This study establishes the chronological framework of the sedimentary sequence deposited Dead Sea, ICDP 5017-1, Radiocarbon chronology during the past 50 ka at the deepest part of the Dead Sea (the ICDP 5017-1 site), which was recovered by the Dead Sea Deep Drilling Project (DSDDP) under the auspices of the International Continental Scientific Drilling Program (ICDP). The age-depth model is constructed using 38 14C dates of terrestrial plant remains in a composite 150-m-long profile, generated by anchoring 32 marker layers identified in five cores. The sedimentary records at the ICDP 5017-1 site fills gaps in those obtained from the exposed sections at the high margins of the lake, particularly in times of lake-level retreat, and allows for a high-resolution comparison between the lake’s margins and deepest floor.

Radiocarbon (14C) dating of protein-containing material (collagen, hair/wool, silk, leather) contaminated with extraneous carbon (e.g. humic substances) might result in unreliable dates when pretreated with the conventional but inadequate protocols. In this study cross-flow nanofiltration was applied to pretreated, protein-containing material. This method is able to remove low-molecular and high-molecular weight contaminants as demonstrated in previous studies. The sample quality improvement by cross-flow nanofiltration is verified by measuring the C:N ratio before and after nanofiltration. If the C:N ratio of the permeate (sample after cross-flow nanofiltration) falls within the C:N boundaries for uncontaminated wool/hair, silk and bone collagen, it is assumed to be contamination free. In our study, we focused on wool, silk, and collagen samples of known historical age. All samples treated by cross-flow nanofiltration effectively outputs C:N ratios within the expected range and yield for more accurate 14C date in agreement with historical expectations whereas bulk samples with C:N ratio out of the expected ranges, give either younger or older dates. We thus highlight both that C:N ratio is a good indicator of contamination and that cross-flow nanofiltration is an efficient method to treat protein-containing materials prior to 14C dating.

This paper discusses the chronology of burial grounds containing specific Seima-Turbino type bronze weaponry (spears, knives, and celts). The “transcultural” Seima-Turbino phenomenon relates to a wide distribution of specific objects found within the sites of different Bronze Age cultures in Eurasia, not immediately related to each other. The majority of the Seima-Turbino objects represent occasional findings, and they are rarely recovered from burial grounds. Here, we present a new set of 14C dates from cemeteries in western Siberia, including the key Asian site Rostovka, with the largest number of graves containing Seima-Turbino objects. Currently, the presented database is the most extensive for the Seima-Turbino complexes. The resulting radiocarbon (14C) chronology for the western Siberian sites (22nd–20th centuries cal BC) is older than the existing chronology based on typological analysis (16th–15th centuries BC) and some earlier 14C dates for the Seima-Turbino sites in eastern Europe. Another important aspect of this work is 14C dating of complexes within specific bronze objects—daggers with figured handles—which some researchers have related to the Seima-Turbino type objects. These items are mostly represented by occasional finds in Central Asia, however, in western Siberia these have been recovered from burials, too. The 14C dating attributes these daggers to the end of the 3rd millennium cal BC, suggesting their similar timing to the Seima-Turbino objects. Further research into freshwater reservoir offsets in the region is essential for a more reliable reconstruction of the chronology of the Seima-Turbino phenomenon and the daggers with figured handles.

In this response to the reply by Shahack-Gross and Finkelstein (2017), we present additional data of our research at Horvat Haluqim. This includes phytolith percentages and multicellular phytolith stomata in a thin section of a layer in Terraced Field 12, dated by radiocarbon (14C) to the Late Bronze–Early Iron Age. We also show thin-section evidence of aggrading sediment laminations in this terraced field. A new 14C date is given of the Early Islamic Period in Terraced Field 7, as differences in terrace wall architecture are highlighted. We revisit the interpretation by Shahack-Gross and Finkelstein in relation to herd management. Our 14C dates attest that terrace agriculture based on runoff/floodwater irrigation occurred in the Negev Highlands during several periods, including the Iron Age.

Archaeological site 3 in Ulów is in an area previously thought not to have been settled before historical times. Systematic excavation work that began there in 2002 revealed long-term occupation from the Late Palaeolithic to the Middle Ages. The majority of archaeological features represent a cemetery belonging to the Late Roman and Early Migration periods (III–V c. AD, Wielbark culture). The site’s relative chronology was determined from analyses of archaeological artifacts. To complete the chronological framework required for a proper interpretation of cultural processes, a group of charcoal fragments was selected for radiocarbon (14C) dating. These charcoals were first taxonomically identified and weighed, and then designated for accelerator mass spectrometry (AMS) and conventional 14C analyses. The datings (n=43) indicated three main chronological horizons. Some of the graves from the Wielbark culture contained charcoals of younger or older age, posing problems in interpreting taphonomic processes at this multicultural site. In the light of the 14C dating results, the chronology of several features previously attributed to the Wielbark culture was re-interpreted.

