Radiocarbon最新文献

{"title":"A TIME-INTEGRATED SAMPLER FOR RADIOCARBON ANALYSIS OF AQUATIC METHANE","authors":"M H Garnett, J F Dean","doi":"10.1017/rdc.2024.31","DOIUrl":"https://doi.org/10.1017/rdc.2024.31","url":null,"abstract":"<p>Freshwater ecosystems are responsible for a large proportion of global methane emissions to the atmosphere. The radiocarbon (<span>14</span>C) content of this aquatic methane is useful for determining the age and source of this important greenhouse gas. Several methods already exist for the collection of aquatic methane for radiocarbon analysis, but they tend to only sample over short periods of time, which can make them unsuitable for characterizing aquatic methane over longer timespans, and vulnerable to missing short-term events. Here, we describe a new time-integrated method for the collection of aquatic methane that provides samples suitable for radiocarbon analysis, that are representative for periods of up to at least 16 days. We report the results of a suite of tests undertaken to verify the reliability of the method, and the <span>14</span>C age of aquatic methane from field trials undertaken at sites within Scotland, UK. We believe that this new method provides researchers with a simple approach that is easily deployable and can be used to collect representative time-integrated samples of methane for radiocarbon analysis from a wide range of aquatic environments.</p>","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"81 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140302603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FIRST DIRECT RADIOCARBON DATING (22–27 CAL KA BP) OF MASSIVE ICE AT THE MECHIGMEN AND LAVRENTIYA BAYS COAST, EASTERN CHUKOTKA","authors":"Yurij K Vasil’chuk, Nadine A Budantseva, Alexey A Maslakov, Alla C Vasil’chuk, Jessica Yu Vasil’chuk","doi":"10.1017/rdc.2024.21","DOIUrl":"https://doi.org/10.1017/rdc.2024.21","url":null,"abstract":"<p>The Eastern Chukotka is considered a unique permafrost region where massive ice bodies are widespread. However, the origin and age of these ice formations are often discussed. The age of the massive ice of Chukotka was established for the first time using AMS <span>14</span>C dating. It was revealed that three massive ice bodies on the coast of Mechigmen Bay were formed at the end of the Late Pleistocene: a) near the Akkani site, 21,612 to 22,147 cal BP; b) near the Lavrentiya settlement, 27,553 cal BP; and c) near the Lavrentiya settlement, 22,193 cal BP. Stable isotope values in the studied massive ice vary in a rather wide range by about 10‰ for δ<span>18</span>O values (from –14.8‰ to –24.5‰) and about 75‰ for the δ<span>2</span>H values (from –116‰ to –191‰). The studied massive ice bodies are of intrasedimental genesis and formed epigenetically during the final stage of MIS2 (22–27 cal ka BP).</p>","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"20 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140302683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ASSESSING 14C BLANKS IN THE SMALL-SCALE ANALYSIS OF N-ALKANE COMPOUND-SPECIFIC-RADIOCARBON-ANALYSIS","authors":"Kristina Reetz, Ronny Friedrich, Jago J Birk, Wilfried Rosendahl, Sabine Fiedler","doi":"10.1017/rdc.2024.26","DOIUrl":"https://doi.org/10.1017/rdc.2024.26","url":null,"abstract":"Compound-specific radiocarbon analysis (CSRA) provides the possibility to date sample material at a molecular level. <jats:italic>N</jats:italic>-alkanes are considered as specific compounds with high potential to CSRA. As these compounds originate from plant waxes, their radiocarbon (<jats:sup>14</jats:sup>C) analysis can provide valuable information about the age and origin of organic materials. This helps to reconstruct and understand environmental conditions and changes in vegetation in the past. However, CSRA has two main challenges: The small sample size of CSRA samples, making them extremely sensitive to blank effects, and the input of unknown amounts of extraneous carbon during the analytical procedure. According to the previous study from Sun and co-workers, we used different-sized aliquots of leaves <jats:italic>Fagus sylvatica</jats:italic> (<jats:italic>n</jats:italic>C27, <jats:italic>n</jats:italic>C29) and <jats:italic>Festuca rubra agg</jats:italic> (<jats:italic>n</jats:italic>C31, <jats:italic>n</jats:italic>C33) as modern standards and two commercial standards (<jats:italic>n</jats:italic>C26, <jats:italic>n</jats:italic>C28) as fossil standards for blank determination. A third commercial standard (<jats:italic>n</jats:italic>C27) with predetermined radiocarbon content of F<jats:sup>14</jats:sup>C = 0.71 (<jats:sup>14</jats:sup>C age of 2700 BP) serves to evaluate the blank correction. We found that the blank assessment of Sun and co-workers is also applicable to <jats:italic>n</jats:italic>-alkanes, with a minimum sample size of 15 µg C for dependable CSRA dates. We determined that the blank introduced during the analytical procedure has a mass of (4.1 ± 0.7) µg carrying a radiocarbon content of F<jats:sup>14</jats:sup>C = 0.25 ± 0.05. Applying the blank correction to a sediment sample from Lake Holzmaar (Germany) shows that all four isolated <jats:italic>n</jats:italic>-alkanes have similar <jats:sup>14</jats:sup>C ages. However, the bulk material of the sediment and branches found in the sediment core are younger than the CSRA dates. We conclude that the disparity between the actual age of analysed organic material and the age inferred from radiocarbon results, which can occur in sediment traps due to delayed deposition, is the reason for the CSRA age.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"30 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140302598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MONITORING OF MODERN CARBON FRACTION IN DISPOSABLE PACKAGING","authors":"Komal Aziz Gill, Danuta J Michczyńska, Adam Michczyński, Natalia Piotrowska","doi":"10.1017/rdc.2024.35","DOIUrl":"https://doi.org/10.1017/rdc.2024.35","url":null,"abstract":"Radiocarbon (<jats:sup>14</jats:sup>C) methodology was used to investigate the presence of biocarbon in different bio-based disposable packaging products. Packaging waste contributes to a municipal solid waste, which is increasing environmental concerns and resulting in the enhancement of EU regulations that aim to reduce packaging waste. The <jats:sup>14</jats:sup>C amount in samples reflects how much of the biocarbon has been used. In this study, the concentration of <jats:sup>14</jats:sup>C was determined in commonly used types of disposable packaging, such as cups, plates, straws, cutlery, and baking paper. Samples were made of materials such as paper, wheat bran, sugarcane, and wood. The mean concentration of the <jats:sup>14</jats:sup>C isotope, measured by the accelerator mass spectrometry (AMS) technique, is greater than 100 pMC in all tested samples, indicating that the samples are modern. The relatively high <jats:sup>14</jats:sup>C concentration values in the waterproof layer of the sample indicate that bioplastic, rather than plastic, was used in its production. The highest <jats:sup>14</jats:sup>C isotope concentration values were measured for samples that used the oldest biomass (wood and paper), and the lowest for products from current crops (sugarcane and wheat bran), which is consistent with the trend of changes in <jats:sup>14</jats:sup>C concentration in the biosphere. The study also addresses the problem of heterogeneity and representativeness of subsamples.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"27 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140302678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RADIOCARBON DATING OF ST. GEORGE’S ROTUNDA IN NITRIANSKA BLATNICA (SLOVAKIA): AN ARCHAEOLOGICAL COMMENT","authors":"Zbigniew Robak","doi":"10.1017/rdc.2024.33","DOIUrl":"https://doi.org/10.1017/rdc.2024.33","url":null,"abstract":"In 2021, a series of radiocarbon dates for St. George’s Rotunda in Nitrianska Blatnica (Slovakia) was published. The samples were acquired during restoration work. Based on the analysis, the authors dated the rotunda to the period of around AD 820–887, with 86% of the probability distribution lying in the period before AD 863. The chronology is based on the combined radiocarbon date 1191 ± 10 BP, which was obtained from four samples of wood fragments found in the oldest mortar layer. However, the date proposed by the authors raises concerns. The conclusions were based on a selection of samples and modeling of radiocarbon dates but put less emphasis on the results of many years of broad archaeological research on the local settlement agglomeration as well as extant historical and archaeological knowledge. The present re-analysis of the early medieval mortar and plaster samples and simple modeling corroborates the alternative hypothesis, providing us with the date 1115 ± 13 BP (cal AD 892–988 2σ). The resulting probability range is consistent with current archaeological and historical knowledge. Consequently, contrary to former conclusions, the construction of the rotunda should be dated to the period between the end of the 9th century and the end of the 10th century.