bluuebunny/crossref_metadata_2025 huggingface dataset:
A Marine Reservoir Correction Database and On-Line Interface
Authors: Reimer P J , Reimer R W
Published: July 2016

Calibration is essential for interpretation of radiocarbon dates, especially when the 14C dates are compared to historical or climatic records with a different chronological basis. 14C ages of samples from the marine environment, such as shells or fish bones, or samples with a marine component, such as human bone in coastal regions, require an additional consideration because of the reservoir age of the ocean. While the pre-industrial global mean reservoir correction, R(t), is about 400 years, local variations (ΔR) can be several hundred years or more. ΔR compilations on a global scale have been undertaken previously (Stuiver et al. 1986; Stuiver and Braziunas 1993), but have not been updated recently. Here we describe an on-line reservoir correction database accessed via mapping software. Rather than publishing a static ΔR compilation, new data will be incorporated when it becomes available. The on-line marine reservoir correction database can be accessed at the website http://www.calib.org/.
Northwest Pacific Marine Reservoir Correction Estimated from Annually Banded Coral from Ishigaki Island, Southern Japan
Authors: Hideshima Shinichiro , Matsumoto Eiji , Abe Osamu , Kitagawa Hiroyuki
Published: July 2016

We assessed marine reservoir age R(t) for the costal area of the northwest Pacific using radiocarbon measurements of the annually banded coral core (Porites sp) collected on Ishigaki Island in southern Japan. Reservoir age R(t) during the early 1900s at the Pacific coast of Ishigaki Island ranged between 290 and 455 14C yr, with a weighted mean of 355 ± 25 14C yr (n=5, ±1 σ). The regional-specific ΔR, defined as 14C age difference of regional and world ocean surface layer, was 35 ± 25 14C yr (n=5, ±1σ) on average and increased between 1900 and 1950.
New Dates from Submerged Late Pleistocene Sediments in the Southern Sea of Galilee, Israel
Authors: Nadel D , Belitzky S , Boaretto E , Carmi I , Heinemeier J , Werker E , Marco S
Published: July 2016

Unusual low water levels in the Sea of Galilee (Dead Sea Fault, Israel) have caused the recent exposure of submerged Late Pleistocene prehistoric sites and lacustrine sediments along the southern shores of the lake. The Ohalo II site is a large fisher-hunter-gatherers camp with in-situ brush hut floors, hearths, and a human grave. The site is radiometrically dated by 25 charcoal dates to 19,430 BP (average, uncalibrated). The archaeological remains include quantities of excellently preserved organic remains. These would not have been preserved without a rapid rise of lake level immediately after the occupation, covering the remains with silts and sand. Recently a concentration of eight tree trunks were found about 1.5 km south of Ohalo II, of which five trunks were identified as Salix species and dated as a single accumulation at about 16,100 BP. The trunks, too, had to be submerged quickly together to ensure excellent preservation. The camp and the trunks were found at −212/−213 m, almost 4 m below modern high water levels. We suggest that the finds represent two separate episodes of deposition during low lake levels, almost 3,000 radiocarbon years apart, each followed by an abrupt water rise. It is possible that climatic changes caused the observed fluctuations, though earthquakes (blocking or lowering the Jordan outlet, for example) cannot be ruled out.
Towards an AMS Radiocarbon Chronology of Predynastic Egyptian Ceramics
Authors: Savage Stephen H
Published: July 2016

The wide and varied connections between Israel and Egypt during the Early Bronze Age/Predynastic are frequently calibrated through ceramics that depend to a large degree on two seriation methods developed for Predynastic Egypt. Petrie's seriation technique and Kaiser'sStufedating method utilize whole forms from mortuary contexts. Because of the ways they were developed and deployed in Predynastic research, a logical tautology exists that makes their usage highly problematic. Radiocarbon dating of the Predynastic is vital if we are to untangle existing ceramic chronologies. But up to now, almost all14C dates have come from domestic contexts where whole vessels are not usually found and which differ significantly from cemeteries in their ceramic assemblages. A14C-based chronology of whole forms in the Petrie Corpus is thus highly desirable, but has proven elusive until now. Samples of organic materials and Black-Topped Red Ware vessels from over 100 graves in the Predynastic Cemetery, N7000, at Naga-ed-Dêr have recently been submitted for dating with AMS methods, providing the first comprehensive14C chronology of a Predynastic cemetery. The results are compared to a suite of recalibrated dates from Upper Egyptian Predynastic domestic contexts, which allows the14C chronology for the region to be further refined. Absolute date ranges for a number of ceramic forms can be estimated for the first time, and results of early analysis are discussed.
Proto, Early Dynastic Egypt, and Early Bronze I-II of the Southern Levant: Some Uneasy14C Correlations
Authors: Braun Eliot
Published: July 2016

A number of recent radiocarbon determinations from several sites in Israel suggest advancing, by some considerable period of time, both the onset of the cultural horizon known as Early Bronze I and the appearance of its latest phases. The logical outcome of the acceptance of these new dates puts such a strain on chronological correlations between the14C data and the archaeological record that the entire system would no longer be tenable if they were accepted. This paper examines in detail the problematic nature of these “uneasy correlations.”
Radiocarbon Dates from Iron Age Strata at Tel Beth Shean and Tel Rehov
Authors: Mazar Amihai , Carmi Israel
Published: July 2016

