bluuebunny/crossref_metadata_2025 huggingface dataset:
A rival to Stonehenge? Geophysical survey at Stanton Drew, England
Authors: David Andrew , Cole Mark , Horsley Tim , Linford Neil , Linford Paul , Martin Louise
Published: January 2017

The development of geophysical survey remains a spearhead-priority for new research and cultural resource management alike – since geophysics can find and map sites without destroying them. However, there are current weaknesses of sensitivity and resolution – the instruments cannot easily “see” small features like graves and post-holes of which so many ancient sites are principally composed. Great hopes have been invested in caesium vapour magnetometers, which the Centre for Archaeology has been promoting in England – perhaps nowhere with such dramatic success as at Stanton Drew, Somerset. Here, geophysical techniques have brought to light the lines of broad circles belonging to a previously unrecognised henge monument, and the caesium magnetometer showed these circles to be composed of individual pits about 1.4 m in diameter. The fine focus achieved for these buried features augers well for the discovery and preservation of similar sites and monuments in the future.
THE EGYPTIAN LABOR CORPS: WORKERS, PEASANTS, AND THE STATE IN WORLD WAR I
Authors: Anderson Kyle J.
Published: January 2017

In this article, I detail the British imperial system of human resource mobilization that recruited workers and peasants from Egypt to serve in the Egyptian Labor Corps in World War I (1914–18). By reconstructing multiple iterations of this network and analyzing the ways that workers and peasants acted within its constraints, this article provides a case study in the relationship between the Anglo-Egyptian colonial state and rural society in Egypt. Rather than seeing these as two separate, autonomous, and mutually antagonistic entities, this history of Egyptian Labor Corps recruitment demonstrates their mutual interdependence, emphasizing the dialectical relationship between state power and political subjectivity.
VULNERABILITY AND RECOGNITION IN SYRIAN PRISON LITERATURE
Authors: Taleghani R. Shareah
Published: January 2017

Connecting the stories of human rights violations perpetrated by the Syrian regime against the children of Darʿa in March 2011 to decades of writings about political detention in Syria, this article argues that particular works of Syrian prison literature (adab al-sujūn) articulate a poetics of recognition that both reaffirms and challenges the foundational dependency on political recognition in human rights theory. By focusing on narrative scenes of recognition and misrecognition, I contend that these texts, much like the stories of the children of Darʿa, depict different forms of acute human vulnerability. In doing so, they offer a mode of sentimental education that evokes readers’ empathy and awareness of human suffering. Yet such texts also demonstrate, in allegorical form, how the foundational reliance on political recognition in human rights regimes can limit their efficacy.
Concubinage and Consent
Authors: Ali Kecia
Published: January 2017

In our imperfect world, rape happens frequently but nearly no one publicly defends the legitimacy of forcible or nonconsensual sex. So pervasive is deference to some notion of consent that even Daʿish supporters who uphold the permissibility of enslaving women captured in war can insist that their refusal or resistance makes sex unlawful. Apparently, one can simultaneously laud slave concubinage and anathematize rape. A surprising assertion about consent also appears in a recent monograph by a scholar of Islamic legal history who declares in passing that the Qurʾan forbids nonconsensual relationships between owners and their female slaves, claiming that “the master–slave relationship creates a status through which sexual relationsmay become licit, provided both parties consent.” She contends that “the sources” treat a master's nonconsensual sex with his female slave as “tantamount to the crime ofzinā[illicit sex] and/or rape.” Though I believe in the strongest possible terms that meaningful consent is a prerequisite for ethical sexual relationships, I am at a loss to find this stance mirrored in the premodern Muslim legal tradition, which accepted and regulated slavery, including sex between male masters and their female slaves.
Knowing your genes: does this impact behaviour change?
Authors: O'Donovan Clare B. , Walsh Marianne C. , Gibney Michael J. , Brennan Lorraine , Gibney Eileen R.
Published: January 2017

It is postulated that knowledge of genotype may be more powerful than other types of personalised information in terms of motivating behaviour change. However, there is also a danger that disclosure of genetic risk may promote a fatalistic attitude and demotivate individuals. The original concept of personalised nutrition (PN) focused on genotype-based tailored dietary advice; however, PN can also be delivered based on assessment of dietary intake and phenotypic measures. Whilst dietitians currently provide PN advice based on diet and phenotype, genotype-based PN advice is not so readily available. The aim of this review is to examine the evidence for genotype-based personalised information on motivating behaviour change, and factors which may affect the impact of genotype-based personalised advice. Recent findings in PN will also be discussed, with respect to a large European study, Food4Me, which investigated the impact of varying levels of PN advice on motivating behaviour change. The researchers reported that PN advice resulted in greater dietary changes compared with general healthy eating advice, but no additional benefit was observed for PN advice based on phenotype and genotype information. Within Food4Me, work from our group revealed that knowledge of MTHFR genotype did not significantly improve intakes of dietary folate. In general, evidence is weak with regard to genotype-based PN advice. For future work, studies should test the impact of PN advice developed on a strong nutrigenetic evidence base, ensure an appropriate study design for the research question asked, and incorporate behaviour change techniques into the intervention.
Widespread Fossil CO2 in the Ansanto Valley (Italy): Dendrochronological, 14C, and 13C Analyses on Tree Rings
Authors: Capano Manuela , Altieri Simona , Marzaioli Fabio , Sirignano Carmina , Pignatelli Olivia , Martinelli Nicoletta , Passariello Isabella , Sabbarese Carlo , Ricci Paola , Gigli Stefania , Terrasi Filippo
Published: January 2017

