A new radiocarbon preparation facility was set up in 2010 at the Godwin Laboratory for Palaeoclimate Research, at the University of Cambridge. Samples are graphitized via hydrogen reduction on an iron powder catalyst before being sent to the Chrono Centre, Belfast, or the Australian National University for accelerator mass spectrometry (AMS) analysis. The experimental setup and procedure have recently been developed to investigate the potential for running small samples of foraminiferal carbonate. By analyzing background values of samples ranging from 0.04 to 0.6 mg C along with similar sized secondary standards, the setup and experimental procedures were optimized for small samples. “Background” modern 14C contamination has been minimized through careful selection of iron powder, and graphitization has been optimized through the use of “small volume” reactors, allowing samples containing as little as 0.08 mg C to be graphitized and accurately dated. Graphitization efficiency/fractionation is found not to be the main limitation on the analysis of samples smaller than 0.07 mg C, which rather depends primarily on AMS ion beam optics, suggesting further improvements in small sample analysis might yet be achieved with our methodology.

This paper presents and discusses radiocarbon dates of the Corded Ware culture (CWC) from different regions of Europe (mainly from southern and central Germany and southern and central Poland). The main questions addressed are the controversial significance of particular results, the incompatibility of the obtained date sequences, and the “imprecision of the method.” There is clearly the problem of hundreds of dates from different laboratories and performed in different years. A slight difference in the results leads to an “elongated” chronology and acceptance of a model with synchronicity of many cultural groups. The proposed verification of the 14C chronology is connected with both the dendrochronological method and the comparison of dating sequences obtained from particular regions. At present, the most reliable dating scheme for the Corded Ware culture is the one based on the dendrochronological dates of settlements on Swiss lakes; therefore, the scheme must constitute a reference point for 14C analyses conducted for other regions. Due to the typological diversity of materials, however, not every situation allows for this approach. Thus, many 14C grave dates, particularly the results referring to the late CWC phase (after ~2400 BC), remain controversial.

The 14C dates given below are continued from our previous list (R, 1974, v 16, p 331-357), and results obtained mainly during 1972-73 are described. A 2.7L stainless steel counter and a 3.3L copper counter are used as previously, yielding background counting rates of 3.9 and 5.6cpm, respectively, when filled with dead CO2 at ca 1.7atm. Dates have been calculated on the basis of the 14C half-life of 5568 ± 30 yr and 95% of NBS oxalic acid is modern standard. Errors (± 1σ) include standard deviations for sample counts, background and modern standard, that of half-life, and, also, effective standard deviations for reading of filling pressure and temperature. No correction has been made for any of the samples in this list.

Evidence of paleoenvironmental changes during the Holocene from the Lower Mahi basin of Western India have been documented. The unpaired S2 surface all along the estuarine zone of the Mahi basin has been identified as an uplifted marine terrace. The terraces have preserved in their lithosections fairly distinct horizons of grayish brown clays rich in marine microfauna. The intervening silty-sand horizons are indicative of freshwater origin. The sedimentary structure and faunal assemblage indicate that these units have been deposited in a marginal marine environment. The 14C ages obtained on these marine mud horizons show that between 3600 and 1700 bp the sea level was higher than at present. The geomorphic evidence suggests that a late Holocene uplift has played a significant role in lowering the relative sea level to its present position.

Radiocarbon is produced within minerals at the earth's surface (in situ production) by a number of spallation reactions. Its relatively short half-life of 5730 yr provides us with a unique cosmogenic nuclide tool for the measurement of rapid erosion rates (>10−3 cm yr−1) and events occurring over the past 25 kyr. At SUERC, we have designed and built a vacuum system to extract 14C from quartz which is based on a system developed at the University of Arizona. This system uses resistance heating of samples to a temperature of approximately 1100° in the presence of lithium metaborate (LiBO2) to dissolve the quartz and liberate any carbon present. During extraction, the carbon is oxidized to CO2 in an O2 atmosphere so that it may be collected cryogenically. The CO2 is subsequently purified and converted to graphite for accelerator mass spectrometry (AMS) measurement. One of the biggest problems in measuring in situ 14C is establishing a low and reproducible system blank and efficient extraction of the in situ 14C component. Here, we present initial data for 14C-free CO2, derived from geological carbonate and added to the vacuum system to determine the system blank. Shielded quartz samples (which should be 14C free) and a surface quartz sample routinely analyzed at the University of Arizona were also analyzed at SUERC, and the data compared with values derived from the University of Arizona system.

This paper is a list of radiocarbon dates obtained at the University of Saskatchewan since the last report was issued (McCallum, 1955). The method used is essentially that of Suess (1954), in which the sample is counted as acetylene gas. The proportional counter has a sensitive volume of one liter and is filled with acetylene to a pressure of one atmosphere. Each sample is counted for at least two 20-hour periods. The modern standards used were obtained from softwood logs grown in Northern Saskatchewan and were either 50 or 100 years old as obtained from ring counts.

Ten medieval permanent teeth were subjected to incremental dentine sectioning and stable isotope analysis to investigate dietary changes in high resolution. In addition to this, eight increments were also selected for radiocarbon measurements to examine possible intra-individual age differences. Results reveal the cessation of weaning, various dietary profiles, and in some cases significantly different 14C ages obtained from a single tooth. This case study illustrates how 14C measurements can function as a proxy alongside the commonly used carbon and nitrogen stable isotope values to interpret the diet of past individuals.

