bluuebunny/crossref_metadata_2025 huggingface dataset:
A Continuous-Flow Gas Chromatography 14C Accelerator Mass Spectrometry System
Authors: McIntyre Cameron P , Galutschek Ernst , Roberts Mark L , von Reden Karl F , McNichol Ann P , Jenkins William J
Published: July 2016

Gas-accepting ion sources for radiocarbon accelerator mass spectrometry (AMS) have permitted the direct analysis of CO2 gas, eliminating the need to graphitize samples. As a result, a variety of analytical instruments can be interfaced to an AMS system, processing time is decreased, and smaller samples can be analyzed (albeit with lower precision). We have coupled a gas chromatograph to a compact 14C AMS system fitted with a microwave ion source for real-time compound-specific 14C analysis. As an initial test of the system, we have analyzed a sample of fatty acid methyl esters and biodiesel. Peak shape and memory was better then existing systems fitted with a hybrid ion source while precision was comparable. 14C/12C ratios of individual components at natural abundance levels were consistent with those determined by conventional methods. Continuing refinements to the ion source are expected to improve the performance and scope of the instrument.
The Origin of Pottery in East Asia and Its Relationship to Environmental Changes in the Late Glacial
Authors: Kuzmin Yaroslav V
Published: July 2016

The chronometry of the origin of pottery in East Asia can give some insights to the question: did environmental changes trigger and/or accelerate innovations such as pottery-making, maritime adaptation, and agriculture? Recent results show that pottery emerged in 3 regions of East Asia: south China (up to ∼14,800 BP), the Japanese Islands (about 13,800–13,500 BP), and the Russian Far East (∼13,300 BP). The earliest pottery in the Old World preceded the Bølling-Allerød warm period (about 13,000–11,500 BP). Thus, the relationship between climate and pottery origin was not “linear.” It seems that the combination of environmental changes and the necessity to process freshwater fish and mollusks and terrestrial plants (including acorns and nuts) resulted in the introduction of pottery-making in East Asia. An important feature is the quite nonuniform nature of the Neolithization process in the eastern part of Asia, where often in 2 neighboring regions pottery appeared at very different times: approximately 15,000–14,000 BP in south China and ∼4000 BP in mainland Southeast Asia. Thus, the kind of eternal question like “What caused what?” still stands in terms of what were the driving forces for the emergence of pottery in East Asia and worldwide.
The Late Paleolithic-Neolithic Transition in Korea: Current Archaeological and Radiocarbon Perspectives
Authors: Bae Christopher J , Kim Jong Chan
Published: July 2016

The application of chronometric dating studies in Korean archaeology has lagged behind similar research in China and Japan. The focus of this article is to provide an update on the accelerator mass spectrometry (AMS) radiocarbon dates derived from Korean Paleolithic and Early Neolithic sites. One of the major highlights from recent AMS 14C studies in Korea is that blade (and microblade) technologies may have diffused directly from Siberia, rather than through northern China as originally thought. In addition, a Neolithic wooden boat has been discovered in Korea that is as old as, if not older than, similar discoveries from eastern China. More detailed archaeological and chronometric studies in Korea in the coming years will certainly clarify many of the points mentioned here. In particular, through more detailed studies, we will be able to further evaluate the causal factors that provided the impetus for the Late Paleolithic-Neolithic transition in Korea.
Environmental Changes of the Aral Sea (Central Asia) in the Holocene: Major Trends
Authors: Krivonogov Sergey K , Kuzmin Yaroslav V , Burr George S , Gusskov Sergei A , Khazin Leonid B , Zhakov Eugeny Y , Nurgizarinov Aijaryk N , Kurmanbaev Rakhat Kh , Kenshinbay Temirbolat I
Published: July 2016

Changes of the Aral Sea level have been observed in 3 sediment boreholes, 2 outcrops, and associated archaeological sites. The obtained results are supported by 25 radiocarbon dates. Major trends of lake-level changes have been reconstructed in some detail for the last 2000 yr, and additional data provide an outline of fluctuations throughout the Holocene. Several distinct changes are shown to precede the modern, human-induced regression of the Aral Sea. These include: 1) the latest maximum in the 16th–20th centuries AD (53 m asl); 2) a Medieval “Kerderi” minimum of the 12th–15th centuries AD (29 m asl); 3) the early Medieval maximum of the 4th–11th centuries AD (52 m asl); and 4) a near BC/AD low-stand, whose level is not well established. Since then, events are only inferred from sparse data. The studied cores contain several sandy layers representing the lowering of the lake level within the Holocene, including the buried shore-bar of ∼4500 cal BP (38 m asl), and shallow-water sediments of ∼5600 cal BP (44 m asl), 7200 cal BP (28 m asl), and 8000 cal BP (26.5 m asl).
Experimental Study on the Origin of Cremated Bone Apatite Carbon
Authors: Hüls C M , Erlenkeuser H , Nadeau M-J , Grootes P M , Andersen N
Published: July 2016

Bones that have undergone burning at high temperatures (i.e. cremation) no longer contain organic carbon. Lanting et al. (2001) proposed that some of the original structural carbonate, formed during bioapatite formation, survives. This view is based on paired radiocarbon dating of cremated bone apatite and contemporary charcoal. However, stable carbon isotope composition of carbonate in cremated bones is consistently light compared to the untreated material and is closer to the δ13C values seen in C3 plant material. This raises the question of the origin of carbonate carbon in cremated bone apatite. That is, does the isotope signal reflect an exchange of carbon with the local cremation atmosphere and thus with carbon from the burning fuel, or is it caused by isotopic fractionation during cremation?

