A zolnik excavated in 2016–2018 at the hillfort identified as the Scythian cultural circle in Chotyniec (southeastern Poland, 8 km west of the current Poland–Ukraine border) provided a very large quantity of archaeological sources and organic materials. From the latter, 17 samples coming from different horizons were selected for dating and were used to build a chronological model of functioning of the zolnik. Absolute dating is particularly important because the discovered artifacts (especially the most common handmade ceramics) do not show large chronological diversity. The use of the zolnik was estimated at 250–300 years, i.e. between 7th/6th and 4th/3rd century BC. Stratigraphic observations and good references of absolute chronology based on artifacts, including imported Greek ceramics, first in this part of Central Europe, proved to be significant. Older radiocarbon dates correspond to typological dating of Greek amphoras (7th/6th–6th century BC).

We conducted a preliminary test of the coupled system of an elemental analyzer and the automated graphitization equipment Ionplus AGE3 (EA-AGE3 method) for accelerator mass spectrometry radiocarbon (AMS 14C) measurements of CaCO3 samples, by comparing with the conventional method where the samples are hydrolyzed in phosphoric acid and resulting CO2 gas is manually graphitized in a vacuum line (HPA method). The samples used in the test were the IAEA C2 travertine, fossil and modern corals from the Ryukyu Islands and the Ogasawara Islands, respectively (both are located in the northwestern subtropical Pacific). Results indicate that, relative to the HPA method, the EA-AGE3 method tends to cause an increase of ~0.4–0.5 pMC with more widely scattered data. This is presumably due to 14C contamination in the EA (the most likely cause seems to be a memory effect of 14C); this effect could be reduced by careful optimization of conditions and procedures in the EA process. The 14C data of pre-bomb annual bands (1931–1949 AD) in the modern Ogasawara coral obtained by the HPA method were used to estimate the marine reservoir 14C-age correction (ΔR) of this region; it ranges from –109 yr to –28 yr with the mean value with standard deviation of –81 ± 29 yr.

To test the hypothesis that cellulose in linen can be carboxylated at high temperatures in the presence of CO2, water and silver, we heated two aliquots of cellulose extracted from old wood in glass ampoules, adding Ag powder to one to test its potential action as a catalyst for the carboxylation reaction. AMS measurement of the heated aliquots showed no statistically significant difference in 14C content from the “uncarboxylated” cellulose. We conclude that carboxylation is not a systematic source of error in the dating of cellulose-containing materials such as the linen in the Shroud of Turin.

The following list includes a selected number of measurements made during 1967-1968 in the Natural Radiocarbon Laboratory of the Centre de Recherches Radiogéologiques de Nancy. This list is a continuation of Nancy Natural Radiocarbon Measurements I (Radiocarbon, 1968, v. 10, p. 119-123). The dating method, counting technique, and equipment are described in that list. All measurements were made in a proportional counter with a capacity of 1.16 L, normally filled with CO2 under a pressure of 736 mm Hg. Ages are calculated using a C14 half-life of 5568 yrs with 1950 as reference yr. Modern standard used following samples Ny-118 is 95% of NBS oxalic acid activity. The SC14 mentioned later in the date list are calculated according to Broecker and Olson (1959).

As an industrialized city, Hong Kong annually consumes a large amount of fossil fuel. In addition, the Daya Bay Nuclear Power Plant in Shenzhen, Guangdong Province, has just begun operation 20 km from Hong Kong. These factors suggest that it may be appropriate and significant to examine the variation of atmospheric 14C levels in Hong Kong. We have collected and tested a variety of samples from different parts of Hong Kong: terrestrial annual grasses, marine plants and atmospheric CO2. We measured their 14C activity and compared it with that of cassia oil samples from Guangxi Province, China. The values obtained indicate that environmental 14C levels in the Hong Kong region agree with those found in Guangxi, both of which are significantly higher than the levels predicted by Povinec, Chudý and Šivo (1986).

