During the past two decades, accelerator mass spectrometry (AMS) has allowed major developments in many areas of geosciences and archaeology. In the near future, AMS should realize a similar potential in the field of biomedical research, leading ultimately to clinical applications. For such applications, the required instrument differs significantly from that presently used in the field of 14C dating. Whereas the needed accuracy and sensitivity is more than an order of magnitude less demanding than that for present state-of-the-art 14C instrumentation, the widespread acceptance of 14C AMS in biomedical research will require AMS spectrometers that are small, simple to operate and capable of handling CO2 samples. In order to satisfy these demands, HVEE has developed a compact 14C AMS spectrometer dedicated to biomedical research. The instrument consists of a compact accelerator with a footprint of 2.25 × 1.25 m and an ion source that features direct CO2 acceptance and optimal user friendliness. Having previously described the layout and design of the accelerator, we here discuss progress on the accelerator and present the design and first results of the CO2 ion source.

To formulate a solid chronology of the northwest Belgian Bronze Age barrow phenomenon, a critical review of the available radiocarbon dates was necessary. The resulting 14C chronology of the barrows was compared with the 14C chronologies of the Late Neolithic Bell Beaker graves, the Bronze Age metalwork depositions, the evidence of barrow reuse, and the Bronze Age longhouses. This research revealed interesting patterns concerning the appearance and disappearance of the barrow phenomenon. The earliest 14C-dated barrows are dated during the Late Neolithic and coincide with the presence of the Bell Beaker culture in the region. The peak of the barrow-building practice occurred between 1700 and 1500/1400 cal BC, a period of flourishing trade networks in the regions along the North Sea basin. The period around 1500 cal BC is characterized by the disappearance of barrow-building practices and the sudden appearance of ritual depositional practices, reflecting changes in society.

The Bayesian statistical method of the OxCal v 4.1 program is used to construct an age-depth model for a set of accelerator mass spectrometry (AMS) radiocarbon ages of organic debris collected from a late Holocene Dead Sea stratigraphic section (the Ein Feshkha Nature Reserve). The model is tested for a case where no prior earthquake information is applied and for a case where there is incorporation of known ages of 4 prominent historical earthquakes as chronological anchor points along the section. While the anchor-based model provided a tightly constrained age-depth regression, the “non-anchored” model still produces a correlation where most of the 68% or 95% age ranges of the 52 seismites can be correlated to historical earthquakes. This presents us with the opportunity for high-resolution paleoseismic analysis and comparison between various sites.

This note describes improvements of UV oxidation method that is used to measure carbon isotopes of dissolved organic carbon (DOC) at the National Ocean Sciences Accelerator Mass Spectrometry Facility (NOSAMS). The procedural blank is reduced to 2.6 ± 0.6 μg C, with Fm of 0.42 ± 0.10 and δ13C of –28.43 ± 1.19‰. The throughput is improved from one sample per day to two samples per day.

The following radiocarbon date list contains dates of samples measured since our previous list (R, 1979, v 21, p 131-137). As before, age calculations are based on the Libby half-life 5570 ± 30 yr and reported in years before 1950. The modern standard is 0.95 of the activity of NBS oxalic acid. Sample pretreatment, combustion, and counting technique are essentially the same as described in R, 1971, v 13, p 135-140, supplemented by new techniques for groundwater processing (R, 1979, v 21, p 131-137) and for soil sample treatment (R, 1977, v 19, p 465-475).

We present radiocarbon (14C) measurements of dissolved inorganic carbon (DIC) from surface waters of 11 lakes, widely distributed in China. Surface lake water DIC F14C values show distinct differences, and we relate these to the physical exchange character (“open” or “closed”) of each lake. Open lakes studied here generally have lower DIC F14C values than closed lakes. We present a simple model of a lake water cycle to calculate an average residence time for each lake. Comparisons between lake DIC F14C and average residence time shows that the DIC F14C increases with the average residence time and reflects a steady-state.