To study the changes in carbon isotopes (14C, 13C) of bone apatite during burning up to 800 °, a modern bovine bone was exposed to a continuous flow of an artificial atmosphere (basically a high-purity O2/N2 gas mix) under defined conditions (temperature, gas composition). To simulate the influence of the fuel carbon available under real cremation conditions, fossil CO2 was added at different concentrations. To yield cremated bone apatite properties similar to archaeological cremated bones, in terms of crystallographic criteria, water vapor had to be added to the atmosphere in the oven. Infrared vibrational spectra reveal large increases in crystal size and loss of carbonate upon cremation. The isotope results indicate an effective carbon exchange between bone apatite carbonate and CO2 in the combustion gases depending on temperature and CO2 concentration. 14C dates on archaeological cremated bone apatite may thus suffer from an old-wood effect. Paired 13C and 14C values indicate that in addition to this exchange, isotope fractionation between CO2 and carbonate, and admixture of carbon from other sources such as possibly collagen or atmospheric CO2, may play a role in determining the final composition of the apatite carbonate.
Radiocarbon Dating, Stable Isotope Analysis, and Diet-Derived Offsets in14C Ages from the Klin-Yar Site, Russian North Caucasus
Authors: Higham Thomas , Warren Rebecca , Belinskij Andrej , Härke Heinrich , Wood Rachel
Published: July 2016

The influence of geothermally derived carbon on the radiocarbon dating of human bone from archaeological sites is poorly understood and has rarely been rigorously examined. This study identifies a previously unknown reservoir effect at the archaeological site of Klin-Yar in the Russian North Caucasus. AMS-dated human bones yielded results that were older than expected when compared with dates of coins found in the same grave contexts. We investigated the reasons for this offset by AMS dating modern plant, fish, and water samples to examine the source of the old carbon. We identified a potential source in geothermally derived riverine and spring water, with an apparent age of several thousand years, and hypothesize that carbon from here is being transferred through the food chain to humans. If humans consume resources from the local rivers, such as fish, then they ought to be affected by this reservoir offset. An extensive analysis of carbon and nitrogen isotopes of human and animal bone showed evidence for a mixed diet that may be masking the amount of freshwater-derived protein being consumed. Due to the highly variable nature of the14C offset (0 to ∼350 yr), no suitable average correction factor is applicable to correct for the human dates at the site. A14C chronology based on dates obtained from terrestrial ungulate bones, which we subsequently obtained, is instead a more reliable indicator of age.
Improved AMS14C Dating of Shell Carbonates Using High-Precision X-Ray Diffraction and a Novel Density Separation Protocol (Cards)
Authors: Douka Katerina , Hedges Robert E M , Higham Thomas F G
Published: July 2016

One critical variable in the successful application of radiocarbon dating is the effective removal of carbonaceous contaminants. In the case of marine carbonates, contamination appears usually in the form of secondary low-magnesium calcite, the stable polymorph of calcium carbonate and byproduct of the post-mortem recrystallization or replacement of the autochthonous phase, originally in the form of high-magnesium calcite or aragonite. Depending on the nature of the depositional environment, the secondary phase may be contemporary in age with the original shell carbonate and may have even been derived from it by dissolution-recrystallization processes, or can be an exogenous contaminant of younger or older age. The limited ability of current pretreatment protocols to detect and remove the secondary mineralogical phases prior to dating carbonates has been one of the reasons marine shell and coral14C determinations are often difficult to validate in terms of their reliability. We have developed a new pretreatment protocol designed to achieve greater reliability and accuracy in the dating of this material. The method entails 2 steps. The first one involves the improved detection and quantification of secondary calcite in aragonite using X-ray diffraction, at a precision of ∼0.1% and ∼0.8%, respectively. Next, where this is required, a novel density separation step using non-toxic heavy liquids (CarDS) is applied to the diagenetic sample. This enables the clear separation of calcite and aragonite, with only the latter kept for dating. We have applied the new steps, screening and separation, on standard and archaeological examples and our initial results suggest that it is successful and reproducible. In this paper, we describe the method and initial results.
Towards On-Line 14C Analysis of Carbonaceous Aerosol Fractions
Authors: Perron Nolwenn , Szidat Sönke , Fahrni Simon , Ruff Matthias , Wacker Lukas , Prévôt André SH , Baltensperger Urs
Published: July 2016

Atmospheric carbonaceous aerosol is traditionally divided into organic carbon (OC) and elemental carbon (EC). Their respective carbon amounts are usually analyzed by means of an OC/EC analyzer and their fossil and non-fossil origins can be determined by radiocarbon analysis, which has proven to be a powerful tool for carbonaceous aerosol source apportionment. Thus far, separation of OC and EC has been performed off-line by manual and time-consuming techniques. We present an on-line system that couples a commercial OC/EC analyzer with the gas ion source of the accelerator mass spectrometer (AMS) MICADAS and its CO2 feeding system. The performance achieved with reference materials and blanks are discussed to demonstrate the potential of this coupling for source apportionment of atmospheric carbonaceous particulate matter.
Laser-Heated Microfurnace: Gas Analysis and Graphite Morphology
Authors: Smith A M , Yang Bin , Hua Quan , Mann Michael
Published: July 2016

