bluuebunny/crossref_metadata_2025 huggingface dataset:
National Physical Laboratory Radiocarbon Measurements V
Authors: Callow W. J. , Hassall Geraldine I.
Published: July 2016

The following list comprises measurements made since those reported in NPL IV.

No changes have been made in measurement technique or in the method of calculating results
Nancy Natural Radiocarbon Measurements 1
Authors: Coppens R. , Durand G. L. A. , Guillet B.
Published: July 2016

This paper is a list of the first results of age determinations made at the Centre de Recherches Radiogéologiques de Nancy (CRR). The Center is the result of a convention between the Commissariat à l'Energie Atomique (CEA) and the University of Nancy. It is part of a group of research laboratories of Earth Sciences headed by Prof. M. Roubault.
University of Tokyo Radiocarbon Measurements I
Authors: Sato Jun , Sato Tomoko , Suzuki Hisashi
Published: July 2016

The University of Tokyo Carbon Dating Laboratory was established to meet the requirements for dating materials from various fields of science at the university. Installation and testing of the apparatus as well as routine assays have been carried out with counsel of Dr. Nobufusa Saito, Professor of Chemistry, and Dr. Yozo Nogami, Professor of Physics, the University of Tokyo. Management of the laboratory is undertaken by the Carbon Dating Committee of he University of Tokyo. The laboratory has actually been working for a year. This article reports the radiocarbon age measurements made from September 1966 to July 1967, together with a brief description of the measuring system.
UCLA Radiocarbon Dates VII
Authors: Berger Rainer , Libby W. F.
Published: July 2016

The measurements reported have been carried out during the first half of 1967 in the Isotope Laboratory of the Institute of Geophysics and Planetary Physics as a continuation of the UCLA date lists I through VI. Samples were analyzed as CO2-gas at close to one atm in a 7.5 L proportional counter with 3 energy channels described earlier. Radiocarbon ages have been calculated for uniformity on the basis of a 5568-yr half-life as was recommended by the Sixth International C14 and H3 Dating Conference, June 1965, in Pullman, Washington. The standard for the contemporary biosphere remains as 95% of the count rate of NBS oxalic acid for radiocarbon laboratories. Background determinations have been based on CO2 obtained from marble. The error listed is always at least a 1σ statistical counting error. In critical cases C13/C12 isotope ratio measurements were made to correct the dates for fractionation. All samples were subjected to accepted NaOH and/or HCl pretreatments depending on the individual case as a minimum to exclude contamination. The annual curve for the atmospheric C14 content at China Lake, California, will be published in the next date list.
Ksu Radiocarbon Dates I
Authors: Yamada Osamu , Kobashigawa Akira
Published: July 2016

It was T Higashimura of Kyoto University who did the first liquid scintillation measurement for 14C in Japan. The External Standard Method (Higashimura et al, 1962) has been accepted the world over as an efficient method of measuring low-level radiation.
Pretoria Radiocarbon Dates III
Authors: Vogel J C , Fuls Annemarie , Visser Ebbie
Published: July 2016

This list contains 14C dates pertaining to the Stone Age in southern Africa and covers the region from Zambia in the north to Natal and the northern Cape Province in South Africa. The southern and southwestern Cape Province are not included. Descriptions are based on information supplied by the submitters.
University of Granada Radiocarbon Dates III
Authors: Gonzalez-Gomez Cecilio , Sanchez-Sanchez Purificacion , Villafranca-Sanchez Elena
Published: July 2016

The following list includes some measurements made from December 1982 to May 1985 in the Radiocarbon Dating Laboratory, Faculty of Science, University of Granada, of samples from Spain, Portugal, and the Sudan. Sample preparation techniques and benzene synthesis remain as described previously (R, 1982, v 24, p 217–221) and equipment and measurement of samples was also reported previously (R, 1985, v 27, p 610–615). Radiocarbon ages are calculated using the 14C half-life of 5570 years and 0.95 activity of NBS oxalic acid is used as modern standard. Sample descriptions are based on information provided by submitters. Age determinations were made with the help of Research Project 0925/81, CAICYT, Spain.
A Discussion of An Alternate Approach to the Evaluation of Sample Contamination
Authors: Gurfinkel D M
Published: July 2016

An approach to the evaluation of sample contamination based on the monitoring of contaminant removal during pretreatment is described. Spot tests and colorimetric reactions which could be adapted for this purpose are suggested.
Cambridge University Natural Radiocarbon Measurements I
Authors: Godwin H. , Willis E. H.
Published: July 2016

The dates given have been obtained up to the end of December, 1958. They have been made with carbon dioxide at 2 atmospheres pressure in a proportional counter of about 2-liter volume. For further details of construction and procedure, see Godwin, Walker, and Willis, 1957. The establishment of the project was made possible by a grant from the Trustees of the Nuffield Foundation, whom we are most happy to thank along with the Imperial Smelting Corporation who have lent us the zinc shielding for the gas-counter.
A Bibliography of Radiocarbon Dating
Authors: Johnson Frederick
Published: July 2016

The scope of the problems which are involved in the determination of radiocarbon dates renders complete, or detailed, classification of the published results of the research most complicated. In assembling this bibliography several such classifications were discarded before the present simplified one emerged. It was found, for example, that in a detailed classification of subject titles a large number of papers would have to be listed under several, sometimes as many as four, different headings. This complicated and lengthened the listing and also materially increased the chance of inaccurately locating a title. In such an event it would be “lost” to all but the most meticulous searcher. The reduction in the number of subject headings is open to criticism. We suspect, however, that these are answered by the simplicity of the present outline.
Bern Radiocarbon Dates II
Authors: Gfeller Chr. , Oeschger H. , Schwarz U.
Published: July 2016