The Ansanto Valley (southern Italy) is characterized by vents and boiling mud lakes that emit typical volcanic exhalations (mostly fossil CO2). This fossil dilution spreads over the Ansanto Valley and its impact on local trees is investigated in this study. Six trees at increasing distance from the emitting sources and 2 aliquots of gas were sampled. Dendrochronological analysis was performed on tree cores in order to check the accuracy of the tree-ring sequences; the results indicate no anomalies in the curves of the analyzed trees. δ13C and radiocarbon (14C) analyses were performed on the α-cellulose extracted from some selected tree rings. The main aim of δ13C analysis was to gain information about the origin of CO2 arising from the source; the results support the hypothesis of a carbonatic origin, with respect to a volcanic origin. 14C analysis was performed to evaluate the influence and to quantify the percentage of fossil dilution characterizing the local atmosphere and affecting the trees at different distances from the source during the years. The results show the presence of a strong fossil dilution affecting the trees, increasing toward the sources (from ∼6% at 80 m distance to ∼30% at 20 m from the nearest vent) with quite stable values over the examined period.
Cross-Dating (Th/U-14C) of Calcite Covering Prehistoric Paintings at Serra da Capivara National Park, Piaui, Brazil
Authors: Fontugne Michel , Shao Qingfeng , Frank Norbert , Thil François , Guidon Niède , Boeda Eric
Published: January 2017

The question of when the first humans arrived in the New World has been a bone of contention for several decades. Similarly, the age of rock paintings has been heatedly debated. Settlements in the Serra da Capivara National Park have been dated to between 5 kyr and >50 kyr, which is far older than the Clovis barrier. Moreover, calcite formation on a rock-wall painting in a rockshelter yielded thermoluminescence (TL) and electron paramagnetic resonance (EPR) ages older than 35 kyr BP (Watanabe et al. 2003). In an attempt to contribute to this ongoing debate, we have studied calcite deposits covering prehistoric paintings from several rockshelters (Toca da Bastiana, Toca do Serrote de Moendas, and Toca da Gameleirinha [Pedra pintada]). Coupled AMS (accelerator mass spectrometry) 14C and MC-ICPMS (multi-collector inductively coupled plasma mass spectrometry) 230Th/U dating was performed in Toca da Gameleirinha. The ages obtained for these cal-cites are younger than 12 kyr and suggest that the paintings could be more recent than proposed by previous studies.
A Devastating Plinian Eruption at Tungurahua Volcano Reveals Formative Occupation at ∼1100 cal BC in Central Ecuador
Authors: Le Pennec J-L , de Saulieu G , Samaniego P , Jaya D , Gailler L
Published: January 2017

Based on archaeological and radiometric constraints, previous studies have divided pre-Columbian times of Ecuador into a succession of cultural periods. The Paleoindian and Preceramic periods encompass the time from the first Amerindian occupation to about 4000 BC. The Formative period extends from ∼4000 to ∼300 BC, while the Regional Development (∼300 BC to ∼AD 700) and Integration periods predate the Columbian period, which starts in AD 1533 in Ecuador. The Formative cultural period is poorly known from earlier studies. Here, we bring the first documentation of Formative age occupation around Tungurahua Volcano, 120 km SW of Quito, and show that local settlements were devastated by a violent eruption around 1100 cal BC. Recent volcanological works combining lithostratigraphic, petrologic, and geochronologic analyses reveal that the steep-sloped Tungurahua edifice suffered a major Late Holocene flank failure. We show that the failure event resulted from a major explosive eruption triggered by massive magma intrusion inside the volcano. Decompression of the magma due to a flank collapse resulted in a violent, high-velocity directed blast explosion, which deposited charcoaland sherd-rich ash layers upon and near the volcano. Our 14C results range from 2225 ± 30 to 5195 ± 45 BP, but most cluster between 2640 ± 45 and 3195 ± 45 BP. A calibration analysis indicates that the event took place at ∼1100 cal BC, in the Formative period. We gathered 38 pottery sherds from 3 localities. The sherds show a diversity of size, shape, color, and ornamentation. Examination of pastes, surface finish, and firing indicates that our material shares many common features from site to site. The material from Tungurahua shares affinities with the Cotocollao tradition, which developed in the Quito region between 1500 and 500 BC, and with the Machalilla tradition (coastal region of Ecuador), with the occurrence of carinated bowls with punctuate decorations at 1500–1000 BC. Our study reveals that the ∼1100 cal BC Plinian eruption of Tungurahua Volcano is among the oldest known volcanic disasters in the Andes.
Radiocarbon Chronology and Paleodiet Studies on the Medieval Rural Site of Zaballa (Spain): Preliminary Insights into the Social Archaeology of the Site
Authors: Lubritto C , Sirignano C , Ricci P , Passariello I , Castillo J A Quiros
Published: January 2017