We describe progress in developing a novel miniaturized laser-heated “microfurnace” aimed at preparing ultra-small (∼5 μg) graphite samples from CO2 (Smith et al. 2006, 2007, 2010). Recent effort has focused on automation of the process using a LabVIEW interface, which has permitted feedback control of the catalyst temperature as the reaction proceeds and the logging of reaction parameters. We trialed a number of different pure iron catalysts as well as Fe2O3 (which is reduced in situ to iron) and discuss the reaction rates. We studied the graphite morphology by scanning electron microscopy (SEM) and found there is a marked difference in graphite morphology with catalyst type. We assessed how each catalyst performs in the cesium sputter ion source of the ANTARES Accelerator Mass Spectrometry (AMS) facility. We utilized a quadrupole mass spectrometer to study the gas composition during the reaction, in order to better understand the underlying chemical reactions for such small samples and to better estimate the overall efficiency of the process. Results show that all CO2 is converted to CO by reduction on the iron catalyst within a few minutes of applying laser power. The reaction pressure stabilizes after 40 min; however, some CO is not converted to graphite. The cold trap temperature of –80 ° is effective at trapping H2O, so there is little CH4 production.
Tree-Ring Dating and AMS Wiggle-Matching of Wooden Statues at Neunggasa Temple in South Korea
Authors: Park Won-Kyu , Kim Yojung , Jeong Ah-Reum , Kim Sang-Kyu , Oh Jung-Ae , Park Suh-Young , Choi Sunil , Park Gyujun , Seo Jeong-Wook
Published: July 2016

This paper reports the results of tree-ring dating and accelerator mass spectrometry (AMS) wiggle-matching for wooden Buddhist statues stored at the Eungjindang Hall of Neunggasa Temple, South Korea. Among 23 statues, 10 were successfully dated by tree rings. The cutting date of logs used for the statues was determined as some time between late fall 1684 and early spring 1685 when the bark ring (AD 1684) completed latewood formation. The 95.4% confidence interval of a radiocarbon date (cal AD 1688–1713, 2 σ), which was obtained by wiggle-matching 7 samples of a statue, is similar to the dendro-date (AD 1684). A historical document recorded that the statues in the Eungjindang of Neunggasa were dedicated in July 1685. The dendro-date and written record indicate that Eungjindang statues were made within 3–8 months after log cutting. This seems rather short if we consider the period required for natural drying to avoid defects such as cracking and crooking.
Zagrada—The New Zagreb Radiocarbon Database
Authors: Portner Antun , Obelić Bogomil , Bronić Ines Krajcar
Published: July 2016

After introducing the liquid scintillation counting (LSC) method and graphite target preparation for accelerator mass spectrometry (AMS) measurements in the Zagreb Radiocarbon Laboratory, the existing database software designed only for gas proportional counting (GPC) (using a DOS operating system) could not satisfy the requirements for parallel conduction of several techniques. This has been enabled recently by the development of the new relational database ZAGRADA, which—using SQL scripts and constraints defined by primary and foreign keys—enforces high data integrity and provides better performances in data filtering and sorting. The structural scheme of this database conceptually comprises 4 basic modules with data on the samples, chemical pretreatment and preparation, measurements and data on the final results. A user-friendly graphical user interface has been designed to perform various actions and data manipulation to the database. The implementation of a new database for 14C samples has significant contribution to scientific research performed in the Radiocarbon and Tritium Laboratory and to quality assurance and quality control, and will enable better and easier communication with customers.
Scandinavian Models: Radiocarbon Dates and the Origin and Spreading of Passage Graves in Sweden and Denmark
Authors: Paulsson Bettina Schulz
Published: July 2016

Approximately 2700 radiocarbon results are currently available from European megalithic contexts. The interpretation of these14C dates is often difficult. It is not easy to connect many of them from their archaeological context to the construction or the burial phase of the graves. This paper focuses on the megaliths of Scandinavia—a special megalith region—as it is the only place in Europe with14C dates directly referable to the construction of the passage graves, the graves have good bone preservation, and new dating sequences are available. Some 18814C results are now available from Scandinavian passage graves. In Sweden, new data suggest that these graves were built from the first half of the 35th century BC onwards. The14C dates from birch bark as filling material between dry walls make it possible to build a sequence for the construction phase of the passage graves in Denmark from the 33rd century BC onward. With an interpretative Bayesian statistical framework, it is possible to untangle the nuances of the differences for the origin and the spreading of the megaliths in the different regions, to define, together with the archaeological remains, possible cultural-historical processes behind these phenomena and to discuss diffusion versus convergence.
Age-Depth Model of Lake Soppensee (Switzerland) Based on the High-Resolution 14C Chronology Compared with Varve Chronology
Authors: Hajdas Irka , Michczyński Adam
Published: July 2016