This list covers measurements made at the Radiocarbon Dating Laboratory, Physics Department, University of Bern, from spring, 1959, until summer, 1960. We have now two low-level counters working (Houtermans and Oeschger, 1958).
Cambridge University Natural Radiocarbon Measurements IV: Nuclear-Weapon Testing and the Atmospheric Radiocarbon Concentration
Authors: Godwin H. , Willis E. H.
Published: July 2016

In continuance of investigations upon successive annual crops of oats reported in Radiocarbon Supplement, Volume 2, we undertook the analysis of successive annual rings of a tree that had been growing throughout the period covered by the oat-crop assays, namely 1953 to 1959. The selected tree was a straight-boled specimen of Populus nigra from the Forestry Commission's plantations at Santon Downham, near Thetford, Norfolk. It had been planted in 1929 and was felled on 21 October, 1959. Shortly afterwards, it was brought into the laboratory and sawn into slices just over 1 in. thick. The surfaces having been smoothed, the annual-ring contacts were marked, and within each annual ring the inner (spring) wood was marked off from the outer (autumn) wood. The tree had been chosen as one exhibiting rapid growth and it proved fairly easy to dissect off with a chisel all the separate half-rings between spring 1953 and the end of 1959. In the event, activities were determined only upon four of the half or whole rings.
Reservoir Ages in Eastern Pacific Coastal and Estuarine Waters
Authors: Ingram B. Lynn , Southon John R.
Published: July 2016

We have refined marine reservoir age estimates for eastern Pacific coastal waters with radiocarbon measurements of mollusk shells collected prior to 1950. We have also investigated interspecific variability in 14C ages for historic and ancient shells from San Francisco Bay.
AMS Radiocarbon Measurements from the Swedish Varved Clays
Authors: Wohlfarth Barbara , Possnert Göran
Published: July 2016

The Swedish varve chronology, or Swedish Time Scale, is an annual chronology based upon the successive correlation of more than 1000 varve-thickness diagrams. The Late Glacial-Early Holocene varved clays were deposited as glaciolacustrine sediments in the Baltic Sea during the recession of the Scandinavian ice sheet. Formation of varved clays continued throughout the Holocene and is still going on in the estuary of River ångermanälven in northern Sweden. Accelerator mass spectrometry (AMS) radiocarbon measurements, which have been performed on terrestrial plant macrofossils extracted from the varved clays, show—in comparison with other annual chronologies—that several hundreds of varve years are missing in the varve chronology. These findings are supported by, among others, pollen stratigraphic investigations on time-equivalent varve year intervals. If an effort were undertaken to evaluate the erroneous parts, the Swedish Time Scale would have the potential of becoming a continuous annual chronology.
Radiocarbon Calibration by Means of Varves Versus 14C Ages of Terrestrial Macrofossils from Lake Gościąż and Lake Perespilno, Poland
Authors: Goslar Tomasz , Arnold Maurice , Tisnerat-Laborde Nadine , Hatté Christine , Paterne Martine , Ralska-Jasiewiczowa Magdalena
Published: July 2016

This paper presents radiocarbon dates of terrestrial macrofossils from Lakes Gościąż and Perespilno, Poland. These data agree very well with most of the German pine calibration curve. In the Late Glacial, they generally agree with the data from Lake Suigetsu, Japan, and indicate constant or even increasing 14C age between 12.9 and 12.7 ka BP, rapid decline of 14C age around 12.6 ka BP, and a long plateau 10,400 14C BP around 12 ka BP. Correlation with corals and data from the Cariaco basin seems to support the concept of site-speficic, constant values of reservoir correction, in contradiction to those introduced in the INTCAL98 calibration. Around the Allerød/Younger Dryas boundary our data strongly disagree with those from the Cariaco basin, which reflects large discrepancy between calendar chronologies at that period. The older sequence from Lake Perespilno indicates two periods of rapid decline in 14C age, around 14.2 and 13.9 ka BP.
Last Ice Age Millennial Scale Climate Changes Recorded in Huon Peninsula Corals
Authors: Yokoyama Yusuke , Esat Tezer M , Lambeck Kurt , Keith Fifield L
Published: July 2016

Uranium series and radiocarbon ages were measured in corals from the uplifted coral terraces of Huon Peninsula (HP), Papua New Guinea, to provide a calibration for the 14C time scale beyond 30 ka (kilo annum). Improved analytical procedures, and quantitative criteria for sample selection, helped discriminate diagenetically altered samples. The base-line of the calibration curve follows the trend of increasing divergence from calendar ages, as established by previous studies. Superimposed on this trend, four well-defined peaks of excess atmospheric radiocarbon were found ranging in magnitude from 100% to 700%, relative to current levels. They are related to episodes of sea-level rise and reef growth at HP. These peaks appear to be synchronous with Heinrich Events and concentrations of ice-rafted debris found in North Atlantic deep-sea cores. Relative timing of sea-level rise and atmospheric 14C excess imply the following sequence of events: An initial sea-level high is followed by a large increase in atmospheric 14C as the sea-level subsides. Over about 1800 years, the atmospheric radiocarbon drops to below present ambient levels. This cycle bears a close resemblance to ice-calving episodes of Dansgaard-Oeschger and Bond cycles and the slow-down or complete interruption of the North Atlantic thermohaline circulation. The increases in the atmospheric 14C levels are attributed to the cessation of the North Atlantic circulation.
Radiocarbon Dating of Holocene Sediments: Flood Events and Evolution of the Labe (Elbe) River in Central Bohemia (Czech Republic)
Authors: Jílek Pavel , Melková Jaroslava , Růžičková Eliška , Šilar Jan , Zeman Antonín
Published: July 2016

