bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiocarbon Dating of Holocene Calcareous Tufa in Southern Poland
Authors: Pazdur Anna , Pazdur Mieczysław F , Szulc Joachim
Published: July 2016

Calcareous tufa from five sites in southern Poland, representing several most typical conditions of tufa sedimentation, were chosen for 14C, 13C, and 18O measurements. These tufas were deposited in a high-energy turbulent stream (the Racławka site), in streams with moderate but variable flow (Rzerzuśnia and Trzebienice), and in semilimnic conditions (Sieradowice site). Sediments of the Gliczarów site represent spring travertines. In all but the latter site, direct comparison of 14C dates of carbonate and organic fractions was possible, leading to an estimate of initial apparent age of carbonate sediments. Clear correlation was found between the value of initial apparent age of tufas and the hydrodynamic conditions of sedimentation. Corresponding values range from ca 3900 yr (Racławka) to 910 yr for semilimnic sediments (Sieradowice). Intermediate, almost identical values, equal to 2460 ± 200 yr and 2100 ± 160 yr, were obtained for tufas from Rzerzuśnia and Trzebienice, respectively. Detailed sedimentologic classification of tufaceous deposits is presented and some primary and secondary factors affecting the accuracy of radiocarbon dates of various types of tufas are also discussed.
University of Lund Radiocarbon Dates XXI
Authors: Håkansson Sören
Published: July 2016

Most of the 14C measurements reported here were made between October 1986 and June 1987. Equipment, measurement, and treatment of samples are as reported previously (R, 1968, v 10, p 36–37; 1976, v 18, p 290; 1986, v 28, no. 3, p 1111).
Hiroshima University Radiocarbon Dates II West and South Coasts of Sri Lanka
Authors: Katupotha Jinadasa
Published: July 2016

Geologic samples for 14C age measurements were collected from the west, southwest and south coasts of Sri Lanka during October and November 1986. Sample points were leveled based on the Colombo datum level. Results presented below were obtained by liquid scintillation counting of methanol for coral and shell samples. Ages were measured from December 1986 to May 1987, at the Department of Geography, Hiroshima University, Radiocarbon Dating Laboratory, using the laboratory procedure described by Fujiwara and Nakata (1984). Sample preparation techniques were similar to those mentioned in the first list (Katupotha, 1988). The results are expressed in radiocarbon years relative to ad 1950 based on the Libby half-life of 5568 ± 30 years, using the new oxalic acid standard (SRM 4900C) as ‘modern’ (Stuiver, 1983).
High-Resolution 14C Dating of Organic Deposits Using Natural Atmospheric 14C Variations
Authors: Geel Bas Van , Mook Willem G
Published: July 2016

The occurrence of atmospheric 14C variations complicates calibration, ie, the translation of 14C ages into real calendar ages. The procedure of wiggle matching, however, allows very precise calibration, by matching known 14C variations with wiggles in the floating chronology. In principle, wiggle matching can also be applied to a series of 14C dates from organic (peat) deposits. Where, in general, 14C ages are required at short distances and on small samples, dating by 14C accelerator mass spectrometry (AMS) is required.
Holocene Variations of Radiocarbon Reservoir Ages in a Mediterranean Lagoonal System
Authors: Sabatier P , Dezileau L , Blanchemanche P , Siani G , Condomines M , Bentaleb I , Piquès G
Published: July 2016

To obtain a precise radiocarbon Holocene chronology in coastal areas, it is necessary to estimate the modern14C reservoir age R(t) and its possible variations with time in relation to paleoenvironmental changes. The modern reservoir14C age was estimated by comparing AMS14C ages of 2 recent mollusk shells found in sediment cores sampled in the Palavasian lagoonal system (south of France) with ages derived from210Pb and137Cs data and historical accounts of identifiable storm events. The calculated modern R(t) value of 943 ± 2514C yr is about 600 yr higher than the global mean sea surface reservoir age. This high value, probably due to the relative isolation of the lagoon from marine inputs, is in good agreement with other R(t) estimates in Mediterranean lagoonal systems (Zoppi et al. 2001; Sabatier et al. 2008).14C ages were also obtained on a series of Holocene mollusk shells sampled at different depths of the ∼8-m-long core PB06. Careful examination of the14C ages versus depth relationships suggests that R(t) in the past was lower and similar to the value presently measured in the Gulf of Lion (618 ± 3014C yr, Siani et al. 2000). The change in R(t) from 618 to 943 yr is thought to result from final closure of the coastal lagoon by the sandy barrier, due to the along-shore sediment transfer.
AMS 14C Dating of Human Bones Using Sequential Pyrolysis and Combustion of Collagen
Authors: Wang Hong , Ambrose Stanley H , Hedman Kristin M , Emerson Thomas E
Published: July 2016

The Radiocarbon Dating Laboratory at the University of Illinois has been using the pyrolysis-combustion technique to separate pyrolysis-volatile (Py-V) or low molecular weight and pyrolysis-residue (Py-R) or high molecular weight compounds for 14C dating of organic remains since 2003. We have applied this method to human collagen dating to examine the 14C age difference between low and high molecular weight organic compounds. Results show that both fractions of late prehistoric period human bones from Illinois archaeological sites yield identical 14C dates but that Py-V or low molecular weight fractions of Archaic period human bones appear to be slightly contaminated. In this case, Py-V components or low molecular weight collagen fraction yield older 14C dates, which could result from contamination from old organic-rich sediments. The pyrolysis-combustion technique provides an economical alternative method to date bones that have not been satisfactorily dated using conventional purification techniques.
The Keck Carbon Cycle AMS Laboratory, University of California, Irvine: Status Report
Authors: Beverly Robert K , Beaumont Will , Tauz Denis , Ormsby Kaelyn M , von Reden Karl F , Santos Guaciara M , Southon John R
Published: July 2016

