation and transport on hillslopes provides important constraints on the rate of sediment output from orogenic systems. Hillslope sediment fluxes are recorded by organic material found in the deposits infilling unchanneled convergent topographic features called hollows. This study describes the first hollow infilling rates measured in the southern Appalachian Mountains. Infilling rates (and bedrock erosion rates) were calculated from the vertical distribution of radiocarbon ages at two sites in the Coweeta drainage basin, western North Carolina. At each site we dated paired charcoal and silt soil organic matter samples from five different horizons. Paired radiocarbon samples were used to bracket the age of the soil material in order to capture the range of complex soil forming processes and deposition within the hollows. These dates constrain hillslope erosion rates of between 0.051 and 0.111mmyr-1. These rates are up to 4 times higher than spatially-averaged rates for the Southern Appalachian Mountains making creep processes one of the most efficient erosional mechanisms in this mountain range. Our hillslope erosion rates are consistent with those of forested mountain ranges in the western United States, suggesting that the mechanisms (dominantly tree throw) driving creep erosion in both the western United States and the Southern Appalachian Mountains are equally effective. ?? 2011 Elsevier B.V.

  15. Thermoluminescence dating of pottery from Sringaverapura -- A Ramayana site

    International Nuclear Information System (INIS)

    The first thermoluminescence (TL) dates of pottery from a Ramayana associated site are reported. The TL dates for pre-NBPW Black-Slipped Ware levels are 730 and 765 B.C., while radiocarbon date takes the earliest Black Slipped Ware Level (for which no TL dates are available) to 905 B.C. (uncorrected). For the OCW level, three TL dates are available which range from 1035 B.C. to 875 B.C. The early NBPW period believed to be associated with the Ramayana episode will thus be post-750 B.C. (author)

  16. Radiocarbon measurements of dissolved organic carbon in sewage-treatment-plant effluent and domestic sewage

    International Nuclear Information System (INIS)

    In an attempt to better characterize dissolved organic carbon (DOC) in several specific sources to Lake Kasumigaura, such as sewage-treatment-plant effluent (STPE), domestic sewage (DS) and forest stream (FS), we analyzed radiocarbon (14C) and stable carbon isotopic compositions (13C) of the DOCs. The measurements of 14C for DOC were performed by an accelerator mass spectrometer (AMS) at the National Institute for Environmental Studies (NIES-TERRA) in Japan. The Δ14C and δ13C values of the DOCs in several sources to Lake Kasumigaura, have low carbon isotopic values, ranging from -470 per mille to -79 per mille and from -27.9 per mille to -24.2 per mille , respectively. These carbon isotopic values are substantially different from those of Lake Kasumigaura. These results imply different origins for the DOC in Lake Kasumigaura. The 14C and 13C analyses of DOC led to a useful classification for DOCs in Lake Kasumigaura, Japan.

  17. Radiocarbon and seismic evidence of ice-sheet extent and the last deglaciation on the mid-Norwegian continental shelf

    International Nuclear Information System (INIS)

    Reconstruction of the ice extent and glacier chronology on the continental shelf off mid-Norway has been severely hampered by the lack of dates from the glacial deposits. Seismic interpretation and new accelerator mass spectrometer radiocarbon dates show that the ice sheet extended to the edge of the continental shelf at the last glacial maximum. The two youngest till units near the shelf edge were deposited about 15000 and 13500 BP. The results indicate that the ice sheet partly reached the shelf break as late as 11000 BP followed by a deglaciation of most of the continental shelf in less than 1000 years

  18. IRSL dating of a deep water core from Pylos, Greece, comparison to post IR blue OSL and TL dating results

    Science.gov (United States)

    Polymeris, G. S.; Kitis, G.

    The 'double SAR' protocol procedure permits the determination of two equivalent dose (De) values for each polymineral aliquot; an IRSL De resulting mostly from feldspars along with a post- IR OSL De for a mixed signal for quartz (mostly) and feldspar grains. The objective of the present study is to test for the first time its usefulness for polymineral, coarse silt, closely-spaced deep-sea sediment samples. A new, 'double SAR' IRSL dataset is presented for the sedimentation ages of a deep-sea sediment core of the Hellenic Trench, drilled from a water depth of 4 km, near the deepest site of the Mediterranean Sea, outside Pylos, Greece. Post IR quartz-based optical dating was previously proved to be consistent with AMS radiocarbon ages, obtained from planktonic foraminifera from the same core. IRSL De values are, with one exception, always much greater than the corresponding (post-IR) OSL results. This result suggests that for the present study 'double SAR' protocol procedure was proved to be extremely effective method for separating the luminescence signals from quartz and feldspars. Furthermore, De values obtained after infra-red stimulation and thermoluminescence generally agree within errors. This quantitative equivalence of those two sets of De values implies that as in the case of IRSL, TL signal is also feldspar-dominated. IRSL ages vary between 3.5 and 7.8 ka with associated errors up to 9%. Application of 'double SAR' protocol to coarse silt, closely-spaced deep-sea sediment samples seems advisable, despite the fact that the post-IR blue OSL signal is the most stable signal, and is preferred for dating.

  19. Developing inorganic carbon-based radiocarbon chronologies for Holocene lake sediments in arid NW China

    Science.gov (United States)

    Zhang, Jiawu; Ma, Xueyang; Qiang, Mingrui; Huang, Xiaozhong; Li, Shuang; Guo, Xiaoyan; Henderson, Andrew C. G.; Holmes, Jonathan A.; Chen, Fahu

    2016-07-01

    Inorganic carbonates are often used to establish radiocarbon (14C) chronologies for lake sediments when terrestrial plant remains (TPR) are rare or when bulk organic matter is insufficient for dating, a problem that is common for many lakes in arid regions. However, the reservoir effect (RE), as well as old carbon contributed from the lakes catchment make it difficult to establish reliable chronologies. Here we present a systematic study of inorganic 14C ages of two lake-sediment sequences, one from a small-enclosed saline lake - Lake Gahai in Qaidam Basin, and the other from a large freshwater lake - Lake Bosten in Xinjiang. Modern dissolved inorganic carbon (DIC) of the lakes, paleo-lake sediments exposed in the catchment, and mollusk shells in core sediments from Lake Gahai were dated to assess the RE and the contribution of pre-aged carbon to the old ages in the cores. We propose a statistical regression to assess more than one RE for the 14C carbonate ages within our sedimentary sequences. Old radiocarbon ages contributed by detrital carbonates were assessed by comparing the ages of mollusk shells with those of carbonates at the same sediment depths. We established the RE of the authigenic component and assessed detrital old carbon contributions to our two sites, and this was used to correct the 14C ages. Based on this approach, we developed age models for both cores, and tested them using 210Pb ages in both cores and TPR-based 14C-ages recovered from Lake Bosten. We further tested our age models by comparing carbonate-based oxygen isotope (δ18O) records from both lakes to an independently-dated regional speleothem δ18O record. Our results suggest if sedimentary sequences are densely dated and the RE and the contribution of old carbon from detrital carbonates can be ascertained, robust chronological frameworks based on carbonate-based 14C determinations can be established.

  20. Efficient Collection of Methane from Extremely Large Volumes of Water for Natural Radiocarbon Analysis

    Science.gov (United States)

    Sparrow, K. J.; Kessler, J. D.

    2014-12-01

    Collecting sufficient amounts of natural methane sample for a high precision radiocarbon (14C-CH4) analysis was previously unfeasible when sampling from low methane concentration waters like the open ocean. A new method incorporating dissolved gas extraction technology (Liqui-Cel® membrane contactors) has been developed to circumvent the challenges that natural 14C-CH4 sampling presents. With this method, adequate amounts of methane-carbon for a traditional 14C-accelerator mass spectrometry (AMS) analysis can be cleanly and efficiently extracted from 1000s L water in a few hours. This technique is currently being improved to enable sampling from > 11,000 L water in less than 1 hr. For transport from the field to the laboratory, each extracted gas sample is compressed into a small (1.68 L) high-pressure aluminum cylinder using an oil-free compressor pump. Due to the small size and portability of the sample cylinders, high resolution sampling plans composed of 30+ samples are possible even in remote locations. The laboratory preparation of these methane samples for 14C-AMS analyses is carried out on a new flow-through vacuum line. While the bulk water vapor and carbon dioxide (CO2) are removed before the sample is compressed in the field, the residual trace amounts of these constituents are cryogenically removed from the sample in the initial phase of the vacuum line. Carbon monoxide in the sample is quantitatively oxidized at 290°C to CO2 and cryogenically removed. Finally, the sample methane is quantitatively oxidized at 950°C to products CO2 and water and then cryogenically isolated. The new vacuum line technique achieves low blanks and purifies and oxidizes the methane contained in the extracted gas sample with high efficiency. At an AMS facility, an aliquot of the methane-produced CO2 is graphitized and analyzed for radiocarbon content using traditional 14C-AMS. Supporting dual-inlet isotope ratio mass spectrometry measurements are conducted to determine both

  1. C-14 dated paleoenvironmental changes on Lake Kolon during the last 25000 years

    International Nuclear Information System (INIS)

    Complete text of publication follows. One of Hungary's geological and environmental treasures is nestled in the heart of the Great Hungarian Plain. The catchment basin of Lake Kolon was subjected to detailed environmental historical studies starting in 2005. Undisturbed cores taken along transects of the basin were subjected to detailed sedimentological, paleoecological, and geochemical studies (Figure 1). To establish a reliable timeframe of the lacustrine and marshland sedimentary sequence identified, 22 samples were analyzed by accelerator mass spectrometry (AMS) in the radiocarbon laboratories of Poznan and Tucson. With the new results in hand (Figure 2), we had the opportunity to elucidate the geological evolution of the area for the past 25,000 yr. This sequence is highly beneficial, as it is probably the most well-dated profile of the Quaternary from the area studied. The new absolute dates enabled the comparison of local geological evolution of the studied area with those of global climatic changes. As seen from our findings, the geological evolution of the catchment basin was congruent with major climatic events during the Pleistocene and the entire Holocene. However, a very peculiar trajectory was identified for the terminal part of the Pleistocene and the opening of the Holocene regarding the evolution of the landscape, the vegetation, and the fauna of this part of the Great Hungarian Plain.

  2. Bomb-spike dating of a mummified baboon in Ludwig Cave, Namibia

    Directory of Open Access Journals (Sweden)

    Hodgins Greg

    2007-01-01

    Full Text Available In 1982 a mummified adult female baboon was discovered on a ledge in Ludwig Cave in Namibia. A toe bone was removed for dating in July 1995. AMS radiocarbon dating of bone collagen, tendon, and skin indicates a post-modern age. Application of the atomic bomb-spike calibration curve suggests death in late 1977 and an age at death of around 19 years. Baboons roost in the cave and the mummified female, along with a mummified juvenile male discovered in 2002 and three rotting corpses discovered in 1995, were probably chased by other baboons or by leopards down a ca. 6 m drop during the rainy season, and were unable to climb the steep and very slippery slope to escape. The large number of baboons trapped in the cave in less than 20 years, and mummification of two individuals on dry, dusty ledges in the cave, may explain why large numbers of baboon skeletons have been discovered in ancient bone breccias (up to 4 Ma old in a number of caves throughout Southern Africa.

  3. Evidence of 11-year solar cycles in tree rings from 1010 to 1110 AD - Progress on high precision AMS measurements

    Energy Technology Data Exchange (ETDEWEB)

    Guettler, D., E-mail: guettler@phys.ethz.ch [Laboratory of Ion Beam Physics, ETH Zurich, HPK G31, Schafmattstrasse 20, 8093 Zurich (Switzerland); Wacker, L. [Laboratory of Ion Beam Physics, ETH Zurich, HPK G31, Schafmattstrasse 20, 8093 Zurich (Switzerland); Kromer, B.; Friedrich, M. [Heidelberg Academy of Sciences, 69120 Heidelberg (Germany); Institute of Botany, University of Hohenheim, 70593 Stuttgart (Germany); Synal, H.-A. [Laboratory of Ion Beam Physics, ETH Zurich, HPK G31, Schafmattstrasse 20, 8093 Zurich (Switzerland)

    2013-01-15

    Oak tree rings from Southern Germany covering the AD 1010-1110 years have been analyzed for radiocarbon with accelerator mass spectrometry (AMS) at the laboratory at ETH Zurich. High-precision measurements with a precision down to 12 years radiocarbon age and a time resolution of 2 years aimed to identify modulations of the {sup 14}C concentration in tree ring samples caused by the 11 years solar cycles, a feature that so far is not visible in the IntCal calibration curve. Our results are in good agreement with the current calibration curve IntCal09. However, we observed an offset in radiocarbon age of 25-40 years towards older values. An evaluation of our sample preparation, that included variations of e.g.: chemicals, test glasses and processing steps did not explain this offset. The numerous measurements using the AMS-MICADAS system validated its suitability for high precision measurements with high repeatability.

  4. Coral Radiocarbon Records of Indian Ocean Water Mass Mixing and Wind-Induced Upwelling Along the Coast of Sumatra, Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Guilderson, T P; Grumet, N S; Abram, N J; Beck, J W; Dunbar, R B; Gagan, M K; Hantoro, W S; Suwargadi, B W

    2004-02-06

    Radiocarbon ({sup 14}C) in the skeletal aragonite of annually banded corals track radiocarbon concentrations in dissolved inorganic carbon (DIC) in surface seawater. As a result of nuclear weapons testing in the 1950s, oceanic uptake of excess {sup 14}C in the atmosphere has increased the contrast between surface and deep ocean {sup 14}C concentrations. We present accelerator mass spectrometric (AMS) measurements of radiocarbon isotope ({Delta}{sup 14}C) in Porites corals from the Mentawai Islands, Sumatra (0 S, 98 E) and Watamu, Kenya (3 S, 39 E) to document the temporal and spatial evolution of the {sup 14}C gradient in the tropical Indian Ocean. The rise in {Delta}{sup 14}C in the Sumatra coral, in response to the maximum in nuclear weapons testing, is delayed by 2-3 years relative to the rise in coral {Delta}{sup 14}C from the coast of Kenya. Kenya coral {Delta}{sup 14}C values rise quickly because surface waters are in prolonged contact with the atmosphere. In contrast, wind-induced upwelling and rapid mixing along the coast of Sumatra entrains {sup 14}C-depleted water from the subsurface, which dilutes the effect of the uptake of bomb-laden {sup 14}C by the surface-ocean. Bimonthly AMS {Delta}{sup 14}C measurements on the Mentawai coral reveal mainly interannual variability with minor seasonal variability. The interannual signal may be a response to changes in the Walker circulation, the development of easterly wind anomalies, shoaling of the eastern thermocline, and upwelling of {sup 14}C-depleted water along the coast of Sumatra. Singular spectrum analysis of the Sumatra coral {Delta}{sup 14}C record reveals a significant 3-year periodicity. The results lend support to the concept that ocean atmosphere interactions between the Pacific and Indian Oceans operate in concert with the El Ni{tilde n}o-Southern Oscillation (ENSO).