We studied the structure and development of the Holocene floodplain of the Labe (Elbe) River by radiocarbon dating sections of the upper and middle courses of the river. We focused on geomorphological and sedimentological conditions, mineralogy and the chemical composition of sediments. We established the stratigraphy of the Holocene deposits of the floodplain. The results of our investigation of fluvial sediments imply that several abrupt changes in temperature and precipitation occurred during the Holocene. These changes led to intervals of hydrological disequilibrium, which caused the formation of two Holocene terraces and a contemporaneous floodplain. The lower terrace was flooded and covered with sediments upon which the recent floodplain formed. During the Holocene, there were four periods during which large tree trunks were deposited in the fluvial sediments, indicating periods of extensive flooding. The supposition that these events were of more global scale is supported by the results of investigations made on the Holocene floodplains of other regions.
Radiocarbon Dating Recent Volcanic Activity on Faial Island (Azores)
Authors: Madeira José , Monge Soares A.M. , Brum Da Silveira António , Serralheiro António
Published: July 2016

Recent fieldwork on the island of Faial (Azores) led to the establishment of a detailed volcanic stratigraphic sequence, which is composed of five main geological formations. One of them, the Caldeira Formation, comprising mainly pumice fall and flow deposits, was judged to be Holocene in age. Organic materials were found preserved in or below some of the pyroclastic deposits from this formation. Wood, charcoal, peat and soil samples were radiocarbon dated, permitting correlation of deposits from different sequences and the establishment of a chronological framework for the Caldeira volcanic activity. These materials yielded ages from ca. 10–1 ka bp. The average dormant interval in the Caldeira pyroclastic activity from 4–1 ka ago is ca. 400 yr, with eruptions approximately every 200–800 yr. This frequency of activity indicates that the Caldeira volcano is an active, dangerous structure that should be closely monitored.
Radiocarbon Dates of the Earliest Neolithic in Central Europe
Authors: Stäuble Harald
Published: July 2016

I discuss here a series of radiocarbon dates from sites of the earliest phase of the Linearbandkeramik (LBK) culture. The samples were collected during excavations directed by Prof. Jens Lüning (Frankfurt am Main) between 1979 and 1987. The samples were mainly charcoal, including cereals and food remains, but bones and potsherds containing organic temper were also included in the study. Although the results on cereal, bone and food remains were consistent, almost all differed from those measured on charred wood. From a series of dates measured by accelerator mass spectrometry (AMS) on organic temper in potsherds, variable amounts of sample contamination were observed, probably deriving from the natural organic components of the clay used in the ceramic production. By critically evaluating 14C dates, individual activities on the sites were dated as accurately as possible. A chronological framework could then be established for the earliest phase of the LBK culture. The dating results provided information on taphonomic processes.
14C AMS Dating the Transition from the Paleolithic to the Neolithic in South China
Authors: Yuan Sixun , Zhou Guoxing , Guo Zhiyu , Zhang Zimo , Gao Shijun , Li Kun , Wang Jiangjun , Liu Kexing , Li Bin , Lu Xiangyang
Published: July 2016

To study the transition from the Paleolithic to the Neolithic period and its duration, samples of charcoal, bone, flowstone and shells excavated from Bailiandong and Miaoyan caves, Guangxi Zhuang autonomous region, South China were dated using the Peking University AMS facility and liquid scintillation counter. The remains excavated from these sites show typical characteristics of the transition from the Paleolithic to the Neolithic. Radiocarbon dating results show a rapid transition from ca. 20 to 10 ka bp.
Evidence for a Lost Millennium in Biblical Chronology
Authors: Aardsma G. E.
Published: July 2016

Biblical and secular data seem to tell entirely different stories about Near Eastern history prior to the first millennium bc. Most modern critical scholars in Bible-related fields regard this as proof of the nonhistoricity of the premonarchical biblical narrative. However, the incongruity between biblical and secular data seems also to be explainable by the postulate that exactly 1000 yr were accidentally dropped from traditional biblical chronology just prior to the first millennium bc. I evaluate this postulate relative to extra-biblical data for the exodus, Joseph's famine and Lot's observation that the Jordan valley was “well watered” in his day. The repeated success of this postulate in integrating much archaeological, historical and geophysical data with the biblical narrative offers support for the historicity of the premonarchical biblical narrative. Biblical chronology, when corrected by the restoration of the lost 1000 yr, promises to reduce present uncertainties in secular historical chronologies in the 3rd and 4th millennia bc by at least an order of magnitude.
Is Tooth Enamel Carbonate a Suitable Material for Radiocarbon Dating?
Authors: Hedges R. E. M. , Lee-Thorp J.A. , Tuross N. C.
Published: July 2016

We present the results of 18 radiocarbon determinations on the carbonate fraction of tooth enamel prepared from nine separate teeth. The known ages of the teeth vary from 11 to >200 ka bp, and are from three sites. The sample preparation procedures varied somewhat, but were broadly based on procedures found to give satisfactory results on carbon stable isotope measurements. All the 14C dates obtained are too young, by an equivalent contamination of ca. 6% Modern (pMC). This value is fairly consistent despite variations in sample preparation. We discuss the implications for using enamel as a possible alternative to bone when insufficient collagen is available.
Problems in Dating Stone-Age Settlements on Sandy Soils: The Hof Ten Damme Site Near Melsele, Belgium
Authors: Van Strydonck Mark J. Y. , Van Roeyen Jean-Pierre , Minnaert Guido , Verbruggen Cyriel
Published: July 2016