An age-depth model for laminated sediments of Lake Soppensee is constructed using radiocarbon ages of macrofossils and a depositional model of the OxCal v 4.1 program with the updated IntCal09 data set. The resulting calendar chronology is compared with the varve chronology that was built for this record in a previous study (Hajdas 1993); there is a very good agreement between the 2 approaches. This illustrates the potential of high-resolution 14C dating for construction of reliable, high-resolution calendar timescales for sedimentary records. Based on the age-depth model of this study, the Vasset/Killian tephra found in sediment of Soppensee dates to a calendar age of 9291–9412 cal BP (2-σ range) while the Lachersee tephra dates to 12,735–12,871 cal BP (2-σ range). Precise dating of the Late Glacial boundaries is possible with this chronology but requires more precise correlation between proxies and records than typically practiced.
Spatial Radiocarbon and Stable Carbon Isotope Variability of Mineral and Thermal Waters in Slovakia
Authors: Povinec P P , Franko O , Šivo A , Richtáriková M , Breier R , Aggarwal P K , Araguás-Araguás L
Published: July 2016

Isotope hydrology investigations were carried out with the aim to study isotope variability in mineral and thermal waters (MTW) of Slovakia. The aquifers of MTW were formed by Triassic limestones and dolomites, which are found in the mountains as well as in the pre-Tertiary substratum of depressions and lowlands. The MTW were of artesian and/or open structures. At present, there are only boreholes available, as natural outflows have already been captured by them. Large spatial isotope variability (14C between 2 and 33.6 pMC, δ18O between −11.8‰ and −9.8‰, and δ13C between −12.7‰ and +3.4‰ for bicarbonates and −21‰ and –4.9‰ for free CO2) and heterogeneity of MTW was observed, indicating different origins of MTW. Corrected radiocarbon apparent ages of MTW indicate that they mostly infiltrated during the Würm and Holocene periods.
High Contribution of Recalcitrant Organic Matter to DOC in a Japanese Oligotrophic Lake Revealed by 14C Measurements
Authors: Nara Fumiko Watanabe , Imai Akio , Uchida Masao , Matsushige Kazuo , Komatsu Kazuhiro , Kawasaki Nobuyuki , Shibata Yasuyuki , Amano Kunihiko , Mikami Hajime , Hanaishi Ryuji
Published: July 2016

Carbon isotopes (14C and 13C) of dissolved organic carbon (DOC) in a Japanese oligotrophic lake (Lake Towada) were measured to study the origin and cycling of dissolved organic matter (DOM) in Lake Towada. Lake water samples were collected at 3 depths (0, 30, and 80 or 85 m) during 4 months (April, June, August, and October) in 2006. 14C measurements of DOC were performed by accelerator mass spectrometry (AMS) at the National Institute for Environmental Studies (NIES-TERRA) in Japan. Δ14C and δ13C values of DOC in Lake Towada showed light carbon isotopic values ranging from –750 to −514‰ and –29.0 to –27.8‰, respectively. These values are similar to those of humic substances reported. The very low carbon isotopic values of DOC in Lake Towada suggest a very small contribution of DOC derived from fresh phytoplankton to the lake DOC. There is an extremely high linear relationship between the Δ14C and δ13C of DOC in Lake Towada when all data points are plotted (r2 =0.818, p < 0.01), suggesting that the DOC in Lake Towada has 2 specific sources contributing heavy and light carbon isotopes. Although the freshly produced DOC of phytoplankton origin can be decomposed easily, the variation in the autochthonous DOC should influence the carbon isotopic values of DOC in Lake Towada.
A New Radiocarbon Pretreatment Method for Molluscan Shell Using Density Fractionation of Carbonates in Bromoform
Authors: Russo Christopher M , Tripp Jennifer A , Douka Katerina , Higham Thomas F G
Published: July 2016

Coastal archaeological sites that lack organic remains for radiocarbon dating are often abundant sources of molluscan shells. As a substitute for materials such as bone and charcoal, shells can be analyzed with14C dating to determine a site's age. Despite their being convenient, non-mobile archaeological artifacts, molluscan shells are plagued by several issues, including carbonate remodeling, in which aragonite in shells is converted to calcite as predicted by thermodynamics. We present here a carbonate density separation technique that addresses the issue of carbonate remodeling. Using a density fractionation with bromoform, aragonite concentrations are enriched in shells that have undergone significant remodeling. The technique has been applied to archaeological shells and has returned dates that are younger than those previously determined for the same shells.
A Thermal and Acid Treatment for Carbon Extraction from Cast Iron and Its Application to Ams Dating of Cast Iron Objects from Ancient Korea
Authors: Park J S , Burr G S , Jull A J T
Published: July 2016

A method of thermal and acid treatments was developed at the Archaeo-metallurgy Laboratory of Hongik University in Korea to extract carbon from cast iron, and carbon objects thus prepared from cast iron artifacts of ancient Korea were dated at the University of Arizona's AMS Facility. The thermal treatments consist of heating a specimen to ∼1000 °C in a controlled environment with reduced oxygen potential, then cooling it rapidly to room temperature. The heating causes the cementite phase in white cast iron to be graphitized and the quenching suppresses pearlite formation. The specimen then consists of flakes of graphite embedded in a matrix of martensite. The next stage of the treatment is to dissolve the martensite matrix in a solution of nitric and hydrochloric acids to release the graphite as a powder. This material is then cleaned, dried, and pressed into target holders for accelerator mass spectrometry (AMS) analysis. The method was applied to a collection of artifacts from the Korean Three Kingdoms period (about AD 300–668) and the AMS results were compared with chronological estimates from other means.
Hydropyrolysis: Implications for Radiocarbon Pretreatment and Characterization of Black Carbon
Authors: Ascough P L , Bird M I , Meredith W , Wood R E , Snape C E , Brock F , Higham T F G , Large D J , Apperley D C
Published: July 2016