We discuss the significance of 32 radiocarbon dates from the archaeological sites of Tel Beth Shean and Tel Rehov in northern Israel. All dates are from Iron Age I and II archaeological contexts (12th–8th centuries BCE). Most of the dates were done on short-lived samples (seeds and olive pits), while some are on charred timber. The samples are organized in several homogeneous clusters according to their context. This series is one of the largest groups of 14C dates from the Iron Age in the Levant. The paper discusses the correlation between the 14C dates and the traditional archaeological dates of the same context. Results from two laboratories and two calibration curves are compared, showing some significant differences in one case. We conclude with an evaluation of the relevance of 14C dating for the current debate about the chronology of the Iron Age in Israel, and in historical periods in general.
Early Iron Age Radiometric Dates from Tel Dor: Preliminary Implications for Phoenicia and Beyond
Authors: Gilboa Ayelet , Sharon Ilan
Published: July 2016

The absolute date of the Iron Age I and IIa periods in Israel, and by inference in the Southern Levant at large, are to date among the hottest debated issues in Syro-Palestinian archaeology. As there are no pegs of absolute chronology throughout this range, conventional chronology had been established on proposed correlations of the material record with events and social phenomena as portrayed in historical and literary sources, chiefly the Hebrew Bible. With the growing impact of so-called “revisionist” notions in Biblical studies, which to various extents question the historicity of the Bible, it is imperative to try to establish a chronological framework for the Iron I–IIa range that is independent of historical and so forth considerations, inter alia in order to be able to offer an independent archaeological perspective of the biblical debate. The most obvious solution is to attempt a radiocarbon-based chronology. This paper explores the possible implications of a sequence of 22 radiometric dates obtained from a detailed Iron I–IIa stratigraphic/ceramic sequence at Tel Dor, on Israel's Mediterranean coast. To date, this is the largest such sequence from any single early Iron Age site in Israel. Having been part of the Phoenician commercial sphere in the early Iron Age, Dor offers a variegated sequence of ceramics that have a significant spatial distribution beyond Phoenicia, and thus transcend regional differences and enable correlation with the surrounding regions. By and large, the absolute dates of these ceramics by the Dor radiometric chronology are up to a century lower than those established by conventional Palestinian ceramic chronology. The ramifications of the lower Dor dates for some Phoenician, Israelite, and Cypriot early Iron Age archaeological issues are explored.
14C and the Iron Age Chronology Debate: Rehov, Khirbet en-Nahas, Dan, and Megiddo
Authors: Finkelstein Israel , Piasetzky Eli
Published: July 2016

A recently published volume, The Bible and Radiocarbon Dating: Archaeology, Text and Science (Levy and Higham 2005), provides data related to the debate over the chronology of the Iron Age strata in the Levant (for a review, see Carmi 2006). The present article comments on several chapters in the volume. The article highlights methodological problems, such as insecure stratigraphic provenance of 14C samples, and demonstrates how unjustified selection of data can bias the result. The article offers a new interpretation to some of the results and shows that the full set of measurements from Tel Rehov supports the Low Chronology system.
Models, Data, Statistics, And Outliers—A Statistical Revolution In Archaeology and 14C Dating
Authors: Scott E Marian
Published: July 2016

Increasingly, the uses of data arc becoming more and more sophisticated as the archaeological and chronological questions being asked become more complex. Statistical models and tools for inference arc a routine part of an archaeological investigation encouraged through the availability of software, and with each release of that software, additional functionality is being added. This comes with enormous benefit but also at a cost—the dreaded black box. Therefore, this article, as the first in a series of short articles, will attempt to cover some of the things one needs to know to make the most of the power of the statistical revolution, while avoiding the pitfalls.
14C Calibration Curves for Modern Plant Material from Tropical Regions of South America
Authors: Ehleringer James R , Casale John F , Barnette Janet E , Xu Xiaomei , Lott Michael J , Hurley Janet
Published: July 2016

Two Δ14C calibration curves have been produced that allow determination of the statistical average age of coca leaf and cocaine base specimens produced for the time period 1979–2009. These calibration curves are based on field collections of specimens in Bolivia, Colombia, Ecuador, and Peru. The coca leaf F14C and Δ14C calibration curves can be used to predict the ages of botanical tissues collected in tropical South America and possibly extended to other tropical locations. The cocaine F14C and Δ14C calibration curves can be used to predict the ages of seized cocaine specimens. Because the Δ14C of the atmosphere is diminishing, the precision of this approach for age determinations will continue to get less precise over time as atmospheric 14C content continues to decline.
Are the Fractionation Corrections Correct: Are the Isotopic Shifts for 14C/12C Ratios in Physical Processes and Chemical Reactions Really Twice Those for 13C/12C?
Authors: Southon John
Published: July 2016

Conventional radiocarbon calculations correct for isotopic fractionation using an assumed value of 2.0 for the fractionation of 14C relative to 13C. In other words, isotopic discrimination in physical and chemical processes is assumed to cause relative shifts in 14C/12C ratios that are exactly double those of 13C/12C. This paper analyzes a 1984 experiment that produced a value for the fractionation ratio in photosynthesis of 2.3, which is used to this day by some researchers in the fields of hydrology and speleothem geochemistry. While the value of 2.3 is almost certainly incorrect, theoretical work suggests that the true value may indeed deviate from 2.0, which would have significant implications for 14C calculations.
Initial Results with Low Energy Single Stage AMS
Authors: Schroeder J B , Hauser T M , Klody G M , Norton G A
Published: July 2016