Archaeological sites on sandy soils often suffer from dislocation of artifacts and datable materials. Because stratigraphy and context lose their meaning in such cases, all 14C dates in this study were put in a dispersion diagram regardless of the sample origin. We drew conclusions about the chronology of the site by comparing this diagram with archaeological analysis of the artifacts and the evolution of the landscape. The dating series, as well as the archaeological analysis, suggest several occupation phases. In general, the archaeological chronology agrees with the 14C dates, although the two can be equated only with caution.
A Computer-Based Database for Radiocarbon Dates of Central Andean Archaeology
Authors: Michczyński Adam , Krzanowski Andrzej , Pazdur Mieczysław F. , Ziołkowski Mariusz S.
Published: July 2016

We established a database of 14C dates from archaeological sites of the Central Andes region of Peru, Ecuador and Bolivia on an IBM PC-compatible microcomputer running on an MS-DOS operating system using software package dBASE IV, version 1.1. Relevant data are stored in three DBF-type database files. The file ANDY.DBF contains information on dates and samples; REFERENC.DBF contains references to relevant publications and CALAND.DBF contains calibrated dates. The total number of records of the ANDY database slightly exceeds 2650.
AMS 14C Dating of Varved Sediments from Lake Suigetsu, Central Japan and Atmospheric 14C Change During the Late Pleistocene
Authors: Kitagawa Hiroyuki , Fukuzawa Hitoshi , Nakamura Toshio , Okamura Makoto , Takemura Keiji , Hayashida Akira , Yasuda Yoshinori
Published: July 2016

We made accelerator mass spectrometry (AMS) 14C measurements on terrestrial macrofossils from the Late Pleistocene/Holocene of the annually laminated sediments of Lake Suigetsu (central Japan). The AMS 14C dates of terrestrial macrofossils showed agreement between varve counting years and calibrated ages (tree rings and U/Th on coral) in the interval of 10.5 and ca. 11.5 ka cal bp. Beyond 11.5 ka cal bp, the age difference between 14C and varve counting years gradually diminish, contradicting published data on corals dated by U/Th and 14C.
Location-Dependent Differences in the 14C Content of Wood
Authors: McCormac F. G. , Baillie M. G. L. , Pilcher J. R. , Kalin R. M.
Published: July 2016

The long 14C chronologies currently used as calibration curves combine results from wood that grew in the western United States, the British Isles and Germany. Although these results show few significant differences in the 14C content of contemporaneous wood when averaged over the length of the chronology (i.e., the means of overlapping sections of chronology are the same), closer examination shows considerable variability. Separating the sections of chronology according to the provenance of the wood used for calibration reveals patterns that suggest small but finite differences in the 14C content of wood from different locations. We conclude that there is some evidence that German and American wood give dates older by between 20 and 40 yr from those of Irish oak for some periods. Additionally we suggest that the shift of the Belfast 1986 calibration data by ca. 18 yr toward older dates may not be valid and that the resultant offset between the Belfast 1986 and Seattle 1993 data shows a small but real difference in the 14C content of contemporaneous American, German and Irish wood. Intralaboratory measurements made in Belfast on contemporaneous German and Irish oak, and bristlecone pine and Irish oak, give offsets of 39 and 41 yr, respectively, with the Irish oak dating younger. Previous studies, in which sample pairs of American and English and French wood were processed in the same laboratory, also showed American wood to be slightly depleted in 14C. None of the findings of this study would significantly alter calibrated 14C dates.
Stratified14C Dates and Ceramic Chronologies: Case Studies for the Early Bronze Age at Troy (Turkey) and Ezero (Bulgaria)
Authors: Weninger Bernhard
Published: July 2016

Prehistoric tell stratigraphies, like deep-sea sediments or peat deposits, store information about past atmospheric14C variations. By matching the14C ages on charcoal samples from settlement deposits with the tree-ring calibration curve, estimates for the time span covered by successive stratigraphic phases can be derived. This method is applied to14C data from the tell mounds at Troy, Turkey and Ezero, Bulgaria. I compare the derived chronologies with the results of pottery shape seriation using correspondence analysis.
Radiocarbon Concentration and Origin of Thermal Karst Waters in the Region of the Bükk Mountains, Northeastern Hungary
Authors: Hertelendi Ede , Veres Mihály , Futó István , Svingor Éva , Mikó Lajos , Lénárt László , Deák József , Süveges Miklós
Published: July 2016

Karst springs are abundant in Hungary, and many are thermal (temperatures >30°). As thermal springs are a significant part of Hungary's water resources, it is important to quantify their travel times in the karst systems. Thus, we chose to measure T and δ18O in the water and δ13C and 14C in dissolved inorganic carbon (DIC) in water from 50 thermal and nonthermal springs and wells in the Bükk Mountains, northeastern Hungary. Environmental isotope data confirm the karst water-flow pattern implied by earlier studies. We found the water in warm springs and boreholes to be mixtures of cold young and old thermal water. We also determined short mean-residence times for some large cold springs. The 14C activities measured in these springs indicate that the recharge area of the karst aquifer is open to the atmosphere, and atmospheric CO2 contributes to the 14C activity of these groundwaters. We observed good correlation between 14C and 3H activities and we determined negative correlations between 14C concentration and δ13C values and temperature. From the δ18O values of the oldest thermal waters, we attribute their origin to precipitation during colder temperatures than at present.
AMS Radiocarbon Dating of Ancient Oriental Iron Artifacts at Nagoya University
Authors: Nakamura Toshio , Hirasawa Masahiro , Igaki Kenzo
Published: July 2016