We present a status report of the accelerator mass spectrometry (AMS) facility at the University of California, Irvine, USA. Recent spectrometer upgrades and repairs are discussed. Modifications to preparation laboratory procedures designed to improve sample throughput efficiency while maintaining precision of 2–3‰ for 1-mg samples (Santos et al. 2007c) are presented.
Developing Ultra Small-Scale Radiocarbon Sample Measurement at the University of Tokyo
Authors: Yokoyama Yusuke , Koizumi Mamito , Matsuzaki Hiroyuki , Miyairi Yosuke , Ohkouchi Naohiko
Published: July 2016

We have developed accelerator mass spectrometry (AMS) measurement techniques for ultra small-size samples ranging from 0.01 to 0.10 mg C with a new type of MC-SNICS ion source system. We can generate 4 times higher ion beam current intensity for ultra-small samples by optimization of graphite position in the target holder with the new ionizer geometry. CO2 gas graphitized in the newly developed vacuum line is pressed to a depth of 1.5 mm from the front of the target holder. This is much deeper than the previous position at 0.35 mm depth. We measured 12C4+ beam currents generated by small standards and ion beam currents (15–30 μA) from the targets in optimized position, lasting 20 min for 0.01 mg C and 65 min for 0.10 mg C. We observed that the measured 14C/12C ratios are unaffected by the difference of ion beam currents ranging from 5 to 30 μA, enabling measurement of ultra-small samples with high precision. Examination of the background samples revealed 1.1 μg of modern and 1 μg of dead carbon contaminations during target graphite preparation. We make corrections for the contamination from both the modern and background components. Reduction of the contamination is necessary for conducting more accurate measurement.
High-Precision Radiocarbon Dating of the Construction Phase of Oakbank Crannog, Loch Tay, Perthshire
Authors: Cook G T , Dixon T N , Russell N , Naysmith P , Xu S , Andrian B
Published: July 2016

Many of the Loch Tay crannogs were built in the Early Iron Age and so calibration of the radiocarbon ages produces very broad calendar age ranges due to the well-documented Hallstatt plateau in the calibration curve. However, the large oak timbers that were used in the construction of some of the crannogs potentially provide a means of improving the precision of the dating through subdividing them into decadal or subdecadal increments, dating them to high precision and wiggle-matching the resulting data to the master 14C calibration curve. We obtained a sample from 1 oak timber from Oakbank Crannog comprising 70 rings (Sample OB06 WMS 1, T103) including sapwood that was complete to the bark edge. The timber is situated on the northeast edge of the main living area of the crannog and as a large and strong oak pile would have been a useful support in more than 1 phase of occupation and may be related to the earliest construction phase of the site. This was sectioned into 5-yr increments and dated to a precision of approximately ±8–16 14C yr (1 σ). The wiggle-match predicts that the last ring dated was formed around 500 BC (maximum range of 520–465 BC) and should be taken as indicative of the likely time of construction of Oakbank Crannog. This is a considerable improvement on the estimates based on single 14C ages made on oak samples, which typically encompassed the period from around 800–400 BC.
Early Bronze Age Strata at Tell Ghanem Al-Ali Along the Middle Euphrates in Syria: A Preliminary Report of 14C Dating Results
Authors: Nakamura Toshio , Hoshino Mitsuo , Tanaka Tsuyoshi , Yoshida Hidekazu , Saito Takeshi , Tsukada Kazuhiro , Katsurada Yusuke , Aoki Yoshiyuki , Ohta Tomoko , Hasegawa Atsunori , Kiuchi Tomoyasu , Ohnuma Katsuhiko , Khabour Anas Al , Maqdissi Michel Al
Published: July 2016

We collected charcoal fragments during an archaeological excavation at the Tell Ghanem al-Ali site, located on the lowest terrace of the middle Euphrates River, and measured their radiocarbon ages with accelerator mass spectrometry (AMS). Two trenches, Square-1 and Square-2, were dug on the slope of the tell; 8 building levels were detected in the Square-2 trench. In total, 31 charcoal samples were collected from the 2 trenches, and their calibrated ages ranged from 3100–2900 cal BC at the lowest building level to 2400–2050 cal BC at the uppermost layers of the mound, and concentrated in the period 2650–2450 cal BC. The pottery fragments collected on the surface of the mound before the excavation survey was started, as well as those collected from the sediment layers during the excavation, were assigned on the basis of typological sequences to the Early Bronze Age (EB)-III and EB-IV periods. Thus, the concentrated dates (2650–2450 cal BC) obtained by 14C dating are consistent with the age estimated by archaeological contexts. However, the oldest dates of the lowest level (level-7) go back to 3100–2900 cal BC, and these dates may suggest the existence of the human residence prior to the EB period at the site, and may therefore lead to a revision of the oldest age limit of the EB period currently accepted in the region.
Radionuclides in Ancient Relics Obtained from the Matsusaki Site and the Hirohata Shellmound on the Pacific Coast of Japan
Authors: Ohta Tomoko , Mahara Yasunori , Kubota Takumi , Saito Yu , Fukutani Satoshi , Fujii Toshiyuki , Ando Atsushi , Nakata Eiji , Nakano Takanori , Abe Yoshiro , Tatematsu Akira
Published: July 2016