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"22 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140166123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RETREATMENT OF BONE MATERIAL IN THE GLIWICE RADIOCARBON LABORATORY USING ULTRAFILTRATION","authors":"Fatima Pawełczyk, Magdalena Niedziałkowska, Sławomira Pawełczyk, Natalia Piotrowska, Maciej Sykut","doi":"10.1017/rdc.2024.32","DOIUrl":"https://doi.org/10.1017/rdc.2024.32","url":null,"abstract":"Preparation of bones for radiocarbon (<jats:sup>14</jats:sup>C) dating is still quite a challenge for researchers. The methods are being tested and improved, to increase reliability of dating results and to verify the previous ones. In this work, a set of gelatine samples, extracted from <jats:italic>Cervus elaphus</jats:italic> and <jats:italic>Cervus canadensis</jats:italic> bones from various sites in Europe and a set of human bones from archaeological sites in Poland were subjected to retreatment using ultrafiltration in Gliwice Radiocarbon Laboratory. The tested samples represent a wide range of ages, from older than 40,000 <jats:sup>14</jats:sup>C years BP to modern. The prepared material was subjected to the measurement of C/N atomic ratios and <jats:sup>14</jats:sup>C dating using the accelerator mass spectrometry (AMS) technique. Also, the stable isotopes (δ<jats:sup>13</jats:sup>C and δ<jats:sup>15</jats:sup>N) values were determined. In a few cases ultrafiltration allows to improve gelatine quality for long-stored samples, by increasing the %C and %N as well as decreasing C/N<jats:sub>at</jats:sub> ratios. Nevertheless, this effect was not observed for majority of the samples. Remeasurements of long-term stored samples give mostly the same <jats:sup>14</jats:sup>C ages for ultrafiltered ones and for those without ultrafiltration.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"1 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140166110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"USING RAPID ATMOSPHERIC 14C CHANGES IN THE 7TH CENTURY BC TO PRECISELY DATE THE FLOATING CHRONOLOGY FOR PINE WOOD FROM JÓZEFOWO (NORTHERN POLAND)","authors":"Damian Wiktorowski, Marek Krąpiec, Jacek Pawlyta, Joanna Barniak, Andrzej Rakowski","doi":"10.1017/rdc.2024.18","DOIUrl":"https://doi.org/10.1017/rdc.2024.18","url":null,"abstract":"<p>The floating dendrochronological sequence of pine wood from Józefowo, N. Poland was expected to cover the ∼660 BC radiocarbon (<span>14</span>C) excursion. The sequence was radiocarbon dated using the OxCal wiggle matching procedure and the IntCal20 calibration curve. <span>14</span>C concentrations were measured in one-year α-cellulose samples from around 660 BC. The published data on the ∼660 BC <span>14</span>C excursion from Grabie, Poland were used to absolute date the Józefowo chronology with 1-year accuracy. The results confirm the occurrence of a rapid increase in Δ<span>14</span>C in 664/663 BC and its potential to be used as a fixing point for floating dendrochronological sequences.</p>","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"143 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140125034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HORIZONTAL WATERMILL CHRONOLOGIES BASED ON 14C DATING OF ORGANICS IN MORTARS: A CASE STUDY FROM JARASH, JORDAN","authors":"David Boyer","doi":"10.1017/rdc.2024.24","DOIUrl":"https://doi.org/10.1017/rdc.2024.24","url":null,"abstract":"<p>Horizontal watermills in the southern Levant have proved difficult to date. This study investigates the use of radiocarbon (<span>14</span>C) dating of various organic carbon fractions in structural mortars and carbonate deposits to identify <span>terminus post quem</span> (TPQ) construction dates for seven arubah watermills and two chute watermills in northern Jordan. Dating results from the various organic fractions are discussed in the contexts of carbon fraction integrity and mortar type. The arubah watermill construction dates fall into two chronological groups. Four arubah watermills have Middle Islamic (late 12th to early 14th century AD) construction dates based on macrocharcoal and bulk organic fraction ages, whereas the bulk organic fraction ages of two earlier arubah watermills straddle the Byzantine-Early Islamic transition. Their possible fifth to seventh-century construction dates are among the earliest in the southern Levant. Limited <span>14</span>C