  5. Bayesian re-evaluation of Lapita settlement in Fiji : radiocarbon analysis of the Lapita occupation at Bourewa and nearby sites on the Rove Peninsula, Viti Levu Island

    International Nuclear Information System (INIS)

    80 radiocarbon dates are presented for Lapita-era sites on the Rove Peninsula, southwest Viti Levu Island, Fiji. Of these, 67 are from the Bourewa site which is the largest and probably the earliest in the area. Of these, 10 are rejected as not being demonstrably associated with its Lapita occupation. Constraints on date interpretation arising from sample materials are highlighted. In particular, charcoals that have not been identified to short-lived tree species, twigs or seeds are evaluated according to observed contextual associations and established understanding of inbuilt age offsets using Bayesian outlier analysis. It is concluded that many of the dates on charcoal are imprecise indicators of settlement age and have an average offset of 149 years. Shell radiocarbon results are similarly evaluated and it is concluded that the majority have 14C values that are in equilibrium with the marine radiocarbon reservoir and therefore yield ages that are accurate indicators of Lapita occupation of Bourewa. Results suggest that initial occupation at Bourewa occurred 2816 ± 25 cal BP (2838-2787 cal BP [68.2% prob.]; 2866-2771 cal BP [95.4% prob.]) and ended 2654 ± 21 cal BP (2675-2640 cal BP [68.2% prob.]; 2689-2613 cal BP [95.4% prob.]). Similar analyses applied to other dated Lapita sites in Fiji shows that, while Bourewa is among the earliest, the Matanamuani (VL 21/5) site on Naigani Island remains the earliest to be securely dated. (author)

  6. High-precision radiocarbon chronometry of ancient Egypt, and comparisons with Nubia, Palestine and Mesopotamia

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, F.A.; Robinson, S.W.

    1987-03-01

    The use of radiocarbon age measurements in historical chronology is examined for ancient Egypt and neighbouring regions. A methodology is presented aimed at improving the reliability and precision of radiocarbon age determinations.

  7. High-precision radiocarbon chronometry of ancient Egypt, and comparisons with Nubia, Palestine and Mesopotamia

    International Nuclear Information System (INIS)

    The use of radiocarbon age measurements in historical chronology is examined for ancient Egypt and neighbouring regions. A methodology is presented aimed at improving the reliability and precision of radiocarbon age determinations. (UK)

  8. Urvina Bay, Galapagos Coral Radiocarbon (delta 14C) Data for 1956 to 1982

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Urvina Bay coral radiocarbon (14C) timeseries. (90 deg W, 0.5 deg S) Coral radiocarbon (Delta-14C) on untreated, low-speed drilled samples. Precision is +/- 4 per...

  9. Recent advances in thermoluminescence dating

    International Nuclear Information System (INIS)

    Initially the application of thermoluminescent dating was to ancient pottery and other baked clay, the detection of forgeries in art ceramics having a particularly powerful impact. In recent years there has been a growing extension of TL into non-pottery materials. Heated flints from paleolithic fire-places is one application. Another is in the dating of igneous rocks from recent volcanic events; formerly this had been impossible on account of the malign phenomenon of non-thermal ('anomalous') fading exhibited by volcanic minerals but this is now being circumvented by utilising TL in the 6000C region of the glow curve. TL dating has also been extended to unburnt calcite, one application being stalagmitic floors in paleolithic caves. Another recent development is the use of TL for dating aeolian sediment and some types of waterborne sediment. These developments give prospect of establishing a TL-based chronology, both for archaeology and quaternary research, extending back well beyond the range of radiocarbon, perhaps reaching a million years ago. (author)

  10. Thermoluminescence dating

    International Nuclear Information System (INIS)

    The influence of radioactive disequilibrium on TL age accuracy is further checked. TL dating applied to pottery sets the beginning of the neolithic period in Lower Austria in the first half of 6th millenium B.C. (orig.)

  11. Juno II (AM-14)

    Science.gov (United States)

    1959-01-01

    Juno II (AM-14) on the launch pad just prior to launch, March 3, 1959. The payload of AM-14 was Pioneer IV, America's first successful lunar mission. The Juno II was a modification of Jupiter ballistic missile

  12. Radiocarbon in tropical tree rings during the Little Ice Age

    International Nuclear Information System (INIS)

    Cross-dated tree-ring cores (Pinus maker's) from north-central Thailand, spanning AD 1620-1780, were used to investigate atmospheric 14C for the tropics during the latter part of the Little Ice Age. In addition, a cross-dated section of Huon pine from western Tasmania, covering the same period of time, was investigated. A total of 16 pairs of decadal samples were extracted to alpha-cellulose for AMS 14C analysis using the ANTARES facility at ANSTO. The 14C results from Thailand follow the trend of the southern hemisphere, rather than that of the northern hemisphere. This is a surprising result, and we infer that atmospheric 14C for north-central Thailand, at 17 deg. N, was strongly influenced by the entrainment of southern hemisphere air parcels during the southwest Asian monsoon, when the Inter-Tropical Convergence Zone moves to the north of our sampling site. Such atmospheric transport and mixing are therefore considered to be one of the principal mechanisms for regional 14C offsets

  13. First Direct Dating for the Construction and Modification of the Baphuon Temple Mountain in Angkor, Cambodia.

    Directory of Open Access Journals (Sweden)

    Stéphanie Leroy

    Full Text Available Architecture represents key evidence of dynastic practice and change in the archaeological world. Chronologies for many important buildings and sequences, including the iconic temples of medieval Angkor in Cambodia, are based solely on indirect associations from inscriptions and architectural styles. The Baphuon temple, one of the last major buildings in Angkor without textual or scientifically-derived chronological evidence, is crucial both for the context and date of its construction and the period when its western façade was modified into a unique, gigantic Reclining Buddha. Its construction was part of a major dynastic change and florescence of the Hindu-Mahayana Buddhist state and the modification is the key evidence of Theravada Buddhist power after Angkor's decline in the 15th century. Using a newly-developed approach based on AMS radiocarbon dating to directly date four iron crampons integrated into the structure we present the first direct evidence for the history of the Baphuon. Comprehensive study of ferrous elements shows that both construction and modification were critically earlier than expected. The Baphuon can now be considered as the major temple associated with the imperial reformations and territorial consolidation of Suryavarman I (1010-1050 AD for whom no previous building to legitimize his reign could be identified. The Theravada Buddhist modification is a hundred years prior to the conventional 16th century estimation and is not associated with renewed use of Angkor. Instead it relates to the enigmatic Ayutthayan occupation of Angkor in the 1430s and 40s during a major period of climatic instability. Accurately dating iron with relatively low carbon content is a decisive step to test long-standing assumptions about architectural histories and political processes for states that incorporated iron into buildings (e.g., Ancient Greece, medieval India. Furthermore, this new approach has the potential to revise chronologies

  14. First Direct Dating for the Construction and Modification of the Baphuon Temple Mountain in Angkor, Cambodia.

    Science.gov (United States)

    Leroy, Stéphanie; Hendrickson, Mitch; Delqué-Kolic, Emmanuelle; Vega, Enrique; Dillmann, Philippe

    2015-01-01

    Architecture represents key evidence of dynastic practice and change in the archaeological world. Chronologies for many important buildings and sequences, including the iconic temples of medieval Angkor in Cambodia, are based solely on indirect associations from inscriptions and architectural styles. The Baphuon temple, one of the last major buildings in Angkor without textual or scientifically-derived chronological evidence, is crucial both for the context and date of its construction and the period when its western façade was modified into a unique, gigantic Reclining Buddha. Its construction was part of a major dynastic change and florescence of the Hindu-Mahayana Buddhist state and the modification is the key evidence of Theravada Buddhist power after Angkor's decline in the 15th century. Using a newly-developed approach based on AMS radiocarbon dating to directly date four iron crampons integrated into the structure we present the first direct evidence for the history of the Baphuon. Comprehensive study of ferrous elements shows that both construction and modification were critically earlier than expected. The Baphuon can now be considered as the major temple associated with the imperial reformations and territorial consolidation of Suryavarman I (1010-1050 AD) for whom no previous building to legitimize his reign could be identified. The Theravada Buddhist modification is a hundred years prior to the conventional 16th century estimation and is not associated with renewed use of Angkor. Instead it relates to the enigmatic Ayutthayan occupation of Angkor in the 1430s and 40s during a major period of climatic instability. Accurately dating iron with relatively low carbon content is a decisive step to test long-standing assumptions about architectural histories and political processes for states that incorporated iron into buildings (e.g., Ancient Greece, medieval India). Furthermore, this new approach has the potential to revise chronologies related to iron

  15. Paleomagnetic Dating of Holocene Rapidly Deposited Layers From the Saguenay Fjord, Quebec, Canada

    Science.gov (United States)

    St-Onge, G.; Mulder, T.; Piper, D. J.; Hillaire-Marcel, C.; Stoner, J. S.

    2006-12-01

    The Saguenay Fjord (Quebec, Canada) area has been struck by several natural disasters in the last 350 years. Among these disasters are the 1663 (M~7) and 1988 (M=6) earthquakes as well as the flood of 1996. These events triggered the deposition of thick layers, ranging from a few centimetres to about sixteen metres in the Saguenay Fjord inner basin. A 38 m-long piston core (core MD99-2222) was sampled from the deepest part of the Saguenay Fjord inner basin as part of the 1999 IMAGES-V (International Marine Past Global Change Study) program in order to determine the frequency of natural hazards such as earthquakes during the Holocene. Based on physical, magnetic and sedimentological data, we identified at least 14 rapidly deposited layers (RDL) in core MD99-2222. These layers contrast sharply from the dark grey bioturbated "background" sediments and are visually recognizable by their light color due to higher CaCO3 content resulting from the incorporation of light grey, slightly calcareous, Laflamme Sea Clays. In addition, most RDL have a sandy base with corresponding peaks in density and magnetic susceptibility, along with generally lower paleomagnetic inclinations that indicate an energetic depositional process where the magnetic particles are plastered horizontally because of high flow velocity and rapid sediment accumulation. Homogeneous, light grey, clayey silt beds generally overlie the sandy bases. Unfortunately, because CaCO3 dissolution occurs in the Saguenay Fjord sediments, little material is available for radiocarbon dating, making the setting of a robust chronology difficult. Here, we will show how changes in the Earth's magnetic field intensity and direction were used, in conjunction with 210Pb dating, one AMS 14C date and the recognition of a turbidite associated with the 1663 earthquake, to construct the age model for core MD99-2222 and thus to date all the RDL.

  16. Bats: A new tool for AMS data reduction

    Energy Technology Data Exchange (ETDEWEB)

    Wacker, L., E-mail: Wacker@phys.ethz.c [Ion Beam Physics, ETH Zurich (Switzerland); Christl, M.; Synal, H.-A. [Ion Beam Physics, ETH Zurich (Switzerland)

    2010-04-15

    A data evaluation program was developed at ETH Zurich to meet the requirements of the new compact AMS systems MICADAS and TANDY in addition to the large EN-Tandem accelerator. The program, called 'BATS', is designed to automatically calculate standard and blank corrected results for measured samples. After almost one year of routine operation with the MICADAS C-14 system BATS has proven to be an easy to use data reduction tool that requires minimal user input. Here we present the fundamental principle and the algorithms used in BATS for standard-sized radiocarbon measurements.

  17. Radiocarbon method in environmental monitoring of CO{sub 2} emission

    Energy Technology Data Exchange (ETDEWEB)

    Rakowski, Andrzej Z., E-mail: arakowski@leibniz.uni-kiel.de [Leibniz Laboratory for Radiometric Dating and Isotope Research, University of Kiel, Max Eyth Str. 11-13, 24118 Kiel (Germany); Radiocarbon Laboratory, Institute of Physics, Silesian University of Technology, ul. Boleslawa Krzywoustego 2, 44-100 Gliwice (Poland); Nadeau, Marie-Josee [Leibniz Laboratory for Radiometric Dating and Isotope Research, University of Kiel, Max Eyth Str. 11-13, 24118 Kiel (Germany); Nakamura, Toshio [Center for Chronological Research, Nagoya University, Furocho, Chikusa-ku, 64-8602 Nagoya (Japan); Pazdur, Anna; Pawelczyk, Slawomira; Piotrowska, Natalia [Radiocarbon Laboratory, Institute of Physics, Silesian University of Technology, ul. Boleslawa Krzywoustego 2, 44-100 Gliwice (Poland)

    2013-01-15

    New results of carbon isotopic composition from tree rings have been analyzed. {Delta}{sup 14}C and {delta}{sup 13}C data, representing the isotopic composition of carbon in 'clean air', were obtained from annual rings of a pine tree (Pinus sylvestris) taken in the Niepolomice area, 25 km east Krakow, Poland. All samples were processed to extract {alpha}-cellulose, and the radiocarbon concentration in each annual ring was measured using AMS at University of Nagoya. Stable isotopic composition of carbon was determined using isotope ratio mass spectrometry. The dataset covers the growth period between 1960 and 2003. The average difference between radiocarbon concentrations in Niepolomice and the North Hemisphere zone 1 (NH zone 1) for the period between 1960 and 1999 is 3.5 {+-} 1.6 Per-Mille-Sign . These data are compared with previously presented results from the city of Krakow, where a local decrease in {sup 14}C concentration was observed due to local CO{sub 2} emission from fossil fuel use. The differences in observed {sup 14}C concentrations were used to estimate a magnitude of the local Suess effect in Krakow. Based on mass balance equations for CO{sub 2}{sup 14}C concentrations, it was possible to calculate the CO{sub 2} concentration associated with fossil fuel emission (C{sub foss}) into the atmosphere. The highest values of C{sub foss} were recorded in the years 1986 (11.9 {+-} 1.4 ppm V) and 1983 (8.1 {+-} 1.3 ppm V), while the lowest value of 0.6 {+-} 1.8 ppm V was recorded in 2001.