We present here the current status of AMS dating of iron artifacts at Nagoya University. We initially developed a “wet” method of carbon collection from iron samples, consisting of a resistance furnace and a “wet” trapping of the evolved CO2 with a saturated Ca(OH)2 solution, in which overall collection efficiency of carbon ranged from 50 to 60%. To improve the carbon-collection efficiency, we more recently constructed a “dry” system, consisting of an induction furnace followed by “dry” separation of the produced CO2 from combustion gases and conversion of the CO2 into a graphite target. We describe here mainly the performance of the “dry” separation system, tested using standard steel samples. We also report previously determined 14C dates on three ancient Oriental artifacts using the earlier “wet” procedure.
Application of AMS 14C Dating to Ice Core Research
Authors: Wilson A T.
Published: July 2016

I describe here the use of the accelerator mass spectrometer (AMS) sublimation technique to 14C-date polar ice cores. An unexpected result of this work has been to extend the understanding of how polar ice sheets entrap and record the past composition of the Earth's atmosphere. This work has led to the discovery of a new phenomenon in which CO2 and other greenhouse gases can be entrapped in cold (never melted) polar ice sheets.
First Results from the Groningen AMS Facility
Authors: Van Der Plicht Johannes , Aerts Anita , Wijma Stef , Zondervan Albert
Published: July 2016

A new generation accelerator mass spectrometer has been installed at the Centre for Isotope Research in Groningen, The Netherlands. It is a dedicated 14C machine, with a capacity of measuring 3000 samples per year with high precision (< 0.5%). The system has been in full operation since the summer of 1994. We present here a short summary of the results and performance obtained thus far.
Breakthrough of the Mini-Cyclotron Mass Spectrometer for 14C Analysis
Authors: Chen Maobai , Li Deming , Xu Senlin , Chen Guosheng , Shen Ligong , Lu Xiangshun , Zhang Weiyu , Zhang Yuexiang , Zhong Zongkun , Zhang Yingji
Published: July 2016

We present results of current measurements on the super-sensitive mini-cyclotron as an accelerator mass spectrometer, successfully developed at Shanghai Institute of Nuclear Research (SINR). We describe new ideas and unique techniques adopted for increasing the transmission efficiency in the injection, acceleration and extraction region, for eliminating various backgrounds and for improving the precision of 14C analysis, which have led to the breakthrough of our Shanghai Mini-Cyclotron Accelerator Mass Spectrometry project. We also discuss further development of the prototype facility.
Reduction in Backgrounds of Microsamples for AMS 14C Dating
Authors: Kirner D. L. , Taylor R. E. , Southon John R.
Published: July 2016

Vogel, Nelson and Southon (1987) determined that the total-system 14C background values in catalytically reduced graphitic carbon samples of 500 mg or less were inversely proportional to their weights. We have used wood reportedly of Pliocene age (i.e., 14C “dead”) to further examine this relation. Our observations are consistent with the conclusions of Vogel, Nelson and Southon (1987). It appears that contamination can be characterized as if a constant level of modern carbon is being added. We also report a significant overall net reduction in total system background values ca. 45% for combusted samples from levels previously reported by Vogel, Nelson and Southon (1987).
Intercomparison of High-Precision ∆14C Analyses Using Gas Counting and AMS
Authors: Druffel Ellen R. M. , Donahue Douglas J. , Griffin Sheila , Burr George S.
Published: July 2016

We report results of a three-year intercomparison experiment between the WHOI Radiocarbon Laboratory (now at University of California, Irvine) and the NSF-University of Arizona AMS Laboratory. The purpose of this study was to compare high-precision measurements of samples obtained routinely using gas proportional counting techniques with results obtained using AMS techniques. Three sets of annually banded, modern coral samples were used for the intercomparison. Each sample was acidified to CO2 at WHOI and split into two fractions. The larger fraction was converted to acetylene gas and counted at WHOI in quartz, gas-proportional beta counters. The smaller fractions were converted to graphite and analyzed for 14C using AMS techniques at the University of Arizona. Results of the three sample sets are presented. Except for a single outlier, the data from the two laboratories are in good agreement. Of the 13 samples in the third set of the intercomparison, for which a new high-intensity ion source was in operation at the Arizona AMS laboratory, agreement of results is excellent. This finding indicates that measurements made with precisions of < 3% are reproducible at both laboratories.
Radiocarbon Determinations from the Mulifanua Lapita Site, Upolu, Western Samoa
Authors: Petchey Fiona J
Published: July 2016

The Mulifanua ferry berth has the distinction of being the only site in Samoa with dentate-stamped Lapita wares, and is the most easterly Lapita site in the Pacific. Two new radiocarbon determinations of material associated with Lapita pottery found at Mulifanua are presented. The accuracy of this data is evaluated according to the results of recent reassessment of pottery from the site, and current theories regarding the age of Lapita settlement in the eastern Pacific. The resulting calibrated radiocarbon ages put occupation of the Mulifanua Lapita site at around 2880–2750 cal BP (930–800 BC). This conclusion is in agreement with the pottery chronology and supports recent hypotheses of rapid Lapita settlement in the Fiji/Tonga region around 2850–2700 cal BP (900–750 BC).
Did the Megafauna Range to 4300 BP in South America?
Authors: Cione Alberto L , Figini Aníbal J , Tonni Eduardo P
Published: July 2016