Charcoal is the result of natural and anthropogenic burning events, when biomass is exposed to elevated temperatures under conditions of restricted oxygen. This process produces a range of materials, collectively known as pyrogenic carbon, the most inert fraction of which is known as black carbon (BC). BC degrades extremely slowly and is resistant to diagenetic alteration involving the addition of exogenous carbon, making it a useful target substance for radiocarbon dating particularly of more ancient samples, where contamination issues are critical. We present results of tests using a new method for the quantification and isolation of BC, known as hydropyrolysis (hypy). Results show controlled reductive removal of non-BC organic components in charcoal samples, including lignocellulosic and humic material. The process is reproducible and rapid, making hypy a promising new approach not only for isolation of purified BC for 14C measurement but also in quantification of different labile and resistant sample C fractions.
Radiocarbon and Stable Carbon Isotope Ratio Data from a 4.7-Mlong Sediment Core of Lake Baikal (Southern Siberia, Russia)
Authors: Nara Fumiko Watanabe , Watanabe Takahiro , Nakamura Toshio , Kakegawa Takeshi , Katamura Fumitaka , Shichi Koji , Takahara Hikaru , Imai Akio , Kawai Takayoshi
Published: July 2016

A sediment core (VER99G12; core length, 4.66 m) was taken from the Buguldeika Saddle of Lake Baikal in 1999. Radiocarbon measurements of total organic carbon (TOC) and pollen concentrate fractions from the VER99G12 core were performed by a Tandetron accelerator mass spectrometry (AMS) system (Model-4130, HVEE) at Nagoya University. The AMS 14C ages showed that the VER99G12 core spans the past ∼30 cal ka BP (from the MIS 3 to present), and the average sedimentation rate of this core was calculated to be 13.6 cm/kyr based on the calibrated ages. This means that the time resolution of VER99G12 sediment samples in this study is better than ∼70–80 yr/cm. Stable carbon isotope ratios of TOC (δ13CTOC) in the VER99G12 core varied widely from about 26.6‰ to 31.3‰ during the last glacial/post-glacial transition period (about 17–12 cal ka BP). Therefore, a rapid change in the carbon sources in Lake Baikal occurred in the last glacial/post-glacial transition period is concluded.
New Radiocarbon Dates from the Late Neolithic Tell Settlement of Hódmezővásárhely-Gorzsa, SE Hungary
Authors: Gulyás Sándor , Sümegi Pál , Molnar Miliáry
Published: July 2016

Understanding the internal chronology of the Late Neolithic Tisza culture and the Neolithic of the Tisza region is the subject of debate in both Hungarian and international prehistoric research. The layer sequence of the Late Neolithic Gorzsa tell from SE Hungary offers ideal match points for determining the successive phases of the Tisza culture. According to the results published so far, in the Gorzsa sequence the Tisza culture was divided into 4 main phases with a fifth phase representing the transitional period to the Early Copper Age. Excavations were carried out in 33 profiles covering about 2% of the original area of the entire settlement. The archaeostratigraphy established was based on the identification of microhorizons corresponding to settlement levels. Radiocarbon dates published thus far were created using a pool of various objects of differing microhorizons deriving from different profiles. However, as archaeological results revealed, the settlement was characterized by frequent, minor spatial shifts during its evolution into a tell complex. Here, we present a succession of 7 14C dates deriving from a single profile located at the northeastern flank of the excavation area. The 7 dates span the entire profile from the uppermost microhorizons down to the lowermost ones. The new dates were compared with the existing relative chronology mentioned above. According to our findings, material was deposited in this part of the site mainly during the first 2 phases of evolution of the tell complex. The later phases are either less developed or missing due to possibly a spatial shift of the center of the tell complex resulting first in a deceleration and finally a complete cessation of artifact accumulation to the northwest flanks of the former natural levee. Thus, the previous hypothesis of spatial shifts based on relative chronologies within the site has been corroborated. Furthermore, the congruence between our new dates corrected for any reservoir effect and the previous dates of Hertelendi (1998) may refer to a correct determination of freshwater shell carbonate reservoir effect in the fluvial system of the Tisza River, which may be used in further studies in the area.
Effects of Vegetation Switch and Subsequent Change in Soil Invertebrate Composition on Soil Carbon Accumulation Patterns, Revealed by Radiocarbon Concentrations
Authors: Toyota Ayu , Tayasu Ichiro , Fujimaki Reiji , Kaneko Nobuhiro , Uchida Masao , Shibata Yasuyuki , Hiura Tsutom
Published: July 2016