Ma'rib is the most famous archaeological site in Yemen. The economical importance of Ma'rib resulted from an ecosystem that was based on irrigation and existed already in the second half of the 3rd millennium BC. In the middle of the 8th century BC Ma'rib rose to the capital of Saba and became the economical and cultural center of southern Arabia. In 1975 the German Archaeological Institute began to investigate and document the antique oasis systematically. Radiocarbon datings were of great importance for clarification of the building's history. Dating series extend from the 10th century BC to the 12th century AD. The temple, of which four building phases could be observed up to now, was used from 9th century BC till the end of the 4th century AD.

Given below are the dates of archaeologic and Quaternary samples measured by the proportional counting of methane gas. Details of the techniques used were published earlier (Agrawal et al., 1965).

After the sharp transition to aridity that followed the “Green Sahara” episode 5500 years ago, human settlements took refuge in Egyptian oases, which have to varying extents been “Green Oases” for centuries. In that period, synchronous with the beginning of historical times, the desert’s aridity is generally regarded as broadly comparable to the current period. Natural and anthropogenic deposits studied during 13 excavation campaigns in Bahariya Oasis (Egyptian Desert) suggest that a fairly clear transition from a relatively green environment to much more arid landscapes occurred in the first millennia BCE and CE. This article aims at establishing the chronology of human occupations and environmental change within this period, by combining archaeological and radiocarbon data, using Bayesian modeling. It reveals that the drying up of the environment experienced by desert farmers occurred at some point between the reigns of Antoninus Pius and Caracalla (2nd–3rd century CE). The accuracy of the produced chronological models made it possible to highlight synchronisms between the end of this “Green Oasis” phase and comparable aridification phenomena on regional and interregional scales. Similar degradation processes on remote sites inside the Roman Empire might be explained by globalized anthropogenic agencies overlapping with a broader climatic drying.

Radiocarbon (14C) dating is often carried out upon multi-specimen samples sourced from bioturbated sediment archives, such as deep-sea sediment. These samples are inherently heterogeneous in age, but existing 14C calibration techniques were originally developed for age homogeneous material, such as archaeological artifacts or individual tree rings. A lack of information about age heterogeneity leads to a systematic underestimation of a sample’s true age range, as well as the possible generation of significant age-depth artifacts during periods of the Earth’s history coinciding with highly dynamic atmospheric Δ14C. Here, a new calibration protocol is described that allows for the application of sedimentological priors describing sediment accumulation rate, bioturbation depth and temporally dynamic species abundance. This Bayesian approach produces a credible calibrated age distribution associated with a particular laboratory 14C determination and its associated sedimentological priors, resulting in an improved calibration, especially in the case of low sediment accumulation rates typical of deep-sea sediment. A time-optimized computer script (biocal) for the new calibration protocol is also presented, thus allowing for rapid and automated application of the new calibration protocol. This new calibration protocol could be applied within existing age-depth modeling software packages to produce more accurate geochronologies for bioturbated sediment archives.

The Santuario della Madonna Cave, located near Praia a Mare (Cosenza), along the northwestern coast of Calabria (southern Italy), has an impressive stratigraphy, with occupation phases spanning from the late Paleolithic to the advanced phases of the Middle Bronze Age. Recently, a new excavation area has been opened in the cave from which shortlived vegetal remains were sampled and submitted for accelerator mass spectrometry (AMS) radiocarbon dating. The aim of this study was to define an accurate chronology of the different cultural aspects and to explore the potentialities resulting from application of advanced statistical tools for 14C data analysis in such a context.

The radiocarbon dates covered in this list were measured during 1978. Chemical and counting procedures are as reported previously (R, 1978, v 20, p 398-404). Age calculations are based on the conventional 14C half-life (5570 yr) and on the contemporary value of 95% of the activity of NBS oxalic acid. Errors quoted correspond to 1σ value which takes into account the counting statistics, the uncertainty in the half-life, and the instability of the counting system. The ages are not corrected for isotopic fractionation in nature.