We compared 2 archaeological relics of different preservation environments, white substances adhering to a vessel from the Matsusaki site and to earthenware from Hirohata, by measuring their environmental radioactivity, 14C, 228Ra/226Ra, 234U/238U, and 87Sr/86Sr, and major element contents (Ca, Sr, Mg, Fe, and Mn). The results showed that the 2 materials were somewhat different and also reflected differences in their preservation environments. The chemical elements that were more abundant in the Matsusaki sample than in the Hirohata sample, Fe, Mn, 238U, and 232Th (parent of 228Ra), are also abundant in seaweed or seagrass. Contamination by 14C derived from rainwater after atmospheric nuclear tests was clearly observed in the white substance from Hirohata.
The Carbon Origin of Structural Carbonate in Bone Apatite of Cremated Bones
Authors: Strydonck Mark Van , Boudin Mathieu , Mulder Guy De
Published: July 2016

In order to reveal a possible carbon exchange between carbon dioxide of the fuel and the bone apatite during the cremation process an experiment was set up using fossil fuel. Two setups were constructed, one using natural gas and one using coal. In both experiments, a carbon substitution in the apatite was revealed.
Refining Background Corrections for Radiocarbon Dating of Bone Collagen at Orau
Authors: Wood R E , Ramsey C Bronk , Higham T F G
Published: July 2016

During the laboratory pretreatment of samples for radiocarbon dating, small amounts of carbon may be added to a sample. Contamination can be incorporated at any stage: during chemical pretreatment, combustion to CO2, graphitization, or accelerator mass spectrometry (AMS) measurement. Such carbon contamination is often modern in age, and so can have an especially severe effect on samples older than ∼25 ka BP. During the extraction of collagen from bone using the ultrafiltration protocol at the Oxford Radiocarbon Accelerator Unit (ORAU), small amounts of young carbon are added to the sample. Currently, this contamination is poorly characterized when less than 10 mg of collagen is extracted from a bone. Demand to date small collagen samples with 14C concentrations that approach the detection limit of AMS measurement has increased recently with the growing interest in, for example, directly dating Neanderthal remains and Upper Paleolithic bone artifacts. This paper aims to reduce the minimum collagen sample size required to produce a reliable date from 10 to 5 mg by re-examining the combustion background and subsequently the pretreatment background for bone. The average of 136 measurements of directly combusted nylon suggests that 0.0007 ± 0.001 mg of modern carbon is added to each sample, although the distribution is positively skewed. Regression analysis of the measurements of 52 collagen samples extracted from a bone of background age results in a background of just less than 50,000 BP for bone treated at ORAU.
Radiocarbon and Tritium Levels Along the Romanian Lower Danube River
Authors: Varlam Carmen , Stefanescu Ioan , Cuna Stela , Vagner Irina , Faurescu Ionut , Faurescu Denisa
Published: July 2016

The Lower Danube Basin covers the Romanian-Bulgarian sub-basin downstream from Cazane Gorge and the sub-basins of the Siret and Prut rivers. To extensively survey the Romanian nuclear power plant impact on the Danube water, tritium and radiocarbon baseline values are required. Therefore, the reported study tried to establish these values based on a 2-yr sampling campaign covering 975 km of the Danube from Cazane Gorge to Tulcea. The tributaries Cerna, Jiu, Olt, and Arges were also included in this study. During the sampling campaigns, tritium concentration of different sampling locations showed values between 7 ± 2.1 and 33.5 ± 2.3 TU. Measured 14C activity for the same locations ranged between 88.45 ± 1.46 and 112.36 ± 1.56 pMC. Lower values were recorded for tributaries: between 8.3 ± 2.1 and 12.2 ± 2.2 TU for tritium and between 67.3 ± 1.29 and 86.04 ± 1.42 pMC for 14C. Despite the nuclear activity in the observed areas, tritium and 14C activities presented slightly higher values for specific locations without any influence on Danube River water.
Bomb-Pulse Dating of Human Material: Modeling the Influence of Diet
Authors: Georgiadou Elisavet , Stenström Kristina
Published: July 2016

The atmospheric testing of nuclear weapons during the 1950s and early 1960s produced large amounts of radiocarbon. This 14C bomb pulse provides useful age information in numerous scientific fields, e.g. in geosciences and environmental sciences. Bomb-pulse dating can also be used to date human material (e.g. in forensics and medical science). Bomb-pulse dating relies on precise measurements of the declining 14C concentration in atmospheric carbon dioxide collected at clean-air sites. However, local variations in the 14C specific activity of air and foodstuffs occur, which are caused by natural processes as well as by various human activities. As 14C enters the human body mainly through the diet, variations of 14C concentration in foodstuffs need to be considered. The marine component of the diet is believed to be of particular importance due to the non-equilibrium in 14C specific activity between the atmosphere and aquatic reservoirs during the bomb pulse. This article reviews the 14C concentration in marine foodstuffs during the bomb-pulse era, and models how the marine component in one's diet can affect the precision of bomb-pulse dating of human material.
Extension of the Southern Hemisphere Atmospheric Radiocarbon Curve, 2120–850 Years BP: Results from Tasmanian Huon Pine
Authors: Zimmerman Susan , Guilderson Thomas , Buckley Brendan , Cook Edward
Published: July 2016