The archaeological site of Zaballa is a Medieval rural site located in the province of álava (Basque Country, northern Iberia). The site has been excavated during a rescue archaeology project, over an area of about 4.5 ha, where human occupation has been documented ranging from the 6th to 15th century. The archaeological operations have shown the transformation of the village, in diachronic terms, by unearthing the structure of production areas (agricultural lands, storage areas, and craft activities), the shape of domestic spaces, and the Saint Tirso monastery, with its adjacent cemetery. Much of the evidence and features related to a peasant community are small and disturbed by recent agricultural activities, and are therefore difficult to be interpreted in social terms. Studying dietary patterns has helped to fill this gap by providing a protein-rich diet of the elitist population and by highlighting the existence of hierarchies separating the inhabitants of Zaballa. In this paper, we discuss the reconstruction of the chronological sequence of the site inhabitation, with a multidisciplinary approach. The archaeological evidences and the critical use of radiocarbon dating have been integrated with stable isotope analysis on human remains found in the cemetery of the church of San Tirso, resulting in a first attempt to find evidence of the social structure of the rural community of Zaballa.
Dynamics of Siberian Paleolithic Complexes (Based on Analysis of Radiocarbon Records): The 2012 State-of-the-Art
Authors: Kuzmin Yaroslav V , Keates Susan G
Published: January 2017

Our updated database of Siberian Paleolithic radiocarbon records (the 2011 date list of ∼800 values) was used to analyze the patterns of population changes, following the methodology developed previously (Kuzmin and Keates 2005). Although the main conclusions remain similar to our 2005 results, some new features were also detected. The intensity of occupation after ∼35,000–34,000 BP was higher than previously thought, and the rise in population began at ∼20,000–19,000 BP. It is once again confirmed that no significant decline can be observed for the Last Glacial Maximum (∼22,000–16,000 BP). The relationship between climate and Paleolithic humans in Siberia was complex and without a clear trend toward the intensification of occupation during the warm phases.
The Early to Late Paleolithic Transition in Korea: A Closer Look
Authors: Bae Christopher J , Bae Kidong , Kim Jong Chan
Published: January 2017

In Korean Paleolithic archaeology, it is traditionally thought that the Late Paleolithic stone tool industries were in some way derived from the Shuidonggou site in northern China. The latter site has long been considered to be the type site of the eastern Asian Late Paleolithic blade technology. However, recent studies suggest that a number of Korean Late Paleolithic sites probably predate Shuidonggou, some by several thousands of years. Here, we present a series of accelerator mass spectrometry (AMS) dates recently analyzed by the AMS laboratory at Seoul National University and discuss further the possibility that the introduction of blade (and later microblade) technologies into Korea may have originated directly from Mongolia, Siberia, and possibly other areas of northeast China, rather than from Shuidonggou.
Initial Results of an Intercomparison of AMS-Based Atmospheric 14CO2 Measurements
Authors: Miller John , Lehman Scott , Wolak Chad , Turnbull Jocelyn , Dunn Gregory , Graven Heather , Keeling Ralph , Meijer Harro A J , Aerts-Bijma Anita Th , Palstra Sanne W L , Smith Andrew M , Allison Colin , Southon John , Xu Xiaomei , Nakazawa Takakiyo , Aoki Shuji , Nakamura Toshio , Guilderson Thomas , LaFranchi Brian , Mukai Hitoshi , Terao Yukio , Uchida Masao , Kondo Miyuki
Published: January 2017

This article presents results from the first 3 rounds of an international intercomparison of measurements of Δ14CO2 in liter-scale samples of whole air by groups using accelerator mass spectrometry (AMS). The ultimate goal of the intercomparison is to allow the merging of Δ14CO2 data from different groups, with the confidence that differences in the data are geophysical gradients and not artifacts of calibration. Eight groups have participated in at least 1 round of the intercomparison, which has so far included 3 rounds of air distribution between 2007 and 2010. The comparison is intended to be ongoing, so that: a) the community obtains a regular assessment of differences between laboratories; and b) individual laboratories can begin to assess the long-term repeatability of their measurements of the same source air. Air used in the intercomparison was compressed into 2 high-pressure cylinders in 2005 and 2006 at Niwot Ridge, Colorado (USA), with one of the tanks “spiked” with fossil CO2, so that the 2 tanks span the range of Δ14CO2 typically encountered when measuring air from both remote background locations and polluted urban ones. Three groups show interlaboratory comparability within l% for ambient level Δ14CO2. For high CO2/low Δ14CO2 air, 4 laboratories showed comparability within 2%. This approaches the goals set out by the World Meteorological Organization (WMO) CO2 Measurements Experts Group in 2005. One important observation is that single-sample precisions typically reported by the AMS community cannot always explain the observed differences within and between laboratories. This emphasizes the need to use long-term repeatability as a metric for measurement precision, especially in the context of long-term atmospheric monitoring.
Allocation of Terrestrial Carbon Sources Using 14CO2: Methods, Measurement, and Modeling
Authors: Lehman Scott J , Miller John B , Wolak Chad , Southon John , Tans Pieter P , Montzka Stephen A , Sweeney Colm , Andrews Arlyn , LaFranchi Brian , Guilderson Thomas P , Turnbull Jocelyn C
Published: January 2017

