bluuebunny/crossref_metadata_2025 huggingface dataset:
La Jolla Natural Radiocarbon Measurements III
Authors: Hubbs Carl L. , Bien George S. , Suess Hans E.
Published: July 2016

During 1962 the La Jolla Radiocarbon Laboratory continued to follow essentially the same technique as in previous years. Three counters were used:

1.

The “Bern Counter,” an Oeschger-Houtermans instrument manufactured at the Physical Institute of the University of Bern; described in La Jolla I (p. 197).

2.

The “Brussels Counter,” another Oeschger-Houtermans instrument, manufactured in Brussels by Manufacture Belge de Campes et de Matériel Électronique, S. A.; characterized in La Jolla II (p. 204).

3.

The “400-cc La Jolla Counter,” recently constructed at the University of California, San Diego to facilitate the age determination of samples containing less than 1 g of carbon. Because the first model, now in use, was constructed of brass—not the optimal material—the background count is relatively high (ca. 5.0 counts/min). Advantages lie in its high stability. For samples that yield 0.5 L or more of acetylene, this counter can be used quite satisfactorily. Check runs, using the same sample in this counter and in the Bern and Brussels counters, agree closely.
Arizona Radiocarbon Dates IV
Authors: Damon Paul E. , Long Austin , Sigalove Joel J.
Published: July 2016

C14 measurements reported here were made in this laboratory between December 1, 1961 and October 1, 1962. Sample descriptions are classified as follows:

I.

Tree-ring dated samples.

II.

Modern shells from Santa Barbara County, California.

III.

Archaeologic samples.

IV.

Palynologic samples.

V.

Geologic samples.

VI.

C14 content of caliche.

VII.

Water samples.

VIII.

Modern organic sample.
Geochron Laboratories, Inc. Radiocarbon Measurements I
Authors: Krueger Harold W. , Weeks C. Francis
Published: July 2016

Geochron Laboratories, Inc. C14 facilities began operations in April 1963. Some of the results obtained during the past year have been released by our clients and are presented below.
University of Michigan Radiocarbon Dates X
Authors: Crane H. R. , Griffin James B.
Published: July 2016

The following is a list of dates obtained since the time of the compilation of List IX in December 1963. The method is essentially the same as that used for the work described in the previous list. Two CO2-CS2Geiger counter systems were used. The equipment and counting techniques have been described elsewhere (Crane. 1961a, 1961b). The dates and estimates of error in this list follow the practice recommended by the International Radiocarbon Dating Conference of 1962, in that (a) dates are computed on the basis of the Libby half-life, 5570 yr, (b) a.d. 1950 is used as the zero of the age scale and (c) the errors quoted are the standard deviations obtained from the numbers of counts only. In previous Michigan date lists up to and including VII we have quoted errors at least twice as great as the statistical errors of counting, in order to take account of other errors in the over-all process. If the reader wishes to obtain a standard deviation figure which will allow ample room for the many other sources of error in the dating process, we suggest he double the figures that are given in this list.
National Physical Laboratory Radiocarbon Measurements III
Authors: Callow W. J. , Baker M. J. , Hassall Geraldine I.
Published: July 2016

The following list comprises measurements made since those reported in NPL II and is complete to the end of November 1964.
Packard Instrument Company Radiocarbon Dates I
Authors: Kowalski Sandra J.
Published: July 2016

The Low Level Counting Laboratory of Packard Instrument Company was organized and began operations in the fall of 1963 with the development and construction of the Packard Tri-carb® Benzene Synthesizer. This instrument is designed to consolidate into a small area (6 ft × 8 ft) the equipment necessary to quickly and efficiently convert carbon-containing material or tritium water samples into benzene—an ideal solvent for liquid scintillation counting.
Tata Institute Radiocarbon Date List III
Authors: Agrawal D. P. , Kusumgar S. , Lal D.
Published: July 2016

In this paper are reported C14 dates of archaeologic samples from the Neolithic, Harappan and Early Historic sites of India. C14 activity was counted in an Oeschger-Houtermans’ gas proportional counter. The counting gas, acetylene, was synthesized using the technique described earlier (Kusumgar and others, 1963). The dates presented here are based on 5568 yr for the half-life of C14. The conversion to A.D./B.C. scale has been made using a.d. 1950 as the reference year.
Uppsala Natural Radiocarbon Measurements V
Authors: Olsson Ingrid U. , Piyanuj Piya
Published: July 2016

The following list covers most of the samples measured at the Uppsala C14 laboratory since the last list (Uppsala IV) except for all of the samples utilized for determining the increase of the C14/C12 ratio due to explosion of nuclear devices.
Vienna Radium Institute Radiocarbon Dates XI
Authors: Felber Heinz
Published: July 2016

Measurements have continued with the same proportional counter system, pretreatment procedure, methane preparation and measurement, and calculation, as described previously (R, 1970, v 12, p 298–318). Uncertainties quoted are single standard deviations originating from standard, sample, background counting rates, and half-life. No 13C/12C ratios were measured. Sample descriptions have been prepared in cooperation with submitters.
Protocol Development for Purification and Characterization of Sub-Fossil Insect Chitin for Stable Isotopic Analysis and Radiocarbon Dating
Authors: Hodgins G W L , Thorpe J L , Coope G R , Hedges R E M
Published: July 2016