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 covers the period 110–995 yr BP. There is good agreement between the 2 records between 995–850 yr BP, between sample replicates and with consensus values for standards. As in the younger data set, 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.
14C Wiggle-Matching of the B-Tm Tephra, Baitoushan Volcano, China/North Korea
Authors: Yatsuzuka Shinya , Okuno Mitsuru , Nakamura Toshio , Kimura Katsuhiko , Setoma Yohei , Miyamoto Tsuyoshi , Kim Kyu Han , Moriwaki Hiroshi , Nagase Toshiro , Jin Xu , Jin Bo Lu , Takahashi Toshihiko , Taniguchi Hiromitsu
Published: July 2016

We performed accelerator mass spectrometry (AMS) radiocarbon dating and wiggle-matching of 2 wood samples from charred trunks of trees (samples A and B) collected from an ignimbrite deposit on the northeastern slope of the Baitoushan Volcano on the border of China and North Korea. The obtained calendar years for the eruption are cal AD 945–960 for sample A and cal AD 859–884 and cal AD 935–963 for sample B in the 2-σ range. These results are unable to determine the precise eruption age. The reason for the difference in reported ages may be due to volcanic gas emission prior to the huge eruption.
The Effect of Storage on the Radiocarbon, Stable Carbon and Nitrogen Isotopic Signatures and Concentrations of Riverine DOM
Authors: Gulliver P , Waldron S , Scott E M , Bryant C L
Published: July 2016

Chemical preservatives (e.g. mercuric chloride) are routinely added to freshwater samples to prevent biological activity compromising the isotopic signature of dissolved organic matter (DOM) with time. However, alternative preservation methods are needed due to regulations restricting the use of preservatives with potentially adverse environmental and health impacts, rendering such additions unviable. This study investigates whether a non-chemical storage method is sufficient to maintain the radiocarbon and stable carbon and nitrogen signatures of freshwater DOM from a low order river system draining a peaty catchment. Some 50 L of stream water were collected in 1 plastic carbuoy and, within 24 hr, 1-L aliquots were transferred to acid-washed plastic bottles. Five aliquots were analyzed immediately to determine the baseline values for 14C (pMC), δ13C (VPDB‰), δ15N (AIR‰), %C (mg L–1), and %N (mg L–1). Of the remaining subsamples, 20 were frozen and a further 20 refrigerated at <4 °C. After 7, 30, 90, and 180 days, 5 frozen and 5 refrigerated aliquots were analyzed in the same manner as the baseline aliquots. Analysis of the results shows that there is no statistically significant interaction between the variables storage method or length of storage for any of the determinants. Storage method has a statistically significant effect on 14C (pMC) and [C] (mg L–1). Length of storage has a statistically significant effect on δ13C (VPDB‰), [C] (mg L–1), and [N] (mg L–1) values. Neither storage method nor length of storage appear to have a statistically significant effect on 815N (AIR‰) values.
Development of Graphitization of μg-Sized Samples at Lund University
Authors: Genberg J , Stenström K , Elfman M , Olsson M
Published: July 2016

To be able to successfully measure radiocarbon with accelerator mass spectrometry (AMS) in atmospheric aerosol samples, graphitization of small sample sizes (<50 μg carbon) must provide reproducible results. At Lund University, a graphitization line optimized for small samples has been constructed. Attention has been given to minimize the reduction reactor volume and each reactor is equipped with a very small pressure transducer that enables constant monitoring of the reaction. Samples as small as 25 μg of carbon have been successfully analyzed, and the mass detection limit of the system has probably not been reached.
Blank Assessment for Ultra-Small Radiocarbon Samples: Chemical Extraction and Separation Versus AMS
Authors: Santos Guaciara M , Southon John R , Drenzek Nicholas J , Ziolkowski Lori A , Druffel Ellen , Xu Xiaomei , Zhang Dachun , Trumbore Susan , Eglinton Timothy I , Hughen Konrad A
Published: July 2016

The Keck Carbon Cycle AMS facility at the University of California, Irvine (KCCAMS/UCI) has developed protocols for analyzing radiocarbon in samples as small as ∼0.001 mg of carbon (C). Mass-balance background corrections for modern and 14C-dead carbon contamination (MC and DC, respectively) can be assessed by measuring 14C-free and modern standards, respectively, using the same sample processing techniques that are applied to unknown samples. This approach can be validated by measuring secondary standards of similar size and 14C composition to the unknown samples. Ordinary sample processing (such as ABA or leaching pretreatment, combustion/graphitization, and handling) introduces MC contamination of ∼0.6 ± 0.3 μg C, while DC is ∼0.3 ± 0.15 μg C. Today, the laboratory routinely analyzes graphite samples as small as 0.015 mg C for external submissions and ≅0.001 mg C for internal research activities with a precision of ∼1% for ∼0.010 mg C. However, when analyzing ultra-small samples isolated by a series of complex chemical and chromatographic methods (such as individual compounds), integrated procedural blanks may be far larger and more variable than those associated with combustion/graphitization alone. In some instances, the mass ratio of these blanks to the compounds of interest may be so high that the reported 14C results are meaningless. Thus, the abundance and variability of both MC and DC contamination encountered during ultra-small sample analysis must be carefully and thoroughly evaluated. Four case studies are presented to illustrate how extraction chemistry blanks are determined.
Buried Ancient Forest and Implications for Paleoclimate Since the Mid-Holocene in South China
Authors: Shen C D , Ding P , Wang N , Yi W X , Ding X F , Fu D P , Liu K X , Zhou L P
Published: July 2016