A date of 4300 ± 90 BP for extinct megafauna in Argentina is discussed. The fossil remains come from the Guerrero Member (area) of the Luján Formation near the city of Luján, Buenos Aires Province. The age of the top of the Guerrero Member is constrained by more than 60 radiocarbon dates obtained from the overlying Río Salado Member of Luján Formation, Las Escobas Formation, and Puesto Callejón Viejo Soil, most of them older than 4300 BP. In view of its low collagen content, the14C measurement of bone sample from Luján should not be accepted uncritically. Because of the poor bone preservation and the possible introduction of “young” contaminants that were not completely eliminated, the14C date of 4300 ± 90 BP is not reliable. Both biostratigraphic and14C dating evidence indicates that the date of 4300 BP for the last representative of extinct megafauna in South America is unsupported.
The Effects of Possible Contamination on the Radiocarbon Dating of the Dead Sea Scrolls I: Castor Oil
Authors: Rasmussen Kaare L , van der Plicht Johannes , Cryer Frederick H , Doudna Gregory , Cross Frank M , Strugnell John
Published: July 2016

Some fragments of the Dead Sea Scroll manuscripts were contaminated with castor oil in the late 1950s. We have conducted experiments in order to establish if the AAA pretreatment cleaning procedures conducted on Dead Sea Scroll manuscript samples in the last two dating series (Bonani et al. 1992; Jull et al. 1995) were effective in removing oil contamination. Our experiments show that not all oil contamination can be expected to have been removed by the acid-alkaline-acid (AAA) pretreatment, and that the radiocarbon ages previously reported therefore cannot be guaranteed to be correct. Any samples contaminated with castor oil were most likely reported with ages that are too young by an unknown amount.
Radiocaron Dates and Archaeology of the Late Pleistocene in the Japanese Islands
Authors: Ono Akira , Sato Hiroyuki , Tsutsumi Takashi , Kudo Yuichiro
Published: July 2016

We discuss the radiocarbon chronology of Late Pleistocene archaeology in the Japanese islands. In sum, 429 samples from more than 100 archaeological sites were compiled and then divided into three periods and four stages. The Early Upper Paleolithic, characterized by Trapezoid industries, lasted during approximately 34-26 ka. The Late Upper Paleolithic period includes both the backed-blade stage and point-tool stage, the latter appearing chronologically later than the former. This stage covers ~25–15 ka. The Final Upper Paleolithic and Incipient Jomon are distinguished by the appearance of microblade industries and the emergence of pottery at the end of this period. This period covers approximately 14-12 ka. The microblade tradition, in the broadest sense, is strongly connected to the background of peopling of the New World. New data on the transitional stage from the Middle to the Upper Paleolithic are also discussed in regards to three archaeological sites. Issues on the application of the 14C calibration to the whole Japanese Upper Paleolithic are critically evaluated.
Radiocarbon Dates from the Jewish Catacombs of Rome
Authors: Rutgers Leonard V , De Jong Arie F M , van der Borg Klaas
Published: July 2016

This paper reports on the first chronological assessment of the Jewish Catacombs of the ancient Rome performed by accelerator mass spectrometry (AMS) dating of small-size charcoal fragments scattered in the mortar used for sealing off the graves in the Villa Torlonia Catacomb complex. The significance of the obtained14C readings has been carefully evaluated by taking into consideration the known technologies of quicklime production during Roman and recent times. The new data are of great concern for providing evidence that the Jewish catacombs were used for burial since the first century AD, thus some two centuries prior to the period traditionally believed to be the starting point of burial in the Jewish catacombs of ancient Rome. Such a significant aging of the Jewish catacombs could result in a deep re-examination of the current understanding of the beginning and the evolution of the custom of catacomb burial in both Jewish and early Christian communities in Rome.
Radiocarbon and Stable Isotope Analyses on the Earliest Jomon Skeletons from the Tochibara Rockshelter, Nagano, Japan
Authors: Yoneda Minoru , Hirota Masashi , Uchida Masao , Tanaka Atsushi , Shibata Yasuyuki , Morita Masatoshi , Akazawa Takeru
Published: July 2016

This study presents the results of carbon and nitrogen isotopic analyses of six human skeletons excavated from the Tochibara rockshelter (Nagano, Japan). The human skeletons were reported to be accompanied by “Oshigata-mon” type pottery dating to the Earliest Jomon period (8900 BP ≃ 6600 BP). A radiocarbon determination from charcoal associated with the human remains was reported to be 8650 ± 180 BP (GaK-1056). However, the depositional context of human skeletons was uncertain because they were recovered by excavations that were dug by prescribed levels. Our results indicated that these skeletons date to the Earliest Jomon period; the 14C determinations place these remains between 8260 ± 100 BP (TERRA-b030799ab38) and 8580 ± 100 BP (TERRA-b011300a35). This coincides with the archaeological evidence that these specimens are some of the oldest Jomon skeletal materials. Furthermore, δ13C and δ15N values provide evidence for the first reconstruction of the diet of an inland Earliest Jomon population. Although the distribution of data indicated a possibility that they had exploited small amounts of seafood, the isotopic data point to this group having relied heavily on a terrestrial ecosystem based on C3 plants.
Pre-Bomb Radiocarbon Variability Inferred from a Kenyan Coral Record
Authors: Grumet Nancy S , Guilderson Thomas P , Dunbar Robert B
Published: July 2016