  18. Regolith slide recurrence history indicated by radiocarbon ages in the hills around Sendai, Northeastern Japan

    International Nuclear Information System (INIS)

    Observation of actual rain-induced regolith slides in the hills around Sendai confirmed that slides were concentrated on particular geomorphic positions and that deposits of slide itself and induced debris flow overlay the humic topsoil on some hillslopes or bottomlands. Then radiocarbon dating was systematically applied to buried humic topsoil horizons overlain by former slide deposits or debris flow deposits on bottomlands and head hollows in order to reconstract the history of regolith slide occurrence in a watershed. It was concluded that regolith slides have repeated at an interval of 300 to 400 years during at least recent 1,000 years on relatively slide-prone segments of a watershed, while the interval is about 2,500 years on relatively stable segment. The knowledge will contribute to the consideration of hillslope development rate controlled chiefly by regolith slides under temperate monsoon climate which has been prevailing since the early Holocene in Northeastern Japan. (author)

  19. Water dating in groundwater resources management

    International Nuclear Information System (INIS)

    It is widely accepted that groundwater dating by tritium or radiocarbon can give valuable data on the groundwater age and, as a consequence, can provide information on the age structure and dynamics of the groundwater bodies. The question is: can they and to what extend can they give us a key to decide on the future dynamics on the man-impacted groundwater bodies? The three examples presented below attempt to demonstrate that the benefits and results can be gained from its use do not so much depend on the tool itself but on the art of using that tool

  20. Geographic and temporal trends in proboscidean and human radiocarbon histories during the late Pleistocene

    Science.gov (United States)

    Ugan, Andrew; Byers, David

    2007-12-01

    The causes of large animal extinctions at the end of the Pleistocene remain a hotly debated topic focused primarily on the effects of human over hunting and climate change. Here we examine multiple, large radiocarbon data sets for humans and extinct proboscideans and explore how variation in their temporal and geographic distributions were related prior to proboscidean extinction. These data include 4532 archaeological determinations from Europe and Siberia and 1177 mammoth and mastodont determinations from Europe, Siberia, and North America. All span the period from 45,000 to 12,000 calendar years BP. We show that while the geographic ranges of dated human occupations and proboscidean remains overlap across the terminal Pleistocene of the Old World, the two groups remain largely segregated and increases in the frequency of human occupations do not coincide with declines in proboscidean remains. Prior to the Last Glacial Maximum (LGM; ca 21,000 years BP), archaeological 14C determinations increase slightly in frequency worldwide while the frequency of dated proboscidean remains varies depending on taxon and location. After the LGM, both sympatric and allopatric groups of humans and proboscideans increase sharply as climatic conditions ameliorate. Post-LGM radiocarbon frequencies among proboscideans peak at different times, also depending upon taxon and location. Woolly mammoths in Beringia reach a maximum and then decline beginning between 16,000 and 15,500 years BP, woolly mammoths in Europe and Siberia ca 14,500 and 13,500 BP, and Columbian mammoth and American mastodont only after 13,000 BP. Declines among woolly mammoths appear to coincide with the restructuring of biotic communities following the Pleistocene-Holocene transition.

  1. Large variations in the Holocene marine radiocarbon reservoir effect reflect ocean circulation and climatic changes

    Science.gov (United States)

    Hua, Quan; Webb, Gregory E.; Zhao, Jian-xin; Nothdurft, Luke D.; Lybolt, Matthew; Price, Gilbert J.; Opdyke, Bradley N.

    2015-07-01

    Accurate radiocarbon dating of marine samples requires knowledge of the marine radiocarbon reservoir effect. This effect for a particular site/region is generally assumed constant through time when calibrating marine 14C ages. However, recent studies have shown large temporal variations of several hundred to a couple of thousand years in this effect for a number of regions during the late Quaternary and Holocene. Here we report marine radiocarbon reservoir correction (ΔR) for Heron Reef and Moreton Bay in southwestern (SW) Pacific for the last 8 ka derived from 14C analysis of 230Th-dated corals. Most of our ΔR for the last ∼5.4 ka agree well with their modern value, but large ΔR variability of ∼410 yr (from trough to peak) with possible decadal/centennial fluctuations is evident for the period ∼5.4-8 ka. The latter time interval also has significant variations with similar features in previously published ΔR values for other sites in the Pacific, including southern Peru-northern Chile in southeastern (SE) Pacific, the South China Sea, Vanuatu and Papua New Guinea, with the largest magnitude of ∼920 yr from SE Pacific. The mechanisms for these large ΔR variations across the Pacific during the mid-Holocene are complex processes involving (1) changes in the quantity and 14C content of upwelled waters in tropical east Pacific (TEP) (frequency and intensity of ocean upwelling in the TEP, and contribution of Subantarctic Mode Water to the upwelled waters, which is influenced by the intensity and position of southern westerly winds), and (2) variations in ocean circulation associated with climate change (La Niña/El Niño conditions, intensity of easterly trade winds, positions of the Intertropical Convergence Zone and the South Pacific Convergence Zone), which control the spreading of the older upwelled surface waters in the TEP to the western sites. Our results imply the need for employing temporal changes in ΔR values, instead of constant (modern) values

  2. Radiocarbon dating reveals different past managements of adjacent forest soils in the Campine region, Belgium

    NARCIS (Netherlands)

    Chiti, T.; Neubert, R. E. M.; Janssens, I. A.; Certini, G.; Yuste, J. Curiel; Sirignano, C.

    2009-01-01

    The soils of adjacent first generation monospecific stands of Scots pine (Pinus sylvestris L.) and pedunculate oak (Quercus robur L.) in the Campine region, Belgium, apparently developed under the same forming factors, were studied for carbon dynamics to disentangle eventual different past land uses

  3. Dendrochronology and radiocarbon dating of conifer trees and buried logs from the Stanley River, Tasmania

    International Nuclear Information System (INIS)

    Full text: Dendrochronological studies are being carried out on two endemic conifer species in the Stanley River area of western Tasmania. Living trees are growing along the river banks, adjacent floodplain areas, and occasionally on the lower hill-slopes. Many ancient logs are exposed in the bed and banks of the river, and several major excavations have been carried out in floodplain sediments up to a hundred metres distant from the present river channel. A tree-ring chronology for Huon pine (Lagarostrobos franklinii) now extends from the present back to 571 BC. This chronology has been constructed using cores from living trees (up to 1400 years old), sections from trees felled during logging operations in the early 1980s, and sections from subfossil logs in the river banks and floodplain sediments. Living celery-top pine (Phyllocladus aspleniifolius) trees are up to 500 years old, and a short chronology is being developed for this species as well. Large excavations have been carried out over several years in floodplain sediments, and sections have now been taken from a total of 350 subfossil logs. Both Huon and celery-top pine are represented in the collection. They range in age from >38 ka to modern, with good coverage for the periods 9-3.5 ka and from 2.5 ka to the present. A floating tree-ring chronology for Huon pine has been established for the period ca. 7200-3500 cal BP, and is gradually being augmented. In the collection of about 350 ancient conifer logs from the Stanley River, about 150 currently have known ages while the remaining 200 have yet to be studied. Most of them have ages less than 9000 cal BP, but about 10% of them are older. Four of them are more than 30,000 years old, and may be Last Interglacial in age. Nine of them are known to be between 18,000 and 10,000 years old, and six are between 10,000 and 9,000 years old. Our augmented collection has become an increasingly important archive for further tree-ring and carbon isotope studies

  4. Radiocarbon dating of elk (Alces alces), an economic and symbolic resource in prehistory

    DEFF Research Database (Denmark)

    Philippsen, Bente

    resource. We can never be certain of the precise meaning of the elk and what it symbolized for prehistoric peoples. Contrary to what one would expect, however, natural sciences could contribute to this discussion by elucidating the nutrition and behavior of the elk: aquatic plants can have very high......The European elk, “moose” in American English, was an important resource in the prehistory of Northern Europe. On some sites, it was the most important species in the economy. Furthermore, numerous examples of mobile and non-mobile art show the importance of the elk as a symbolic or ritualistic...... animal belonging to “two worlds”, the terrestrial and the aquatic....

  5. Archaeomagnetic studies in central Mexico—dating of Mesoamerican lime-plasters

    Science.gov (United States)

    Hueda-Tanabe, Y.; Soler-Arechalde, A. M.; Urrutia-Fucugauchi, J.; Barba, L.; Manzanilla, L.; Rebolledo-Vieyra, M.; Goguitchaichvili, A.

    2004-11-01

    For the first time results of an archaeomagnetic study of unburned lime-plasters from Teotihuacan and Tenochtitlan in central Mesoamerica are presented. Plasters made of lime, lithic clasts and water, appear during the Formative Period and were used for a variety of purposes in floors, sculptures, ceramics and supporting media for mural paintings in the Oaxaca and Maya area. In Central Mexico, grinded volcanic scoria rich in iron minerals is incorporated into the lime-plasters mixture. Samples were selected from two archaeological excavation projects in the Teopancazco residential compound of Teotihuacan and the large multi-stage structure of Templo Mayor in Tenochtitlan, where chronological information is available. The intensity of remanent magnetization (natural remanent magnetization (NRM)) and low-field susceptibility are weak reflecting low relative content of magnetic minerals. NRM directions are well grouped and alternating field demagnetization shows single or two-component magnetizations. Rockmagnetic experiments point to fine-grained titanomagnetites with pseudo-single domain behavior. Anisotropy of magnetic susceptibility (AMS) measurements document a depositional fabric, with normal to free-surface minimum AMS axes. Characteristic mean site directions were correlated to the paleosecular variation curve for Mesoamerica. Data from Templo Mayor reflect recent tilting of the structures. Teopancazco mean site declinations show good correspondence with the reference curve, in agreement with the radiocarbon dating. Dates for four stages of Teotihuacan occupancy based on the study of lime-plasters range from AD 350 to 550. A date for a possible Mazapa occupation around AD 850 or 950 is also suggested based on the archaeomagnetic correlation. The archaeomagnetic record of a plaster floor in Teopancazco differed from the other nearby sites pointing to a thermoremanent magnetization; comparison with the reference curve suggests dates around AD 1375 or 1415. The

  6. Radiometric Dating of tephras from Pre-caldera and Caldera-forming stages, Towada volcano, Northeast Japan

    International Nuclear Information System (INIS)

    Towada volcano is an active volcano located in the northern part of the Northeast Japan arc. We carried out fission-track (FT) and AMS radiocarbon (14C) dating of tephras from Towada and Hakkoda volcanoes to establish a detailed eruptive history during the Pre-caldera and Caldera-forming stages of Towada volcano. The obtained FT ages were 0.23 ± 0.05 Ma for Shirobeta tephra (WP), 0.19 ± 0.05 Ma for T-6 tephra, 0.08 ± 0.03 Ma for Zarame 1 tephra (ZP1), and 0.09 ± 0.03 Ma for Okuse Pyroclastic Flow Deposits. Although these FT ages are consistent with stratigraphy, they have large error ranges of several tens of thousands of years. Therefore, further examinations including application of other chronological dating methods are necessary to obtain more precise estimates of the eruptive age of these tephras. The obtained 14C age was 17,730 ± 70 BP for Biscuit 2 tephra (BP2). Based on stratigraphical consistency, this 14C age is appropriate for the eruptive age of BP2. (author)

  7. OSL dating in palaeoenvironmental reconstructions. A discussion from a user’s perspective

    OpenAIRE

    Kolstrup, Else

    2007-01-01

    Four studies with series of OSL dated aeolian sediments are outlined and used for a discussion of the reliability of this dating method in palaeoenvironmental reconstructions. The OSL ages form series controlled by interfingering radiocarbon ages, historical records or relative position of the samples. A locality dated by a thermoluminescence method is also included. The examples range from subrecent to more than 200 kyr. It is suggested that in most cases the precision and accuracy of the OS...

  8. Thermoluminescence dating

    International Nuclear Information System (INIS)

    Thermoluminescence (TL) dating of sediments depends upon the acquisition and long term stable storage of TL energy by crystalline minerals contained within a sedimentary unit. This energy is stored in the form of trapped electrons and quartz sand is the most commonly used mineral employed in the dating process. Prior to the final depositional episode it is necessary that any previously acquired TL is removed by exposure to sunlight. After burial the TL begins to build up again at a rate dependent upon the radiation flux delivered by long-lived isotopes of uranium, thorium and potassium. The presence of rubidium and cosmic radiation generally play a lesser but contributory roll, and the total radiation dose delivered to the TL phosphor is modified by the presence of water. The period since deposition is therefore measured by determining the total amount of stored TL energy, the palaeodose (P), and the rate at which this energy is acquired, the annual radiation dose (ARD). TL dating may be applied to eolian, fluvial, coastal and in some cases, marine sediments. the technique is also successfully applied to volcanic materials and to a certain extent to archeological specimens

  9. Thermoluminescence dating

    Energy Technology Data Exchange (ETDEWEB)

    Price, D.M. [University of Wollongong, Wollongong, NSW (Australia). School of Geosciences

    1999-11-01

    Thermoluminescence (TL) dating of sediments depends upon the acquisition and long term stable storage of TL energy by crystalline minerals contained within a sedimentary unit. This energy is stored in the form of trapped electrons and quartz sand is the most commonly used mineral employed in the dating process. Prior to the final depositional episode it is necessary that any previously acquired TL is removed by exposure to sunlight. After burial the TL begins to build up again at a rate dependent upon the radiation flux delivered by long-lived isotopes of uranium, thorium and potassium. The presence of rubidium and cosmic radiation generally play a lesser but contributory roll, and the total radiation dose delivered to the TL phosphor is modified by the presence of water. The period since deposition is therefore measured by determining the total amount of stored TL energy, the palaeodose (P), and the rate at which this energy is acquired, the annual radiation dose (ARD). TL dating may be applied to eolian, fluvial, coastal and in some cases, marine sediments. the technique is also successfully applied to volcanic materials and to a certain extent to archeological specimens

  10. MICADAS C-14 AMS applications in environmental research in Hungary

    International Nuclear Information System (INIS)

    Radiocarbon (C-14) analyses are applied in environmental protection, archaeology, geology, hydrology, climatology and other scientific branches in Hungary since the 1980’s. In 2011 a more modern AMS technology took over our old C-14 radiometric (GPC) method, which is based on isotope separation by accelerator mass spectrometry. AMS method requires much less sample quantity (0.1-100 mg) than the older GPS technique and gives ten times higher throughput. For our laboratory a MICADAS type AMS system was developed by ETHZ (Zürich, Switzerland) in connection with environmental research, equipped with a gas inlet system to transfer CO2 gas sample into the AMS ion source. Final acceptance of the EnvironMICADAS was completed at Debrecen, Hungary the autumn of 2011. In the first three year of operation more than 8000 targets were analyzed in the new AMS lab of Hungary. Analytical performance, novel technical developments, interesting samples and results will be presented in this talk. (author)

  11. Vertebral Bomb Radiocarbon Suggests Extreme Longevity in White Sharks

    OpenAIRE

    Li Ling Hamady; Natanson, Lisa J.; Skomal, Gregory B.; Simon R Thorrold

    2013-01-01

    Conservation and management efforts for white sharks (Carcharodon carcharias) remain hampered by a lack of basic demographic information including age and growth rates. Sharks are typically aged by counting growth bands sequentially deposited in their vertebrae, but the assumption of annual deposition of these band pairs requires testing. We compared radiocarbon (Δ(14)C) values in vertebrae from four female and four male white sharks from the northwestern Atlantic Ocean (NWA) with reference c...