Reliable radiocarbon dating depends upon well-defined samples. We have been investigating whether or not reliable 14C dates can be obtained directly from sub-fossil insect cuticle or biochemical fractions derived from it. Initial carbon and nitrogen stable isotope measurements on sub-fossil insect chitin from species with known feeding behaviors found within a single site (St Bees, Cumbria) clustered in a manner reminiscent of trophic level effects seen in terrestrial ecosystems. Although this finding implied some chemical stability, the measurement of CN ratios from the same samples indicated compositional variability. In addition, 14C dates obtained from these same samples were different from dates obtained from plant macrofossils found at the same depth. We have experimented with protocols designed to biochemically reduce chitin to its principle carbohydrate component glucosamine with the aim of using this compound to generate reliable 14C dates. Solvent extractions of sub-fossil chitin were carried out to remove both endogenous and exogenous lipid-soluble materials. Base hydrolysis reactions designed to extract polypeptides retained surprisingly high levels of contaminating amino acids. Proteinase K enzyme treatment had little affect on the level of amino acid contamination. Strong acid hydrolysis reactions designed to depolymerize chitin to glucosamine yielded only 5% glucosamine. Clearly alternative methods of chitin depolymerization must be identified before the purification and 14C dating of glucosamine from sub-fossil chitin becomes practical.
Is Comparability of 14C Dates an Issue?: A Status Report on the Fourth International Radiocarbon Intercomparison
Authors: Bryant C , Carmi I , Cook G T , Gulliksen S , Harkness D D , Heinemeier J , McGee E , Naysmith P , Possnert G , Scott E M , van der Plicht J , van Strydonck M
Published: July 2016

For more than 15 years, the radiocarbon community has participated in a series of laboratory intercomparisons in response to the issue of comparability of measurements as perceived within the wider user communities (Scott et al. 1990; Rozanski et al. 1992; Gulliksen and Scott 1995; Scott et al. 1997). In this report, we provide an update on the current 14C laboratory intercomparison and reflect on future issues linked to the laboratory intercomparison program, not least those resulting from a significant growth in the number of accelerator mass spectrometry (AMS) facilities providing routine dating of small samples (milligram size).
Radiocarbon and Dendrochronological Dating of Logboats from Poland
Authors: Pazdur Anna , Krąpiec Marek , Michczyński Adam , Ossowski Waldemar
Published: July 2016

The earliest dating of samples taken from logboats found in the area of Poland was done at the Gliwice Radiocarbon Laboratory in the late 1970s and early 1980s. After a 10-year break, the study of their chronology was renewed. The 14C dates (56) include all previously published and new, unpublished results obtained during last several years. Here, we discuss and provide probabilistic interpretation of the calendar age of the dated boats. The calibration of 14C dates was done with the OxCal program for dates less than 300 BP, and with the GdCALIB program for all remaining dates. In distribution of calibrated dates we find a lack of samples between the ages of around 800 BC and 300 AD. This result is surprising and differs from results observed for Central Europe. The remaining age ranges, with high frequency of dates, are in good coincidence with similar periods obtained for Central Europe.

Tree-ring dating of oak logboats was carried out on 60 growth sequences, dated against standard chronologies defined for the area of Poland. The results of 14C dating and tree-ring analyses give consistent chronologies.
Dendrochronology and Radiocarbon Dating Methods in Archaeological Studies of Scythian Sites
Authors: Dergachev V A , Vasiliev S S , Sementsov A A , Zaitseva G I , Chugunov K A , Ju Sljusarenko I
Published: July 2016

We propose a new method of cross-dating the wood samples based on the classical methods of spectral estimation. This method uses the average cross-spectral density as a function of the relative position of the series. Because it is not sensitive to phase shifts in data it is appropriate for cross-dating samples originating from geographically distinct areas.

The accuracy of cross dating depends on the integrity of the samples used, and in the case of well-preserved wood samples, the precision of relative age comparison may reach a single year. The method was tested on two dendrochronological series from Scythian barrows of known age in Southern Siberia: the Pazyryk barrows (the Altai Mountains) and the Dogee-Baary-2 burials (Western Sayan Mountains) separated by 450 km. The analysis has shown that the Pazyryk barrow is younger by 80 ± 4 yr than the Dogee-Baary −2 burials. This result is in agreement with the new chronology of Scythian-related sites suggested for Southern Siberia and Central Asia.
Marine Radiocarbon Reservoir Effect in the Western North Pacific Observed in Archaeological Fauna
Authors: Yoneda Minoru , Hirota Masashi , Uchida Masao , Uzawa Kazuhiro , Tanaka Atsushi , Shibata Yasuyuki , Morita Masatoshi
Published: July 2016

Faunal remains originating from terrestrial and marine mammals, and belonging to the same archaeological deposits were compared to evaluate the marine radiocarbon reservoir ages around the Hokkaido island, Japan. From five shell middens of different ages from the Jomon period (4900 BP) to the Ainu cultural period (800 BP), 107 animal bone samples were selected for radiocarbon measurements. The apparent age differences between Japanese deer and northern fur seal showed the clear effect of deep-water upwelling in this region. Our data showed relatively stable age differences from 4500 BP to 800 BP, with an estimated ΔR values around 380 14C yr. Results are consistent with previous estimation based on simulation models and oceanographic properties.
Radiocarbon Dating in Near-Eastern Contexts: Confusion and Quality Control
Authors: van der Plicht Johannes , Bruins Hendrik J
Published: July 2016