The historical evolution of an ancient forest that developed at Gaoyao, south China, can be divided into 4 stages of radiocarbon intervals (1.1–1.5, 2.0–3.5, 3.6–4.0, and 4.3–4.9 ka) in which the last 3 stages all developed in a wetland and formed humic layers of 2.0, 0.5, and 0.7 m depth, respectively. The humic layers were interrupted by 2 white-gray silty clay layers that most likely formed during climate fluctuations. Four drought events were identified during the evolution of the ancient forest, occurring around 4.3, 3.6, 2.0, and 1.1 ka, respectively, with durations of ∼1000 14C yr. These events are consistent with other records both in low- and high-latitude areas, in particular with the little ice ages occurring since the mid-Holocene. Precipitation likely increased from 5.0 to 3.6 ka in south China, then decreased, which is probably the main cause for the development as well as the demise of the ancient forest.
Marine Reservoir Variation in the Bismarck Region: An Evaluation of Spatial and Temporal Change in ΔR and R Over the Last 3000 Years
Authors: Petchey Fiona , Ulm Sean
Published: July 2016

Interactions between islands, ocean currents, and winds cause large-scale eddies and upwelling in the lee of islands that can result in spatial variation in the marine radiocarbon reservoir. For waters around New Ireland and the Bismarck Sea, ΔR values ranging from 365 to −32014C yr have been reported (Kirch 2001; Petchey et al. 2004). Petchey et al. (2004) proposed that some of this variation was caused by seasonal reversals in the South Equatorial Current and North Equatorial Counter Current system, combined with Ekman upwelling from the Equator. McGregor et al. (2008) suggested additional complexity within this region caused by a change in the reservoir value over time in response to changing climatic conditions. We present a series of 14 new and extant published ΔR andRvalues on historic shells, combined with 8 values from archaeological terrestrial/marine pairs and U-Th dated coral, that support observations of localized variability caused by a complex interplay between seasonal currents, riverine input, and ocean eddies. On the basis of these values and oceanographic data, we divide the Bismarck Sea surface marine14C reservoir into 6 tentative subregions. In particular, our results support significant variation within channels at the southwest and southeast ends of New Britain and towards the equatorial boundary of the sea. Our results indicate that within the Bismarck Sea geographical variation appears to be more extreme than temporal over the last 3000 yr.
Jean-François Saliège (1943–2012)
Authors: Zazzo Antoine
Published: July 2016

Jean-François Saliège passed away on Friday, 1 June 2012, following a heart attack at age 68. Jean-François was born in Chartres and spent his entire career in Paris, a city that he particularly enjoyed. He was hired in 1965 as a junior technician at the Laboratoire de Géologie Dynamique de la Faculté des Sciences de Paris at La Sorbonne University (Director Louis Glangeaud), where he participated in the creation of the radiocarbon and mass spectrometry laboratory under supervision of René Létolle, Jean-Charles Fontes, and Colette Vergnaud-Grazzini. In 1975, he moved to the University of Paris VI and worked more specifically with J-C Fontes in the 14C laboratory as an engineer. In 1981, he helped J-C Fontes to create the Hydrology and Isotope Geochemistry lab at Orsay University. The following year, he returned to the University of Paris VI and joined the team led by Colette Vergnaud-Grazzini at the Laboratoire de Géologie Dynamique, where Jean-François set up the new stable isotope and radiocarbon lab. Between 1990 and 2008, he continued to work at the University of Paris VI at the LODYC lab (Dir. Lilianne Merlivat), then at the LOCEAN lab (Dir. Laurence Eymard) on Catherine Pierre's team.
Tell Sabi Abyad, Syria: An Interpretation of Stable Isotope Values of Faunal Bone Collagen
Authors: van der Plicht J , Akkermans P M M G , Buitenhuis H , Kaneda A , Nieuwenhuyse O , Russell A
Published: July 2016

At Tell Sabi Abyad, Syria, radiocarbon dating previously provided a robust chronology for the 7th–early 6th millennium BC, the Late Neolithic. The continuous inhabitation spans the 8.2 ka climate event. This chronology has been used here in a study of stable isotope (13C and 15N) data of animal bones. This is the first isotope study undertaken on material from this area. The results are used to explore diet and therefore animal management practices through the period ∼6800–5800 BC. A climatic signal could not be detected in the bone samples.
Early Bronze Age Chronology: Radiocarbon Dates and Chronological Models from Tel Yarmuth (Israel)
Authors: Regev Johanna , De Miroschedji Pierre , Boaretto Elisabetta
Published: July 2016

Over the years, 40 radiocarbon samples (charcoal and seeds) have been measured from the site of Tel Yarmuth. These samples originate from 3 major archaeological periods: Final Early Bronze Age (henceforth EB) I, EB II, and EB IIIB-C. The samples are further on divided into 8 separate archaeological phases. Bayesian modeling analyses were performed on the data. Separate models were run with seeds and charcoals to detect a possible old-wood effect. Outliers were detected, and finally models with gaps were run to account for the lack of samples from 2 archaeological layers. The results suggest that at Tel Yarmuth the end of the EB II occurred ∼2950–2880 BC, and that the EB III endedat the latest∼2450 BC, perhaps before 2500 BC. Although these dates are somewhat earlier than traditionally assumed, they are in close accordance with the new analysis of other14C dates for the Early Bronze Age in the southern Levant (Regev et al., these proceedings).
Chronology of the Early Bronze Age in the Southern Levant: New Analysis for a High Chronology
Authors: Regev Johanna , De Miroschedji Pierre , Greenberg Raphael , Braun Eliot , Greenhut Zvi , Boaretto Elisabetta
Published: July 2016