  12. A new AMS facility in Mexico

    Science.gov (United States)

    Solís, C.; Chávez-Lomelí, E.; Ortiz, M. E.; Huerta, A.; Andrade, E.; Barrios, E.

    2014-07-01

    A new Accelerator Mass Spectrometry system has been installed at the Institute of Physics of the National Autonomous University of Mexico (UNAM). A sample preparation chemistry laboratory equipped with computer controlled graphitization equipment (AGEIII) has also been established. Together both facilities constitute the LEMA (Laboratorio de Espectrometría de Masas con Aceleradores) first of its kind in Mexico. High sensitivity characterization of the concentration in a sample of 14C as well as 10Be, 26Al, 129I and Pu are now possible. Since the demand for 14C dating is far more abundant, a data analysis program was developed in the cross-platform programming language Python in order to calculate radiocarbon age. Results from installation, acceptance tests and the first results of 14C analyses of reference materials prepared in our own facility are presented.

  13. A new AMS facility in Mexico

    International Nuclear Information System (INIS)

    A new Accelerator Mass Spectrometry system has been installed at the Institute of Physics of the National Autonomous University of Mexico (UNAM). A sample preparation chemistry laboratory equipped with computer controlled graphitization equipment (AGEIII) has also been established. Together both facilities constitute the LEMA (Laboratorio de Espectrometría de Masas con Aceleradores) first of its kind in Mexico. High sensitivity characterization of the concentration in a sample of 14C as well as 10Be, 26Al, 129I and Pu are now possible. Since the demand for 14C dating is far more abundant, a data analysis program was developed in the cross-platform programming language Python in order to calculate radiocarbon age. Results from installation, acceptance tests and the first results of 14C analyses of reference materials prepared in our own facility are presented

  14. A new AMS facility in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Solís, C., E-mail: corina@fisica.unam.mx; Chávez-Lomelí, E.; Ortiz, M.E.; Huerta, A.; Andrade, E.; Barrios, E.

    2014-07-15

    A new Accelerator Mass Spectrometry system has been installed at the Institute of Physics of the National Autonomous University of Mexico (UNAM). A sample preparation chemistry laboratory equipped with computer controlled graphitization equipment (AGEIII) has also been established. Together both facilities constitute the LEMA (Laboratorio de Espectrometría de Masas con Aceleradores) first of its kind in Mexico. High sensitivity characterization of the concentration in a sample of {sup 14}C as well as {sup 10}Be, {sup 26}Al, {sup 129}I and Pu are now possible. Since the demand for {sup 14}C dating is far more abundant, a data analysis program was developed in the cross-platform programming language Python in order to calculate radiocarbon age. Results from installation, acceptance tests and the first results of {sup 14}C analyses of reference materials prepared in our own facility are presented.

  15. Late Holocene Radiocarbon Variability in Northwest Atlantic Slope Waters

    Energy Technology Data Exchange (ETDEWEB)

    Sherwood, O; Edinger, E; Guilderson, T P; Ghaleb, B; Risk, M J; Scott, D B

    2008-08-15

    Deep-sea gorgonian corals secrete a 2-part skeleton of calcite, derived from dissolved inorganic carbon at depth, and gorgonin, derived from recently fixed and exported particulate organic matter. Radiocarbon contents of the calcite and gorgonin provide direct measures of seawater radiocarbon at depth and in the overlying surface waters, respectively. Using specimens collected from Northwest Atlantic slope waters, we generated radiocarbon records for surface and upper intermediate water layers spanning the pre- and post bomb-{sup 14}C eras. In Labrador Slope Water (LSW), convective mixing homogenizes the pre-bomb {Delta}{sup 14}C signature (-67 {+-} 4{per_thousand}) to at least 1000 m depth. Surface water bomb-{sup 14}C signals were lagged and damped (peaking at {approx} +45{per_thousand} in the early 1980s) relative to other regions of the northwest Atlantic, and intermediate water signals were damped further. Off southwest Nova Scotia, the vertical gradient in {Delta}{sup 14}C is much stronger. In surface water, pre-bomb {Delta}{sup 14}C averaged -75 {+-} 5{per_thousand}. At 250-475 m depth, prebomb {Delta}{sup 14}C oscillated quasi-decadally between -80 and -100{per_thousand}, likely reflecting interannual variability in the presence of Labrador Slope Water vs. Warm Slope Water (WSW). Finally, subfossil corals reveal no systematic changes in vertical {Delta}{sup 14}C gradients over the last 1200 years.

  16. Radiocarbon measurements by liquid scintillation spectrometry at the Gran Sasso National Laboratory

    International Nuclear Information System (INIS)

    Full text: Radiocarbon measurements by two QuantulusTM ultra low level liquid scintillation spectrometers were performed at the Gran Sasso National Laboratory (National Institute for Nuclear Physics) and the Radiocarbon Laboratory of ENEA-Bologna to study the efficiency and background variations related to measurements sites. For the background, two sets of three Teflon vials with benzene volumes ranging form 1 ml to 5 ml filled with pure analytical benzene were used. For the modern standards two sets of three Teflon vials with the same benzene volumes filled with pure analytical benzene enriched with radiocarbon to give the same activity as the standard sucrose ANU (sucrose ANU/modern=1.0866) were used. The scintillation cocktail comprised 15 mg butyl-PBD/ml benzene [1]. For each of these standards, spectra were obtained for 40 one-hour periods [2]. Cylindrical Teflon-S vials designed by ISTA Ltd (Faenza, Italy) with Derlin cap sealed with epoxy resin have been used. The vials characteristics are: height of 50 mm, external diameter 27 mm, thickness of the bottom Teflon base 12 mm, capacity of 9 ml. Cosmic background and its variation have been removed in Gran Sasso National Laboratory by its 1400 m rock overburden. Stable high performance liquid scintillation counting conditions are obtained, when any remaining variable components of the environmental background, such as radon, are eliminated. Ultra low level liquid scintillation spectrometer QuantulusTM has an anti-Compton guard detector, which allows monitoring of gamma radiation in the background. Guard detector efficiency in 14C background reduction is 8% in Gran Sasso National Laboratory while 80% is observed on surface. The big difference in the guard detector efficiency between surface and Gran Sasso laboratories is related to the absence of cosmic and associated lower energy Compton radiation. Masked vials approach same zero volume background on surface as an unmasked vial in Gran Sasso National Laboratory

  17. Online coupling of pure O2 thermo-optical methods - 14C AMS for source apportionment of carbonaceous aerosols

    Science.gov (United States)

    Agrios, Konstantinos; Salazar, Gary; Zhang, Yan-Lin; Uglietti, Chiara; Battaglia, Michael; Luginbühl, Marc; Ciobanu, Viorela Gabriela; Vonwiller, Matthias; Szidat, Sönke

    2015-10-01

    This paper reports on novel separation methods developed for the direct determination of 14C in organic carbon (OC) and elemental carbon (EC), two sub-fractions of total carbon (TC) of atmospheric air particulate matter. Until recently, separation of OC and EC has been performed off-line by manual and time-consuming techniques that relied on the collection of massive CO2 fractions. We present here two on-line hyphenated techniques between a Sunset OC/EC analyzer and a MICADAS (MIni radioCArbon DAting System) accelerator mass spectrometer (AMS) equipped with a gas ion source. The first implementation facilitates the direct measurement in the low sample size range (<10 μg C) with high throughput on a routine basis, while the second explores the potential for a continuous-flow real-time CO2 gas feed into the ion source. The performance achieved with reference materials and real atmospheric samples will be discussed to draw conclusions on the improvement offered in the field of 14C aerosol source apportionment.

  18. AMS Data Analysis Overview

    Energy Technology Data Exchange (ETDEWEB)

    Malchow, Russell L. [National Security Technologies, LLC

    2015-04-20

    This presentation discusses standard techniques and processes used for radiation mapping (RM) via an AMS, Aerial Measurement System. The advantages and shortcomings of standard AMS-based RM are presented, along with some suggested areas for improvement. Issues touched on include what gets counted, data quality, background correction, data processing, altitude correction, isotope extraction, contouring, and time shift.

  19. Isolation of individual fatty acids in sediments using preparative capillary gas chromatography (PCGC) for radiocarbon analysis at NIES-TERRA

    International Nuclear Information System (INIS)

    Compound-specific radiocarbon analysis (CSRA) of individual fatty acids (140-1190 μg C) in an estuarine sediment sample collected from Tokyo Bay was carried out using a recently developed preparative capillary gas chromatography (PCGC) system and accelerator mass spectrometry (AMS). The results showed that the estimated 14C ages of four components greatly varied from modern age (combined iso and anteiso C15:0, C16:0) to 17 000 years BP (C22:0), while a bulk-phase 14C age of organic matter is 5000 years BP. The 14C ages of the fatty acids derived from phytoplankton and bacteria are much younger than that of the bulk phase. On the other hand, the fatty acid originated from terrestrial higher plants (C22:0) shows an older 14C age of 17 000 years BP

  20. Measurements of radiocarbon in the NW Pacific Ocean and its marginal seas

    International Nuclear Information System (INIS)

    Radiocarbon is an important tracer in the oceans. Small amounts of radiocarbon can easily be measured by accelerator mass spectrometry on mg-sized samples of carbon extracted from 250 ml water samples. Dumping of liquid and solid radioactive wastes at sites in the NW Pacific Ocean and its marginal seas can be a potential source of radiocarbon contamination in the oceans. The purpose of this paper is to discuss some preliminary measurements designed to study this problem. (author)

  1. Radiocarbon Dioxide detection based on Cavity Ring-Down Spectroscopy and a Quantum Cascade Laser

    OpenAIRE

    Genoud, Guillaume; Vainio, Markku; Phillips, Hilary; Dean, Julian; Merimaa, Mikko

    2015-01-01

    Monitoring of radiocarbon ($^{14}$C) in carbon dioxide is demonstrated using mid-infrared spectroscopy and a quantum cascade laser. The measurement is based on cavity ring-down spectroscopy, and a high sensitivity is achieved with a simple setup. The instrument was tested using a standardised sample containing elevated levels of radiocarbon. Radiocarbon dioxide could be detected from samples with an isotopic ratio $^{14}$C/C as low as 50 parts-per-trillion, corresponding to an activity of 5 k...

  2. ARCHAEOMAGNETIC DATING OF THE ERUPTION OF XITLE VOLCANO, BASIN OF MEXICO: IMPLICATIONS FOR THE MESOAMERICAN CENTERS OF CUICUILCO AND TEOTIHUACAN (Datación arqueomagnética de la erupción del volcán Xitle, cuenca de México: implicaciones para los centros mesoamericanos de Cuicuilco y Teotihuacan)

    OpenAIRE

    Jaime Urrutia-Fucugauchi; Avto Goguitchaichvili; Ligia Pérez-Cruz; Juan Morales

    2016-01-01

    The Cuicuilco archaeological site in southern Basin of Mexico is covered by lava flows from the Xitle volcano. Dating the Xitle eruption and Cuicuilco abandonment has long been attempted. Contrasting results with radiocarbon dates around 2000 and 1670 yr BP have been reported, with implications for the development of the Mesoamerican centers of Cuicuilco and Teotihuacan. Here, we analyze radiocarbon dates and paleomagnetic data for the Xitle lava flows. New age estimates for the eruption are ...

  3. Associated terrestrial and marine fossils in the late-glacial Presumpscot Formation, southern Maine, USA, and the marine reservoir effect on radiocarbon ages

    Science.gov (United States)

    Thompson, Woodrow B.; Griggs, Carol B.; Miller, Norton G.; Nelson, Robert E.; Weddle, Thomas K.; Kilian, Taylor M.

    2011-05-01

    Excavations in the late-glacial Presumpscot Formation at Portland, Maine, uncovered tree remains and other terrestrial organics associated with marine invertebrate shells in a landslide deposit. Buds of Populus balsamifera (balsam poplar) occurred with twigs of Picea glauca (white spruce) in the Presumpscot clay. Tree rings in Picea logs indicate that the trees all died during winter dormancy in the same year. Ring widths show patterns of variation indicating responses to environmental changes. Fossil mosses and insects represent a variety of species and wet to dry microsites. The late-glacial environment at the site was similar to that of today's Maine coast. Radiocarbon ages of 14 tree samples are 11,907 ± 31 to 11,650 ± 50 14C yr BP. Wiggle matching of dated tree-ring segments to radiocarbon calibration data sets dates the landslide occurrence at ca. 13,520 + 95/-20 cal yr BP. Ages of shells juxtaposed with the logs are 12,850 ± 65 14C yr BP ( Mytilus edulis) and 12,800 ± 55 14C yr BP ( Balanus sp.), indicating a marine reservoir age of about 1000 yr. Using this value to correct previously published radiocarbon ages reduces the discrepancy between the Maine deglaciation chronology and the varve-based chronology elsewhere in New England.

  4. Extension of the Southern Hemisphere Atmospheric Radiocarbon Curve, 2120-850 years BP: Results from Tasmanian Huon Pine

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, S R; P.Guilderson, T; Buckley, B M; Cook, E

    2010-02-12

    Decadal samples of dendrochronologically-dated pine (Lagorostrobos franklinii) from the Stanley River basin, Tasmania have been radiocarbon dated between 2120-850 yr BP. This data set overlaps and extends the current Southern Hemisphere record, which currently covers the period 110-995 yr BP. There is good agreement between the two records between 995-850 yr BP, between sample replicates and with consensus values for standards. As in the younger dataset, we find evidence for a distinct but variable offset between the southern hemisphere data and IntCal04; although this is likely due to real temporal variability in the interhemispheric offset, further work is planned to rule out possible laboratory or sample preparation differences.

  5. AMS ready for launch

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    On 29 April, the Alpha Magnetic Spectrometer (AMS) will complete its long expedition to the International Space Station on board the space shuttle Endeavour. The Endeavour is set to lift off from NASA’s Kennedy Space Station at 15:47 EST (21:47 CET).   Samuel Ting, principal investigator for the AMS project, and Rolf Heuer, CERN Director-General, visit the Kennedy Space Centre before the AMS launch.  Courtesy of NASA and Kennedy Space Center. AMS is a CERN recognised experiment, created by an internal collaboration of 56 institutes. It will be the first large magnetic spectrometer to be used in space, and has been designed to function as an external module on the ISS. AMS will measure cosmic rays without atmospheric interference, allowing researchers on the ground to continue their search for dark matter and antimatter in the Universe. Data collected by AMS will be analysed in CERN’s new AMS Control Centre in Building 946 (due for completion in June 2011). The End...