A new radiocarbon sample record form has been compiled for consensus among radiocarbon daters and users. The form is designed to obtain comprehensive standardized documentation of radiocarbon dates for reporting and disseminating valuable data. This method of reporting 14C dates will help resolve problems which include: 1) publication of all dated samples, 2) selection of significant samples, 3) interpretation of data, 4) recognition of problematic dates, 5) maintenance of an active archive of 14C dates, and 6) implementation of an international retrieval system for dates.

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.

We present a novel application for radiocarbon dating by aging 4 scales from a single large adult lungfish (Neoceratodus forsteri) from the Burnett River, in Queensland, Australia. The relict fish species lack a solid crystalline otolith, which precludes the use of the otolith annuli as a reliable age indicator. Previous attempts to age lungfish using a number of techniques have had only limited success. We report on ages obtained from the dense lamellar bone of the scale, which were isolated from the organic layers that thicken and subsequently obscure the 14C signal. Using the characteristics of the bomb curve, 2 parameter von Bertanalffy growth functions were fit, providing an estimate of absolute age to be ∼65–70 yr. The information gleaned from this study will aid in assessing the population structure, and therefore management, of this vulnerable species.

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.

We performed a new series of measurements on samples that were part of early measurements on radiocarbon (14C) dating made in 1948–1949. Our results show generally good agreement to the data published in 1949–1951, despite vast changes in technology, with only two exceptions where there was a discrepancy in the original studies. Our new measurements give calibrated ages that overlap with the known ages. We dated several samples at four different laboratories, and so we were also able to make a small intercomparison at the same time. In addition, new measurements on samples from other Egyptian materials used by Libby and co-workers were made at UC Irvine. Samples of tree rings used in the original studies (from Broken Flute Cave and Centennial Stump) were obtained from the University of Arizona Laboratory of Tree-Ring Research archive and remeasured. New data were compared to the original studies and other records.

Radiocarbon variations in the atmosphere have been observed at the Žlkovce monitoring station of the Bohunice nuclear power plant (NPP), situated only 5 km ESE from the NPP. The observed 14C levels provide unique evidence of a decreasing long-term impact of the Bohunice NPP on the region. Simultaneously, decreasing emissions of fossil fuel carbon dioxide in the atmosphere of the monitoring site have been found. The observed Δ14C variations with time have attenuating amplitudes and decreasing mean values, showing maxima in summer and minima in winter, the latter primarily caused by increased emission of fossil CO2 in winter months. Sporadic short-term releases of 14C from the Bohunice NPP were observed at the Žlkovce station. The annual atmospheric Δ14C variations compared with tree-ring data collected at the Žlkovce village show reasonable agreement. The observed Δ14C levels after 2005 are close to the European clean-air levels as measured at the Jungfraujoch (3450 m asl) monitoring station.

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 soil 14C 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 high 14C concentrations even in deeper soil layers, which suggests the bomb-induced 14C 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.

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.

Sixty-two 14C dates are analyzed in combination with a recently established local floating tree-ring sequence for the Early Neolithic site of La Draga (Banyoles, northeast Iberian Peninsula). Archaeological data, radiometric and dendrochronological dates, as well as sedimentary and micro-stratigraphical information are used to build a Bayesian chronological model, using the ChronoModel 2.0 and OxCal 4.4 computer programs, and IntCal 2020 calibration curve. The dendrochronological sequence is analyzed, and partially fixed to the calendrical scale using a wiggle-matching approach. Depositional events and the general stratigraphic sequence are expressed in expanded Harris Matrix diagrams and ordered in a temporal sequence using Allen Algebra. Post-depositional processes affecting the stratigraphic sequence are related both to the phreatic water level and the contemporaneous lakeshore. The most probable chronological model suggests two main Neolithic occupations, that can be divided into no less than three different “phases,” including the construction, use and repair of the foundational wooden platforms, as well as evidence for later constructions after the reorganization of the ground surface using travertine slabs. The chronological model is discussed considering both the modern debate on the Climatic oscillations during the period 8000–4800 cal BC, and the origins of the Early Neolithic in the western Mediterranean region.

A number of recent radiocarbon determinations from several sites in Israel suggest advancing, by some considerable period of time, both the onset of the cultural horizon known as Early Bronze I and the appearance of its latest phases. The logical outcome of the acceptance of these new dates puts such a strain on chronological correlations between the 14C data and the archaeological record that the entire system would no longer be tenable if they were accepted. This paper examines in detail the problematic nature of these “uneasy correlations.”

In 2008, a large African baobab (Adansonia digitata L.) from Makulu Makete, South Africa, split vertically into 2 sections, revealing a large enclosed cavity. Several wood samples collected from the cavity were processed and radiocarbon dated by accelerator mass spectrometry (AMS) for determining the age and growth rate dynamics of the tree. The 14C date of the oldest sample was found to be of 1016 ± 22 BP, which corresponds to a calibrated age of 1000 ± 15 yr. Thus, the Makulu Makete tree, which eventually collapsed to the ground and died, becomes the second oldest African baobab dated accurately to at least 1000 yr. The conventional growth rate of the trunk, estimated by the radial increase, declined gradually over its life cycle. However, the growth rate expressed more adequately by the cross-sectional area increase and by the volume increase accelerated up to the age of 650 yr and remained almost constant over the past 450 yr.

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

The C14 Laboratory of the German Academy of Sciences of Berlin (DAW) began to obtain dates in 1961. The focus of research is in archaeology. Samples, coll. in close collaboration with the DAW's Institut für Vor- und Frühgeschichte, are mainly from the Neolithic of central and southeastern Europe, and contribute to the continuing discussion (Milojčić, 1961; Müller-Beck, 1961) of the chronology of this period.