We report results from AMS radiocarbon measurements (δ14C) in corals recovered off the coast of Kenya. Bimonthly samples which span the pre-bomb era average −51 (±3.7; n=43), when age and Suess effect are corrected, and over the time of interest (1946–1954) do not exhibit any discernible seasonality. Relative to regional pre-bomb δ14C values in the western Indian Ocean, our results indicate 14C enrichment off the coast of Kenya. Furthermore, the absence of a distinct subannual δ14C signal suggests that open and coastal upwelling is negligible off the coast of Kenya. Unlike pre-bomb values south of the equator near Seychelles and Madagascar, our pre-bomb value are enriched by more than 10. The enrichment of pre-bomb Kenyan δ14C values relative to sites around Mauritius, northern Madagascar and Seychelles, suggest that the influence of depleted δ14C water transported in the SEC is limited to regions south of 3 to 4°S.
Correcting for Contamination in AMS 14C Dating
Authors: Mueller Ken , Muzikar Paul
Published: July 2016

When using accelerator mass spectrometry (AMS) for radiocarbon dating, it is important to correct for carbon contamination that is added to the sample and the standard during chemical processing. We derive an equation for making this correction that generalizes previous work in several ways. We treat the case in which contaminating carbon is added during both the combustion step and graphitization step. Taking this two-stage contamination process into account is particularly important when only a fraction of the CO2 produced in the combustion is graphitized. We also allow for the fact that the 13C fractions of the sample, the standard, and the contaminants may be different.
High-Precision Radiocarbon Measurements of Contemporaneous Tree-Ring Dated Wood from the British Isles and New Zealand: Ad 1850–950
Authors: Hogg A G , McCormac F G , Higham T F G , Reimer P J , Baillie M G L , Palmer J G
Published: July 2016

The University of Waikato, Hamilton, New Zealand and The Queen's University of Belfast, Northern Ireland radiocarbon dating laboratories have undertaken a series of high-precision measurements on decadal samples of dendrochronologically dated oak (Quercus petraea) from Great Britain and cedar (Libocedrus bidwillii) and silver pine (Lagarostrobos colensoi) from New Zealand. The results show an average hemispheric offset over the 900 yr of measurement of 40 ± 13 yr. This value is not constant but varies with a periodicity of about 130 yr. The Northern Hemisphere measurements confirm the validity of the Pearson et al. (1986) calibration dataset.
Calibration of the Radiocarbon Time Scale for the Southern Hemisphere: Ad 1850–950
Authors: McCormac F G , Reimer P J , Hogg A G , Higham T F G , Baillie M G L , Palmer J , Stuiver M
Published: July 2016

We have conducted a series of radiocarbon measurements on decadal samples of dendrochronologically dated wood from both hemispheres, spanning 1000 years (McCormac et al. 1998; Hogg et al. this issue). Using the data presented in Hogg et al., we show that during the period AD 950–1850 the 14C offset between the hemispheres is not constant, but varies periodically (∼130 yr periodicity) with amplitudes varying between 1 and 10% (i.e. 8–80 yr), with a consequent effect on the 14C calibration of material from the Southern Hemisphere. A large increase in the offset occurs between AD 1245 and 1355. In this paper, we present a Southern Hemisphere high-precision calibration data set (SHCal02) that comprises measurements from New Zealand, Chile, and South Africa. This data, and a new value of 41 ± 14 yr for correction of the IntCal98 data for the period outside the range given here, is proposed for use in calibrating Southern Hemisphere 14C dates.
Preliminary Report of the First Workshop of the Intcal04 Radiocarbon Calibration/Comparison Working Group
Authors: Reimer Paula J , Hughen Konrad A , Guilderson Thomas P , McCormac Gerry , Baillie Mike G L , Bard Edouard , Barratt Phillip , Warren Beck J , Buck Caitlin E , Damon Paul E , Friedrich Michael , Kromer Bernd , Bronk Ramsey Christopher , Reimer Ron W , Remmele Sabine , Southon John R , Stuiver Minze , VAN der Plicht Johannes
Published: July 2016

The first meeting of the IntCal04 working group took place at Queen's University Belfast from April 15 to 17, 2002. The participants are listed as co-authors of this report. The meeting considered criteria for the acceptance of data into the next official calibration dataset, the importance of including reliable estimates of uncertainty in both the radiocarbon ages and the cal ages, and potential methods for combining datasets. This preliminary report summarizes the criteria that were discussed, but does not yet give specific recommendations for inclusion or exclusion of individual datasets.
New Radiocarbon Calibration Software
Authors: Jones Martin , Nicholls Geoff
Published: July 2016

We have developed a software utility, “DateLab”, for conventional radiocarbon age (CRA) calibration and Bayesian analysis of CRAs. The current version has a smaller range of applicability than other similar utilities such as Bcal, Oxcal, and Mexcal. However, it enables analysis of some common types of CRA datesets. The main advantages of DateLab are its high quality sampling algorithm, the possibility of carrying out model comparison and hypothesis testing in a straightforward way, and the unbiased character of the summary statistics on which the analysis depends.
Natural Abundances of Carbon Isotopes (14C,13C) in Lichens and Calcium Oxalate Pruina: Implications for Archaeological and Paleoenvironmental Studies
Authors: Beazley Melanie J , Rickman Richard D , Ingram Debra K , Boutton Thomas W , Russ Jon
Published: July 2016