  6. Radiocarbon ages of soil charcoals from the southern Alps, Ticino, Switzerland

    International Nuclear Information System (INIS)

    Radiocarbon dating of macroscopic charcoal is a useful tool for paleoclimatic and paleoecologic reconstructions. Here we present results of 14C dating of charcoals found in charcoal-rich soils of Ticino and the Misox Valley (southern Switzerland) which indicate that the Late Glacial and early Holocene fires coincided with warm phases in the North Atlantic region and low lake levels in the Central Europe. Late Holocene charcoals found in these soils document an earlier than believed presence of sweet chestnut (Castanea sativa Mill.) in southern Switzerland. Sweet chestnut trees play a key role in Mediterranean woodlands, and for longer than two millennia have been used as a food source. Based on palynological evidence it is commonly believed that in southern Switzerland C. sativa was first introduced 2000 years ago by the Romans, who cultivated it for wood and fruit production. Our results indicate that this tree species was present on the southern slopes of the Alps ∼1500 years earlier than previously assumed, and therefore was likely introduced independently from cultivation by the Romans

  7. AMS analyses at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, E.M. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia). Physics Division

    1998-03-01

    The major use of ANTARES is Accelerator Mass Spectrometry (AMS) with {sup 14}C being the most commonly analysed radioisotope - presently about 35 % of the available beam time on ANTARES is used for {sup 14}C measurements. The accelerator measurements are supported by, and dependent on, a strong sample preparation section. The ANTARES AMS facility supports a wide range of investigations into fields such as global climate change, ice cores, oceanography, dendrochronology, anthropology, and classical and Australian archaeology. Described here are some examples of the ways in which AMS has been applied to support research into the archaeology, prehistory and culture of this continent`s indigenous Aboriginal peoples. (author)

  8. AMS analyses at ANSTO

    International Nuclear Information System (INIS)

    The major use of ANTARES is Accelerator Mass Spectrometry (AMS) with 14C being the most commonly analysed radioisotope - presently about 35 % of the available beam time on ANTARES is used for 14C measurements. The accelerator measurements are supported by, and dependent on, a strong sample preparation section. The ANTARES AMS facility supports a wide range of investigations into fields such as global climate change, ice cores, oceanography, dendrochronology, anthropology, and classical and Australian archaeology. Described here are some examples of the ways in which AMS has been applied to support research into the archaeology, prehistory and culture of this continent's indigenous Aboriginal peoples. (author)

  9. AMS 14C performance test of a new automated bone preparation system

    International Nuclear Information System (INIS)

    Complete text of publication follows. Bone is one of the most complex sample materials for radiocarbon dating. After burial, its physical state and chemical composition can be affected by many environmental processes. In case of our new AMS bone preparation technique, after ultrasonication in distilled water, drying, surface cleaning and grinding, the sample is sieved to get the appropriate sized sample fraction (0.5 - 1 mm) out of which 500 - 1000 mg is measured, depending on the state of the bone. We have developed our own continuous flow bone sample preparation equipment. In this unit OMNIFITTM columns are used as flow cells to construct our own automatic ABA (acid-base-acid) cleaning system. From 3 types of reagent, each one is injected via a 4 way valve and inert plastic tubing to an IsmatechTM IPC 12 channel peristaltic pump to ensure a constant flow rate. Reagents are selectively pumped to the reaction cells containing the powdered bone samples, with a sequence of 0.5 M HCl and 0.1 M NaOH solution, interspersed with flushing with distilled water. During the sixteen-hour-long process, reagents follow a well-defined sequence that is controlled by a computer program and a special electronic driver device. The cleaned sample is inserted into a test tube containing 5 ml, pH 3 aqueous solutions, and it is placed into a heating block at 75 deg C for 24 hours. Dissolved collagen is filtered via a 45 μm glass fibre filter (WhatmanTM AUTOVIAL 5) into a clean vial, and after freezing, it gets freeze-dried, a process which takes at least a day. To investigate the sample-preparation reproducibility and possible extra contamination effect by an optional ultra-filtration process a known-age bone sample, previously dated by an independent method (GPC at HEKAL), was prepared several times using the new AMS preparation line for 14C analyses. The results obtained (Figure 1.) showed very good reproducibility and excellent agreement with the classical GPC measured 14C age in

  10. Isotope fractionations and radiocarbon ages of beach rock samples collected from the Nansei Islands, southwest of Japan

    International Nuclear Information System (INIS)

    Beach rocks are observed frequently on the tropical and subtropical sandy beaches where they express thin beds dipping seaward at less than 15 degrees. They consist of beach sediments including fossil shells, fragments of corals, diatoms and other biocarbonates, and are well cemented within the inter-tidal zone with calcium carbonate originated in sea water. Therefore, they are not only good indicators which show the past sea level, but also provide good sample material for radiocarbon dating. The locations of beach rocks give us an optimum condition studying a carbon cycle between land and marine environment by analyzing their isotope fractionations. In order to estimate the origin of calcium carbonate which worked as an adhesive when beach rocks were formed and to estimate the formative ages of beach rocks, a total of 330 fossil corals, fossil shells and calcarenite or calcirdite samples were collected from 128 sites of 16 islands consisting of the Nansei Islands, southwest of Japan. The Nansei Islands are chains of islands located between Kyushu Island and Taiwan Island for 1,500 km in length. They are divided into three major islands groups, namely from north to south, Amami Islands, Okinawa Islands and Sakishima Islands, respectively. Isotope corrections and reservoir corrections are indispensable for marine organisms to correct their radiocarbon ages in years BP. Isotope fractionations and radiocarbon ages of beach rock samples collected from the Nansei Islands were determined at the Radiocarbon Laboratory of the Nihon University and the radiocarbon dates were corrected. According to Geyh and Schleicher isotope fractionations for marine organisms were in the range within 0±2 per mille. Isotope fractionation (δ13C) of all beach rock samples collected from the Nansei Islands ranged between 9.4 per mille and -6.0 per mille, with an average of 2.1 per mille. Although the average values of isotope fractionations over the 16 islands indicated nearly the same

  11. Can UK fossil fuel emissions be determined by radiocarbon measurements?

    Science.gov (United States)

    Wenger, Angelina; O'Doherty, Simon; Rigby, Matthew; Manning, Alistair; Palmer, Paul

    2016-04-01

    The GAUGE project evaluates different methods to estimate UK emissions. However, estimating carbon dioxide emissions as a result of fossil fuel burning is challenging as natural fluxes in and out of the atmosphere are very large. Radiocarbon (14C) measurements offer a way to specifically measure the amount of recently added carbon dioxide from fossil fuel burning. This is possible as, due to their age, all the radiocarbon in fossil fuels has decayed. Hence the amount of recently added CO2 from fossil fuel burning can be measured as a depletion of the 14C content in air. While this method has been successfully applied by several groups on a city or a regional scale, this is the first attempt at using the technique for a national emission estimate. Geographically the UK, being an island, is a good location for such an experiment. But are 14CO2 measurements the ideal solution for estimating fossil fuel emissions as they are heralded to be? Previous studies have shown that 14CO2emissions from the nuclear industry mask the 14C depletion caused by fossil fuel burning and result in an underestimation of the fossil fuel CO2. While this might not be a problem in certain regions around the world, many countries like the UK have a substantial nuclear industry. A correction for this enhancement from the nuclear industry can be applied but are invariably difficult as 14CO2emissions from nuclear power plants have a high temporal variability. We will explain how our sampling strategy was chosen to minimize the influence form the nuclear industry and why this proved to be challenging. In addition we present the results from our ground based measurements to show why trying to estimate national emissions using radiocarbon measurements was overambitious, and how practical the technique is for the UK in general.

  12. 78 FR 61446 - Fourteenth Meeting: RTCA Special Committee 222, Inmarsat AMS(R)S

    Science.gov (United States)

    2013-10-03

    ... Federal Aviation Administration Fourteenth Meeting: RTCA Special Committee 222, Inmarsat AMS(R)S AGENCY... RTCA Special Committee 222, Inmarsat AMS(R)S. SUMMARY: The FAA is issuing this notice to advise the public of the fourteenth meeting of the RTCA Special Committee 222, Inmarsat AMS(R)S DATES: The...

  13. 78 FR 8684 - Twelfth Meeting: RTCA Special Committee 222, Inmarsat AMS(R)S

    Science.gov (United States)

    2013-02-06

    ... Federal Aviation Administration Twelfth Meeting: RTCA Special Committee 222, Inmarsat AMS(R)S AGENCY... RTCA Special Committee 222, Inmarsat AMS(R)S. SUMMARY: The FAA is issuing this notice to advise the public of the twelfth meeting of the RTCA Special Committee 222, Inmarsat AMS(R)S. DATES: The...

  14. Kimberley rock art dating project

    International Nuclear Information System (INIS)

    The art's additional value, unequalled by traditionally recognised artefacts, is its permanent pictorial documentation presenting a 'window' into the otherwise intangible elements of perceptions, vision and mind of pre-historic cultures. Unfortunately it's potential in establishing Kimberley archaeological 'big picture' still remains largely unrecognised. Some of findings of the Kimberley Rock Art Dating Project, using AMS and optical stimulated luminescence (OSL) dating techniques, are outlined. It is estimated that these findings will encourage involvement by a greater diversity of specialist disciplines to tie findings into levels of this art sequence as a primary reference point. The sequence represents a sound basis for selecting specific defined images for targeting detailed studies by a range of dating technique. This effectively removes the undesirable ad hoc sampling of 'apparently old paintings'; a process which must unavoidably remain the case with researchers working on most global bodies of rock art

  15. Early Bomb Radiocarbon Detected in Palau Archipelago Corals

    OpenAIRE

    Glynn, Danielle; Druffel, Ellen; Griffin, Sheila; Dunbar, R. B.; Osbourne, M.; Sanchez-Cabeza, J.-A.

    2013-01-01

    In order to evaluate the variability in surface water masses in the western Pacific warm pool, we report high-precision radiocarbon measurements in annual and seasonal bands from Porites lutea corals collected from the Palau Archipelago (7°N, 134°E). Annual coral bands from 1945 to 2008 and seasonal samples from 1953 to 1957 were analyzed to capture the initial early input of bomb 14C from surface thermonuclear weapons testing in the Marshall Islands. Results show a pre-bomb average Δ14C valu...

  16. Why Am I Dizzy?

    Medline Plus

    Full Text Available Video: "Why Am I Dizzy?" A few of the more common balance orders that affect older adults ... disease, and benign paroxysmal positional vertigo, or BPPV. Video excerpts courtesy of Johns Hopkins Center for Hearing ...

  17. I Am Canadian

    DEFF Research Database (Denmark)

    Goddard, Joe

    "I Am Canadian: Immigration and Multiculturalism in the True North" looks at Canadian immigration history from a contemporary point of view. The article scrutinizes recent discussions on dual nationality and what this may mean for Canadianness......."I Am Canadian: Immigration and Multiculturalism in the True North" looks at Canadian immigration history from a contemporary point of view. The article scrutinizes recent discussions on dual nationality and what this may mean for Canadianness....

  18. Elements in biological AMS

    International Nuclear Information System (INIS)

    AMS (Accelerator Mass Spectrometry) provides high detection sensitivity for isotopes whose half-lives are between 10 years and 100 million years. 14C is the most developed of such isotopes and is used in tracing natural and anthropogenic organic compounds in the Earth's biosphere. Thirty-three elements in the main periodic table and 17 lanthanides or actinides have long lived isotopes, providing potential tracers for research in elemental biochemistry. Overlap of biologically interesting heavy elements and possible AMS tracers is discussed

  19. AMS-02 in Space: Physics Results

    CERN Document Server

    Tomassetti, Nicola

    2015-01-01

    The Alpha Magnetic Spectrometer (AMS-02) is a particle physics experiment designed to study origin and nature of Galactic Cosmic Rays (CRs) up to TeV energies from space. With its high sensitivity, long exposure and excellent identification capabilities, AMS is conducting a unique mission of fundamental physics research in space. To date, more than 60 billion CR events have been collected by AMS. The new results on CR leptons and the analysis and light-nuclei are presented and discussed. The new leptonic data indicate the existence of new sources of high-energy CR leptons, that may arise either by dark-matter particles annihilation or by nearby astrophysical sources of $e^{\\pm}$ pairs. Future data at higher energies and forthcoming measurements on the antiproton spectrum and the boron-to-carbon ratio will be crucial in providing the discrimination among the different scenario.

  20. AMS in Phytonutrition

    Energy Technology Data Exchange (ETDEWEB)

    Dueker, S R; Buchholz, B A

    2003-08-26

    As public interest in phytonutrition continues to increase, the result will be an augmented demand for extensive phytochemical research. The fact that foods are inherently phytochemically complex dictates a need to apply scientific techniques, which can detect synergistic interaction among the many active principles and adjuvant substances in the plant, and furthermore, modify the activities of these components. As illustrated by the experiments discussed in this presentation, the advantages of AMS are unique and extensive. These advantages are best summarized by Dr. John Vogel, an originator of biological AMS experimentation: ''AMS brings (at least) three advantages to biochemical tracing: high sensitivity for finding low probability events or for use of physiologic-sized doses; small sample sizes for painless biopsies or highly specific biochemical separations; and reduction of overall radioisotope exposures, inventories, and waste streams.'' AMS opens the door to increased phytochemical tracing in humans to obtain biochemical data concerning human health at dietary relevant levels of exposure. AMS, thus, obviates the need for uncertain extrapolations from animal models, which express marginal relevance to human metabolism. The unparalleled capabilities and benefits of AMS will undoubtedly establish this particular MS technique as an important analytical tool in phytochemical research.