The chronology of the Early Bronze Age (EBA) in the southern Levant and the synchronization between the sites, considering seriation and radiocarbon dates, have shown large inconsistencies and disagreement. We have assembled 42014C dates, most of them previously published and a few provided directly by the excavators. The dates have been re-evaluated on the basis of their archaeological context and using analytical criteria. Bayesian modeling has been applied to the selected dates in relation to the given seriation of the EBA subperiods (EB I, II III, IV). Sites with 2 or more sequential sub-phases were individually modeled in order to define the transitions between the subperiods. The new chronology indicates that the EB I–II transition occurred site-dependently between 3200–2900 BC, with EB II–III around 2900 BC, and EB III–IV ∼2500 BC.
Improving the 14C Dating of Marine Shells from the Canary Islands for Constructing More Reliable and Accurate Chronologies
Authors: Martins José M Matos , Martín Alfredo Mederos , Portela Paulo J Cesário , Soares António M Monge
Published: July 2016

Radiocarbon dating of closely associated marine mollusk shells and terrestrial material (charred wood or bone) collected from archaeological contexts on Tenerife and Fuerteventura islands allowed us to quantify the marine 14C reservoir effect (ΔR) around the Canary Archipelago. Coastal Fuerteventura has a positive weighted mean ΔR value of +185 ± 30 14C yr, while for Tenerife a range of negative and positive values was obtained, resulting in a ΔR weighted mean value of 0 ± 35 14C yr. These values are in accordance with the hydrodynamic system present off the Canary Islands characterized by a coastal upwelling regime that affects the eastern islands (Fuerteventura and Lanzarote) but not the other islands of the archipelago, namely Tenerife. Because of this oceanographic pattern, we recommend the extrapolation of these results to the remaining islands of the archipelago, i.e. the first value must be used for the eastern islands, while for the central and western islands the acceptable ΔR value is 0 ± 35 14C yr.
Evidence for Late Polynesian Colonization of New Zealand: University of Waikato Radiocarbon Measurements
Authors: Higham T. F. G. , Hogg A. G.
Published: July 2016

We present radiocarbon determinations for 271 New Zealand archaeological samples measured at the University of Waikato Radiocarbon Dating Laboratory between 1975 and 1995. A discard protocol is applied to the series and the list culled to winnow the acceptable dates from those that may incorporate error. None of the 221 acceptable 14C determinations older than 600 bp (in the case of terrestrial samples) or 930 bp (in the case of marine and estuarine shell) extends beyond cal ad 1250. This conclusion supports the short chronology model of New Zealand prehistory presented by Anderson (1991).
Letter to the Editor
Authors: Gove H. E.
Published: July 2016

Dear Editor,

Professor R. E. Taylor, in his review for R adiocarbon of my book Relic, Icon or Hoax? Carbon Dating the Turin Shroud (Taylor 1997) noted that I had incorrectly used the word “invent” and its derivatives in connection with the origins of accelerator mass spectrometry (AMS). A more accurate description of the development of AMS is to be found in the papers that I co-authored (Gove, Litherland and Purser 1987) and authored (Gove 1992) prior to publication of my book. Who actually “invented” AMS is not clear. Certainly, strong contenders are L. W. Alvarez and R. Cornog (Alvarez and Cornog 1939) and K. H. Purser (Purser 1977). The contributions made by Purser, A. E. Litherland and me to the development of AMS were recognized by Pergamon Press in 1980 when the Board of Editors of the International Journal of Applied Radiation and Isotopes (JARI) voted to give us the first JARI award. I should note that neither of my two colleagues with whom I was involved in the development of AMS, Professor Litherland nor Dr. Purser, saw a copy of my book before publication. If they had, this unintended contretemps would not have occurred.

Yours sincerely,
Reassessing Human Settlement on the South Coast of San Miguel Island, California: The Use of 14C Dating as a Reconnaissance Tool
Authors: Braje Todd J , Erlandson Jon M , Rick Torben C
Published: July 2016

California's San Miguel Island contains over 600 archaeological sites, some occupied as early as 12,000 yr ago and most located along the island's north coast. Archaeologists have long believed the south coast to have been marginal or largely uninhabited. Burial of some landforms by sand dunes deposited after historical overgrazing, the lack of systematic survey, and a dearth of radiocarbon dating have also contributed to an underestimation of the intensity of human land use along the south coast of San Miguel Island. Our recent reconnaissance and dating of shell middens on the island's south coast indicate more intensive occupation than previously thought, with numerous south coast sites spanning at least the past 9000 yr, and demonstrate the utility of combining systematic archaeological reconnaissance and radiometrics in reconstructions of human settlement and historical ecology in coastal environments.
Radiocarbon Updates
Authors: Morlan Richard E
Published: July 2016

New Laboratory

A new laboratory has opened in Miami, Florida. Ronald Hatfield and Darden Hood are the Directors of BIOCAMS International, which provides “AMS dating designed exclusively for art, antiques, and materials of potential commercial value”. See http:/www.biocams.com/ for details.
Comparisons and Interpretations of Charcoal and Organic Matter Radiocarbon Ages from Buried Soils in North-Central Colorado, USA
Authors: Mayer James H , Burr George S , Holliday Vance T
Published: July 2016