The radiocarbon content of whole air provides a theoretically ideal and now observationally proven tracer for recently added fossil-fuel-derived CO2 in the atmosphere (Cff). Over large industrialized land areas, determination of Cff also constrains the change in CO2 due to uptake and release by the terrestrial biosphere. Here, we review the development of a Δ14CO2 measurement program and its implementation within the US portion of the NOAA Global Monitoring Division's air sampling network. The Δ14CO2 measurement repeatability is evaluated based on surveillance cylinders of whole air and equates to a Cff detection limit of <0.9 ppm from measurement uncertainties alone. We also attempt to quantify additional sources of uncertainty arising from non-fossil terms in the atmospheric 14CO2 budget and from uncertainties in the composition of “background” air against which Cff enhancements occur. As an example of how we apply the measurements, we present estimates of the boundary layer enhancements of Cff and Cbio using observations obtained from vertical airborne sampling profiles off of the northeastern US. We also present an updated time series of measurements from NOAA GMD's Niwot Ridge site at 3475 m asl in Colorado in order to characterize recent Δ14CO2 variability in the well-mixed free troposphere.
Radiocarbon Dating of Recent Intertidal Microbial Mats on Atoll Rims
Authors: Trichet Jean , Hatté Christine , Fontugne Michel
Published: January 2017

Microbial mats (koparain Polynesian) that develop in shallow brackish to hypersaline ponds on the rims of atolls were investigated for their accumulation process and rate. Two sequences of ∼30-cm-deep kopara, composed of 7 and 5 layers distinguished by their colors and sedimentological facies were collected in 1996 from the Tetiaroa atoll, French Polynesia. The combination of radiocarbon activity measurements on both organic and carbonate constituents, reservoir effect estimation, and comparison with the Southern Hemisphere atmospheric bomb-peak14C record allowed us to establish a fine chronology of the layer successions documenting the mode of formation, erosion, and restoration of these microbial mat deposits.
Age Determination of Pearls: A New Approach for Pearl Testing and Identification
Authors: Krzemnicki Michael S , Hajdas Irka
Published: January 2017

For this radiocarbon study, 7 saltwater pearls and 3 shells from pearl oysters have been analyzed. The declared ages of the samples range from the mid-19th century to very recent formations. The analyzed data show the potential of the bomb peak time marker to provide additional information when testing pearls. The analyzed pearls could be distinctly separated in pearls of pre- and post-bomb peak ages, in agreement with the distinction based on the declared ages. The analyzed data further reveals the potential of this method to provide supporting evidence for the historic provenience of a pearl or as an indication of a natural or cultured formation of a pearl.
Radiocarbon Dating and Authentication of Ethnographic Objects
Authors: Richardin P , Gandolfo N
Published: January 2017

This article describes the contribution of the radiocarbon dating method to the authentication of ethnographic objects on some significant examples coming from the collections of the Quai Branly Museum (Paris, France) and the Museum of African Arts (Marseilles, France). The first object is a bludgeon of hard wood from the Tupinambá ethnic group and thought to be brought from Brazil by Andre Thévet, cosmographer of King Francis I. This object supposedly dates to the 16th century. Another example concerns a series of architectural columns, brought from Peru in 1910 by Captain Paul Berthon from the archaeological site of Pachacamac, the largest sanctuary on the central coast of Peru. These pieces have induced a strong reaction in the French scientific community, which has described them as “some vulgar fake” because of a particular decoration and also their unique typology. We will present also the dating of 2 Tibetan textiles and 2 pre-Columbian ponchos made with feathers, which were not well documented. The last example concerns a decorated skull covered with a mosaic of blue and black turquoises and belonging to a civilization predating the Aztecs (AD 1300–1500). All these examples illustrate the decisive contribution of 14C dating to the authentication of museum objects that lack information about their origin.
Radiocarbon Measurements on Early Photographs: Methods Development for Testing Waxed Paper Negatives
Authors: Canosa Elyse , Hodgins Gregory , Weaver Gawain
Published: January 2017

The earliest years of photography were full of experimentation and innovation; many photographers from this era carefully documented their experimental procedures. Consequently, it is possible to reproduce historically accurate photographs and negatives today. One of the oldest forms of photographic technology is the waxed paper negative, popular during the mid-19th century. It consists of a photosensitive sheet of writing paper coated with a layer of wax to render it transparent. Modern waxed paper negatives made using 19th century paper can potentially pass for historically significant 19th century negatives. This poses problems to museums and others interested in studying or collecting authentic 19th century photographic images. We have developed methods for separating the organic components of waxed paper negatives and measuring their radiocarbon content as a means of distinguishing between modern and historic waxed paper negatives. By detecting the presence or lack of bomb carbon in a given negative, this process can act as a tool for authentication. We have mainly focused on the extraction and 14C measurement of the wax component, reasoning that modern photographers might have easy access to 19th century paper, but would less likely use 19th century beeswax.
High-Current 14C Measurements on an HVE 1MV AMS System
Authors: Klein Matthias , Gottdang A , Mous D J W
Published: January 2017

High radiocarbon sample throughput is an increasingly important requirement of accelerator mass spectrometry (AMS) systems, which in turn requires high source output. To accomplish this, HVE AMS systems use a model SO-110B ion source, which can run at outputs of more than 200 μA 12C. It is known that high source output may compromise precision. To quantify this effect, we have tested an HVE 1MV AMS system for the influence of medium (100 μA) and high (200 μA) source outputs on the precision. These early measurements indicate for a 200 μA 12C source output, equivalent to a ≃1 kHz 14C count rate for Ox II samples, a 13C/12C precision of 1% and a 14C/12C precision of 3% can be obtained.
AMS Measurement of 237Np at CIAE
Authors: Wang Xianggao , Jiang Shan , He Ming , Dong Kejun , Chen Hongtao , He Guozhu , Wang Wei , Wu Shaoyong , Hu Yuemei
Published: January 2017