The National Electrostatics Corporation has built and tested a prototype low energy, open-air, single stage carbon accelerator mass spectrometry (AMS) system (patent pending). The configuration tested has a standard 40-sample, multi-cathode SNICS source on a 300-kV deck. The beam is mass analyzed before acceleration to a gas stripper located at ground. The 14C+ ions are separated from 13C+ and 12C+ arising from the molecular breakup by a 90° analyzing magnet immediately after the gas stripper which acts as a molecular dissociator. The 14C+ beam passes through an electrostatic spherical analyzer before entering the particle detector. The observed 14C/12C precision is better than 5% with a sensitivity of better than 0.05 dpm/gmC. A first single stage AMS system has been ordered. The configuration of this system will be discussed.
The New 14C Analysis Laboratory in Jena, Germany
Authors: Steinhof A , Adamiec G , Gleixner G , van Klinken G J , Wagner T
Published: July 2016

The new accelerator mass spectrometry (AMS) Radiocarbon Analysis Laboratory in Jena is described. The laboratory developed a combustion system for solid samples and a CO2 extraction system for air samples. Thus far, sample preparation, including graphitization, was performed in the laboratory, and the samples were measured subsequently by other AMS facilities. Currently, the laboratory owns a 3MV AMS system from HVEE (Netherlands) that has passed the acceptance tests and will be used for routine 14C determinations in the near future. The AMS system is equipped with 2 ion sources, one suitable for graphite targets and the second for both graphite and CO2 targets.
Fast and Accurate Sequential Injection AMS with Gated Faraday Cup Current Measurement
Authors: Klein M , Mous D J W , Gottdang A
Published: July 2016

Sequential injection or bouncing has a number of properties which can lead to a reduction of the analysis accuracy if no appropriate measures are taken. A special injection system has been developed in order to eliminate these shortcomings. The influence of source glitches or instabilities on the measured isotopic ratio is substantially reduced by a high cycling frequency. A fast beam-blanking unit guarantees the needed accuracy of the injection periods. Background currents are avoided by synchronizing the current measurement for the stable isotopes with their injection periods. To achieve the required speed and precision of the gated measurement, new instrumentation was developed. The elimination of background contributions allows an efficiency for radiocarbon counting as high as 95% at a cycling frequency of 100 Hz.
Surface and Underground Ultra Low-Level Liquid Scintillation Spectrometry
Authors: Plastino Wolfango , Kaihola Lauri
Published: July 2016

Cosmic background and its variation have been removed in the Gran Sasso National Laboratory (National Institute of Nuclear Physics) by its 1400-m rock overburden. Stable, high-performance liquid scintillation counting conditions are obtained when any remaining variable components of the environmental background, such as radon, are eliminated. The ultra low-level liquid scintillation spectrometer Quantulus™ has an anti-Compton guard detector (guard for short) that allows monitoring of gamma radiation in the background. The guard detector efficiency in radiocarbon background reduction is 8% in the Gran Sasso National Laboratory, while 80% is observed in surface laboratories. Thus, atmospheric pressure variations in surface laboratories cause variation in cosmic radiation flux. The Quantulus anti-Compton detector is highly efficient in detecting cosmic radiation, and the sample count rate remains stable in long-term counting. Also, correlation of sample backgrounds with environmental gamma radiation in various laboratories is examined.
Rehabilitation of the Laboratoire De Carbone 14-Dakar (Senegal) with a Super Low-Level Liquid Scintillation Counting System
Authors: Ndeye Maurice , Ka Oumar , Bocoum Hamady , Diallo Alpha O
Published: July 2016

Following the passing of Prof Cheikh Anta Diop in 1986, the radiocarbon laboratory (LC14) he created 20 yr earlier at the Institut Francophone d'Afrique Noire (IFAN), Dakar, Senegal, fell into a long hibernation. It took nearly 3 yr to renovate the laboratory and reinstall new equipment in order to return LC14 to full functionality and resume its activity. A new dating system has been implemented around a super low-level liquid scintillation spectrometer from Packard, the Tri-Carb 3170TR/LS, located in an underground room.

In this paper, we assess the performance of the dating setup (background level and figure of merit) using known samples from Paris 6 and international standards from the International Atomic Energy Agency (IAEA). After the calibration, the setup was used to study bolé seashells from the Khant area in the northern part of Senegal (West Africa). The aim is to present evidence of the correlation between the transgression of the Nouakchottan (5500 BP) and a few industries in the Khant area. The corresponding ages are difficult to assess and the dates available for this cultural site are randomly distributed, ranging from 4500 to 1500 BP, i.e., a chronological period spanning from the Neolithic to the Iron Age.
Improvements to the Pretreatment of Bone at Oxford
Authors: Bronk Ramsey Christopher , Higham Thomas , Bowles Angela , Hedges Robert
Published: July 2016