The reliability of radiocarbon ages based on soil organic matter (SOM) from Holocene buried soils in Middle Park, Colorado, is assessed by comparison with ages of charcoal. On average,14C ages of SOM from buried surface horizons are 880 ± 23014C yr younger than charcoal ages from the same horizon. Humic acid (HA) and low-temperature (400 °) combustion residue (LT) fractions are 390 ± 230 and 1290 ± 23014C yr younger than charcoal ages, respectively, and HA ages are on average 860 ± 14014C yr older than LT fractions. We interpret the offsets between14C ages of charcoal and SOM fractions and the consistent offsets between the HA and LT fractions to reflect the duration of pedogenesis and different residence times of the SOM fractions examined here. The stratigraphic coherence of charcoal14C ages suggests short residence time on the landscape, with little subsequent reworking.14C ages of HA and LT fractions are complimentary to charcoal, and HA ages are interpreted to represent minimum ages for the onset of pedogenesis and LT ages are considered maximum ages for burial. The14C chronology from buried soils indicates an episode of hillslope erosion in Middle Park during the early Holocene, followed by a long period of land surface stability and soil formation between 9000–4500 BP. Two episodes of late Holocene hillslope erosion between 3500–2500 and 1000–500 BP correspond with warming recognized in the Colorado Front Range, while surface stability and soil formation between 2500–1000 BP is contemporaneous with evidence for cooling at higher elevations.
Sample Dilution for AMS 14C Analysis of Small Samples (30–150 μg C)
Authors: de Rooij M , van der Plicht J , Meijer H A J
Published: July 2016

We investigated sample dilution as a technique for accelerator mass spectrometry (AMS) radiocarbon analysis of very small samples (down to 30 μg). By diluting such samples up to a total weight of 200 μg, we can still perform reliable AMS measurements and improve the success rate significantly for targets that are difficult to measure. A disadvantage of this dilution technique is a loss of measurement precision. In addition, calculations of the 14C/12C isotope ratios and the uncertainties therein are not straightforward because of peculiarities in isotope fractionation processes in the AMS system. Therefore, to make sample dilution a routine method in our laboratory, we did extensive theoretical and experimental research to find the optimum conditions for all relevant parameters. Here, we report on the first detailed study dealing with all aspects of sample dilution. Our results can be applied in general. As an illustrative test case, we analyze 14C data for CO2 extracted from an ice core, from which samples of 35 μg C or less are available.
14C Dating of Cremated Bones: The Issue of Sample Contamination
Authors: van Strydonck Mark , Boudin Mathieu , De Mulder Guy
Published: July 2016

Recent comparative studies have proven the validity of radiocarbon dates of cremated bones. The issue of sample contamination has, however, been overlooked in most studies. Analyses of cremated bone samples has shown that in some cases, cremated bones are contaminated. This contamination is more distinct near the surface of the bones and depends on the compactness of the cremated bone as well as on the site conditions. δ13C is not a good estimator to discriminate between contaminated and uncontaminated bones. An acetic acid pretreatment is the most appropriate method to clean samples, but it is better to remove the surface and to avoid cremated bones that are not entirely white (cremation temp. <725 °).
AMS Radiocarbon Dating of Paleolithic-Aged Charcoal from Europe and the Mediterranean Rim Using ABOx-SC
Authors: Brock F , Higham T F G
Published: July 2016

Radiocarbon dating of charcoal >25–30 kyr can be problematic due to contamination from exogeneous carbon and the variable effectiveness of 14C pretreatments to remove it. Bird et al. (1999) developed the ABOx-SC (acid-base-oxidation-stepped combustion) method for removing contaminants from older charcoal samples, which involves a harsher treatment than traditional acid-base-acid (ABA) pretreatments. This method has been shown to considerably improve the reliability of dating old charcoal from sites in Australia, South Africa, Brazil, and Malaysia (Bird et al. 1999, 2003; Turney et al. 2001; Santos et al. 2003; Higham et al. 2009a). Here, we apply the technique to material from 5 Paleolithic sites from Europe and the Mediterranean Rim. For 2 of the sites (Kebara Cave, Israel and Taramsa Hill, Egypt), the ABOx-SC and ABA methods produced similar dates. However, in the case of 1 site, the Grotta di Fumane in Italy, ABOx-SC pretreatment produced significantly older results from those of ABA methods, requiring substantial reinterpretation of the archaeological sequence of the site. The rigorous nature of the technique resulted in a high failure rate for sample pretreatment, and insufficient material survived the pretreatment for dating from Grotte des Pigeons, Morocco or Gorham's Cave, Gibraltar.
The Impact of Holocene Climate on the Development of Prehistoric Societies in Southern Siberia
Authors: Kulkova Marianna , Krasnienko Sergey
Published: July 2016

Geochemical data of 10Be, 14C, δ18O obtained from natural archives (tree rings, ice sheets, varves, corals) indicates that the climate during the Holocene was not stable. The cosmogenic isotope fluctuations are bound by the periodicity on solar activity and climatic changes. The sharpest and most abrupt climatic deteriorations are registered in the Early and Middle Holocene at 8200, 5800, 5400, 4300, and 2800 cal BP. These events are characterized by cold conditions. The impact of climate on human communities in steppe depressions in southern Siberia (Nazarovo, Minusinsk, and Turano-Uyuk) was noticeable. The differences of local landscape-climatic conditions in these depressions were connected with global climatic changes to determine the processes of occupation, development, and migrations of ancient societies during the Neolithic, Bronze Age, and Iron Age. The chronology of archaeological cultures was also correlated with the local and global climatic changes during the Early and Middle Holocene in southern Siberia. Here, we generalize the literature data about Holocene climatic changes and archaeological cultures in the southern Siberia region.
The Application of ICELS Systems for Radiocarbon Dating
Authors: Tudyka Konrad , Pazdur Anna , Theodórsson Páll , Michczyński Adam , Pawlyta Jacek
Published: July 2016