This is the first of a series of new lists of English archaeological dates commissioned for measurement by the Historic Buildings and Monuments Commission within prescribed contractual periods. This list, containing 121 dates, refers to the measurement period, April 1985 to March 1986, and results are reported irrespective of whether the associated projects are completed or ongoing.

We have worked in collaboration with the Westinghouse Savannah River Company and Packard Instrument Company to develop a prototype instrument for remote, near real-time, in situ analysis of environmental levels of tritium in surface and ground water samples. The unit consists of a Packard Radiomatic™ 525TR liquid scintillation counter that has been modified to achieve lower detection levels through background reduction using Packard's After-Pulse Burst Discrimination electronics and an auxiliary Bi4Ge3O12 scintillation detector guard. The system is fully programmable to enable remote calibration, sample collection, sample analysis, reconfiguration of operational mode and interrogation for analytical results.

We present here the principal ideas of a new, fully computerized data acquisition system with pulse-rise background reduction, developed in the Gliwice Radiocarbon Laboratory, and our first results. The new system uses a microprocessor-controlled pulse and coincidence analyzer for acquisition of data from 3 of 4 proportional counter sets. The analyzer acquires and stores information on the pulse's amplitudes and rise-times and their coincidence with guard counters and radio-frequency shield. This feature allows us to separate pulses using anticoincidence information and pulse-shape discrimination. The described method of background reduction led to a significant increase in the factor of merit on 2 of 3 counters tested.

A simple procedure for the conversion of 14C NBS oxalic acid standard to benzene without direct combustion or wet oxidation is reported. Fractionation in the synthesized benzene was not detected.

The rich architectural heritage of Cyprus from the period of Byzantine and Latin rule includes 10 churches inscribed in the UNESCO World Heritage list. Most of these monuments preserve wooden elements: whether structural, decorative or furnishings. Many preserve wall paintings that are considered among the best examples of Byzantine and Medieval art in the Eastern Mediterranean. The dating of these paintings as well as the church buildings themselves, has been based mainly on style, with occasional dedicatory inscriptions and related historical interpretation. We report early results from a project investigating the wooden cultural heritage of Cyprus and in particular the combined use of dendrochronology with radiocarbon via tree-ring sequenced 14C wiggle-matching to help place initial tree-ring sequences. This includes a floating 264-year Pinus brutia chronology from several monuments, which, with a ca. 5-year gap, suggests prospects for >700-years of P. brutia chronology for Cyprus, and, with one gap of several decades to fill, ca. 1100 years of Pinus nigra chronology for Cyprus. Several currently floating elements from the multi-phase UNESCO-listed Timios Stravros church at Pelendri, including a terminus post quem for the celebrated liturgical wooden cross, are approximately dated across the 11th to 16th centuries AD.

This list includes ages measured from August 1974 to May 1976 using the benzene scintillation method. All archaeologic and geologic samples except Sahara Libico series, come from Italian territory. These datings were carried out partly with the liquid scintillation counter previously described (Alessio et al, 1973) and partly with a new liquid scintillation counter (Alessio et al, 1976b). Vials, 4.5ml in volume, described in Alessio et al, 1973. Mixture consists of 3.5ml of benzene from sample and 1ml of commercial liquid scintillator NE 216. The characteristics of new counter are: background 2.90 cpm and figure of merit

We have studied the isotopic composition of recently precipitated travertines to determine the initial 14C activity of ancient travertine deposits. We found that the 14C activity of recent travertines of northeastern Spain was a function of the distance from the spring, resulting in variations in the initial 14C activity of the ancient travertine formations. We calculated the ancient travertine radiocarbon ages by using the ratio between the 14C activity of recent travertines and that of present atmospheric CO2 as the initial 14C activity.