Bone is one of the most widely used materials for dating archaeological activity. It is also relatively difficult to pretreat effectively and new methods are an area of active research. The purpose of the chemical pretreatment of bone is to remove contaminants present from burial and to do so in a way which does not add any additional laboratory contaminant. To some extent, these two aims must be balanced since, on the whole, the more complex the procedure and the more steps included, the greater the chance for contamination. At the Oxford Radiocarbon Accelerator Unit (ORAU), the method used is a continuous-flow or manual acid/base/acid (ABA) treatment followed by gelatinization and ultrafiltration (based on Brown et al. [1988]; documented in Bronk Ramsey et al. [2000]). We find this overall method is very effective at removing more recent contamination in old bones. However, two aspects of the method have recently been improved and are reported here: the redesign of ORAU's continuous flow pretreatment and a new protocol in our pretreatment ultrafiltration stage.
Problems Associated with the AMS Dating of Small Bone Samples: The Question of the Arrival of Polynesian Rats to New Zealand
Authors: Higham T F G , Hedges R E M , Anderson A J , Bronk Ramsey C , Fankhauser B
Published: July 2016

We have AMS dated samples of Pacific rat (Rattus exulans) bone “collagen” and filtered gelatin samples from the prehistoric site of Shag River Mouth, New Zealand. The age of occupation of this site has previously been determined based on 50 radiocarbon measurements. The site dates to the late Archaic phase of southern New Zealand prehistory (about 650–500 BP; 14th–15th century AD). The results of rat bones which we have dated produce a range in ages, from about 980–480 BP, a difference we attribute to a combination of effects. Pretreatment appears to be an important variable, with results showing differences in 14C age between the progressive “collagen” and filtered gelatin chemical treatment stages. Amino acid profiles suggest there is a proteinaceous but non-collagenous contaminant which is removed by the more rigorous pretreatment. Stable isotopes vary between pretreatments, supporting the removal of a contaminant, or contaminants. Variation in δ15N values imply a range in uptake of dietary protein, and might suggest a potential influence from the local aquatic environment or the consumption of marine-derived protein. Rats are opportunistic, omnivorous mammals, and, therefore, obtain carbon from a variety of reservoirs and so we ought to expect that in environments where there is a variety of reservoirs, these will be exploited. Taken together, the results show that rat bone AMS 14C determinations vary in comparison with the established age of the site, but are in notably better agreement with non-collagenous data than in previously published determinations (Anderson 1996).
14C Dating Compared to Art Historical Dating of Roman and Coptic Textiles from Egypt
Authors: Van Strydonck Mark , De Moor Antoine , Bénazeth Dominique
Published: July 2016

A representative selection of Roman and Coptic textiles is used to compare the radiocarbon dating results with the chronology proposed by art historians. In some cases, the comparison was made on individual objects, but in other cases, groups of stylistically and/or technologically related textiles were compared. In the case of the latter, the interquartile range was calculated. The results of this comparison show that some individual samples and groups are dated older than expected, while for another group the opposite is the case. One group was matching well with the presumed period as a whole, but not on the basis of the individual pieces. The analyses showed the necessity of 14C dating to obtain a more accurate dating of Coptic textiles.
Chronology and Possible Links Between Climatic and Cultural Change During the First Millennium Bc in Southern Siberia and Central Asia
Authors: Zaitseva G I , van Geel B , Bokovenko N A , Chugunov K V , Dergachev V A , Dirksen V G , Koulkova M A , Nagler A , Parzinger G , van der Plicht J , Bourova N D , Lebedeva L M
Published: July 2016

We reconstructed climate change during the second half of the Holocene for the Minusinsk (southern Siberia) and the Uyuk (Central Asia) valleys in the Eurasian steppe zone. Sediment cores from 2 lakes and a soil profile from the Arzhan-2 burial mount were investigated. We combined pollen and geochemical analyses and radiocarbon dating with the archaeological record. A sharp increase of human population density occurred at the transition from the Bronze Age to Iron Age (about 2700 cal BP). The most representative Scythian culture started in the Uyuk and the Minusinsk valleys after increased humidity and occupation capacity of the steppe zone during the 9th century BC.
Neolithic Massacres: Local Skirmishes or General Warfare in Europe?
Authors: Maria Wild Eva , Stadler Peter , Häußer Annemarie , Kutschera Walter , Steier Peter , Teschler-Nicola Maria , Wahl Joachim , Windl Helmut J
Published: July 2016

The Neolithic site of Schletz in Lower Austria comprises a fortified settlement from the end of the Linearbandkeramik (LBK) culture. Large numbers of human bones were found at the base of the fortification ditches, and many of the excavated bones and skulls showed evidence of trauma which most likely originates from violence. This remarkable deposit of human remains has been considered evidence for an abrupt end to the Early Neolithic settlement at Schletz. In order to investigate this interpretation, radiocarbon accelerator mass spectrometry (AMS) measurements of human bone samples from this site were performed at VERA. The χ2 test of the results from specimens with clearly identified lesions suggests that these may be contemporaneous. Further, it may be concluded that all individuals with evidence of trauma from Schletz were probably the victims of a single event: a massacre at the end of the LBK.