Vegetation types strongly affect soil organic carbon (SOC) accumulation in the terrestrial ecosystem through multiple factors such as litter quality and soil biodiversity. However, the roles of soil fauna in SOC accumulation remain unclear. The objectives of this study were to (1) examine how changes in litter types and soil animal communities affect SOC accumulation in continuously forested or vegetation-switched forest areas; and (2) discuss the role of soil animals in SOC accumulation in forest ecosystems. We focused on soils that have accumulated on top of a volcanic ash layer in the 268 yr since a volcanic eruption in 1739. The radiocarbon “bomb spike”' in the late 1950s and early 1960s provides a unique isotopic signature of soil carbon age. We investigated the combined effects of litter quality and soil invertebrate function on soil14C accumulation patterns. To determine the effects of vegetation types on SOC accumulation, we selected 4 types of cool temperate forests, 2 of which had undergone a vegetation switch in about 1960 (conifer to broadleaved forest, CB; broadleaved forest to conifer, BC), and 2 that had continuous forests (conifer forest, CC; broadleaved forest, BB). The Δ14C values at depth intervals in CC were consistent with the expected bomb-14C profile. In contrast, Δ14C patterns in BB, BC, and CB differed from that of CC. Compared to CC, Δ14C values of the other sites showed relatively high14C concentrations even in deeper soil layers, which suggests the bomb-induced14C has been transported to a greater depth by soil animals. Current broadleaved forests (BB and CB) had higher biomass of litter-feeding invertebrates than in current coniferous forests (CC and BC). These results suggest that carbon from leaf litter was vertically translocated to deeper soil layers by the abundant soil invertebrates in broad-leaved forests. Disagreement with the expected soil profile in BC suggests that past vegetation (broadleaved forest) has affected the present SOC accumulation pattern.
Radiocarbon Dating of the Last Volcanic Eruptions of Ciomadul Volcano, Southeast Carpathians, Eastern-Central Europe
Authors: Harangi Sz , Molnár M , Vinkler A P , Kiss B , Jull A J T , Leonard A G
Published: July 2016

This paper provides new accelerator mass spectrometry (AMS) radiocarbon age data for the last volcanic events in the Carpathian-Pannonian region of eastern-central Europe. The eruption ages were determined on charcoal fragments collected from pumiceous pyroclastic flow deposits at 2 localities of the Ciomadul Volcano. Two charcoal samples from the southeastern margin of the volcano (Bixad locality) set the date of the last volcanic eruption to 27,200 ± 260 yr BP (29,500 ± 260 cal BC). On the other hand, our data show that the Tusnad pyroclastic flow deposit, previously considered as representing the youngest volcanic rock of the region, erupted at ∼39,000 yr BP (∼41,300 cal BC). Thus, a period of dormancy more than 10,000 yr long might have elapsed between the 2 volcanic events. The different ages of the Tusnad and Bixad pyroclastic flow deposits are confirmed also by the geochemical data. The bulk pumices, groundmass glass, and the composition of the main mineral phases (plagioclase and amphibole) suggest eruption of slightly different magmas. Considering also the assumed long volcanic history (∼600 ka) of the Ciomadul, these data suggest that further detailed studies are necessary on this seemingly inactive volcano in order to evaluate the possible renewal of volcanic activity in the future.
Dating the End of the Neolithic in an Eastern Sahara Oasis: Modeling Absolute Chronology
Authors: Wuttmann Michel , Briois François , Midant-Reynes Béatrix , Dachy Tiphaine
Published: July 2016

The Neolithic site KS043, excavated by the Institut français d'archéologie orientale (IFAO), is situated in the southern basin of the Kharga Oasis (Egypt). It is one of the very few stratified prehistoric sites of the eastern Sahara. The archaeological remains were found near artesian springs that provided water for pastoralists during the dry Middle Holocene. In situ settlement features provided well-preserved material (charcoal, ashy sediment, ostrich eggshell) sufficient to perform radiocarbon dating in the IFAO laboratory in Cairo by the conventional liquid scintillation method. In 2 cases, ostrich eggshell and charcoal within the same in situ context gave significantly different results of, respectively, ∼600 and ∼1200 yr younger dates for the ostrich eggshells. The strong discrepancy is here highlighted for the first time and we suggest that it may be linked with postdepositional phenomena in the vicinity of the artesian springs. A thorough review of 14C dates available for the Holocene in eastern Sahara shows that ostrich eggshells have been widely used. They seem slightly more prone to be discarded than other material but were never the object of a particular study in this context. Bayesian modeling shows that the Neolithic occupation at site KS043 spans a range from 5000 to 3950 cal BC (and concentrated around 4600–4350 cal BC). Characteristic flint tools and pottery relate this occupation to the end of the Neolithic and show links with the Tasian culture, confirming the timing of the presence of this cultural complex in the desert before its appearance in the Nile Valley.
Problems in the Measurement, Calibration, Analysis, and Communication of Radiocarbon Dates (With Special Reference to the Prehistory of the Aegean World)
Authors: Wiener Malcolm H
Published: July 2016

Radiocarbon dating encounters (1) problems of reservoir effects and regional/seasonal variation affecting the chronological reliability of measurements, (2) problems of calibration of measurements via comparison with tree segments of known dendrochronological dates, (3) problems of statistical inference with respect to the data pre- and post-calibration, and (4) problems of the analysis and communication of information to archaeologists, historians, and other interested parties. This paper considers the special characteristics of each of the problem areas indicated in order to improve communication between14C scientists and the disciplines of archaeology, anthropology, and ancient history.
The Date of the Minoan Santorini Eruption: Quantifying the “Offset”
Authors: Höflmayer Felix
Published: July 2016