Near-Eastern archaeology has long remained oblivious to radiocarbon dating as unique historical calendars brought about a perception that 14C dating is superfluous. Circular chronological reasoning may occur as a result. There is now strong 14C evidence that the early part of Egyptian history seems older than age assessments currently in vogue among scholars. It is vital to apply systematic and high-quality 14C dating to each and every excavation in the Near East to measure time with the same yardstick. Such a strategy will enable chronological comparison of different areas at an excavation site and also between sites and regions, independent of cultural deliberations. This is essential for proper interpretation of archaeological layers and association with data from other fields. Radiocarbon (14C) is the most common radiometric dating tool applied in archaeology, geosciences, and environmental research. Stringent quality control is required to build up a reliable 14C chronology for the historical periods in Near-Eastern contexts. Important aspects of quality control involve regular laboratory intercomparisons, transparent duplicate and triplicate analysis of selected samples, conventional versus accelerator mass spectrometry (AMS) (i.e. sample size), sample selection and association. Finally, bones may provide short-lived dates in important stratigraphic archaeological contexts.
Load Structure Seismites in the Dead Sea Area, Israel: Chronological Benchmarking with14C Dating
Authors: Bowman D , Bruins H J , van der Plicht J
Published: July 2016

The Dead Sea is a terminal lake located in the seismically active zone of the Syro–African Rift Valley. The water level of the Dead Sea has been receding dramatically during the last decades, resulting in significant entrenchment of wadis towards its shores. Exposed sections in fan deltas reveal abruptly changing facies of alluvial fan, beach, and shallow lacustrine environments. Our study focuses on soft sediment deformations of the load-structure type. Though of limited lateral extent, their field characteristics concur with the widely accepted criteria that define seismites. This paper demonstrates the potential of load-structures as seismic-chronological benchmarks through radiocarbon dating. We present the first evidence of14C correlation between two types of seismites in different locations: load structure and mixed layer.
Intrashell Radiocarbon Variability in Marine Mollusks
Authors: Culleton Brendan J , Kennett Douglas J , Ingram B Lynn , Erlandson Jon M , Southon John R
Published: July 2016

We demonstrate variable radiocarbon content within 2 historic (AD 1936) and 2 prehistoric (about 8200 BP and 3500 BP)Mytilus californianusshells from the Santa Barbara Channel region, California, USA. Historic specimens from the mainland coast exhibit a greater range of intrashell variability (i.e. 180–24014C yr) than archaeological specimens from Daisy Cave on San Miguel Island (i.e. 12014C yr in both shells). δ13C and δ18O profiles are in general agreement with the up welling of deep ocean water depleted in14C as a determinant of local marine reservoir correction (ΔR) in the San Miguel Island samples. Upwelling cycles are difficult to identify in the mainland specimens, where intrashell variations in14C content may be a complex product of oceanic mixing and periodic seasonal inputs of14C-depeleted terrestrial runoff. Though the mechanisms controlling ΔR at subannual to annual scales are not entirely clear, the fluctuations represent significant sources of random dating error in marine environments, particularly if a small section of shell is selected for accelerator mass spectrometry (AMS) dating. For maximum precision and accuracy in AMS dating of marine shells, we recommend that archaeologists, paleontologists, and14C lab personnel average out these variations by sampling across multiple increments of growth.
14C Dating of ∼2500-Yr-Old Choukai Jindai Cedar Tree Rings from Japan Using Highly Accurate LSC Measurement
Authors: Sakurai Hirohisa , Kato Wataru , Takahashi Yosuke , Suzuki Kayo , Takahashi Yui , Gunji Shuichi , Tokanai Fuyuki
Published: July 2016

Radiocarbon ages of 8 decadal tree rings and 66 single-yr tree rings have been measured with a highly accurate liquid scintillation counting (LSC) system (0.2% error) after synthesizing 10.5 g of benzene for each α-cellulose sample produced from tree rings of Choukai Jindai cedar in Japan (39°N). The 14C ages were between 2449 and 2539 14C yr BP for the 21 samples. From the wiggle-matching of the data set using the IntCal04 (Reimer et al. 2004) calibration data in OxCal v 3.10 (Bronk Ramsey 2005), the estimated age of the outer edge of the Choukai tree rings was 477.5 BC (±12.5 yr) with a confidence level of 95.5%; hence, the Choukai tree rings range from 2757 to 2437 cal BP. The age indicates an improved eruption date of the Choukai Volcano. The statistical errors at 1 σ are approximately ± 10 and ± 7 14C yr for the 5-yr data and the decadal data from the single-yr measurements, respectively. For the interval between 2580 and 2520 cal BP, it is statistically significant that the Choukai 14C ages are ∼16 14C yr older on average than both the IntCal04 and QL German oak (∼50°N) data sets. The ∼2.0% offset is informative for the study of regional offset in the Far East.
Over 16,000 Years of Fire Frequency Determined from AMS Radiocarbon Dating of Soil Charcoal in an Alluvial Fan at Bear Flat, Northeastern British Columbia
Authors: Jull A J Timothy , Geertsema Marten
Published: July 2016