The standard procedure for storing/preserving seawater dissolved organic carbon (DOC) samples after field collection is by freezing (–20°C) until future analysis can be made. However, shipping and receiving large numbers of these samples without thawing presents a significant logistical problem and large monetary expense. Access to freezers can also be limited in remote field locations. We therefore test an alternative method of preserving and storing samples for the measurement of DOC concentrations ([DOC]), stable carbon (δ13C), and radiocarbon (as ∆14C) isotopic values via UV photooxidation (UVox). We report a total analytical reproducibility of frozen DOC samples to be [DOC]±1.3 µM, ∆14C±9.4‰, and δ13C±0.1‰, comparable to previously reported results (Druffel et al. 2013). Open Ocean DOC frozen versus acidified duplicates were on average offset by ∆DOC±1.1 µM, ∆∆14C± –1.3‰, and ∆δ13C± –0.1‰. Coastal Ocean frozen vs. acidified sample replicates, collected as part of a long-term (380-day) storage experiment, had larger, albeit consistent offsets of ∆DOC±2.2 µM, ∆∆14C±1.5‰, and ∆δ13C± –0.2‰. A simple isotopic mass balance of changes in [DOC], ∆14C, and δ13C values reveals loss of semi-labile DOC (2.2±0.6 µM, ∆14C=–94±105‰, δ13C=–27±10‰; n=4) and semi-recalcitrant DOC (2.4±0.7 µM, ∆14C=–478±116‰, δ13C=–23.4±3.0‰; n=3) in Coastal and Open Ocean acidified samples, respectively.

This paper summarizes the present knowledge on the variation of summer temperatures in the European Alps throughout the Holocene by combining the results of an extraordinary archaeological find with the information gathered from glacier and tree-line movements. As it turns out, there were several distinct periods were the glaciers were smaller than today, allowing in some periods the growth of trees in areas, which even now are still covered with ice. On average, the first half of the Holocene was warmer than the second half, with temperatures starting to decrease around the time of the Iceman some 5000 yr ago. One of the coldest periods during the Holocene, the so-called Little Ice Age (LIA), lasted from about AD 1300 to 1850. It is well known that since then the Alpine glaciers have been receding, most likely amplified by anthropogenic impact. The study of temperature variations before human influence may help to eventually disentangle natural and anthropogenic causes for the global warming of our time.

We estimate the blank carbon mass over the course of a typical Ramped PyrOx (RPO) analysis (150–1000°C; 5°C×min–1) to be (3.7±0.6) μg C with an Fm value of 0.555±0.042 and a δ13C value of (–29.0±0.1) ‰ VPDB. Additionally, we provide equations for RPO Fm and δ13C blank corrections, including associated error propagation. By comparing RPO mass-weighted mean and independently measured bulk δ13C values for a compilation of environmental samples and standard reference materials (SRMs), we observe a small yet consistent 13C depletion within the RPO instrument (mean–bulk: μ=–0.8‰; ±1σ=0.9‰; n=66). In contrast, because they are fractionation-corrected by definition, mass-weighted mean Fm values accurately match bulk measurements (mean–bulk: μ=0.005; ±1σ=0.014; n=36). Lastly, we show there exists no significant intra-sample δ13C variability across carbonate SRM peaks, indicating minimal mass-dependent kinetic isotope fractionation during RPO analysis. These data are best explained by a difference in activation energy between 13C- and 12C-containing compounds (13–12∆E) of 0.3–1.8 J×mol–1, indicating that blank and mass-balance corrected RPO δ13C values accurately retain carbon source isotope signals to within 1–2‰.