237Np (≃2.14 × 106 yr half-life) is potentially applicable in studies on nuclear safeguards and radioactive waste migration. The atomic ratio of 237Np/U in nature is 10−12 or even lower, depending strongly on the integral neutron flux received by the material. As an ultra-sensitive technique, accelerator mass spectrometry (AMS) is the best for measuring ultratrace 237Np. By extracting negative molecular ions NpO– from the oxide sample using 238UO– and 208Pb16O2– pilot beams for the simulation of 237Np ion transport, identifying the interference isotopes by high-resolution dedicated injector, electrostatic analyzer, and time of flight (TOF) detector, a method for AMS measurement of 237Np was set up on the HI-13 accelerator at the China Institute of Atomic Energy (CIAE). A sensitivity of <10–11 has been achieved for the isotopic ratio 237Np/238U.
AMS Measurement of 59Ni at China Institute of Atomic Energy
Authors: He Ming , Ruan Xiangdong , Wang Wei , Dou Liang , Xie Lingbo , Dong Kejun , Li Zhenyu , Zheng Guowen , Hu Hao , Jiang Shan , Liu Jianchen , Wu Shaoyong
Published: January 2017

The long-lived radioisotope 59Ni is of interest in various research fields including neutron dosimetry, radioactive waste management, and astrophysics. In order to achieve the sensitivity required for such applications, the technique of accelerator mass spectrometry (AMS) 59Ni measurement has been developed at the AMS facility at China Institute of Atomic Energy (CIAE). Based on the AE-Q3D detection system in the CIAE AMS facility, the interference in 59Ni counting from the isobar 59Co has been reduced by a factor of 8 × 106. A series of laboratory reference samples and a blank sample were measured to check the performance of 59Ni measurement. A detection sensitivity of about 5 × 10−13 (59Ni/Ni) has been obtained.
The New 250kV Single Stage AMS System at CAIS, University of Georgia: Performance Comparison with a 500kV Compact Tandem Machine
Authors: Prasad G V Ravi , Noakes John E , Cherkinsky Alexander , Culp Randy , Dvoracek Doug
Published: January 2017

A new 250kV single stage AMS accelerator (SSAMS) was installed at the Center for Applied Isotope Studies, University of Georgia. The accelerator is intended to be used primarily for radiocarbon measurements of natural and biobased samples, while all other samples such as marine, geological, atmospheric and archaeological samples are measured on the decade-old 500kV compact tandem accelerator (CAMS). The new AMS system is equipped with a 134-cathode MC-SNICS ion source. In this article, we show the results of the tests carried out on standards and blanks and compare the performance of the new machine with that of the CAMS unit. We have also compared the stable isotope data from AMS measurements to the conventional isotope ratio mass spectrometers (IRMS) data.
The Brazilian AMS Radiocarbon Laboratory (LAC-UFF) and the Intercomparison of Results with CENA and UGAMS
Authors: Macario K D , Gomes P R S , Anjos R M , Carvalho C , Linares R , Alves E Q , Oliveira F M , Castro M D , Chanca I S , Silveira M F M , Pessenda L C R , Moraes L M B , Campos T B , Cherkinsky A
Published: January 2017

After 22 yr of the low-level liquid scintillation counting 14C laboratory at the Center for Nuclear Energy in Agriculture (CENA) at São Paulo University (USP), Piracicaba, Brazil, and several collaborative projects with Brazilian and international researchers from distinct scientific areas, the first 14C accelerator mass spectrometry (AMS) laboratory in Latin America was installed at the Physics Institute of the Universidade Federal Fluminense (UFF), Niterói, Brazil. A 250kV single stage accelerator produced by National Electrostatics Corporation began its operation in 2012. In this work, we compare measurements performed at the AMS Radiocarbon Laboratory at UFF (LAC-UFF) with those performed at CENA and the University of Georgia (UGAMS), Georgia, USA. All the results obtained from distinct inorganic and organic samples were in very good agreement.
Research and Development of the Artemis 14C AMS Facility: Status Report
Authors: Moreau C , Caffy I , Comby C , Delqué-Količ E , Dumoulin J-P , Hain S , Quiles A , Setti V , Souprayen C , Thellier B , Vincent J
Published: January 2017

The Artemis accelerator mass spectrometry (AMS) facility is dedicated to high-precision radiocarbon measurements. It routinely measures over 4500 samples a year for French laboratories. This paper is a status report, showing the measurements of standard, blank, and FIRI intercomparison samples. Since 2008, research and development programs have been established by the Artemis team. During the collaborations with other research laboratories, intercomparisons on archaeological samples were performed and are listed here to show the quality of the Artemis measurements. Three areas of specific research and development are investigated: technical development, beam optic simulations, and specific archaeological studies. The technical developments of the facility are based on the setup of a new bench for water sample preparation and routine microsample preparation and measurement. Beam optic simulations are carried out to control the quality of the measurement related to the tuning of the facility. International collaborations are always in progress. In 2012, the programs include improving the accuracy of reigns for the dynastic Egypt period and the 14C dating of ancient iron.
Carbonate Sample Preparation for 14C Dating Using an Elemental Analyzer
Authors: Lindauer Susanne , Kromer Bernd
Published: January 2017