We present results of radiocarbon dating of charcoal from paleosols and buried charcoal horizons in a unique sequence, which potentially records the last 36,000 yr, from a fan at Bear Flat, British Columbia (BC) (56°16'51’N, 121°13'39”W). Evidence for forest-fire charcoal is found over the last 13,500 ± 110 14C yr before present (BP) or 16,250 ± 700 cal BP. The study area is located east of the Rocky Mountains in an area that was ice-free at least 13,970 ± 170 14C yr BP (17,450–16,150 cal BP) ago. The latest evidence of fire is during the Medieval Warm Period (MWP). The charcoal ages show a periodicity in large fires on a millennial scale through the Holocene—an average of 4 fires per thousand years. Higher fire frequencies are observed between 2200 to 2800 cal BP, ∼5500 and ∼6000 cal BP, ∼7500 to 8200 cal BP, and 9000 to 10,000 cal BP. These intervals also appear to be times of above-average aggradation of the fan. We conclude that fire frequency is related to large-scale climatic events on a millennial time scale.
Radiocarbon Dating Sites of Itaparica Dam, São Francisco River Valley, Brazil
Authors: de Andrade Lima L R P
Published: July 2016

This paper reports radiocarbon dates of samples from archaeological sites in the Itaparica Dam region of the São Francisco River (Brazil). This region is important due to the evidence of its use by several prehistoric groups of hunter-gatherers. In the 1980s, a Brazilian state hydroelectric company (CHESF) engaged the federal universities of Bahia and Pernambuco to perform an archaeological rescue excavation at the Itaparica Dam reservoir area. This excavation allowed the collection of a large number of ceramics and lithic artifacts as well as fireplace charcoal. In this study, fireplace charcoal samples from the Bahia State riverside of the Itaparica Dam were selected and used for dating purposes. The 14C ages were between 3840 and 210 BP, and the values of δ13C range from −22.93 to −24.81%. The 14C dates, in addition to the archaeological findings, indicate that the presence of humans in the region was contemporary with the intermediate levels of older sites found in the adjacent area, and also indicate different settlement periods.
Response to Moss et al. “An Early Holocene/Late Pleistocene Archaeological Site on the Oregon Coast? Comments on Hall et al. (2005)”
Authors: Davis Loren G , Hall Roberta A , Willis Samuel C
Published: July 2016

Moss et al. (2006) provided comments and criticisms of our recent paper in this journal (Hall et al. 2005). We can appreciate the need for promoting vigorous dialogue among those interested in the research of early sites along the New World Pacific Margin and thus welcome their intervention; however, we are compelled to respond because they raise several points that require clarification and introduce a critical error that must be corrected.
AMS14C Dating Of Balearic Lime Burials
Authors: Van Strydonck Mark , Boudin Mathieu , Decq Louise , Van Den Brande Tess , Borms Herlinde , Ramis Damià , De Mulder Guy
Published: July 2016

The Balearic quicklime burials of the Iron Age have been radiocarbon dated. Because the bones found are unsuitable for dating, lime was dated using the titration method, with results indicating that in some samples there is still fossil limestone carbonate present, while other samples suffered from recarbonation. Nevertheless,14C dates on lime and organic matter agree when both arc present. The titration method allows calculating a consensus value.
Chronological Development of the Tripolye Culture Giant-Settlement of Talianki (Ukraine): 14C Dating vs. Pottery Typology
Authors: Rassamakin Yuri , Menotti Francesco
Published: July 2016

The long tradition of relative chronology based on pottery typology has often hindered the development of radiocarbon dating amongst the Tripolye giant-settlement in Ukraine. Although it is fairly reliable, relative chronology encounters insurmountable obstacles in identifying internal phases of development within a single settlement. This paper presents the first attempt to use 14C dates to monitor the chronological development of the Talianki giant-settlement, from its formation to the various phases of development and the final decline. It then goes one step further by proving genetic links between 2 “neighboring” settlements, confirming that one is the result of migration processes of the other. This study does not intend to prove that one of the dating techniques is better than the other, but to demonstrate that a synergetic combination of the 2 methods will certainly lead to more reliable results.
Δ14C and Δ13C of Seawater DIC as Tracers of Coastal Upwelling: A 5-Year Time Series from Southern California
Authors: Santos Guaciara M , Ferguson Julie , Acaylar Karla , Johnson Kathleen R , Griffin Sheila , Druffel Ellen
Published: July 2016

Marine radiocarbon (14C) is a widely used tracer of past ocean circulation, but very few high-resolution records have been obtained. Here, we report a time series of carbon isotope abundances of dissolved inorganic carbon (DIC) in surface seawater collected from the Newport Beach pier in Orange County, within the Southern California Bight, from 2005 to 2010. Surface seawater was collected bimonthly and analyzed for Δ14C, δ13C, and salinity. Results from May 2005 to November 2010 show no long-term changes in δ13C DIC values and no consistent variability that can be attributed to upwelling. Δ14C DIC values have lowered from ∼34‰ to about ∼16‰, an 18‰ decrease from the beginning of this project in 2005, and is consistent with the overall 14C depletion from the atmospheric thermonuclear bomb pulse at the end of the 1950s. Δ14C DIC values, paired with salinity, do appear to be suitable indicators of upwelling strength with periods of upwelling characterized by more saline and lower DIC Δ14C values. However, a similar signal was not observed during the strong upwelling event of 2010. These results were obtained in the Southern California Bight where upwelling is fairly weak and there is a complex occanographic circulation in comparison with the remaining western USA coastline. It is therefore likely that the link between DIC Δ14C, salinity, and upwelling would be even stronger at other sites. These data represent the longest time series of Δ14C data from a coastal Southern California site performed to date.
Towards High-Precision AMS: Progress and Limitations
Authors: Bronk Ramsey Christopher , Higham Thomas , Leach Philip
Published: July 2016