Radiocarbon ages of calcium oxalate that occurs naturally on rock surfaces have been used recently in archaeological and paleoenvironmental studies. Oxalate rock coatings are found globally, with most appearing to be residues from epilithic lichens. To explore the source(s) of carbon used by these organisms for the production of oxalate we measured the natural abundances of14C and13C in 5 oxalate-producing lichen species, 3 growing on limestone in southwestern Texas and 2 on sandstone in Arkansas. We also examined the distribution of the isotopes between the calcium oxalate and lichen tissues by separating these components and measuring the13C/C independently. The results demonstrate that the limestone species were slightly enriched in14C, by 1.7%, relative to the sandstone species, which suggests that “dead” carbon from the limestone substrate does not constitute a significant source of carbon for the production of oxalate. The calcium oxalate produced by the lichens is also enriched in13C by 6.5% compared to the lichen tissues, demonstrating that there is a large carbon isotope discrimination during oxalate biosynthesis. These results support the reliability of14C ages of calcium oxalate rock coatings used for archaeological and paleoclimate studies.
Dating of Prehistoric Burial Mounds by 14C Analysis of Soil Organic Matter Fractions
Authors: Kristiansen Søren M , Dalsgaard Kristian , Holst Mads K , Aaby Bent , Heinemeier Jan
Published: July 2016

Dating of prehistoric anthropogenic earthworks requires either excavation for archaeological artifacts or macroscopic organic matter suitable for 14C analysis. Yet, the former, in many cases, is undesirable and the latter is difficult to obtain. Here we present a soil science procedure, which has the potential to overcome these problems. It includes careful sampling of buried former soil surfaces, acid-alkali-acid fractionation of soil organic matter (SOM), and subsequent 14C AMS dating. To test the procedure, soil from one of the largest known burial mounds in Scandinavia, Hohøj, and 9 other Danish burial mounds were sampled. The 14C dates from extracted SOM fractions were compared to reference ages obtained by other methods. We show that humic acid fractions in 7 of the 10 mounds had the same age as the reference, or were, at maximum, 280 yr older than the reference ages. The best age estimates were derived from an organic-rich layer from the upper cm of buried soil or sod. Differences among SOM fraction ages probably indicate the reliability of the dating. Hohøj dated to approximately 1400 BC and, thus, was up to 500 yr older than other dated Scandinavian mounds of comparable size. The remaining investigated burial mounds were dated to between 1700 and 1250 BC. We conclude that combined sampling of buried soil surfaces, SOM fractionation, and 14C analysis allows for dating of archaeological earthworks when minimal disturbance is required, or if no macroscopic organic remains are found.
Reply to Israel Carmi (2002): “Are the 14C Dates of the Dead Sea Scrolls Affected by Castor Oil Contamination?”
Authors: Rasmussen Kaare L , van der Plicht Johannes , Doudna Gregory , Cross Frank M , Strugnell John
Published: July 2016

Carmi (2002) is a response to our study published in Radiocarbon 43(1) by Rasmussen et al. (2001). We noted widespread possible exposure to castor oil of the Dead Sea Scrolls (DSS) in the Rockefeller Museum in the 1950s and reported experiments showing that the AAA pretreatment used in the first 2 series of radiocarbon datings of the DSS (Bonani et al. [1992] and Jull et al. [1995]), “cannot be guaranteed to have removed all of the modern carbon in any samples if they had been contaminated with castor oil and hence could have produced some 14C dates that were younger than the texts' true ages.” Carmi, a coauthor of the Bonani et al. (1992) study, criticizes our analysis on 4 grounds:
The 12,460-Year Hohenheim Oak and Pine Tree-Ring Chronology from Central Europe—A Unique Annual Record for Radiocarbon Calibration and Paleoenvironment Reconstructions
Authors: Friedrich Michael , Remmele Sabine , Kromer Bernd , Hofmann Jutta , Spurk Marco , Felix Kaiser Klaus , Orcel Christian , Küppers Manfred
Published: July 2016

The combined oak and pine tree-ring chronologies of Hohenheim University are the backbone of the Holocene radiocarbon calibration for central Europe. Here, we present the revised Holocene oak chronology (HOC) and the Preboreal pine chronology (PPC) with respect to revisions, critical links, and extensions. Since 1998, the HOC has been strengthened by new trees starting at 10,429 BP (8480 BC). Oaks affected by cockchafer have been identified and discarded from the chronology. The formerly floating PPC has been cross-matched dendrochronologically to the absolutely dated oak chronology, which revealed a difference of only 8 yr to the published 14C wiggle-match position used for IntCal98. The 2 parts of the PPC, which were linked tentatively at 11,250 BP, have been revised and strengthened by new trees, which enabled us to link both parts of the PPC dendrochronologically. Including the 8-yr shift of the oak-pine link, the older part of the PPC (pre-11,250 BP) needs to be shifted 70 yr to older ages with respect to the published data (Spurk 1998). The southern German part of the PPC now covers 2103 yr from 11,993–9891 BP (10,044–7942 BC). In addition, the PPC was extended significantly by new pine chronologies from other regions. A pine chronology from Avenches and Zürich, Switzerland, and another from the Younger Dryas forest of Cottbus, eastern Germany, could be crossdated and dendrochronologically matched to the PPC. The absolutely dated tree-ring chronology now extends back to 12,410 cal BP (10,461 BC). Therefore, the tree-ring-based 14C calibration now reaches back into the Central Younger Dryas. With respect to the Younger Dryas-Preboreal transition identified in the ring width of our pines at 11,590 BP, the absolute tree-ring chronology now covers the entire Holocene and 820 yr of the Younger Dryas.