Radiocarbon dating of carbonates is of increasing importance for archaeology and climate research. Like most samples, these usually require pretreatment to remove surface contamination. We studied several pretreatment techniques using snails and shells of different stages of preservation and sensitivity to dissolution during the acid step of the pretreatment. We find that simple acid treatment leads to reliable results, and is applicable especially to very fragile specimens. We also compare conversion of calcite using an elemental analyzer (EA) to the conventional acid dissolution technique.
Molecular Sieves in 14CO2 Sampling and Handling
Authors: Palonen V , Oinonen M
Published: January 2017

Molecular sieves are a promising way to sample and manipulate gaseous samples for radiocarbon analyses. Molecular sieve material can adsorb CO2 selectively, enabling sampling of CO2 from large air volumes in a small amount of adsorbent. The sieve material can be regenerated via heating and reused without removing the sieve material from its container. This results in ease of use and reduced risks of atmospheric contamination. Because sieve container volume is small and can be filled with synthetic air or nitrogen, it does not introduce underpressure to the system under study. Hence, sieves are suitable for many different experimental setups, from collection of CO2 from small soil chambers to atmospheric CO2 collection. The most common sieve material in use for sampling CO2 is the 13X zeolite. For environmental measurements starting this year, we have studied the properties of 13X zeolites in more detail. For reliable 14CO2 sampling, there are several caveats that should and can be avoided. In this contribution, we discuss these caveats and solutions to optimize the molecular sieve sampling process.
Ultrafiltration of Bone Samples is Neither the Problem nor the Solution
Authors: Fülöp Réka-Hajnalka , Heinze Stefan , John Svetlana , Rethemeyer Janet
Published: January 2017

We conducted analyses to identify the most suitable bone pretreatment protocol to be used by the recently established Radiocarbon Laboratory at the University of Cologne, CologneAMS. In 2 sets of analyses, we determined 14C ages for subsamples taken from 3 14C bone standards (Oxford Mammoth, VIRI I, and VIRI H) complemented by age determinations of 12 unknown bone samples. Our results suggest that the strength and duration of the acid and alkali steps and the temperature of gelatinization might have a larger influence on the obtained ages than the presence or absence of ultrafiltration as a pretreatment step.
14C Measurements of Ice Samples from the Juvfonne Ice Tunnel, Jotunheimen, Southern Norway—Validation of a 14C Dating Technique for Glacier Ice
Authors: Zapf A , Nesje A , Szidat S , Wacker L , Schwikowski M
Published: January 2017

Establishing precise age-depth relationships of high-alpine ice cores is essential in order to deduce conclusive paleoclimatic information from these archives. Radiocarbon dating of carbonaceous aerosol particles incorporated in such glaciers is a promising tool to gain absolute ages, especially from the deepest parts where conventional methods are commonly inapplicable. In this study, we present a new validation for a published 14C dating method for ice cores. Previously 14C-dated horizons of organic material from the Juvfonne ice patch in central southern Norway (61.676°N, 8.354°E) were used as reference dates for adjacent ice layers, which were 14C dated based on their particulate organic carbon (POC) fraction. Multiple measurements were carried out on 3 sampling locations within the ice patch featuring modern to multimillennial ice. The ages obtained from the analyzed samples were in agreement with the given age estimates. In addition to previous validation work, this independent verification gives further confidence that the investigated method provides the actual age of the ice.
Are Coral Clasts from a Turbid Near-Shore Reef Environment a Suitable Material for Radiocarbon Analysis?
Authors: Gulliver Pauline , Palmer Suzanne , Perry Chris , Smithers Scott
Published: January 2017

Use of coral skeletons to determine growth histories of reefs situated in warm, clear tropical waters is well established. Recently, however, there has been increasing awareness of the significance of reefs occurring in environments that are considered as marginal for coral growth, such as turbid inshore settings characterized by episodes of elevated turbidity, low light penetration, and periodic sediment burial. While these conditions are generally considered as limiting for coral growth, coral reefs in these settings can exhibit high live coral cover and species diversity, and thus can be both ecologically and geologically significant. Turbid-zone reefs are also commonly concentrated along eroding shorelines with many analogues to erosional shorelines developed during the Holocene transgression. A growing number of studies of these previously undocumented reefs reveal that the reef deposits are detrital in nature, comprising a framework dominated by reef rubble and coral clasts and set within a fine-grained terrigenous sediment matrix. In addition to the recognized effects of diagenesis or algal encrustations on the radiocarbon signature of coral samples, episodic high-energy events may rework sediments and can result in age reversals in the same stratigraphic unit. As in other reef settings, the possibility of such reworking can complicate the reconstruction of turbid-zone reef growth chronologies. In order to test the accuracy of dating coral clasts for developing growth histories of these reef deposits, 5 replicate samples from 5 separate coral clasts were taken from 2 sedimentary units in a core collected from Paluma Shoals, an inshore turbid-zone reef located in Halifax Bay, central Great Barrier Reef, Australia. Results show that where care is taken to screen the clasts for skeletal preservation, primary mineralogical structures, and δ13C values indicative of marine carbonate, then reliable 14C dates can be recovered from individual turbid reef coral samples. In addition, the results show that these individual clasts were deposited coevally.
ABA and ABOx Radiocarbon Cross-Dating on Charcoal from Middle Pleniglacial Loess Deposits in Austria, Moravia, and Western Ukraine
Authors: Haesaerts Paul , Damblon Freddy , Nigst Philip , Hublin Jean-Jacques
Published: January 2017