Precision and accuracy in accelerator mass spectrometry (AMS) dating relies on the systematic reduction of errors at all stages of the dating process, from sampling to AMS measurement. With new AMS systems providing much better precision and accuracy for the final stage of the process, we need to review the process as a whole to test the accuracy of reported results. A new High Voltage Engineering Europa (HVEE) AMS system was accepted at Oxford in September 2002. Since then, the system has been in routine use for AMS dating and here we report on our experiences during the first year. The AMS system itself is known to be capable of making measurements on single targets to a precision of better than 0.2% for the 14C/13C ratio and better than 0.1% for the 13C/12C ratio. In routine operation, we measure known-age wood to a precision of just above 0.3%, including uncertainties in background and pretreatment. At these levels, the scatter in results is no higher than reported errors, suggesting that uncertainties of ±25 to ±30 14C yr can be reliably reported on single target measurements. This provides a test of all parts of the process for a particular material in a particular state of preservation. More generally, sample pretreatment should remove as much contamination as feasible from the sample while adding as little laboratory contamination as possible. For more complex materials, such as bone, there is clearly more work needed to prove good reproducibility and insignificant offsets in all circumstances. Strategies for testing accuracy and precision on unknown material are discussed here, as well as the possibilities of one day reaching precisions equivalent to errors of <±20 14C yr.
Preparation of Graphite Targets from Small Marine Samples for AMS Radiocarbon Measurements
Authors: Liong Wee Kwong Laval , Povinec Pavel P , Timothy Jull J A
Published: July 2016

A vacuum sample processing line was set up and methods were developed for the determination of radiocarbon in small-volume seawater and biota samples. Seawater samples (500 mL per borosilicate glass bottle and poisoned with HgCl2) were acidified with 5 mL concentrated hydrochloric acid. Pure N2 was used as a carrier gas to strip CO2 from the samples for 10 min in a circulation mode. After purification through several water traps, the CO2 was isolated cryogenically. Using Na2CO3 standard solutions, recovery yields were calculated superior to 95 ± 5%. Freeze-dried marine biota samples were thoroughly mixed with Cu(II)O and combusted at 900°. The CO2 was purified by passing through Ag wool and Cu granules at 450° before reduction to graphite. Finally, graphite was synthesized using Zn dust heated to 450° in the presence of an Fe catalyst at 550°. Although this method takes about 8 hr (synthesis done overnight), the advantage is that no water vapor by-product is formed to hinder the reaction. The graphite yields, measured both by gravimetric methods and by pressure readings, were 95 ± 5%. Accelerator mass spectrometry (AMS) measurements were carried out at the NSF-Arizona AMS Facility. Results for water samples from the northwest Pacific Ocean are reported which are in agreement with data reported elsewhere.
Radiocarbon Dating of Iron Artifacts at the Erlangen AMS Facility
Authors: Scharf Andreas , Kretschmer Wolfgang , Morgenroth Gerhard , Uhl Thomas , Kritzler Karin , Hunger Katja , Pernicka Ernst
Published: July 2016

One problem in preparing iron for radiocarbon dating is the low carbon content which makes the sample size needed too large for some sample combustion systems. Also, the metallic character of the samples complicates sample combustion or oxidation. The Erlangen accelerator mass spectrometry group uses an elemental analyzer for the sample combustion, directly followed by a reduction facility. As the carbon content and sample size for iron samples are unsuitable for combustion in an elemental analyzer, 2 alternative approaches are to (a) avoid oxidation and reduction, or (b) extract the carbon from the iron, prior to combustion. Therefore, 2 different pathways were explored. One is direct sputtering of the unprocessed iron sample in the ion source. The other is the complete chemical extraction of carbon from the iron sample and dating of the carbonaceous residue. Also, different methods for cleaning samples and removing contamination were tested. In Erlangen, a Soxhlet extraction is employed for this purpose. Also, the sampling of the iron sample by drilling or cutting can be a source of contamination. Thus, the measurement of iron drill shavings yielded ages that were far too high. The first results for iron samples of known age from 2 archaeological sites in Germany are presented and discussed.
Chronological Studies of the Arzhan-2 Scythian Monument in Tuva (Russia)
Authors: Zaitseva G I , Chugunov K V , Dergachev V A , Nagler A , Parzinger G , Scott E M , Sementsov A A , Vasiliev S , van Geel B , van der Plicht J , Lebedeva L M
Published: July 2016

The first radiocarbon dates from the unique early Scythian monument Arzhan-2, discovered in 2001, are presented. The monument contained a royal burial (grave nr 5). Unfortunately, precise dating is hampered by the Hallstatt plateau in the calibration curve. However, using both accelerator mass spectrometry measurements from buried materials and conventional dates for floating tree rings from the burial chamber, we were able to date the construction of the monument to the 7th century BC. This is consistent with archaeological expectations. Other graves located inside the barrow were also dated. Grave nr 11, located on the edge of the barrow, is younger, showing that the monument was a place of burial ritual for many years for this ancient population.
A Puzzling Body from the River Thames in London
Authors: Bayliss Alex , Marshall Peter , Sidell Jane
Published: July 2016