  1. Aquifer recharging in South Carolina: radiocarbon in environmental hydrogeology

    International Nuclear Information System (INIS)

    Radiocarbon activities of dissolved inorganic carbon (and tritium activities where infiltration rates are rapid and aquifers shallow) provide relatively unambiguous and inexpensive evidence for identification of significant recharge areas. Such evidence is for the actual occurrence of modern recharge in the aquifer and thus is less inferential than stratigraphic or potentiometric evidence. These underutilized isotopic techniques are neither arcane nor complex and have been more-or-less standardized by earlier researchers. In South Carolina, isotopic evidence has been used from both calcareous and siliceous sedimentary aquifers and fractured crystalline rock aquifers. The Tertiary limestone aquifer is shown not to be principally recharged in its subcrop area, unlike conditions assumed for many other sedimentary aquifers in southeastern United States, and instead receives considerable lateral recharge from interfingering updip Tertiary sand aquifers in the middle coastal plain. Induced recharging at Hilton Head Island is mixing ancient relict water and modern recharge water. Recharging to deeper portions of the Cretaceous Middendorf basal sand aquifer occurs at least as far coastward as the middle coastal plain, near sampling sites that stratigraphically appear to be confined. Pronounced mineralization of water in fractured rocks cannot be considered as evidence of ancient or relict ground water that is isolated from modern contaminants, some of these waters contain considerable radiocarbon and hydrogen-bomb tritium

  2. An Interim Investigation of the Potential of Vibrational Spectroscopy for the Dating of Cultural Objects in Ivory

    OpenAIRE

    O’Connor, Sonia; Edwards, Howell G.M.; Ali , Esam

    2013-01-01

    Radiocarbon dating of ivory requires destructive sampling on a scale not always compatible with the requirements of the preservation and curation of cultural objects. The development of a minimally-destructive dating technique is urgently needed. Raman spectroscopy can detect the changes in the organic and inorganic molecular components of ivory that occur with time. It has been suggested that these vibrational spectroscopic changes could be used to assess the relative date of mammoth ivories...

  3. Synchronizing the Greenland ice core and radiocarbon timescales over the Holocene – Bayesian wiggle-matching of cosmogenic radionuclide records

    Directory of Open Access Journals (Sweden)

    F. Adolphi

    2015-07-01

    Full Text Available Investigations of past climate dynamics rely on accurate and precise chronologies of the employed climate reconstructions. The radiocarbon dating calibration curve (IntCal13 and the Greenland ice core chronology (GICC05 represent two of the most widely used chronological frameworks in paleoclimatology of the past ∼ 50 000 years. However, comparisons of climate records anchored on these chronologies are hampered by the precision and accuracy of both timescales. Here we use common variations in the production rates of 14C and 10Be recorded in tree-rings and ice cores, respectively, to assess the differences between both timescales during the Holocene. We employ a novel statistical approach which leads to strongly reduced and yet, more robust, uncertainty estimates in comparison to earlier work. We demonstrate that the inferred timescale differences are robust independent of (i the applied ice core 10Be records, (ii assumptions of the mode of 10Be deposition, as well as (iii carbon cycle effects on 14C, and in agreement with independent estimates of the timescale differences. Our results imply that the GICC05 counting error is likely underestimated during the most recent 2000 years leading to a dating bias that propagates throughout large parts of the Holocene. Nevertheless, our analysis indicates that the GICC05 counting error is generally a robust uncertainty measurement but care has to be taken when treating it as a nearly Gaussian error distribution. The proposed IntCal13-GICC05 transfer function facilitates the comparison of ice core and radiocarbon dated paleoclimate records at high chronological precision.

  4. An Alluvial Surface Chronology Based on Cosmogenic 36Cl Dating, Ajo Mountains (Organ Pipe Cactus National Monument), Southern Arizona

    Science.gov (United States)

    Liu, Beiling; Phillips, Fred M.; Pohl, Molly M.; Sharma, Pankaj

    1996-01-01

    A chronology of alluvial surfaces on piedmont slopes below the western Ajo Mountains, southern Arizona, has been obtained using cosmogenic 36Cl accumulation and AMS radiocarbon dating. The apparent 36Cl ages of individual boulders range from 520,000 to 13,000 yr, and the 14C ages of organic material in the two young terraces are 2750-2350 and 17,800 cal yr B.P. The sequence of 36Cl ages is consistent with the apparent stratigraphic order, but groupings of similar ages for different surfaces appear to result from repeated reworking of older surfaces associated with the deposition of younger ones. The youngest surface gave a distribution of 36Cl ages about 30,000 yr older than the 14C and soil ages; however, this distribution had 36Cl ages that overlapped with 36Cl ages from active channels and hillslopes. We attribute the older-than-expected exposure ages of sampled boulders to inheritance of 36Cl while residing near the surface during very slow erosion on the mountain front. Our results show that although cosmogenic nuclide accumulation can help establish chronologies for surfaces in piedmont settings, care must be used in evaluating the effects of complex exposure histories.

  5. Dating mortars: three medieval Spanish architectures

    Directory of Open Access Journals (Sweden)

    Quirós Castillo, Juan Antonio

    2011-12-01

    Full Text Available One of the major issues in building archaeology is finding the age of elements and structures discovered. Mortars represent a class of material basically constituted by a mixture of different phases (i.e. binder, aggregates, water and are widely used for constructive uses and artworks. Current scientific literature regarding the possibility of accurate radiocarbon dating for mortars reports different and still contradictory results. In this study, a new protocol for radiocarbon dating of mortar developed at the Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE is used to perform 14C measurements on archaeological mortars coming from three medieval architectures of northern Spain (two churches and the walls of a castle. Results observed will be discussed and compared with independent age estimations (i.e. radiocarbon dating performed on organic materials found in the same study site, archaeological analyses in order to frame experimental observations in the actual site knowledge by means of a multidisciplinary approach.Una de las principales problemáticas a las que se enfrenta la arqueología de la arquitectura es datar los elementos y las estructuras. Las argamasas son un tipo de material constituido por una mezcla de diferentes elementos (agregados, agua y empleadas en muchos tipos de construcciones. Los estudios realizados hasta la actualidad en torno a la posibilidad de realizar dataciones radiocarbónicas precisas han proporcionado resultados contradictorios. El objetivo de este artículo es el de presentar un nuevo protocolo para datar la arquitectura histórica desarrollado por el Centre for Isotopic Research on Cultural and Enviromental Heritage (CIRCE, basado en la realización de dataciones radiocarbónicas de argamasas a partir del análisis de tres arquitecturas medievales del norte del España, dos iglesias y la muralla de un castillo. Los resultados obtenidos han sido confrontados y comparados con otros

  6. A coupled model for carbon and radiocarbon evolution during the last deglaciation

    Science.gov (United States)

    Mariotti, Véronique; Paillard, Didier; Bopp, Laurent; Roche, Didier M.; Bouttes, Nathaëlle

    2016-02-01

    Changes in the ventilation of the Southern Ocean are thought to play an important role on deglacial carbon and radiocarbon evolution but have not been tested within a coupled climate-carbon model. Here we present such a simulation based on a simple scenario of transient deglacial sinking of brines—sea ice salt rejections—around Antarctica, which modulates Southern Ocean ventilation. This experiment is able to reproduce deglacial atmospheric changes in carbon and radiocarbon and also ocean radiocarbon records measured in the Atlantic, Southern, and Pacific Oceans. Simulated for the first time in a fully coupled climate-carbon model of intermediate complexity including radiocarbon, our modeling results suggest that the deglacial changes in atmospheric carbon dioxide and radiocarbon were achieved by means of a breakdown in the glacial brine-induced stratification of the Southern Ocean.

  7. Late Holocene radiocarbon ages from Blueskin Bay estuary : relevance to local eustatic sea-level during the last 7000 years

    International Nuclear Information System (INIS)

    Eight unpublished and ten published radiocarbon dates from Blueskin Bay estuary, East Otago reflect local eustatic sea levels trends during the last 7000 yrs. The elevation data are corrected to a common datum (MSL) and the sources of error assessed. Using modern lithological and biological relationships relative to present sea-level, radiocarbon dates can be converted into paleosea-level indicators. The upper and lower limit of the paleosea-level dataset provide an envelope representing local relative sea-level changes. The envelope is consistent with a culmination of the post-glacial transgression after 6.5 kyr, followed by a minor regression of -2 m at 5.5-5 kyr, followed by a minor transgression of 1.9 m between 5-3.2 kyr. Both the timing and magnitude of the minor regression and transgression at Blueskin Bay estuary differs somewhat from Gibb (1986), who proposed a minor regression of approximately -0.4 m from 5-4.5 kyr, followed by a minor transgression of 0.6-0.9 m at 4.5-3.5 kyr. The estuaries of Weiti River and Blueskin Bay were both proposed as reference localities for recording New Zealand regional Holocene eustatic sea-levels. Twenty four pulished radiocarbon dates, corrected to a common datum (MSL) are used to constrain relative local sea levels for the Weiti River estuary. The limits of this paleosea-level dataset are consistent with a culmination of the post-glacial transgression at 6.5 kyr, followed by stable eustatic sea-level during the last 6 kyr. Prior to 6.5 kyr a regression of -5.2 m is apparent from 8-7.7 kyr, followed by a transgression of 6.6 m between 7.6-6.2 kyr. The comparison of local relative sea-levels between the two reference localities suggests local variations in eustatic sea-levels maybe significant. Variations in eustatic sea-level will be discussed in the context of the Great Barrier Reef sea-level curve of Larcombe et al. (1995). (auth.)

  8. Dating of two Paleolithic human fossil bones from Romania by accelerator mass spectrometry

    CERN Document Server

    Olariu, A; Faarinen, M P; Hellborg, R; Persson, P; Skog, G; Stenström, K; Alexandrescu, Emilian; Faarinen, Mikko; Hellborg, Ragnar; Olariu, Agata; Persson, Per; Skog, Goran; Stenstrom, Kristina

    2003-01-01

    In this study we have dated two human fossil remains found in Romania, by the method of radiocarbon using the technique of the accelerator mass spectrometry. The human fossil remains from Woman's cave, Baia deFier, have been dated to the age 30150 $\\pm$ 800 years BP, and the skull from the Cioclovina cave has been dated to the age 29000 $\\pm$ 700 years BP. These are the most ancient dated till now human fossil remains from Romania, possibly belonging to the upper Paleolithic, the Aurignacian period.

  9. Carbon 14 dating method; Methode de datation par le carbone 14

    Energy Technology Data Exchange (ETDEWEB)

    Fortin, Ph

    2000-07-01

    This document gives a first introduction to {sup 14}C dating as it is put into practice at the radiocarbon dating centre of Claude-Bernard university (Lyon-1 univ., Villeurbanne, France): general considerations and recalls of nuclear physics; the {sup 14}C dating method; the initial standard activity; the isotopic fractioning; the measurement of samples activity; the liquid-scintillation counters; the calibration and correction of {sup 14}C dates; the preparation of samples; the benzene synthesis; the current applications of the method. (J.S.)

  10. OSL dating in palaeoenvironmental reconstructions. A discussion from a user’s perspective

    Directory of Open Access Journals (Sweden)

    Kolstrup, Else

    2007-09-01

    Full Text Available Four studies with series of OSL dated aeolian sediments are outlined and used for a discussion of the reliability of this dating method in palaeoenvironmental reconstructions. The OSL ages form series controlled by interfingering radiocarbon ages, historical records or relative position of the samples. A locality dated by a thermoluminescence method is also included. The examples range from subrecent to more than 200 kyr. It is suggested that in most cases the precision and accuracy of the OSL method are insufficient for the establishment of detailed, late Quaternary stratigraphies and associated palaeoenvironmental reconstructions. It is suggested to start a discussion on the potentials and limitations of luminescence dating.

  11. Forensic applications of 14C bomb-pulse dating

    International Nuclear Information System (INIS)

    After a brief review of the basics of 14C bomb-pulse dating, this paper presents two unique forensic applications. Particular attention is dedicated to the use of the 14C bomb-pulse to establish the time of harvest of illicit drugs such as heroin and opium. Preliminary measurements of 14C concentrations in milligram samples taken from seized drugs are presented. 14C bomb-pulse dating can determine whether drug distribution originates from stockpiles or recent manufacture, and support the action of law enforcement authorities against criminal organisations involved in drug trafficking. In addition, we describe the dating of wine vintages for a number of authenticated single label vintage red wines from the Barossa Valley - South Australia. Our results show that radiocarbon dating can be used to accurately determine wine vintages and therefore reveal the addition of unrelated materials of natural and synthetic origin

  12. Forensic applications of {sup 14}C bomb-pulse dating

    Energy Technology Data Exchange (ETDEWEB)

    Zoppi, U. E-mail: ugo@ansto.gov.au; Skopec, Z.; Skopec, J.; Jones, G.; Fink, D.; Hua, Q.; Jacobsen, G.; Tuniz, C.; Williams, A

    2004-08-01

    After a brief review of the basics of {sup 14}C bomb-pulse dating, this paper presents two unique forensic applications. Particular attention is dedicated to the use of the {sup 14}C bomb-pulse to establish the time of harvest of illicit drugs such as heroin and opium. Preliminary measurements of {sup 14}C concentrations in milligram samples taken from seized drugs are presented. {sup 14}C bomb-pulse dating can determine whether drug distribution originates from stockpiles or recent manufacture, and support the action of law enforcement authorities against criminal organisations involved in drug trafficking. In addition, we describe the dating of wine vintages for a number of authenticated single label vintage red wines from the Barossa Valley - South Australia. Our results show that radiocarbon dating can be used to accurately determine wine vintages and therefore reveal the addition of unrelated materials of natural and synthetic origin.

  13. Forensic applications of 14C bomb-pulse dating

    Science.gov (United States)

    Zoppi, U.; Skopec, Z.; Skopec, J.; Jones, G.; Fink, D.; Hua, Q.; Jacobsen, G.; Tuniz, C.; Williams, A.

    2004-08-01

    After a brief review of the basics of 14C bomb-pulse dating, this paper presents two unique forensic applications. Particular attention is dedicated to the use of the 14C bomb-pulse to establish the time of harvest of illicit drugs such as heroin and opium. Preliminary measurements of 14C concentrations in milligram samples taken from seized drugs are presented. 14C bomb-pulse dating can determine whether drug distribution originates from stockpiles or recent manufacture, and support the action of law enforcement authorities against criminal organisations involved in drug trafficking. In addition, we describe the dating of wine vintages for a number of authenticated single label vintage red wines from the Barossa Valley - South Australia. Our results show that radiocarbon dating can be used to accurately determine wine vintages and therefore reveal the addition of unrelated materials of natural and synthetic origin.

  14. The puzzle of dating the Santorini eruption

    International Nuclear Information System (INIS)

    Full text: Some 3500 years ago the Aegean island of Thera (modern Santorini) exploded in a cataclysmal volcanic eruption. This event provides, in principle, a distinct time marker in the Second Millennium B.C. An exact date would be of particular importance for the synchronization of ancient civilizations in the East Mediterranean in this time period. However, despite great efforts from different fields there is no consensus on the date. In essence, new 14C dating measurements determined the eruption to a period between 1650 to 1600 B.C., whereas archaeological evidence linked to the Egyptian historical chronology favors a date well after the beginning of the New Kingdom in Egypt (1530 B.C.). Although the difference of 100 to 140 years translates into an uncertainty of only 3 to 4 % in the absolute age of the eruption, it is nevertheless decisive for a correct understanding of the interactions of cultures in this time period. The radiocarbon evidence and the prospects of identifying Thera eruptive material in ice cores from Greenland - at present also controversial - will be discussed. (author)

  15. BCal: an on-line Bayesian radiocarbon calibration tool

    Directory of Open Access Journals (Sweden)

    Caitlin E. Buck

    1999-09-01

    Full Text Available In this paper we describe newly launched software for on-line Bayesian calibration of archaeological radiocarbon determinations. The software is known as BCal and we invite members of the world-wide archaeological research community to use it should they so wish. All that is required to gain access to the software is a computer connected to the Internet with a modern World-wide Web browser (of the sort you are probably using to read this. BCal does not require access to any additional 'Plug-ins' on your machine. Since the computations needed to obtain the calibrations are undertaken on the BCal server, if you have enough computer power to run your World-wide Web browser you have enough power to use BCal.