We report and compare the results of long-term observations (1998–2006) of monthly mean soil CO2 fluxes and their carbon isotope composition, carried out at 3 sites with contrasting characteristics: 1) a grassland site located in the urban area of Krakow, southern Poland, which was exposed to anthropogenic impact for more than a century; 2) a mixed forest site; and 3) cultivated agricultural field site. A closed-chamber, dynamic sampling system was used to collect monthly cumulative samples of soil-respired CO2. The CO2 collected at the mixed forest site was enriched in 14C with respect to European free-atmosphere continental 14CO2 background (high-altitude station Jungfraujoch in Swiss Alps) by approximately 40%, while the urban site revealed 14C depletion by ∼30% against the same reference. The Δ14C values observed at the agricultural site were lying in between, clustering along the regional reference atmospheric Δ14CO2 trend curve. The Δ14C values of soil-respired CO2 at the urban site turned out to be indistinguishable from the Δ14CO2 values in the local atmosphere. For the estimation of mean turnover time of soil carbon for each of the monitored sites, we used a multicompartment model (MCM) accounting for input of carbon to the soil profile via deposition of fresh organic matter, as well as 3 different sources of CO2 in the soil profile: 1) root respiration; 2) “fast”; and 3) “slow” pools of soil carbon. The estimated mean turnover time of carbon in the “fast” carbon pool was ∼14 yr for both urban grassland and mixed forest sites, and ∼22 yr for the cultivated agricultural field. From the observed differences in Δ14C values of the measured fluxes of soil-respired CO2, we conclude that 14C content of the biogenic component in the local atmospheric CO2 is site-specific and may differ significantly from the regional atmospheric background Δ14CO2 value. Therefore, the assumption widely used in 14C-based assessments of the fossil-fuel contribution local atmospheric CO2 load, stating that 14C concentration in the biogenic CO2 component is equal to that of regional atmospheric reference value, needs to be carefully evaluated on a case-by-case basis.

Luzia woman is considered one of the oldest Paleoindian skeletons found in the Americas. Luzia was found at the Lapa Vermelha IV site (Lagoa Santa, Minas Gerais, Brazil) in 1975 by the archaeologist Annette Laming-Emperaire (1917–1977) who sent to the Gif laboratory charcoals collected in the vicinity of the skeleton for radiocarbon dating. Twenty-nine charcoal samples were dated from different levels of the stratigraphy of the cave (Délibrias et al. 1986). Recently, new charcoal samples were discovered within Laming-Emperaire's correspondence and were subsequently dated by the Saclay AMS laboratory. The new results confirm the age of Luzia; however, the ages correspond to the younger part of the interval: charcoals found near Luzia's skull give an age of 10,030 ± 60 14C yr BP (11,243–11,710 cal BP).

We present the current status of accelerator mass spectrometry (AMS) dating of iron artifacts at Seoul National University (SNU). In ancient iron production, charcoal was widely used as carbon for the smelting process, whereas coal is used in modern times. If reliable data could be obtained from carbon by using AMS, ancient iron artifacts could be traced to their production age. In normal acid treatment, it is not easy to extract carbon due to its colloidal property. The negative charge property of the carbon colloid, however, makes it possible for it to be precipitated with positive ions by dissolving the iron chemically. An extraction yield of the carbon incorporated in modern cast iron of about 70% is attained. More refined methods to increase the extraction rate are under progress for archaeological applications.

The Institut Français d’Archéologie Orientale (IFAO) in Cairo is one of the major French research centers abroad. It is placed under the aegis of the French Ministry of Higher Education and Research and manages an archaeometry department that features laboratories for three units of research: conservation, material studies, and radiocarbon (14C). The 14C laboratory was founded in 2006 to offer the possibility of 14C dating in Egypt. It is totally devoted to archaeological issues, uses the conventional liquid scintillation counting (LSC) method, and is equipped with two benzene synthesis lines. This paper reports on the performances and quality-control procedures of the IFAO 14C laboratory, both from the perspective of the chemical syntheses and from the radiometric measurements (background dispersion, standards, intercomparison programs). It shows how this lab occupies a privileged position to develop interdisciplinary studies of Egyptian chronology and to offer high-standard competencies to the IFAO scientific research programs. Finally, it raises the question of the future perspectives of the laboratory.

Radiocarbon variations in dated tree-ring samples represent an important tool for the study of the history of solar activity and sun-earth relationships. From this point of view, an investigation of the 11-year radiocarbon cycle is very important. Our cyclogram analysis of the Δ 14C record in tree-ring samples during the last century has confirmed previous results obtained by conventional harmonic analysis, eg, the average amplitude of 2, the phase shift of 3–5 yr for different 11-yr solar cycles, and the anticorrelation dependence of Δ 14C on Wolf sunspot numbers. The observed shorter periodicity (ca 9 yr for Δ 14C compared to 10.5 yr for sunspots), may be due to extra factors in sun-earth relationships.

The I.V.I.C. laboratory started operation in December, 1963 using liquid scintillation techniques and the benzene method. The syntheses are carried out in a Packard benzene synthesizer and the solutions counted by a Packard automatic tri-carb spectrometer. For routine dating, a 4 cc counting vial is used with 2 cc benzene coming from the sample being dated and 2 cc commercial toluene added with the PPO and POPOP scintillators.