Similar evidence is found at Early Neolithic sites at Talheim and Herxheim in the western part of Germany. Analysis of the 14C ages of bones from both sites suggests that the Talheim event may have been coeval with the massacre of Schletz, whereas an event at Herxheim might have happened some time earlier. For Herxheim, the massacre theory is still under discussion, and a change in the burial rite is also considered as an alternative interpretation.
14C Dating of the Settlement of Iceland
Authors: Sveinbjörnsdóttir Arny E , Heinemeier Jan , Gudmundsson Gardar
Published: July 2016

The dating of the settlement of Iceland has been debated for many years. According to written sources (sagas) from the early 12th century, the first Norwegian settlers arrived in Iceland in AD 874. However, some14C dates from the earliest archaeological sites in Iceland, invariably from samples of birch and other indigenous wood species, have yielded surprisingly old ages, older by 100–150 yr than the historical date, suggesting that the settlement took place in the 7th or 8th century. In this paper, we report 16 new14C dates of pairs of barley grain and wood samples from an excavation in Reykjavík in 2001. The new results show that the wood samples tend to be older than the grain samples by up to about 100 yr. We argue that the barley grains give the true date (AD 890), whereas the wood dates are too old. The grain dates are in close agreement with the settlement year quoted in the written sources. In particular, our new data eliminate the need of any of the ad hoc theories introduced up to now to explain the suspiciously high14C ages of wood samples from the settlement of Iceland, namely, 1) the island effect, 2) the volcanic or geothermal effect, or 3) that settlement actually took place significantly before the time recorded in the sagas.
AMS 14C Dating Using Black Pottery and Fiber Pottery
Authors: Mihara Shozo , Miyamoto Kazuo , Ogawa Hidefumi , Kurosaka Teiji , Nakamura Toshio , Koike Hiroko
Published: July 2016

A technique of accelerator mass spectrometry (AMS) has made it possible to directly measure radiocarbon ages of pottery by isolating organic materials sealed in the pottery when the pottery was formed. We analyzed the carbon contents and 14C ages for “black pottery” from the Philippines and “fiber pottery” from Japan using the relevant carbonaceous materials extracted from the pottery samples, i.e., adhered chaff or grass fibers that were incorporated in the pottery matrix, respectively. The carbon yield of the pottery sample varied largely depending on the pottery types, the preservation conditions, as well as the chemical pretreatment methods to purify carbonaceous materials for 14C dating. We will discuss criteria for sample selection of well-preserved pottery, and a modified method, instead of the standard alkali treatment, to obtain sufficient material for precise 14C dating.
Tartu Radiocarbon Dates XI
Authors: Ilves Evald
Published: July 2016

This list includes dates of geologic samples measured using a single-channel liquid scintillation 14C counter at the Geochemical and Statistical Laboratory, Tartu, Estonian SSR. Our modern standard is made of benzene enriched in 14C and its activity is checked with NBS oxalic acid standard sample. Dates are given in conventional radiocarbon years, based on the Libby half-life of 5570 ± 30 yr. AD 1950 is the reference year. Errors refer only to 1σ standard deviation calculated from count rates involved.
Isotope-Ratio and Background Corrections for Accelerator Mass Spectrometry Radiocarbon Measurements
Authors: Donahue D J , Linick T W , Jull A J T
Published: July 2016

We present here the method we use to convert to radiocarbon ages (14C/13C) ratios measured in the Arizona Accelerator Mass Spectrometer facility. We describe the procedures we use to convert sample and standard isotope ratios to values appropriate for calculation of radiocarbon ages. We also discuss, in some detail, corrections to account for sample contamination.
Preparative High-Performance Liquid Chromatographic Separation of Individual Amino Acids Derived from Fossil Bone Collagen
Authors: van Klinken Gert Jaap , Mook Willem G
Published: July 2016

Extracting a series of amino acids from fossil “collagen” makes it possible to compare chemically well-characterized molecules from one bone sample, both chemically and by isotopic analysis. Thus, the integrity of collagen samples and possible contamination can be checked. We describe the routine high-performance liquid chromatographic extraction of five amino acids: glycine, hydroxyproline, glutamate, threonine and alanine. Humates are eliminated during the extraction, which can be monitored continuously.
Radiocarbon in Seawater and Organisms from the Pacific Coast of Baja California
Authors: Druffel Ellen R. M. , Williams Peter M.
Published: July 2016

Radiocarbon was measured in dissolved inorganic carbon (DIC) and living organisms collected off the west coast of Baja California in October 1980. Samples from three locations were examined. Δ14C of DIC at the southernmost station was higher than those further north, which reflects reduced upwelling in the southern region. Crabs and anchovies had Δ14C values significantly lower than surface DIC Δ14C, indicating the incorporation of ‘older', sediment-derived carbon sources from their diets. Comparisons are made between our DIC Δ14C measurements and those obtained during other cruises and at a coastal site, from 1959 through 1987. Two distinct time histories of DIC Δ14C are apparent for the post-bomb period: 1) a lower Δ14C curve for sites close to the coast influenced by enhanced coastal upwelling; and 2) a higher Δ14C curve for sites further offshore within the California Current.
University of Granada Radiocarbon Dates V
Authors: Gonzalez-Gomez Cecilio , Sanchez-Sanchez Purificacion
Published: July 2016

This paper includes some determinations of archaeological, art and palaeobotanical samples from Spain and Portugal, obtained at the University of Granada Radiocarbon Dating Laboratory, mostly from 1986 to 1988. Pretreatment of charcoal and wood samples is a standard acid-basic procedure using 8% HC1 and 2% NaOH at boiling temperature. The collagen of bone samples is obtained by the Longin (1971) method.