Four charcoal samples from loess key sites in Austria, Moravia, and western Ukraine were submitted to ABOx (acid-base oxidation) pretreatment to compare results with the classical ABA (acid-base-acid) method. For this purpose, charcoal samples already dated in Groningen laboratory were selected from 3 archaeological sites: Molodova V in western Ukraine (subunit 10–1, ∼32.6 ka BP), Willendorf II in Austria (unit C4, ∼32.1 ka BP and unit C8, ∼38.9 ka BP) and Vedrovice V in Moravia (unit 4, upper part of Bohunice soil, ∼39.5 ka BP). Each selected charcoal sample has been homogenized and divided into 3 subsamples, which were submitted to ABA in Groningen and to ABA and ABOx pretreatments in Oxford. The results show that the ABOx dates are older than the ABA dates. Nevertheless, down to ∼40 ka BP ABOx and Groningen ABA dates appear in good agreement within a time interval of ∼1 millennium at 1σ. However, Groningen ABA pretreatment produces older dates than the Oxford ABA pretreatment. Both Oxford ABOx and Groningen ABA pretreatments provide sets of dates in good agreement with the chronological background of each selected site.
Advances in Handling Small Radiocarbon Samples at the Laboratoire de Mesure du Carbone 14 in Saclay, France
Authors: Delqué-Količ E , Caffy I , Comby-Zerbino C , Dumoulin J P , Hain S , Massault M , Moreau C , Quiles A , Setti V , Souprayen C , Tannau J F , Thellier B , Vincent J
Published: January 2017

The Artemis accelerator mass spectrometry (AMS) facility, installed in 2003 in Saclay, France, is devoted to radiocarbon measurements. Samples are submitted by scientists in the fields of Quaternary geology, environmental sciences, and archaeology. The entire preparation process, originally optimized for samples with about 1 mg of carbon, has been tested in recent years for samples with a lower carbon content. In particular, we prepared and measured carbonate and organic background and reference samples ranging in mass from 0.01 to 1 mg C. These tests helped define our protocol's practical limits and determine necessary improvements. Furthermore, our experiments demonstrated that satisfactory graphitization yields (80% and higher) and low background values can be obtained with samples down to 0.2 mg of carbon. For handling smaller samples, we developed a specific process. We tested smaller reactors (5 mL in volume) and adapted the reduction parameters (H2 pressure and temperature) accordingly. We also tested the effect of a chemical water trap on graphitization yields and 14C results. This paper presents in detail the aforementioned developments and reports the 14C results obtained for background and standard small samples prepared with the modified reactors.
Improved Precision of Radiocarbon Measurements for CH4 and CO2 Using GC and Continuous-Flow AMS Achieved by Summation of Repeated Injections
Authors: McIntyre Cameron P , McNichol Ann P , Roberts Mark L , Seewald Jeffrey S , von Reden Karl F , Jenkins William J
Published: January 2017

Compound specific radiocarbon measurements can be made instantaneously using a gas chromatograph (GC) combustion system coupled to a 14C AMS system fitted with a gas ion source. Samples below 10 μg C can be analyzed but the precision is reduced to 5–10% because of lower source efficiency. We modified our GC for CH4 and CO2 analysis and injected samples multiple times to sum data and increase precision. We attained a maximum precision of 0.6% for modern CO2 from 25 injections of 27 μg C and a background of ≃0.5% (40 kyr) for ancient methane. The 14C content of dissolved CO2 and CH4 in water samples collected at a deep-sea hydrothermal vent and a serpentine mud volcano was measured and the results for the vent sample are consistent with previously published data. Further experiments are required to determine a calibration and correction procedure to maximize accuracy.
Hydroxyproline Dating: Experiments on the 14C Analysis of Contaminated and Low-Collagen Bones
Authors: Marom Anat , McCullagh James S O , Higham Thomas F G , Hedges Robert E M
Published: January 2017

Dating of the amino acid hydroxyproline from bone collagen has been shown to produce accurate and reliable radiocarbon dates. This article presents further application of the method demonstrating it can be used to obtain dates for both low-collagen and contaminated bones, extending the capability of 14C dating archaeological bone from conventional limits imposed by alternative pretreatment methods. The method therefore has the potential for significantly benefiting the accelerator mass spectrometry (AMS) dating community in the 14C dating of archaeological bone.
Iron Age Chronology in Israel: Results from Modeling with a Trapezoidal Bayesian Framework
Authors: Lee Sharen , Ramsey Christopher Bronk , Mazar Amihai
Published: January 2017