Bayesian models have proved very powerful in analyzing large datasets of radiocarbon (14C) measurements from specific sites and in regional cultural or political models. These models require the prior for the underlying processes that are being described to be defined, including the distribution of underlying events. Chronological information is also incorporated into Bayesian models used in DNA research, with the use of Skyline plots to show demographic trends. Despite these advances, there remain difficulties in assessing whether data conform to the assumed underlying models, and in dealing with the type of artifacts seen in Sum plots. In addition, existing methods are not applicable for situations where it is not possible to quantify the underlying process, or where sample selection is thought to have filtered the data in a way that masks the original event distribution. In this paper three different approaches are compared: “Sum” distributions, postulated undated events, and kernel density approaches. Their implementation in the OxCal program is described and their suitability for visualizing the results from chronological and geographic analyses considered for cases with and without useful prior information. The conclusion is that kernel density analysis is a powerful method that could be much more widely applied in a wide range of dating applications.

In the present work, we assess the chronology of archaeological sites known as earthen mounds, commonly found at the Pampas biome, among the lowlands of Brazil, Uruguay, and Argentina. We focused on the Pontal da Barra settlement, which is a testimony of the long-term occupation of indigenous groups in the swamp and wet environment of Patos Lagoon, southern Brazil. A Bayesian chronological model based on the radiocarbon (14C) dating of 17 samples of fish otolith, 5 charcoal fragments, and 2 bones (human and dog) allowed determination of the beginning of the occupation as well as the occupational synchronism of the different mounds. The nature of the samples allows us to study the local 14C reservoir effect through the comparison between the group of marine and terrestrial samples, deriving a reservoir offset value of 63±53 14C yr for this particular area, indicating a strong freshwater influence in the lagoon system. We estimate the start of human intervention in the landscapes of southern Patos Lagoon to be around 2200 cal BP, with the most intense activity between 1800 and 1200 cal BP.

A new type of miniaturized, externally heated graphitization reaction furnace, the microconventional furnace (MCF), was constructed following our development of the laser heated furnace (LHF). The MCF is comprised of a gas reactor, a cold finger cooling system, and a compact resistive heater, which can raise the temperature of the hot finger to 850°C. The gas reactor is provided with three integrated valves to connect with the hydrogen/vacuum manifold, to isolate the reactor, and to connect with sample vessels. We made two types of MCF: the type 1 furnace (volume of 0.9 mL), with an integral stainless steel cold finger, and the type 2 furnace (volume from 1.3 to 10 mL), with a changeable glass cold finger. The MCF is designed for above atmospheric pressure (up to 2500 mbar) operation to decrease the overall graphitization time and improve the carbon yield. The MCF provides an effective solution for producing graphite from carbon dioxide (CO2) sample gas from 5 to 2000 µg of carbon with only 0.083 μg of 100 pMC extraneous carbon added. Cross-contamination tests show that the MCFs have no memory effect from previous samples.

We conducted an isotopic analysis of groundwater in Orange County, California, USA, around the Talbert Seawater Injection Barrier to determine if recycled water, used to artificially recharge local aquifers, carries a unique isotopic signature that can be used as a tracer. From September 2014 to April 2015, we collected groundwater from six privately owned wells within the coastal groundwater basin, along with various surface waters. All water samples were analyzed for their stable isotopic composition (δ18O, δD), the δ13C and 14C signature of the dissolved inorganic carbon (DIC) pool, DIC concentration, pH, and salinity. The DIC of groundwater mixing with recycled water is enriched in 14C above natural background levels, with varying signal strength through time, depleted in δ13C, and low in DIC concentration. Water isotopes further suggest that recycled water is a mixture of Colorado River water and regional groundwater. In contrast, groundwater found further away from the injection barrier has carbon and water isotope composition consistent with regional groundwater and Santa Ana River water. Our findings imply that recycled water injected through the Talbert Barrier is isotopically unique, and that 14C enrichment may be used as an intrinsic tracer of artificial recharge within the basin.

Only domestic mammals (sheep, goat, cattle, pig, and dog) and two rodent species constituted the faunal package introduced to the Balearic Islands by the early settlers in the 3rd millennium cal BC. Later animal introductions in the archipelago were thought to occur by the end of the 1st millennium cal BC due to contacts with Punic merchants or, more than likely, to the Roman conquest of the islands. Recently, several faunal remains belonging to different vertebrates (red deer, chicken, and rabbit) were found in the Talayotic site of Cornia Nou (Minorca), in contexts that date to the early 1st millennium cal BC. A series of radiocarbon (14C) dates was made directly on samples of small species to exclude the possibility of infiltration into lower layers. The obtained results show that chicken and rabbit were already present on Minorca in the early 1st millennium cal BC. Chicken is recorded in Phoenician colonies in south Iberia as early as the 8th century cal BC. Rabbit, on the other hand, is indigenous to the Iberian Peninsula. These new faunal introductions recorded in Minorca could be related to the Late Bronze and Phoenician maritime activity.