Liquid scintillation counting (LSC) for radiocarbon dating is a less expensive method than accelerator mass spectrometry (AMS), provides a high degree of accuracy, and is less prone to contamination due to the larger sample sizes. However, to obtain high precision, a long counting time is needed. The Gliwice Radiocarbon Laboratory is seeking to obtain an increased counting capacity with 2–3 mL benzene samples than we presently can achieve with our 2 Quantulus systems. We are therefore investigating the possibility of using a simple, single-phototube LS system (ICELS) for dating samples younger than 5000 yr. We present the first results of this investigation, including the measurement of 3 VIRI and 3 FIRI intercomparison samples.
Marine Radiocarbon Reservoir Effect of Coastal Waters Off Cape Verde Archipelago
Authors: Soares António M Monge , Martins José M Matos , Luís Cardoso João
Published: July 2016

Quantification of the marine radiocarbon reservoir effect (ΔR) is essential in order to calibrate conventional 14C dates from marine shell samples with reliability. ΔR also provides information concerning the intensity of coastal upwelling in marine regions influenced by this phenomenon. 14C ages of closely associated marine samples (mollusk shells) and terrestrial samples (goat bones) from São Vicente Island, Cape Verde Archipelago, permitted the first calculation of the marine 14C reservoir effect in this region. A ΔR weighted mean value of 70 ± 70 14C yr was obtained. This value is in accordance with the previously published oceanographic conditions of the region indicating the existence of a seasonal active upwelling regime.
Evidence for a Solar Flare Cause of the Pleistocene Mass Extinction
Authors: LaViolette Paul A
Published: July 2016

The hypothesis is presented that an abrupt rise in atmospheric radiocarbon concentration evident in the Cariaco Basin varve record at 12,837 ± 10 cal yr BP, contemporaneous with the Rancholabrean termination, may have been produced by a super-sized solar proton event (SPE) having a fluence of ~1.3 × 1011 protons/cm2. A SPE of this magnitude would have been large enough to deliver a lethal radiation dose of at least 3–6 Sv to the Earth's surface, and hence could have been a principal cause of the final termination of the Pleistocene megafauna and several genera of smaller mammals and birds. The event time-correlates with a large-magnitude acidity spike found at 1708.65 m in the GISP2 Greenland ice record, which is associated with high NO-3 ion concentrations and a rapid rise in 10Be deposition rate, all of which are indicators of a sudden cosmicray influx. The depletion of nitrate ions within this acidic ice layer suggests that the snowpack surface at that time was exposed to intense UV for a prolonged period, which is consistent with a temporary destruction of the polar ozone layer by solar cosmic rays. The acidity event also coincides with a large-magnitude, abrupt climatic excursion and is associated with elevated ammonium ion concentrations, an indicator of global fires.
University of Waikato Radiocarbon Dates I
Authors: Hogg Alan G , Lowe David J , Hendy Chris H
Published: July 2016

The radiocarbon dating laboratory at Waikato was established in 1975, primarily as a research tool in the fields of geomorphology, volcanology, tephrostratigraphy, coastal studies, and paleolimnology, to cope with the increasing supply of late Quaternary lake sediment, wood, peat, and shell samples submitted by University staff and postgraduate students undertaking research in the North Island of New Zealand. The method employed is scintillation counting of benzene using the procedures and vacuum systems designed by H A Polach for the Australian National University (ANU) Radiocarbon Dating Research Laboratory (Hogg, 1982). This date list reports on samples submitted by University of Waikato researchers and assayed in the Waikato laboratory mainly between 1979 and 1985. Other dates on material submitted by individuals working in other organizations in New Zealand, and overseas, are to be reported later.
Preparation of Small Samples for 14C Accelerator Targets by Catalytic Reduction of CO
Authors: Slota P J , Jull A J T , Linick T W , Toolin L J
Published: July 2016

Graphite in various forms has become the standard target for accelerator 14C dating. Graphite has been made by catalytic graphitization of charcoals (Lowe, 1984). Thin films of graphite have also been produced by thermal cracking (Beukens & Lee, 1981), electric discharge (Andrée et al, 1984; Wand, Gillespie & Hedges, 1984). Vogel et al (1984) pointed out the ease of graphite formation on iron from CO2 and H2 mixtures at ca 600°C. The deposition reactions of carbon from the CO, H2, and CO2 equilibria are well known (Wagman et al, 1945) and well studied. Formation of graphite from CO2 was discussed extensively by Boudouard (1902) and Schenck and Zimmerman (1903), and was known to chemists in France in 1851. We have used a related method, where graphite forms away from the iron, by using a higher temperature, and reduction of CO2 to CO over Zn in the presence of H2 (Jull et al, 1986) as an alternative to the use of Fe alone. The object of this paper is to point out an even simpler graphite preparation system, which eliminates hydrogen. The decomposition reaction of CO (Boudouard, 1902) takes place according to reaction (1).