data from the chute water mills suggests that the earliest may date to the sixth–seventh century period, concurrent with the older arubah watermills. The study supports the viability of the AMS <span>14</span>C method to provide estimated TPQ construction dates for watermills, providing caution is exercised. Short-lived macrocharcoals have the highest integrity but are subject to severe sample loss during pretreatment. <span>14</span>C ages from humic and humin fractions in earthen mortars are influenced by “old carbon” contamination, possibly a soil reservoir effect, and are centuries older than the probable construction date. Attention is drawn to the potential use of arubah carbonate deposits as proxy records of water flow, watermill use, and hydroclimate.</p>","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"115 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140099872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CHRONOLOGICAL STUDY OF COLLECTIVE BURIALS IN THE NORTHERN IBERIAN PLATEAU: ANALYSIS OF RADIOCARBON DATES ON HUMAN BONES FROM THE MEGALITHIC COMPLEX OF LA LORA (BURGOS, SPAIN)","authors":"Angélica Santa Cruz","doi":"10.1017/rdc.2024.19","DOIUrl":"https://doi.org/10.1017/rdc.2024.19","url":null,"abstract":"<p>This paper offers a temporal analysis of the megalithic group of La Lora in the context of northern Iberian Plateau megalithism. For this purpose, 67 accelerator mass spectrometry radiocarbon (AMS <span>14</span>C) dates were obtained on human bone from the minimum number of individuals recovered from nine tombs. This is the first systematic dating project carried out in this dolmen group and has enabled the chronology of the main funerary series to be updated. The results reveal that the actual funerary use dates mainly to the 4th millennium BC, although, as deduced from the archaeological material, some tombs were reused in later periods. Additionally, the significant architectural polymorphism of the group, consisting mainly of simple dolmens and large corridor tombs, suggested a temporal evolution to monumentality. However, the dating shows a more complex reality, since it is likely that the large tombs functioned as funerary pantheons during the 4th millennium BC, characterized by a cyclical and recurrent use. In contrast, the simpler structures were preferred to be of shorter use and restricted to the first half of the 4th millennium.</p>","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"27 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140100205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DATED HOLOCENE HUMAN REMAINS FROM SOUTH AFRICA: RECALIBRATION AND BROAD CONTEXTUALIZATION","authors":"Emma Loftus, Marlize Lombard, Maryna Steyn","doi":"10.1017/rdc.2024.22","DOIUrl":"https://doi.org/10.1017/rdc.2024.22","url":null,"abstract":"<p>The study of human remains can provide valuable information about aspects of past populations. Here we present an updated database consisting of 590 radiocarbon (<span>14</span>C) dates for human remains from Holocene South Africa before European contact. We calibrated or recalibrated all the previously published dates using the most recent calibration curve for the southern hemisphere. Each date is roughly georeferenced and plotted according to their Stone Age or Iron Age contexts, revealing the broad distribution pattern of dated Holocene human remains across South Africa—perhaps reflecting aspects of past population distribution and densities, but also underscoring historical collection practices, archaeological research focus, and preservation conditions. We use Kernel Density Estimation models to show peaks and troughs of dated remains through time, with Later Stone Age peaks at ∼5.5 ka cal BP, ∼2 ka cal BP and ∼0.5 ka cal BP, and Iron Age peaks ∼1.1 ka cal BP and ∼0.5 ka cal BP, some of which show broad correspondence to climatic data. Our data, based on dated remains only, do not provide a full reflection of past populations, and our large-scale, coarse-grained analysis cannot yet assess the reasons for the peaks in dated human remains in detail. Yet, the study provides a new resource, and a data-driven overview that highlights aspects to be explored with further contextual analyses against the available archaeological records, population histories and climatic indicators through time and across space.</p>","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"17 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140099874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}