Bayesian methods have been widely used to address the Iron Age chronological debate in Israel, which has implications for the entire eastern Mediterranean Iron Age chronology. However, a consensus has not been reached. This is largely because radiocarbon dates of materials in this period lie on an oscillation in the calibration curve. This study focuses on the modeling of 14C dates from the Iron I and Iron II periods, discusses the underlying assumptions and limitations of existing Bayesian chronologies, and proposes the use of a more appropriate model that allows for the phase transitions not being instantaneous. The new trapezoidal model sheds light on the probable duration of the transitions between the Iron Age phases.
Radiocarbon Ages of Annual Rings from Japanese Wood: Evident Age Offset Based on IntCal09
Authors: Nakamura Toshio , Masuda Kimiaki , Miyake Fusa , Nagaya Kentaro , Yoshimitsu Takahiro
Published: January 2017

To investigate the radiocarbon concentration of atmospheric CO2 over the past few millennia in Japan, we measured the 14C age of annual rings from 3 Japanese trees with calendar dates ranging from ∼2000 yr old to present, and we compared the tree-ring 14C age with the corresponding 14C age from IntCal09. In some instances, the 14C ages of the annual rings of Japanese trees are not consistent with the IntCal09 data sets. Often, the 14C ages of tree rings are older than those from IntCal09, but younger than those from the SHCal04 data sets. The average shifts in the Nagoya 14C age from IntCal09 data sets and 1σ errors were determined to be +26 ± 36, +24 ± 30, +16 ± 22, +5 ± 21, and +14 ± 22 14C yr for the intervals AD 72– 382, 589–1072, 1413–1615, 1617–1739, and 1790–1860, respectively. The Japanese Archipelago is situated near the boundary of the Intertropical Convergence Zone in summer, and the 14C concentration of atmospheric CO2 over Japan can be influenced by air masses of the Southern Hemisphere with lower 14C concentrations during periods of higher solar activity and heightened East Asian summer monsoons. Our results suggest that the Japanese Archipelago is located in a critical zone where it is difficult to calibrate the 14C age of tree-ring samples using existing calibration data sets. It should be noted that calibration of the 14C dates of Japanese samples with IntCal09 may induce additional systematic shifts of calibrated ages toward older ages by about 30 yr compared with the sample optimum calendar ages.
14C in Radioactive Waste for Decommissioning of the Ignalina Nuclear Power Plant
Authors: Vaitkevičiene Violeta , Mažeika Jonas , Skuratovič Žana , Motiejūnas Stasys , Vaidotas Algirdas , Oryšaka Aleksandr , Ovčinikov Sergej
Published: January 2017

Radiocarbon is one of the most significant radionuclides affecting the safety margins of near-surface repositories for the disposal of low- and intermediate-level, short-lived radioactive waste, arising from the operation and decommissioning of nuclear power plants (NPPs). One of the goals of the present study was to characterize radioactive waste from Ignalina NPP (Lithuania) (storage tanks TW18B01 and TW11B03) from the spent ion-exchange resins/perlite stream to determine the 14C-specific activity of inorganic and organic carbon compounds. The approach applied is based on classical radiochemical separation methods, including acid-stripping techniques and wet oxidation with subsequent catalytic combustion. The suitability of the method for 14C-specific activity determination in ion-exchange resin samples with a minimum detectable activity of 0.5 Bq/g by liquid scintillation counting (LSC) was demonstrated. The extraction efficiency of inorganic and organic carbon compounds based on model samples with known 14C activity was estimated. The fraction of 14C associated with organic compounds ranged from 42% to 63% for storage tank TW18B01 and from 30% to 63% for storage tank TW11B03. The specific activity of inorganic 14C was estimated as 12.6 Bq/g with a relative standard deviation (RSD) of 29% for storage tank TW18B01, and 177.5 Bq/g with a RSD of 35% for storage tank TW11B03. Based on volume and density data, the total 14C activity for radioactive waste stored in tanks TW18B01 and TW11B03 was estimated as 3.59E + 10 Bq (±32%) and 4.15E + 11 Bq (±28%), respectively.
A Comparison of Distribution Maps of Δ14C in 2010 and 2011 in Korea
Authors: Park J H , Hong W , Park G , Sung K S , Lee K H , Kim Y E , Kim J K , Choi H W , Kim G D , Woo H J , Nakanishi T
Published: January 2017

Δ14C values of leaves of deciduous trees provide a means to map the regional-scale fossil fuel ratio in the atmosphere. We collected a batch of ginkgo (Ginkgo biloba Linnaeus, a deciduous tree) leaf samples from across Korea in the month of July in both 2010 and 2011 to obtain the regional distribution of Δ14C. The Δ14C values of the samples were measured using accelerator mass spectrometry (AMS) at the Korea Institute of Geoscience and Mineral Resources (KIGAM). The average of the Δ14C values from clean air sites in Korea in 2011 measured slightly lower than the average of Δ14C values in 2010. Distribution maps of Δ14C of 2011 and 2010 in Korea were made based on a series of Δ14C values of ginkgo leaf samples from Korea using the Geostatistical and Spatial analyst tools in ESRI's ArcMap software. The distribution maps of Δ14C showed that Δ14C values in the western part of Korea are lower than those in the eastern part of Korea. This is because the western part of Korea is densely populated and contains many industrial complexes, and also because westerly winds from China, containing CO2 from fossil fuel use, blow into Korea. We compared the distribution maps of 2010 and 2011 and tried to find traces of the Fukushima power plant accident in Japan.