The method of dating is benzene synthesis and liquid scintillation counting as previously reported (González-Gómez, López-González & Domingo-García 1982; González-Gómez, Sánchez-Sánchez and Domingo-García 1985; González-Gómez, Sánchez-Sánchez and Villafranca-Sánchez 1986, 1987).14C activity was measured in a Packard Tri-Carb Mod 4640 liquid scintillation spectrometer, using 20 ml low 40K counting vials with 5 ml benzene and 10 ml PPO-toluene as scintillator with a background of ca. 9 cpm. Efficiency was approximately 70% using the part of spectrum above the end point of tritium.
The Rapid Preparation of Seawater ΣCO2 for Radiocarbon Analysis at the National Ocean Sciences Ams Facility
Authors: McNichol A.P. , Jones G. A. , Hutton D. L. , Gagnon A. R. , Key R. M.
Published: July 2016

We have established a laboratory for extracting ΣCO2 from seawater samples for AMS analysis of the radiocarbon content. The seawater samples are collected at sea, poisoned and stored until analysis in the laboratory. Each sample is acidified; the inorganic carbon is stripped out as CO2 with an inert carrier gas and then converted to graphite. We present results for Buzzards Bay surface H2O and Na2CO3 standards that demonstrate we strip >98% of inorganic carbon from seawater. Stable isotope analyses are performed to better than 0.2‰, and the reproducibility of 14C measurements on Buzzards Bay seawater is better than 13‰. Finally, we compare data from samples collected in 1991 to those collected in the 1970s and to large volume samples.
Gliwice Radiocarbon Dates Xii
Authors: Pazdur Anna , Pazdur Mieczysław F. , Zastawny Andrzej
Published: July 2016

The following list presents results of dating archaeological samples from excavations in Africa. Most results reported in this list were obtained from 1982 to 1993 for international research projects studying the origin and early development of food-producing cultures in northeastern Africa, including the Nile basin and the Sahara. Detailed information on these projects may be found in the series of conference proceedings edited by Krzyżaniak and Kobusiewicz (1984, 1989, 1993).
Radiocarbon Ages of Mammoths in Northern Eurasia: Implications for Population Development and Late Quaternary Environment
Authors: Vasil'Chuk Yurij , Punning Jaan-Mati , Vasil'Chuk Alla
Published: July 2016

Many mammoth remains have been radiocarbon-dated. We present here more than 360 14C dates on bones, tusks, molars and soft tissues of mammoths and discuss some issues connected with the evolution of mammoths and their environment: the problem of the last mammoth; mammoth taphonomy; the plant remains and stable isotope records accompanying mammoth fossils; paleoclimate during the time of the mammoths and dating of host sediments. The temporal distribution of the 14C dates of fossils from the northern Eurasian territory is even for the entire period from 40 to 10 ka bp.
Calibration of Radiocarbon Dates for the Late Pleistocene Using U/Th Dates on Stalagmites
Authors: Vogel John C. , Kronfeld Joel
Published: July 2016

Twenty paired 14C and U/Th dates covering most of the past 50,000 yr have been obtained on a stalagmite from the Cango Caves in South Africa as well as some additional age-pairs on two stalagmites from Tasmania that partially fill a gap between 7 ka and 17 ka ago. After allowance is made for the initial apparent 14C ages, the age-pairs between 7 ka and 20 ka show satisfactory agreement with the coral data of Bard et al. (1990, 1993). The results for the Cango stalagmite between 25 ka and 50 ka show the 14C dates to be substantially younger than the U/Th dates except at 49 ka and 29 ka, where near correspondence occurs. The discrepancies may be explained by variations in 14C production caused by changes in the magnetic dipole field of the Earth. A tentative calibration curve for this period is offered.
Characterization of Groundwater in the Cariri (Ceará, Brazil) By Environmental Isotopes and Electric Conductivity
Authors: Santiago Marlucia F. , Silva C. M. S. V. , Filho J. Mendes , Frischkorn H.
Published: July 2016

The Cariri region is the largest sedimentary basin in the state of Ceará, Brazil. Located in the southern portion of the state, it comprises the Araripe Plateau and the Cariri Valley on its northern foot. The region's groundwaters are being heavily exploited. Using electric conductivity (EC) and 18O, 14C and 3H data, we differentiate groundwaters from various origins. We identified three horizons of springs on the slope of the Plateau through their geologic environment and the EC of their waters. Groundwaters from wells in the Cariri Valley are classified according to the aquifers exploited as indicated by the drilling profiles. However, strong tectonic features and intense fracturing in the Valley produce a great many horizontal discontinuities, which result in a mixing of groundwaters from different aquifers. Mixing systems are described in terms of δ18O–14C and EC–14C linear trends.
Radiocarbon Dating of δ18O-δD Plots in Late Pleistocene Ice-Wedges of the Duvanny Yar (Lower Kolyma River, Northern Yakutia)
Authors: Vasil'chuk Yurij K , Vasil'chuk Alla C , Rank Dieter , Kutschera Walter , Kim Jong-Chan
Published: July 2016

The Duvanny Yar cross-section located in the Lower Kolyma River valley of Northern Yakutia (69°N, 158°E, height above the Kolyma River level 55 m), has been studied and dated in detail by radiocarbon. The sequence mainly consists of sandy loam sediments with large syngenetic ice wedges. Their width at the top is 1–3.5 m. Allochthonous organic material occurs in high content, concentrating as 0.5–0.7 m lenses. Shrub fragments, twigs, and mammoth bones are accumulated in peaty layers. Through interpolation based on a series of 14C dates, dating of the host sediments provides an approximate age for the ice wedges. The 14C dates of various types of organic material are sometimes very close, but not all in agreement. Therefore, the dates do not accurately show the age of the δ18O and δD plots. A new approach is developed to a 14C dating strategy of syncryogenic sediments with high admixture of allochthonous organic material. The main purpose of this study is to consider detection of inversions or disturbances in the syngenetic permafrost sediment at the Duvanny Yar cross-section by 14C date series. Direct accelerator mass spectrometry (AMS) dating of the ice confirmed the relatively young age of ice wedges.
A New 13C Correction for Radiocarbon Samples from Elevated-CO2 Experiments
Authors: Torn Margaret S , Southon John
Published: July 2016