Despite many recent attempts to settle the dispute concerning the absolute date of the Minoan Santorini eruption, there are still differences between some archaeologists and scientists on the absolute dates and the reliability of radiocarbon dating. The recent publication of over 200 new14C dates for dynastic Egypt rules out a major flaw in the historical chronology of Egypt and proves the reliability of14C dating in the Nile Valley. Therefore, the student of Aegean archaeology and eastern Mediterranean interconnections is still confronted with an archaeologically based conventional, or “low,” chronology and a14C-backed “high” chronology. New14C determinations from different sites of the Aegean support the high chronology for the Late Minoan (LM) IA, while recent re-evaluation of LM IB determinations are slightly higher but more or less in agreement with archaeological estimations. The present contribution reviews archaeological and scientific data for the LM IA period and argues that a reduced (∼30 to 50 yr) offset between archaeological and14C dates for the Minoan Santorini eruption may be possible, thus offering new perspectives for potential solutions for this problem.
Radiocarbon Age for the Cultural Layer of the Neolithic-Bronze Age Settlement Pesochnoe-1 (Lake Nero, Russia)
Authors: Alexandrovskiy A L , Voronin K V , Dolgikh A V , Kovalukh N N , Skripkin V V , Glavatskaya E V
Published: July 2016

Organic matter in the cultural layer of the ancient settlement Pesochnoe-1 near Lake Nero (NE of Moscow) yields reliable radiocarbon dates. The reason for this is the high concentrations of calcium and phosphorus in the cultural layer, especially in calcined bones. Several cultural epochs are distinguished in the cultural layer consisting of more or less homogeneous habitation deposits colored with humic susbstances. Artifacts of the Ljalovo culture are found in the lower part of the cultural layer; above these, artifacts of the Volosovo culture are present, and the upper part of the cultural layer corresponds to the Textile Ceramics culture. The 14C dates for humic substances in the layers show a good chronological stratification and correspond to known ages of these cultural stages. The 14C dates for the Ljalovo cultural layer cover 5600–5100 BP (4430–3900 cal BC), and dates for the Volosovo cultural layer span 4400–4200 BP (3000–2840 cal BC). Most dates from the upper part of the cultural layer correspond to the chronological interval of the Textile Ceramics culture and range from 3700 to 3200 BP (2100–1460 cal BC). More precise 14C dates were obtained for humic substances from archaeological objects in the upper cultural layer (hearths, fillings of pottery vessels, etc.): 3900–3500 BP (2100–1800 cal BC).
Potential of the Radiocarbon Method for Dating Known Historical Events: The Case of Yaroslavl, Russia
Authors: Engovatova A V , Zaitseva G I , Dobrovolskaya M V , Burova N D
Published: July 2016

We address here the methodological question of potentially using the radiocarbon method for dating historical events. The archaeological investigations in Yaroslavl (central Russia) provide an example. The Institute of Archaeology of the Russian Academy of Sciences (IARAS) has been conducting excavations at the site for many years, and many archaeological complexes dating to different times have come to light. The most interesting of these are connected with the founding of the city by Prince Yaroslav the Wise in AD 1010 (the first fortifications) and with the devastation of the city by the Tatar Mongols in 1238 (evidenced by sanitary mass burials of Yaroslavl's inhabitants). We have conducted a certain experiment, a “reverse” investigation of the chronology of the events. The dates of the events are known from chronicles, archaeological materials, and dendrochronological data for several assemblages. We have taken a large series of 14C samples from the same assemblages, dated them in 2 different laboratories, and compared the data. The accuracy of the 14C dates proved to be compatible with dates found via the archaeological material. The article shows the potential for 14C dating of archaeological assemblages connected with known historical events. The results of the research conducted by the authors serve as an additional argument for the broader use of the 14C dating method in studies of archaeological sites related to the Middle Ages in Russia.
Paired Dating of Pith and Outer Edge (Terminus) Samples from Pre-Hispanic Caribbean Wooden Sculptures
Authors: Brock Fiona , Ostapkowicz Joanna , Ramsey Christopher Bronk , Wiedenhoeft Alex , Cartwright Caroline
Published: July 2016

Radiocarbon dating of historical and archaeological wood can be complicated, sometimes involving issues of “inbuilt” age in slow-growing woods, and/or the possibility of reuse or long delays between felling and use of the wood. Terminus dates can be provided by dating the sapwood, or the outermost edge of heartwood, while a date from the pith can give an indication of the first years of growth. A sequence of samples from specific points within the bole can be used to determine the growth rate of the tree. Such a combined dating strategy is particularly useful in cross-referencing dates from a single piece, better placing it in its chronological context. This paper reports paired or multiple dates from 11 wooden sculptures dated as part of the Pre-Hispanic Caribbean Sculptural Arts in Wood project, which studied 66 wooden artifacts attributed to the pre-colonial Taíno, the indigenous peoples of the Caribbean's Greater Antilles. The calibrated ages of the pieces published here range from ∼AD 700–1500, indicating that the Taíno were producing elaborate sculptures much earlier than previously thought. The paired or multiple dates from these carvings confirmed the accuracy of the results, and were also used to construct a growth rate model of what was expected to be a slow-growing species (Guaiacum sp.). This model demonstrates that the boles used to create the sculptures grew on average 1 cm every 6–13 yr.
Radiocarbon Chronology of the Shigir and Gorbunovo Archaeological Bog Sites, Middle Urals, Russia
Authors: Zaretskaya Natalia E , Hartz Sönke , Terberger Thomas , Savchenko Svetlana N , Zhilin Mikhail G
Published: July 2016