Radiocarbon was measured in atmospheric CO2 from La Jolla, California and in living organic materials from six sites in the northern hemisphere. Atmospheric CO2 ∆14C values from La Jolla agreed with those previously published records from China Lake, California (Berger et al. 1987) and Vermunt, Austria (Levin et al. 1985). ∆14C values of fruit and grain samples that grew during 1980 agreed with the atmospheric CO2 ∆14C measurements. Most of the ∆14C results of fruit and corn samples stored since the 1940s agreed with tree-ring ∆14C values for the same time period. In general, agreement was found between the atmospheric CO2 or tree-ring ∆14C records available for the Northern Hemisphere and the ∆14C signatures of rapidly exchanging organic matter pools examined in this study. Exceptions were the ∆14C values of carbonate from egg shells and that of organic carbon from egg insides, which demonstrate that bicarbonate and organic carbon within the egg follow different biochemical pathways.

Archaeological excavations carried out at the sites of Laion/Lajen (Bolzano/Bozen) and Stufles-Oberegger (Bressanone/Brixen) in northern Italy uncovered well-preserved wooden samples in cultural layers archaeologically dated to the Iron Age. From the 2 sites, different wooden samples were recovered that were well preserved enough to allow clear identification of the tree species and of the ring structure. Among the different wooden samples, 2 were selected for radiocarbon analyses: from Laion/Lajen, a beam with an unbroken sequence of 158 rings; from Stufles-Oberegger, a combusted trunk with a sequence of 217 rings. Both samples were identified as Larix decidua species. From each sequence, single rings were selected and submitted for accelerator mass spectrometry (AMS) 14C dating analysis at CEDAD. Conventional 14C ages were then calibrated to calendar ages using the IntCal04 atmospheric data set, while the statistical constraints resulting from the defined ring sequence were used to develop a wiggle-matching approach by making use of the Bayesian analysis functions available in OxCal. The obtained results are an important contribution in refining the chronology of the studied sites.

This list reports routine measurements made at thislaboratory since the preparation of Texas IV.Samples numbered through Tx-309 were counted underthe supervision of Pearson, who left the laboratoryearly in 1966. Valastro, Associate Director sinceAugust, 1966, is responsible for samples beginningwith Tx-310. Laboratory administration and samplescreening have been handled by Davis, M. A. Tamers,formerly Director, resigned in 1966.

This study investigates human environmental adaptation in northern Finland at the cemetery of Iin Hamina. The cemetery was in use in the 15th and 16th centuries AD during the cool climate anomaly called the Little Ice Age. It is possible that these extreme climatic conditions may have impacted human survival in this agriculturally marginal region. In previous studies, carbon and nitrogen isotopes in the bone collagen of humans and fauna have shown that the main protein source for people at Iin Hamina was fish. In this study, I observe annual changes in diet derived from isotopic studies of teeth. Apart from one individual whose protein source shifted radically during tooth formation, the results show the inhabitants of Iin Hamina experienced only minor changes in diet over periods of several years. Moreover, none of the dietary profiles provided evidence of dietary or physiological stress through raised nitrogen isotope ratios. The results indicate that the individuals in this study appear to have been well-adapted to their environment.

The Xi'an Laboratory of Loess and Quaternary Geology has developed a small sample 14C dating facility consisting of a Wallac 1220 Quantulus™ liquid scintillation spectrometer, and a miniature benzene synthesis line based on the synthesis procedures used at the Australian National University (ANU). This line can produce ca. 0.3-ml benzene samples, which are then measured for 14C activity using 0.3-ml Teflon vials developed by Wallac Oy. The counting performance of the Quantulus™ spectrometer using 0.3-ml vials has been evaluated, and a potential age limit of ca. 45,000 BP has been obtained for samples containing up to 250 mg carbon. This dating facility fills the gap between large sample (2.4–6 g carbon) and microsample (<1 mg carbon) handling to form a 14C dating method sequence.

An annotated card index of 14C dates directly relating to Old World cultural material of Palaeolithic and Mesolithic age (> 50,000 − ∼7000 BP) and New World material older than 7000 BP was compiled in 1972 to include all previously published dates. It is updated annually and currently correct to the end of 1981. The need for such an index to reduce duplication of research time spent in primary data acquisition has long been implicity recognized. Indeed, many such data files may already exist. We wish to discover the nature, scope, and intercompatibility of other lists both to improve our own system and to allow for an exchange of information without unnecessary duplication. Our sources include SCIENCE and NATURE but RADIOCARBON is the major source of information. The general scientific and archaeologic literature has not been systematically searched. Where possible, other published lists have been consulted and additional dates incorporated in our list.

The accepted state-of-the-art 14C dating method relies on calibration curves to determine initial 14C levels in a sample. The paper reconsiders the basis of 14C dating and offers a possible alternative that eliminates the need to employ calibration curves. The idea is to measure the level of radiogenic nitrogen atoms retained in the sample molecules after 14C β-decay. The practicality of this alternative method still has to be proven.