Radiocarbon measurements on a partially articulated female human skeleton, recovered from the foreshore of the river Thames in London, raised interesting questions of interpretation when the body did not produce the anticipated Neolithic date. A relatively recent 14C age and a strong marine component to the individual's diet, identified by stable isotope measurements, means that the date of death is difficult to estimate accurately, although the body probably does not constitute a forensic case.
Radiocarbon and Stable Isotope Evidence of Dietary Change from the Mesolithic to the Middle Ages in the Iron Gates: New Results from Lepenski Vir
Authors: Bonsall C , Cook G T , Hedges R E M , Higham T F G , Pickard C , Radovanović I
Published: July 2016

A previous radiocarbon dating and stable isotope study of directly associated ungulate and human bone samples from Late Mesolithic burials at Schela Cladovei in Romania established that there is a freshwater reservoir effect of approximately 500 yr in the Iron Gates reach of the Danube River valley in southeast Europe. Using the δ15N values as an indicator of the percentage of freshwater protein in the human diet, the 14C data for 24 skeletons from the site of Lepenski Vir were corrected for this reservoir effect. The results of the paired 14C and stable isotope measurements provide evidence of substantial dietary change over the period from about 9000 BP to about 300 BP. The data from the Early Mesolithic to the Chalcolithic are consistent with a 2-component dietary system, where the linear plot of isotopic values reflects mixing between the 2 end-members to differing degrees. Typically, the individuals of Mesolithic age have much heavier δ15N signals and slightly heavier δ13C, while individuals of Early Neolithic and Chalcolithic age have lighter δ15N and δ13C values. Contrary to our earlier suggestion, there is no evidence of a substantial population that had a transitional diet midway between those that were characteristic of the Mesolithic and Neolithic. However, several individuals with “Final Mesolithic” 14C ages show δ15N and δ13C values that are similar to the Neolithic dietary pattern. Provisionally, these are interpreted either as incomers who originated in early farming communities outside the Iron Gates region or as indigenous individuals representing the earliest Neolithic of the Iron Gates. The results from Roman and Medieval age burials show a deviation from the linear function, suggesting the presence of a new major dietary component containing isotopically heavier carbon. This is interpreted as a consequence of the introduction of millet into the human food chain.
Anomalous Radiocarbon Dates from Easter Island
Authors: Butler Kevin , Prior Christine A , Flenley John R
Published: July 2016

The largest volcanic crater on Easter Island in the South Pacific contains a lake 1 km in diameter with large floating mats of vegetation, mainly Scirpus californicus. A core taken through a mat near the center produced anomalous dates, with older dates above younger ones. The possibility that the mat had become inverted was considered, but palynological evidence refutes this idea because it shows a progressive upward decline of forest pollen, which is well known from other swamp cores on the island. A new series of radiocarbon dates made directly on pollen concentrates was obtained. These dates also produced inconsistencies, particularly when pollen concentrate ages were compared with 14C ages on plant fragments from the same depth. This series of 14C ages seems to indicate that both old and young organic components in the sediment are deposited contiguously and that the depositional history of these cores is more complex than previously known. Previous age determinations on bulk sediments from Easter Island, which also show anomalous dates, may be too simplistic. This paper provides a warning to other researchers dating sediments from Easter Island. We suggest that sample selection and dating procedures be carefully considered for these sediments.
10Be, 14C Distribution, and Soil Production Rate in a Soil Profile of a Grassland Slope at Heshan Hilly Land, Guangdong
Authors: Shen CD , Beer J , Ivy-Ochs S , Sun Y , Yi W , Kubik P W , Suter M , Li Z , Peng S , Yang Y
Published: July 2016

Concentrations of organic carbon, carbon isotopes (13C and 14C), atmospheric 10Be in soil, and in situ 10Be in bedrock and weathering rock were determined in a study of a profile of a grassland slope at the Heshan Hilly Land Interdisciplinary Experimental Station, Chinese Academy of Sciences, in Guangdong Province, China. A good linear relationship between depth and the 14C apparent age of the organic carbon demonstrates that the rock weathering process and the accumulation process of organic matter in the slope are relatively stable. Both 14C and 10Be results show that about 34% of soil in the grassland slope has been eroded during the past 3800 yr. The 10Be results for interstitial soil from weathered rocks show that the 90-cm-thick weathering rock layer above the bedrock has evolved over a period of 1.36 Myr. The concentrations of in situ 10Be in the weathered rock and bedrock are 10.7 × 104 atoms/g and 8.31 × 104 atoms/g, respectively. The weathering rate of the bedrock, equivalent to the soil production rate, was estimated at 8.8 × 10-4 cm/yr, and the exposure ages of the weathered rock and the bedrock were 72 kyr and 230 kyr, respectively.
Temporal Variation of Radiocarbon Concentration in Airborne Particulate Matter in Tokyo
Authors: Shibata Ken , Endo Michio , Yamamoto Naomichi , Yoshinaga Jun , Yanagisawa Yukio , Endo Osamu , Goto Sumio , Yoneda Minoru , Shibata Yasuyuki , Morita Masatoshi
Published: July 2016