Two well-known archaeological sites, the peat bogs of Shigir and Gorbunovo (Middle Urals, Russia), have been radiocarbon dated (61 conventional and accelerator mass spectrometry [AMS] dates from various natural and artifact samples). For the first time, a detailed chronology of Early to Late Mesolithic and Early Neolithic occupation for this region has been obtained, and a paleoenvironmental history reconstructed. Based on these results, we propose that the Mesolithic settlement of the Middle Urals region started in the early Holocene, at the same time as in central and eastern Europe.
Integrating Non-Destructive Ion Beam Analysis Methods and AMS Radiocarbon Dating for the Study of Ancient Bronze Statues
Authors: Quarta Gianluca , Calcagnile Lucio , Vidale Massimo
Published: July 2016

Analytical methods based on particle accelerators are widely used in cultural heritage diagnostics and archaeological sciences from the absolute dating of organic materials by means of radiocarbon accelerator mass spectrometry (AMS) to the analysis of the elemental composition of a wide range of materials (metals, obsidians, pottery) via ion beam analysis (IBA) techniques. At CEDAD (Centre for Dating and Diagnostics), the accelerator facility of the University of Salento, AMS 14C dating and PIXE (particle-induced X-ray emission)-PIGE (particle-induced gamma-ray emission) compositional analysis in external beam mode are combined to study certain archaeological materials. We present a review of the combined application of these analytical methods in the study of casting cores of the Riace bronzes, 2 classical Greek statues of extraordinary importance for the history of art.
Radiocarbon Dating of Calcined Bones: Insights from Combustion Experiments Under Natural Conditions
Authors: Zazzo Antoine , Saliège Jean-François , Lebon Matthieu , Lepetz Sébastien , Moreau Christophe
Published: July 2016

Radiocarbon dating of the carbonate remaining in calcined bones is widely regarded as a viable alternative to date skeletal remains in situations where collagen is no longer present. However, anomalously low δ13C values measured in calcined bones prompted questions about the origin of the carbon used for dating. The goal of this study was to quantify the magnitude of carbon isotope exchange between bone carbonate and environmental CO2 for bones calcined under natural conditions. Four archaeological bones ranging in age between the Neolithic and the Medieval period were combusted on a separate open fire for up to 4 hr and subsamples of calcined bones were taken every hour. All the bones experienced a significant increase in IRSF values and decrease in carbonate content and δ13C values. 14C ages measured in the carbonate fraction of well-calcined bones indicate that 67 ± 3% to 91 ± 8% of the carbon present in bone carbonate was replaced by carbon from the atmosphere of combustion. This finding confirms previous results obtained under laboratory conditions and has serious implications for 14C dating of calcined bones found in archaeological contexts. The 14C age obtained on a calcined bone will only reflect the true age of the bone sample if the age difference between the bone and the charcoal can be neglected. Our results show also that δ13C values of calcined bones can be used to estimate the degree of C exchange and control for post-burial diagenetic alteration.
Reliability of Nitrogen Content (%N) and Carbon:Nitrogen Atomic Ratios (C:N) as Indicators of Collagen Preservation Suitable for Radiocarbon Dating
Authors: Brock Fiona , Wood Rachel , Higham Thomas F G , Ditchfield Peter , Bayliss Alex , Ramsey Christopher Bronk
Published: July 2016

A recent study into prescreening techniques to identify bones suitable for radiocarbon dating from sites known for poor or variable preservation (Brock et al. 2007, 2010a) found that the percent nitrogen (%N) content of whole bone powder was the most reliable indicator of collagen preservation. Measurement of %N is rapid, requires little preparation or material, and is relatively cheap. The technique reduces the risk of needlessly sampling valuable archaeological objects, as well as saving time and money on their unsuccessful pretreatment prior to dating. This method of prescreening is now regularly used at the Oxford Radiocarbon Accelerator Unit (ORAU). In the original study, linear regression analysis of data from 100 bones from 12 Holocene sites across southern England showed that when 0.76% N was chosen as a threshold, 84% of bones were successfully identified as containing sufficient (i.e. >1%) or insufficient (i.e. <1%) collagen for dating. However, it has been observed that for older, Pleistocene bones the failure rate may be higher, possibly due to the presence of more degraded, short-chain proteins that pass through the ultrafilters used in pretreatment, resulting in lower yields. Here, we present linear regression analysis of data from nearly 600 human and animal bones, antlers, and teeth, from a wide range of contexts and ages, to determine whether the 0.76% threshold identified in the previous study is still applicable. The potential of carbon:nitrogen atomic weight ratios (C:N) of whole bone to predict collagen preservation is also discussed.
Lime Mortar and Plaster: A Radiocarbon Dating Tool for Dating Nabatean Structures in Petra, Jordan
Authors: Al-Bashaireh Khaled , Hodgins Gregory W
Published: July 2016

This research aims at radiocarbon dating 2 structures of archaeological interest from Petra, south Jordan, using lime plaster and mortar. Initially, the samples' content of calcareous contamination was examined by petrography and cathodoluminescence. In order to date clean lime binders, the samples were gently crushed and 63–45 μm powders were collected by dry sieving, then the CO2 gases, collected by a hydrochloric acid hydrolysis of the powders, were dated. The interpreted 14C dates clarify the chronology of the studied structures, show an agreement with the archaeological and historical data, and may indicate the efficiency of the cleaning and hydrolysis procedures.