Radiocarbon can be a valuable tracer of carbon cycling in elevated CO2 experiments. However, the standard method of calculating Δ14C, which corrects sample 14C activity for isotopic fractionation by correcting the sample δ13C to – 25‰, introduces significant errors to the reported 14C values. For elevated-CO2 treatments the error arises because the δ13C of the sample is not an appropriate measure of isotopic fractionation to use when correcting sample 14C activity for isotopic fractionation. A suggested replacement approach, developed in this paper, is to use the δ13C of the same type of material (e.g. leaf, soil organic matter) from the control (ambient-CO2) treatment in place of the sample δ13C in the correction.
Measurement of Radiocarbon Content in Leaves from Some Japanese Sites
Authors: Muraki Yasushi , Masuda Kimiaki , Arslanov Kh A , Toyoizumi Hiroaki , Kato Masataka , Naruse Yukiko , Murata Takuya , Nishiyama Tohru
Published: July 2016

We have measured radiocarbon contents in leaves collected from 15 sites in Japan, including mountain areas and big city areas for last three years. Comparing the radiocarbon contents in various areas, high 14C concentrations (80–100‰ as δ14C) are seen for the leaves from the mountain and country sites. On the contrary, low concentrations (5–40‰) were observed for the leaves from city region, especially near the road with heavy traffic. These results indicate that the atmosphere of the mountain and country sites in Japan is still clean but the CO2 gas coming from fossil non-radioactive carbon significantly pollutes the atmosphere of the city sites. The value of δ14C for the mountain areas implies that 14C produced by nuclear bomb test in 1960s still remains. The decrease of δ14C at heavy traffic sites in Tokyo is consistent with the increase of CO2 concentration in the atmosphere assuming that almost all CO2 gas in this region originates from the fossil fuel.
Distribution of Radiocarbon in the Southwestern North Pacific
Authors: Aramaki T , Mizushima T , Kuji T , Povinec P P , Togawa O
Published: July 2016

Radiocarbon measurements in seawater samples taken at six stations in the southwestern North Pacific visited during the International Atomic Energy Agency (IAEA) 1997 Pacific Ocean Expedition were carried out at the accelerator mass spectrometry (AMS) facility of the Japan Atomic Energy Research Institute (JAERI). Three stations were located close to GEOSECS stations, and three were in the vicinity of Bikini and Enewetak Atolls, which may be influenced by former nuclear weapons testing. Compared with the GEOSECS data (1973), our results show an increase of 14C in intermediate waters. Furthermore, it is estimated that bomb-produced 14C inventories in the water column have increased by more than 20% during the last 24 years. However, vertical profiles of Δ14C at the stations near Bikini and Enewetak Atolls show a similar general trend to those found in other stations.
Absolute Dating of Recent Sediments in the Cyclone-influenced Shelf Area Off Bangladesh: Comparison of Gamma Spectrometric (137Cs, 210Pb, 228Ra), Radiocarbon, and 32Si Ages
Authors: Suckow Axel , Morgenstern Uwe , Kudrass Herrmann-Rudolf
Published: July 2016

A geochronological survey of the Bengal shelf area involved results from more than 20 sediment cores dated using gamma spectrometry and the nuclides 137Cs, 228Ra, 226Ra, and 210Pb. In some cores, which contained older sediments, 32Si and 14C were determined to examine the possibility to extrapolate the obtained chronologies to century and millennial scale. Geochronological work in this region is faced with problems of cyclone-induced sediment reworking, grain-size effects on fallout nuclides, scarcity of carbonates, unknown 14C reservoir effect and sedimentation rates that are too high to obtain sediment cores long enough to establish a chronology. Despite these problems, comparison between the results of the different dating methods provided the most reliable sediment balance to date for the submarine delta of the Ganges-Brahmaputra river system and indicated that on a time scale of several centuries at least 35% of the annual sediment load is deposited.
Compound-Specific Radiocarbon Ages of Fatty Acids in Marine Sediments from the Western North Pacific
Authors: Uchida Masao , Shibata Yasuyuki , Kawamura Kimitaka , Kumamoto Yuichiro , Yoneda Minoru , Ohkushi Ken'ichi , Harada Naomi , Hirota Masashi , Mukai Hitoshi , Tanaka Atsushi , Kusakabe Masashi , Morita Masatoshi
Published: July 2016