The temporal radiocarbon variation (in terms of percent Modern Carbon: pMC) of size-fractionated airborne particulate matter (APM) collected in Tokyo between April 2002 and February 2003 was analyzed in order to get an insight into the sources of carbonaceous particles. Results indicated significant biogenic origins (approximately 40 pMC on average). In general, the seasonal and particle size variations in pMC were relatively small, with 2 exceptions: elevated pMC in coarse particles in April and October 2002, and relatively low pMC in the finest particle size fraction collected in August 2002. The former finding could be tentatively attributed to the abundance of coarse particles of biological origins, such as pollen; the latter might be due to an increased fraction of anthropogenic secondary particles.
Re-Evaluation of British Museum Radiocarbon Dates Issued Between 1980 and 1984
Authors: Bowman S G E , Ambers J C , Leese M N
Published: July 2016

Dates issued by the British Museum radiocarbon laboratory between 1980 and 1984 are known to have been in error. This paper outlines the cause of the problem and the procedures adopted to revise the results affected. Where revision has been possible, on average this has given dates older by 200 to 300 radiocarbon years. The individual revised results are tabulated.
Marine Turtle Bones from an Archaeological Site in Polynesia Yield Reliable Age Determinations
Authors: Dye T S
Published: July 2016

Accelerator mass spectrometry dating of three 50g samples of marine turtle bone from the basal cultural stratum of the Tongoleleka archaeological site, Lifuka Island, Kingdom of Tonga, South Pacific yields results that agree with conventional 14C dates on marine shell. A method for calibrating these dates that takes into account the long distance migrations of marine turtles in the South Pacific is proposed. A sample size greater than 50g is recommended for routine AMS dating of marine turtle bone.
Radiocarbon Dating of the Neolithic Early Bronze Age Site of Mandalo, W Macedonia
Authors: Maniatis Yannis , Kromer Bernd
Published: July 2016

The following list of dates was obtained in a joint German-Greek project to establish a radiocarbon dating laboratory in the National Research Centre for Physical Sciences “Demokritos,” Athens, Greece.1 Although our initial aim in selecting these samples was to study laboratory procedures, we found that when the dates were arranged in stratigraphic order they provided a chronological framework for Thessalian and northern Macedonian site of the Late Neolithic and Early Bronze Ages (Kotsakis et al 1989; Papanthimou & Papasteriou 1987a).
14C Dating of Peat and δ18O-δd in Ground Ice From Northwest Siberia
Authors: Vasil'chuk Yurij K , Jungner Högne , Vasil'chuk Alla C
Published: July 2016

We present new radiocarbon dates from a number of Holocene peat deposits along a north-south transect across the Yamal Peninsula. The samples were collected from frozen peat deposits with large ice wedges in: the northern tundra near Seyaha Settlement, in the Central Yamal Peninsula, the southern tundra in Shchuch'ya River valley at the Edem'yaha mouth, the southern part of the Yamal Peninsula, and the southern forest tundra near Labytnangi Town. 14C dates of wood remains from the tundra in the Yamal Peninsula could be used to reconstruct a northern limit of forest during the Holocene Optimum. The wood layers at the bottom of the peat give evidence for immigration of trees further north beyond the present boundary. The first forest appearance in the Seyaha River valley area is dated about 9 ka BP according to the oldest peat date in the Seyaha cross section. This suggests that summer temperatures were higher than at present. Very fast accumulation of peat (around 5 m/ka: about 9–8 ka BP at Seyaha and about 7–6 ka BP at Shchuch'ya) also supports this observation.

In contrast, oxygen isotope composition of Holocene syngenetic ice wedges from the area (δ18O= −19.1 to −20.3‰ in the Seyaha cross-section and −17.3 to −20.3‰ in the Shchuch'ya River) show that winter temperatures were significantly lower than presently, i.e. the climate during the Holocene Optimum was slightly more continental. The frozen peat near Labytnangi has thawed during the last 20 years, indicating global warming.
Radiocarbon Age of Vertisols and Its Interpretation Using Data on Gilgai Complex in the North Caucasus
Authors: Kovda Irina , Lynn Warren , Williams Dewayne , Chichagova Olga
Published: July 2016

Radiocarbon dates were analyzed to assess Vertisols age around the world. They show an increase of radiocarbon age from mainly modern–3000 BP in 0–100 cm layer up to 10,000 BP at a depth 100–200 cm. Older dates reflect the age of parent material. The inversion of 14C dates seems to be a frequent phenomenon in Vertisols. A series of new dates of Vertisols from gilgai microhigh, microslope and microlow in the North Caucasus was done in order to understand the nature of this inversion. 14C age in the gilgai soil complex ranges from 70 ± 45 BP in the microlow to 5610 ± 180 BP in the microhigh. A trend of similar depths being younger in the microslope and microlow was found. We explain this by intensive humus rejuvenation in the microlows due to water downward flow. The older date in the microhigh represents the old humus horizon sheared laterally close to the surface and preserved by impermeable water regime. We explain inversions of 14C age-depth curves by the sampling procedures. In a narrow pit, genetically different parts of former gilgai could easily be as a genetically uniform soil profile. Because of this strong microvariability, Vertisols require sampling in a trench accounting for gilgai elements, even when gilgai are not obvious.
Chronology of Soil Evolution and Climatic Changes in the Dry Steppe Zone of the Northern Caucasus, Russia, During the 3rd Millennium BC
Authors: Alexandrovskiy A L , van der Plicht J , Belinskiy A B , Khokhlova O S
Published: July 2016