In this paper, first results comparing modified Longin and ninhydrin collagen extraction methodologies are presented. The goal of this study is to investigate the bones of several species with different ages, preservation conditions, and collagen contents to determine the most suitable preparation method. Different types of samples are used such as VIRI samples, previously dated bones, and background samples. Each bone has undergone elemental analysis, infrared analysis, and 14C measurement. The results are presented and the advantages and disadvantages of each preparation method are discussed. In general, results obtained by the two methods are in accordance with the consensus value for 2σ uncertainty. For VIRI I and a mammoth bone, the ninhydrin preparation gives, respectively, 8450±70 BP and 14,870±60 BP whereas the modified Longin process gives 8365±45 BP and 14,750±100 BP in agreement with the expected values. From the experimental point of view, the modified Longin process is easier to implement than the ninhydrin protocol. From this approach, we can conclude that the modified Longin process could be preferred in most cases and particularly when the amount of bone is small and the sample is not too contaminated.

The relic “the sack of Saint Francesco” has for the first time been investigated by scientific means. The sack is kept at the Franciscan Friary of Folloni near Montella in southern Italy. According to legend, the sack appeared on the doorstep of the Friary in the winter of 1224 containing bread sent from St Francesco (St Francis of Assisi), who at that time was in France. The bread was allegedly brought to the friary by an angel. We analyzed samples of the sack to obtain a radiocarbon (14C) date and to search for any remaining traces of bread. The 14C date yielded a calibrated age range of AD 1220–1295 (2σ), which places the textile in the right timeframe according to the legend. Chemical analysis by gas-chromatography with mass spectrometric detection (GC-MS) revealed the presence of ergosterol (5, 7, 22-ergostatrien-3b-ol), a known biomarker of brewing, baking, or agriculture. In this paper we have further substantiated the validity of ergosterol as a biomarker for the past presence of bread. It appears that there is a fine correspondence between the Franciscan legend and the two most decisive scientific methods relevant for analyzing the sack. Although it is not proof, our analysis shows that the sack indeed could be authentic.

To measure chronological changes in the marine reservoir effect in western Japan, 47 marine shells and 35 terrestrial plants from the same horizons in two cores of Holocene sediments were radiocarbon dated by the KIGAM AMS facility. These cores were obtained from the central and northern parts of Hakata Bay using a Geoslicer device. This drilling tool provided us continuous coverage and many samples. In order to determine the species effects on the marine reservoir effect, both filter feeders and a deposit feeder were selected for study. Based on the analysis of lithology, mollusk assemblage, and 14C dating, two sedimentary units were determined: the upper bay floor sediment and lower estuarine sediment. Reservoir ages of 280±150 yr (n=17) and 340±140 yr (n=18) were obtained from the central and northern parts of Hakata Bay during 2000 to 10,000 cal BP, respectively. Based on these results, it is clear that a paleoenvironmental change occurred here as a result of sea-level rise during the deglacial period.

Combining atmospheric Δ14CO2 data sets from different networks or laboratories requires secure knowledge on their compatibility. In the present study, we compare Δ14CO2 results from the Heidelberg low-level counting (LLC) laboratory to 12 international accelerator mass spectrometry (AMS) laboratories using distributed aliquots of five pure CO2 samples. The averaged result of the LLC laboratory has a measurement bias of –0.3±0.5‰ with respect to the consensus value of the AMS laboratories for the investigated atmospheric Δ14C range of 9.6 to 40.4‰. Thus, the LLC measurements on average are not significantly different from the AMS laboratories, and the most likely measurement bias is smaller than the World Meteorological Organization (WMO) interlaboratory compatibility goal for Δ14CO2 of 0.5‰. The number of intercomparison samples was, however, too small to determine whether the measurement biases of the individual AMS laboratories fulfilled the WMO goal.

Seven radiocarbon laboratories: Åbo/Aarhus, CIRCE, CIRCe, ETHZ, Poznań, RICH, and Milano-Bicocca performed separation of carbonaceous fractions suitable for 14C dating of four mortar samples selected for the MOrtar Dating Inter-comparison Study (MODIS). In addition, optically stimulated luminescence (OSL) analyses were completed by Milano-Bicocca and IRAMAT-CRP2A Bordeaux. Each laboratory performed separation according to laboratory protocol. Results of this first intercomparison show that even though consistent 14C ages were obtained by different laboratories, two mortars yielded ages different than expected from the archaeological context.