Compound-specific radiocarbon analysis of five fatty-acid biomarkers was conducted for marine sediments collected from the western North Pacific. The fatty acids (C12 to C34) showed a typical bimodal distribution pattern with two maxima at C16 and C26. Their carbon isotopic compositions ranged from −25.1‰ (C16) to −31.8‰ (C28), suggesting that they derived from terrestrial higher plants and marine organisms. A large variations of 14C ages were found among the fatty acids detected in the same sedimentary horizon of the core, ranging from 530 BP (C18) to 3250 BP (C28). The results of 14C analysis of fatty acids could be divided into two groups, i.e., lower molecular weight (LMW) fatty acids (C16, C18) derived from marine organisms and higher molecular weight (HMW) fatty acids (C24, C26, C28) derived from terrestrial higher plants. The HMW fatty acids showed older ages, ranging from 2550 BP (C24) to 3250 BP (C28), than LMW fatty acids (530 BP [C18] to 1,820 years BP [C16]). On the other hand, bulk-phase total organic matter (TOM) showed the age of 2260 BP that is between those two groups, suggesting that it was likely a mixture of organic matter derived from marine and terrestrial sources. The compound specific 14C ages and δ13C data of sedimentary fatty acids presented here could provide useful information to decipher the fate and transport process of terrestrial organic matter to marine sediments.
Major Recent Tectonic Uplift in Iskenderun Bay, Turkey
Authors: Koral H , Kronfeld J , Avsar N , Yanko V , Vogel J C
Published: July 2016

Radiocarbon dating was carried out in the sediment profiles of four marine sediment cores taken from Iskenderun Bay, Turkey. The bay is quite shallow in the present day, and a previous tectonic study had considered that the bay floor might have been subsiding. However, this cannot be so, for the14C ages would thereby lead to the apparent paradox of normal marine sedimentation having taken place during times when glacio-eustatic sea level lowering would have exposed the bay floor. Rather, we conclude that the floor of Iskenderun Bay on the whole has been experiencing rapid uplift since the end of the Last Glacial, due to a combination of tectonic factors linked to the compression between the Anatolian and African plates.
The Kennewick Skeleton: Chronological and Biomolecular Contexts
Authors: Taylor R E , Smith David Glenn , Southon John R
Published: July 2016

A human skeleton recovered near Kennewick, Washington, USA in 1996 has been dated to the early Holocene on the basis of multiple radiocarbon determinations, an analysis of a style of a temporally diagnostic projectile point found embedded in the ilium of the skeleton, and geological investigations of the locality where the skeleton was recovered. Based on morphological criteria, the Kennewick skeleton, which is one of the most complete early Holocene human skeletons recovered so far in the Western Hemisphere, appears to be more similar to those of modern South Asians and Europeans than to modern Native Americans or to contemporary indigenous populations of Northeast Asia.
Radiocarbon as a Tool for Modeling the Diachronic Analysis of the Occupation Phases at the Velzeke Site (Belgium)
Authors: Strydonck Mark Van , Mulder Guy De , Deschieter Johan
Published: July 2016

The oldest traces of Velzeke go back to the Late Bronze Age and Early Iron Age, followed by a Gallo-Roman settlement and a later medieval village. Although the excavations document the history of the site in general, radiocarbon was used to clarify the successive phases within each feature. The results showed that the ditches at the Roman settlement and the neighboring temple area were already used during the Late Iron Age. The filling up of the ditches could be 14C correlated to a Gallo-Roman occupation phase. The oldest Christian cemetery at the site of the medieval church predates the construction of an important Carolingian stone building (9th to 10th centuries.). The stratigraphically lowest sediments of the ditches, surrounding the Carolingian church, are synchronous with the latest fill of the Iron Age ditch. According to historical and top-onymical sources the area of the Iron Age ditch becomes at that time part of a medieval agricultural field system.
Age Determination of Fossil Bones from the Vindija Neanderthal Site in Croatia
Authors: Wild Eva Maria , Paunovic Maja , Rabeder Gernot , Steffan Ilse , Steier Peter
Published: July 2016

Vindija cave in Croatia is famous for the Neanderthal bones found in layer G of its sediment profile. Radiocarbon dating has been performed mainly on this layer due to the great interest in its fossils. In addition to Neanderthal remains, the sediment in layer G contains bones from the cave bear. Cave bear bones are found also in other layers of the sediment profile and offer the possibility of studying the bears' evolutionary mode. Therefore, we tried to determine the time span covered by the entire profile. The U/Th age determination method was applied to cave bear bones from different layers of the profile. For the younger part of the profile, the U/Th ages were compared with the results of the 14C and the amino-acid racemization method. The agreement of the different methods indicates that closed-system behavior can be assumed for the fossil bones from Vindija cave. From this finding it may be deduced that bones from the lower sediment layers are also closed systems and that the U/Th ages of these layers are reliable. This conclusion is corroborated by the stratigraphy of the cave profile.
AMS Radiocarbon Dating of Tianma-Qucun Site in Shanxi, China
Authors: Guo Zhiyu , Liu Kexin , Lu Xiangyang , Ma Hongji , Li Kun , Yuan Jinglin , Yuan Sixun , Wu Xiaohong , Liu Xu
Published: July 2016

Tianma-Qucun is the biggest site of Western Zhou Dynasty discovered in Shanxi Province, China. It has been recognized as the early capital of Jin, a vassal state of Western Zhou. The territories were granted to the first Marquis of Jin with the title in the early days of Western Zhou. Bone sample series from the site were radiocarbon-dated by accelerator mass spectrometry (AMS) and calibrated with the Oxford calibration program OxCal 3.5. Bayesian analysis of the calibrated ages shows that the earliest residents of the Western Zhou came to Tianma-Qucun area in 1020–940 BC and the lower boundary of the Western Zhou is 796–754 BC, which corresponds well to the historical record 770 BC.