  16. Radiocarbon mass balance for a Magnox nuclear power station

    International Nuclear Information System (INIS)

    Highlights: • First comprehensive assessment of C-14 arisings in a Magnox nuclear power station. • C-14 production in graphite and coolant gas quantified by activation modelling. • Principal C-14 production pathway is via C-13 with a small contribution from N-14. • C-14 mass balance model provides a basis for analyses on other reactors. - Abstract: Nuclear power generation in the United Kingdom is based principally on graphite-moderated gas-cooled reactors. The mass of irradiated graphite associated with these reactors, including material from associated experimental, prototype and plutonium production reactors, exceeds 96,000 tonnes. One of the principal long-lived radionuclides produced during graphite irradiation is radiocarbon (C-14). Its potential as a hazard must be taken into account in decommissioning and graphite waste management strategies. While C-14 production processes are well-understood, radionuclide distributions and concentrations need to be characterised. A common misconception is that generic statements can be made about C-14 precursors and their location. In fact, the composition of the original manufactured material, the chemical environment of the graphite during service and its irradiation history will all influence C-14 levels. The analysis presented here provides the first assessment of the principal C-14 activation pathways for a UK Magnox reactor. Activation modelling has been used to predict C-14 production rates in both the graphite core and the carbon dioxide coolant over a selected period of operation and the results compared with monitored site C-14 discharges. Principal activation routes have been identified, which should inform future graphite waste management strategies relating to radiocarbon

  17. IA, I AM

    DEFF Research Database (Denmark)

    Munk, Timme Bisgaard; Mørk, Kristian

    2004-01-01

    Hvad er informationsarkitektur? Mørk & Munk gennemgår de forskellige metaforiske konstruktioner af begrebet og kommer med deres helt egen selvstændige definition. Informationsarkitektur er en samtale, strukturation, en klassifikationskamp og et konceptuelt blend. Læs hvorfor i dette working paper...... om et af de meste centrale begreber videnssamfundet. For nu er vi alle informationsarkitekter: IA, I AM....

  18. Compound-specific radiocarbon analysis of polycyclic aromatic hydrocarbons (PAHs) in sediments from an urban reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Kanke, Hirohide; Uchida, Masao E-mail: uchidama@jamstec.go.jp; Okuda, Tomoaki; Yoneda, Minoru; Takada, Hideshige; Shibata, Yasuyuki; Morita, Masatoshi

    2004-08-01

    A quantitative apportionment of polycyclic aromatic hydrocarbons (PAHs) derived from fossil fuel combustion ({sup 14}C-free) and biomass burning (contemporary {sup 14}C) was carried out using a recently developed compound-specific radiocarbon analysis (CSRA) method for a sediment core from an urban reservoir located in the central Tokyo metropolitan area, Japan. The {sup 14}C abundance of PAHs in the sediments was measured by accelerator mass spectrometry (AMS) after extraction and purification by three types of column chromatography, by high performance liquid chromatography (HPLC), and, subsequently, by a preparative capillary gas chromatography (PCGC) system. This method yielded a sufficient quantity of pure compounds and allowed a high degree of confidence in the determination of {sup 14}C. The fraction modern values (f{sub M}) of individual PAHs (phenanthrene, alkylphenanthrenes, fluoranthene, pyrene and benz[a]anthracene) in the sediments ranged from 0.06 to 0.21. These results suggest that sedimentary PAHs (those compounds mentioned above) were derived mostly from fossil fuel combustion. Three sectioned-downcore profiles ({approx}40 cm) of the {sup 14}C abundance in phenanthrene and alkylphenanthrenes showed a decreasing trend with depth, that was anti-correlated with the trend of {sigma}PAHs concentration. The f{sub M} values of phenanthrene were also larger than those of alkylphenanthrenes in each section of the core. This result indicates that phenanthrene received a greater contribution from biomass burning than alkylphenanthrenes throughout the core. This finding highlights the method used here as an useful approach to elucidate the source and origin of PAHs in the environment00.

  19. Modeling radiocarbon dynamics in soils: SoilR version 1.1

    Directory of Open Access Journals (Sweden)

    C. A. Sierra

    2014-05-01

    Full Text Available Radiocarbon is an important tracer of the global carbon cycle that helps to understand carbon dynamics in soils. It is useful to estimate rates of organic matter cycling as well as the mean residence or transit time of carbon in soils. We included a set of functions to model the fate of radiocarbon in soil organic matter within the SoilR package for the R environment for computing. Here we present the main system equations and functions to calculate the transfer and release of radiocarbon from different soil organic matter pools. Similarly, we present functions to calculate the mean transit time for different pools and the entire soil system. This new version of SoilR also includes a group of datasets describing the amount of radiocarbon in the atmosphere over time, data necessary to estimate the incorporation of radiocarbon in soils. Also, we present examples on how to obtain parameters of pool-based models from radiocarbon data using inverse parameter estimation. This implementation is general enough so it can also be used to trace the incorporation of radiocarbon in other natural systems that can be represented as linear dynamical systems.

  20. Modeling radiocarbon dynamics in soils: SoilR version 1.1

    Directory of Open Access Journals (Sweden)

    C. A. Sierra

    2014-09-01

    Full Text Available Radiocarbon is an important tracer of the global carbon cycle that helps to understand carbon dynamics in soils. It is useful to estimate rates of organic matter cycling as well as the mean residence or transit time of carbon in soils. We included a set of functions to model the fate of radiocarbon in soil organic matter within the SoilR package for the R environment for computing. Here we present the main system equations and functions to calculate the transfer and release of radiocarbon from different soil organic matter pools. Similarly, we present functions to calculate the mean transit time for different pools and the entire soil system. This new version of SoilR also includes a group of data sets describing the amount of radiocarbon in the atmosphere over time, data necessary to estimate the incorporation of radiocarbon in soils. Also, we present examples on how to obtain parameters of pool-based models from radiocarbon data using inverse parameter estimation. This implementation is general enough so it can also be used to trace the incorporation of radiocarbon in other natural systems that can be represented as linear dynamical systems.

  1. Constraint on radiocarbon age correction in Lake Biwa environment from the middle to late Holocene

    International Nuclear Information System (INIS)

    Using data from previous studies and newly collected data, we compared the measured radiocarbon ages of molluscan shells, common reed (Phragmites australis) and pine needles (Pinus thunbergii) collected in 1966, 1970, 1990 and 2008 at Lake Biwa in Japan, and of archaeological samples, to examine radiocarbon reservoir effects at Lake Biwa. We also tested for differences in the radiocarbon reservoir effect between species and locations in the lake. The effects of nuclear bomb tests conducted in the 1950s and 1960s are clear, the offset between atmospheric 14C and the Lake Biwa freshwater 14C is larger for this period because the atmospheric 14C is so high. The semiclosed Lake Biwa system is in dynamic equilibrium with the atmosphere, resulting in the 14C content of the water following the changes in atmospheric 14C caused by nuclear testing. The shells collected after 1990 had radiocarbon ages that were 330–450 14C years older than those of the coeval atmosphere. The apparent differences in radiocarbon age (about 300 14C years) between shell fossils and wood samples excavated from the same layer of the submerged Awazu shell midden at Lake Biwa suggest that the radiocarbon reservoir effect also existed in the middle Holocene (the Middle Jomon period, about 5000 years ago). Because the present-day average residence time of Lake Biwa water is 3–6 years, its direct influence on the radiocarbon reservoir effect is small, which suggests that old carbon has been supplied into Lake Biwa.

  2. Paleoclimate reconstruction based on tritium and radiocarbon measurements at Focul Viu Ice Cave, Bihor Mts., Romania

    International Nuclear Information System (INIS)

    Complete text of publication follows. For predicting the climate change in the near future we have to understand the climate change happened in the past. Several methods and tools have been developed or are under development for palaeoclimate reconstruction (palynology, dendrochronology, isotope analysis, etc.) but none of them can reveal perfectly the past changes in the climate. Little research has been devoted to the role of cave ice in paleoclimatology despite the fact that a significant number of ice caves in temperate climatic region contain ice and wood remnants from same site and probably same time span. In Romania numerous studies dealt with the relation between ice formation, external climate and cave climate, respectively [1-2] but there is still limited information on the process of ice formation, age of ice and growth rate of ice. Perennial ice block of about 14 meter vertical thickness and estimated volume of 12 000 m3, including subfossil wood, can be found in the Focul Viu Ice Cave, Bihor Mountains, Romania at 1120 m elevation a.s.l. on a karstic highland under temperate climate. The annual mean temperature of the highland area is about 7 deg C. The cave ice forms mainly from drip water in springtime, when the temperature of the ice and the rock wall is below freezing point in the cave and over freezing point on surface. Near-surface samples were taken from the upper surface and the side wall of the ice block for tritium, δ18O and δD measurements [3] and two wood samples were extracted from different depths (6.7 m and 11.1 m, respectively) for radiocarbon dating. The tritium activity-concentration indicates 1.9 cm/yr short-term growth rate for the ice, while the long-term growth rate based on radiocarbon ages gave 0.85 cm/yr. This big difference between the long and short term growth rates confirms the theory that on long time span (few hundred years) there were periods when the balance of ice growth was negative, more ice melt than formed. This

  3. The Sea Peoples, from cuneiform tablets to carbon dating.

    Directory of Open Access Journals (Sweden)

    David Kaniewski

    Full Text Available The 13(th century BC witnessed the zenith of the Aegean and Eastern Mediterranean civilizations which declined at the end of the Bronze Age, ∼3200 years ago. Weakening of this ancient flourishing Mediterranean world shifted the political and economic centres of gravity away from the Levant towards Classical Greece and Rome, and led, in the long term, to the emergence of the modern western civilizations. Textual evidence from cuneiform tablets and Egyptian reliefs from the New Kingdom relate that seafaring tribes, the Sea Peoples, were the final catalyst that put the fall of cities and states in motion. However, the lack of a stratified radiocarbon-based archaeology for the Sea People event has led to a floating historical chronology derived from a variety of sources spanning dispersed areas. Here, we report a stratified radiocarbon-based archaeology with anchor points in ancient epigraphic-literary sources, Hittite-Levantine-Egyptian kings and astronomical observations to precisely date the Sea People event. By confronting historical and science-based archaeology, we establish an absolute age range of 1192-1190 BC for terminal destructions and cultural collapse in the northern Levant. This radiocarbon-based archaeology has far-reaching implications for the wider Mediterranean, where an elaborate network of international relations and commercial activities are intertwined with the history of civilizations.

  4. The Sea Peoples, from cuneiform tablets to carbon dating.

    Science.gov (United States)

    Kaniewski, David; Van Campo, Elise; Van Lerberghe, Karel; Boiy, Tom; Vansteenhuyse, Klaas; Jans, Greta; Nys, Karin; Weiss, Harvey; Morhange, Christophe; Otto, Thierry; Bretschneider, Joachim

    2011-01-01

    The 13(th) century BC witnessed the zenith of the Aegean and Eastern Mediterranean civilizations which declined at the end of the Bronze Age, ∼3200 years ago. Weakening of this ancient flourishing Mediterranean world shifted the political and economic centres of gravity away from the Levant towards Classical Greece and Rome, and led, in the long term, to the emergence of the modern western civilizations. Textual evidence from cuneiform tablets and Egyptian reliefs from the New Kingdom relate that seafaring tribes, the Sea Peoples, were the final catalyst that put the fall of cities and states in motion. However, the lack of a stratified radiocarbon-based archaeology for the Sea People event has led to a floating historical chronology derived from a variety of sources spanning dispersed areas. Here, we report a stratified radiocarbon-based archaeology with anchor points in ancient epigraphic-literary sources, Hittite-Levantine-Egyptian kings and astronomical observations to precisely date the Sea People event. By confronting historical and science-based archaeology, we establish an absolute age range of 1192-1190 BC for terminal destructions and cultural collapse in the northern Levant. This radiocarbon-based archaeology has far-reaching implications for the wider Mediterranean, where an elaborate network of international relations and commercial activities are intertwined with the history of civilizations. PMID:21687714

  5. Otoliths as recorders of palaeoenvironments: comparison of radiocarbon age and isoleucine epimerization in Pleistocene golden perch 'Macquaria ambigua' otoliths from Willandra Lakes

    International Nuclear Information System (INIS)

    Fish otoliths form by the accretion of layers of calcium carbonate and organic-rich material that often form distinctive layers over time scales ranging from days to years. These layers are not resorbed during the life of the fish and have potential to provide data relevant to both the biology of the fish and the environment to which the fish has been exposed. Environmental variability based on otoliths can be estimated through measures of stable oxygen isotopes, trace elements, and the widths of both daily and annual increments. Although otoliths can be dated based on measurement of radiocarbon by accelerator mass spectrometry this method is relatively expensive. An alternative method for dating golden perch otoliths is based on measurements of isoleucine D/L ratios. Miller and Rosewater (1995) demonstrated that golden perch otoliths are near a perfect closed system for racemization and that otoliths have potential of dating surrounding sediments older than 100 ka. Despite the suitability of these structures for racemization measurements, many of collections of Pleistocene otoliths from Willandra Lakes are not appropriate for determination of sample age. Most otoliths sampled in the region have been derived from surface collections, while it is recommended that samples should have been buried at least 1 m during most of their history. Therefore, the majority of existing otolith collections are not appropriate for geochronology or palaeothermometry. Nevertheless, when used in conjunction with radiocarbon dates, racemization data may be of value in assessing the relationship among otoliths in an assemblage. Radiocarbon ages and isoleucine D/L ratios were determined for 30 otoliths collected from Willandra Lakes. The rostrum of each otolith was analysed for D/L ratios and a portion of the posterior of the same otolith was analysed for radiocarbon by accelerator mass spectrometry. Sample weights for both analyses ranged from 14.0 to 25.6 mg. The central portion of the

  6. Otoliths as recorders of palaeoenvironments: comparison of radiocarbon age and isoleucine epimerization in Pleistocene golden perch `Macquaria ambigua` otoliths from Willandra Lakes