Chrono-sequences of paleosols buried under different mounds of the large Ipatovo Kurgan, constructed during the Bronze Age, have been studied to reconstruct climatic changes in the dry steppe zone of the Northern Caucasus, Russia. Abrupt climatic and environmental changes in the third millennium BC have been reconstructed, using morphological and analytical data of the soil. Based on accelerator mass spectrometry (AMS) dates of small charcoal fragments from the soil chrono-sequence, we concluded that two upper paleosols (with the clearest evidence of arid pedogenesis) developed between about 2600–2450 BC.
Changes of 14C Concentration in Modern Trees from Upper Silesia Region, Poland
Authors: Rakowski Andrzej Z , Pawełczyk Sławomira , Pazdur Anna
Published: July 2016

Radiocarbon concentration measurements in tree rings from Upper Silesia indicate significantly lower 14C concentration as compared to the concentrations occurring in “clean air” areas. This phenomenon is known as the Suess effect and is caused by contamination with inactive carbon that originates from fossil fuels combustion. This effect is observed in large urban and industrial areas. Samples for the measurements presented in the paper were collected in some of the largest cities in Upper Silesia: Gliwice, Ruda Śląska, and Chorzów. The samples were annual tree rings (Populus nigra, Pinus silvestris) covering years 1965–1992 and the atmospheric CO2 collected weekly between December 1994 and December 1995.
Absolute Production of Radiocarbon and the Long-Term Trend of Atmospheric Radiocarbon
Authors: Goslar Tomasz
Published: July 2016

This paper presents simulations of the long-term trend of atmospheric radiocarbon, performed with the modified PANDORA model. The author shows that taking into account the outflow-supply carbon fluxes makes the decrease of D14C between 40 and 0 ka BP larger by 40–80‰, not much depending on which data (sedimentary magnetism, archaeomagnetism or10Be) is used for the scenario of relative variations of14C production. This, together with the effect of CO2increase reasonably reconciles model-simulated and observed decline of atmospheric Δ14C.
Radiocarbon Dating of Porewater – Correction for Diffusion and Diagenetic Processes
Authors: Sivan Orit , Herut Barak , Yechieli Yoseph , Lazar Boaz
Published: July 2016

Two simple algorithms are suggested here to correct for the effect of diffusion and diagenetic sulfate reduction on radiocarbon age determination of marine porewater. The correction algorithms were developed from mass balances of sulfate, dissolved inorganic carbon (DIC), and 14C of the DIC (14CDIC) in vertical concentrations profiles in porewater starting from the sediment water interface. The algorithms were tested on data collected during our recent study of sediment porewaters extracted from the deep Eastern Mediterranean. The real ages of these porewaters varied from present (top of the core) to approximately 30 ka BP (bottom of the core) covering most of the dynamic range of the 14C method (approximately 5 half lives). These ages were markedly older than the ages calculated from 14CDIC analyses by the regular age equation.

It is clearly demonstrated that in this case the correction of the apparent age for diffusion across the sediment/water interface is overwhelmingly larger than the correction for the effect of sulfate reduction. The correction for the effect of 14C diffusion alone results in a perfect match between the calculated apparent 14C ages and the real ages of porewater and therefore is the preferred algorithm for correcting apparent ages of porewater.
Spatial Variations of Radiocarbon in the Coastal Aquifer of Israel—Indicators of Open and Closed Systems
Authors: Bruce Debbie , Friedman Gerald M , Kaufman Aaron , Yechieli Yoseph
Published: July 2016

The spatial variation in radiocarbon concentration was studied in the Coastal Aquifer of Israel. Lower concentrations were found in the western section of the aquifer (55–70 pMC) as compared to the eastern section (80–100 pMC). Since no correlation was found between the tritium and radiocarbon values, these variations could not simply be explained by a difference in ages, or by a difference in the degree of old calcite dissolution as similar δ13C values were found throughout the aquifer. The results are best explained when viewing the differences in 14C values within the same coastal aquifer, where the eastern section of the aquifer is a more open system and the western section is a more closed system. In general, the age of the groundwater in the coastal aquifer was found to be less than 50 years old (14C >55 and measurable tritium).
Chronology of the Atmospheric Mercury in Lagoa da Pata Basin, Upper Rio Negro Region of Brazilian Amazon
Authors: Santos G M , Cordeiro R C , Filho E V Silva , Turcq B , Lacerda L D , Fifield L K , Gomes P R S , Hausladen P A , Sifeddine A , Albuquerque A L S
Published: July 2016

We present prehistoric mercury accumulation rates in a dated sediment core from Lagoa da Pata, a remote lake in São Gabriel da Cachoeira, northern Amazon. The sediment samples were subdivided for mercury and radiocarbon analyses. A group of 18 samples have been prepared at ANU for 14C dating by accelerator mass spectrometry (AMS). The dating results show a good correlation with depth in the core, down to 41,500 BP. Three distinct sections are clearly identified in the core. They consist of upper and lower organic-rich layers, separated by an inorganic layer which represents a short period of rapid accumulation around 18 ka BP. The mercury accumulation rate is found to be larger in the upper layer (18 ka to present) than in the lower one (41 ka to 25 ka), by a factor of three. The larger accumulation rate of mercury is probably associated with warmer temperatures and a higher frequency of forest fires during the Holocene.