    Energy Technology Data Exchange (ETDEWEB)

    Kalish, J.M.; Pritchard, C. [Australian National Univ., Canberra, ACT (Australia); Miller, G.H.; Rosewater, A. [Colorado Univ., Boulder, CO (United States). Dept. of Geological Sciences; Tuniz, C.; Lawson, E. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1997-12-31

    Fish otoliths form by the accretion of layers of calcium carbonate and organic-rich material that often form distinctive layers over time scales ranging from days to years. These layers are not resorbed during the life of the fish and have potential to provide data relevant to both the biology of the fish and the environment to which the fish has been exposed. Environmental variability based on otoliths can be estimated through measures of stable oxygen isotopes, trace elements, and the widths of both daily and annual increments. Although otoliths can be dated based on measurement of radiocarbon by accelerator mass spectrometry this method is relatively expensive. An alternative method for dating golden perch otoliths is based on measurements of isoleucine D/L ratios. Miller and Rosewater (1995) demonstrated that golden perch otoliths are near a perfect closed system for racemization and that otoliths have potential of dating surrounding sediments older than 100 ka. Despite the suitability of these structures for racemization measurements, many of collections of Pleistocene otoliths from Willandra Lakes are not appropriate for determination of sample age. Most otoliths sampled in the region have been derived from surface collections, while it is recommended that samples should have been buried at least 1 m during most of their history. Therefore, the majority of existing otolith collections are not appropriate for geochronology or palaeothermometry. Nevertheless, when used in conjunction with radiocarbon dates, racemization data may be of value in assessing the relationship among otoliths in an assemblage. Radiocarbon ages and isoleucine D/L ratios were determined for 30 otoliths collected from Willandra Lakes. The rostrum of each otolith was analysed for D/L ratios and a portion of the posterior of the same otolith was analysed for radiocarbon by accelerator mass spectrometry. Sample weights for both analyses ranged from 14.0 to 25.6 mg. The central portion of the

  7. Microstructural evolution and Am migration behaviour in Am-containing fuels at the initial stage of irradiation

    International Nuclear Information System (INIS)

    In order to investigate the effect of americium addition to MOX fuels on the irradiation behaviour, the 'Am-1' programme is being conducted in JAEA. The Am-1 programme consists of two short-term irradiation tests of 10-minute and 24-hour irradiations and a steady-state irradiation test. The short-term irradiation tests were successfully completed and the post-irradiation examinations (PIE) are in progress. The PIE for Am-containing MOX fuels focused on the microstructural evolution and redistribution behaviour of Am at the initial stage of irradiation and the results to date are reported. The successful development of fabrication technology with remote handling and the evaluation of thermo-chemical properties based on the out-of-pile experiments are described with an emphasis on the effects of Am addition on the MOX fuel properties. (authors)

  8. AMS and climate change

    Energy Technology Data Exchange (ETDEWEB)

    Kutschera, Walter, E-mail: walter.kutschera@univie.ac.a [Vienna Environmental Research Accelerator (VERA), Fakultaet fuer Physik - Isotopenforschung, Universitaet Wien, Waehringerstrasse 17, A-1090 Wien (Austria)

    2010-04-15

    This paper attempts to draw a connection between information that can be gained from measurements with accelerator mass spectrometry (AMS) and the study of climate change on earth. The power of AMS to help in this endeavor is demonstrated by many contributions to these proceedings. Just like in archaeology, we are entering a phase of an 'integrated approach' to understand the various components of climate change. Even though some basic understanding emerged, we are still largely in a situation of a phenomenological description of climate change. Collecting more data is therefore of paramount interest. Based on a recent suggestion of 'geo-engineering' to take out CO{sub 2} from the atmosphere, this radical step will also be briefly discussed.

  9. AMS and climate change

    Science.gov (United States)

    Kutschera, Walter

    2010-04-01

    This paper attempts to draw a connection between information that can be gained from measurements with accelerator mass spectrometry (AMS) and the study of climate change on earth. The power of AMS to help in this endeavor is demonstrated by many contributions to these proceedings. Just like in archaeology, we are entering a phase of an 'integrated approach' to understand the various components of climate change. Even though some basic understanding emerged, we are still largely in a situation of a phenomenological description of climate change. Collecting more data is therefore of paramount interest. Based on a recent suggestion of 'geo-engineering' to take out CO 2 from the atmosphere, this radical step will also be briefly discussed.

  10. Progress in ESR dating of fossils

    International Nuclear Information System (INIS)

    In this review the progress of ESR dating is briefly described together with its historical development. Examples of fossil dating include shells and corals in geological sediments, fossil bones and teeth in anthropology and fossil woods in geology. The total dose of natural radiation (TD) equivalent to the archaeological dose in TL dating was obtained by the additive dose method. Initially, the TDs were plotted against the known ages; using the apparent annual dose-rate thus obtained gives the ESR age within a factor of 2 or 3 for a fossil. Precise assessment of the radiation environment was made later taking the disequilibrium of uranium series disintegration into account. ESR ages of corals agreed well with those obtained by radiocarbon and uranium-thorium methods. The time-independent accumulation rate or a linear accumulation or uranium was adopted as a first sensible model for the opensystem fossil bones: the relation between the TD and the age explains the ages of anthropologically important bones. Lastly, geological assessment of fossil woods was made by ESR based on the organic radicals and electron traps in the silicified part. (author)

  11. Solar activity around AD 775 from aurorae and radiocarbon

    Science.gov (United States)

    Neuhäuser, R.; Neuhäuser, D. L.

    2015-04-01

    A large variation in 14C around AD 775 has been considered to be caused by one or more solar super-flares within one year. We critically review all known aurora reports from Europe as well as the Near, Middle, and Far East from AD 731 to 825 and find 39 likely true aurorae plus four more potential aurorae and 24 other reports about halos, meteors, thunderstorms etc., which were previously misinterpreted as aurorae or misdated; we assign probabilities for all events according to five aurora criteria. We find very likely true aurorae in AD 743, 745, 762, 765, 772, 773, 793, 796, 807, and 817. There were two aurorae in the early 770s observed near Amida (now Diyarbak\\i r in Turkey near the Turkish-Syrian border), which were not only red, but also green-yellow - being at a relatively low geomagnetic latitude, they indicate a relatively strong solar storm. However, it cannot be argued that those aurorae (geomagnetic latitude 43 to 50°, considering five different reconstructions of the geomagnetic pole) could be connected to one or more solar super-flares causing the 14C increase around AD 775: There are several reports about low- to mid-latitude aurorae at 32 to 44° geomagnetic latitude in China and Iraq; some of them were likely observed (quasi-)simultaneously in two of three areas (Europe, Byzantium/Arabia, East Asia), one lasted several nights, and some indicate a particularly strong geomagnetic storm (red colour and dynamics), namely in AD 745, 762, 793, 807, and 817 - always without 14C peaks. We use 39 likely true aurorae as well as historic reports about sunspots together with the radiocarbon content from tree rings to reconstruct the solar activity: From AD {˜ 733} to {˜ 823}, we see at least nine Schwabe cycles; instead of one of those cycles, there could be two short, weak cycles - reflecting the rapid increase to a high 14C level since AD 775, which lies at the end of a strong cycle. In order to show the end of the dearth of naked-eye sunspots, we

  12. Age validation of quillback rockfish (Sebastes maliger) using bomb radiocarbon

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, L A; Andrews, A H; Munk, K; Coale, K H; Frantz, B R; Cailliet, G M; Brown, T A

    2005-01-05

    Rockfishes (Sebastes spp.) support one of the most economically important fisheries of the Pacific Northwest and it is essential for sustainable management that age estimation procedures be validated for these species. Atmospheric testing of thermonuclear devices during the 1950s and 1960s created a global radiocarbon ({sup 14}C) signal in the ocean environment that scientists have identified as a useful tracer and chronological marker in natural systems. In this study, we first demonstrated that fewer samples are necessary for age validation using the bomb-generated {sup 14}C signal by emphasizing the utility of the time-specific marker created by the initial rise of bomb-{sup 14}C. Second, the bomb-generated {sup 14}C signal retained in fish otoliths was used to validate the age and age estimation methodology of the quillback rockfish (Sebastes maliger) in the waters of southeast Alaska. Radiocarbon values from the first year's growth of quillback rockfish otoliths were plotted against estimated birth year producing a {sup 14}C time series spanning 1950 to 1985. The initial rise of bomb-{sup 14}C from pre-bomb levels ({approx} -90 {per_thousand}) occurred in 1959 {+-} 1 year and {sup 14}C levels rose relatively rapidly to peak {Delta}{sup 14}C values in 1967 (+105.4 {per_thousand}), with a subsequent declining trend through the end of the record in 1985 (+15.4 {per_thousand}). The agreement between the year of initial rise of {sup 14}C levels from the quillback rockfish record and the chronometer determined for the waters of southeast Alaska from yelloweye rockfish (S. ruberrimus) otoliths validated the ageing methodology for the quillback rockfish. The concordance of the entire quillback rockfish {sup 14}C record with the yelloweye rockfish time series demonstrated the effectiveness of this age validation technique, confirmed the longevity of the quillback rockfish up to a minimum of 43 years, and strongly supports higher age estimates of up to 90 years.

  13. Soil organic carbon dynamics in the Soils of Svalbard (by results of radiocarbon researches)

    OpenAIRE

    2010-01-01

    The radiocarbon analysis can be applied in soil ecology. One of the problems of soil ecology is an estimation of rate of carbon exchange between soils and atmosphere. The model for evaluation of soils humus renovation has been created on the basis of radiocarbon measurements. It is a unique integrated method of direct measurements of humus activity. For evaluation of organic carbon renovation rate in soils there was offered the coefficient of renovation (Kr), which is the integral index of o...

  14. Age of soil organic matter and soil respiration: radiocarbon constraints on belowground C dynamics

    OpenAIRE

    Trumbore, Susan

    2000-01-01

    Radiocarbon data from soil organic matter and soil respiration provide powerful constraints for determining carbon dynamics and thereby the magnitude and timing of soil carbon response to global change. In this paper, data from three sites representing well-drained soils in boreal, temperate, and tropical forests are used to illustrate the methods for using radiocarbon to determine the turnover times of soil organic matter and to partition soil respiration. For these sites, the average age of...

  15. Age validation of great hammerhead shark (Sphyrna mokarran), determined by bomb radiocarbon analysis

    OpenAIRE

    Passerotti, Michelle S.; John K. Carlson; Piercy, Andrew N.; Campana, Steven E.

    2010-01-01

    Preliminary validation of annual growth band deposition in vertebrae of great hammerhead shark (Sphyrna mokarran) was conducted by using bomb radiocarbon analysis. Adult specimens (n=2) were collected and thin sections of vertebral centra were removed for visual aging and use in radiocarbon assays. Vertebral band counts were used to estimate age, and year of formation was assigned to each growth band by subtracting estimated age from the year of capture. A total of 10 samples were extra...

  16. Very little in situ produced radiocarbon retained in accumulating Antarctic ice

    International Nuclear Information System (INIS)

    Ice samples from Dronning Maud Land, Antarctica, were analyzed for 14CO2 and 14CO by accelerator mass spectrometry. Only a small amount (∼2%) of in situ produced radiocarbon was detected. The calibrated radiocarbon ages, corrected for in situ produced 14C, are in fair agreement with age estimates obtained from stratigraphical methods added to a gas inclusion model. The ages of the entrapped air range from recent to ca. 1200 AD

  17. Oldest Directly Dated Remains of Sheep in China

    Science.gov (United States)

    Dodson, John; Dodson, Eoin; Banati, Richard; Li, Xiaoqiang; Atahan, Pia; Hu, Songmei; Middleton, Ryan J.; Zhou, Xinying; Nan, Sun

    2014-11-01

    The origins of domesticated sheep (Ovis sp.) in China remain unknown. Previous workers have speculated that sheep may have been present in China up to 7000 years ago, however many claims are based on associations with archaeological material rather than independent dates on sheep material. Here we present 7 radiocarbon dates on sheep bone from Inner Mongolia, Ningxia and Shaanxi provinces. DNA analysis on one of the bones confirms it is Ovis sp. The oldest ages are about 4700 to 4400 BCE and are thus the oldest objectively dated Ovis material in eastern Asia. The graphitisised bone collagen had δ13C values indicating some millet was represented in the diet. This probably indicates sheep were in a domestic setting where millet was grown. The younger samples had δ13C values indicating that even more millet was in the diet, and this was likely related to changes in foddering practices

  18. Teen Dating Violence

    Science.gov (United States)

    ... dating violence prevention initiative seeks to reduce dating violence and increase healthy relationships in high-risk urban communities through comprehensive, multisector prevention. Division of Adolescent ...

  19. Applications of AMS to hydrology

    International Nuclear Information System (INIS)

    The evaluation and management of water as a resource requires an understanding of the chemical, and geological interactions that water effects or undergoes in the hydrologic cycle. Delivery of water to the land surface by precipitation, subsequent streamflow, circulation in surface waters and evapotranspiration, infiltration, recharge, movement of waters in the subsurface, and discharge are of interest. Also important are the quality of water, water's role in mineral dissolution, transport, and deposition, and the various water-related geotechnical problems of subsidence, tectonics, slope instability, and earth structures. Mathematical modeling techniques are available and are being improved which describe these phenomena and predict future system behavior. Typically, however, models suffer from substantial uncertainties due to insufficient data. Refinement, calibration,and verification of hydrologic models require expansion of the data base. Examination of chemical constituents of water which act as tracers can often supply the needed information. Unfortunately, few tracers are available which are both mobile and chemically stable. Several long-lived radioisotopic hydrologic tracers exist, however, which have received little attention in hydrologic studies to date because of low concentration, low specific activity, or sample size limitations. Recent development of ultra-sensitive accelerator mass spectrometry techniques (AMS) by Purser and others (1977), Nelson and others (1977), Bennett and others (1978), Muller and others (1978), Raisbeck and others (1978) is now expected to provide access to many of these tracers

  20. Isotopic analyses of food crusts on pottery: Implications for dating and palaeocuisine reconstructions

    DEFF Research Database (Denmark)

    Philippsen, Bente

    2015-01-01

    The concentrations of the stable carbon and nitrogen isotopes, δ13C and δ15N, can be used to roughly reconstruct the former content of Stone Age cooking vessels. This was supported by measurements on experimental food crusts. The reconstruction of the ingredients used in the vessels is not only...... relevant for reconstructing the diet, but also important for 14C-dating. Resources from sea- or freshwater can cause substantial radiocarbon reservoir effects. For a reliable 14C-dating, they therefore have to be identified. This study presents 14C-datings of the earliest pottery of Schleswig-Holstein at...