Bethan Linscott, Luke Spindler, Jamie Cameron, David Chivall, Rachel Wood
ABSTRACT Accelerator mass spectrometry (AMS) radiocarbon ( 14 C) dating is central to the development of robust chronologies in archaeological and paleoenvironmental contexts spanning the last 50,000 years. For dates to be accurate, samples must be free of exogenous carbon contamination. At the Oxford Radiocarbon Accelerator Unit (ORAU), considerable advancements in the dating of bone collagen have been made through the development of a high performance liquid chromatography (HPLC) method for the dating of the amino acid hydroxyproline, which can mitigate the effects of carbon contamination. However, recent changes in ligand manufacturing methods for the mixed-mode column used in the ORAU protocol (Primesep A, SIELC Technologies; IL, USA) have resulted in unacceptably high analytical backgrounds. Prior to the manufacturing change, backgrounds of > 50k BP were achievable. Since the manufacturing change, a mean background of 32.5k BP has been measured. Due to column bleed, the Primesep A is therefore no longer suitable for 14 C measurement of hydroxyproline from older material. Here, we present background data and the chromatography conditions used to isolate hydroxyproline using an alternative column, a preparative-scale Newcrom AH, which shows promising potential as an alternative for the routine isolation and AMS dating of hydroxyproline—especially approaching the age and mass limits of the method.
加速器质谱法(AMS)放射性碳(14c)定年对于在过去5万年的考古和古环境背景下建立可靠的年表至关重要。为了使日期准确，样品必须没有外源性碳污染。在牛津放射性碳加速器单元(ORAU)，通过开发一种高效液相色谱(HPLC)方法来测定氨基酸羟基脯氨酸的年代，在骨胶原的年代测定方面取得了相当大的进展，这种方法可以减轻碳污染的影响。然而，最近ORAU协议中使用的混合模式色谱的配体制造方法发生了变化(Primesep A, SIELC Technologies;IL，美国)导致了不可接受的高分析背景。在制造业变革之前，>50k BP是可以实现的。自制造业变化以来，测量了32.5k BP的平均背景。由于柱出血，Primesep A因此不再适用于旧材料中羟脯氨酸的14c测量。在这里，我们提供了背景数据和色谱条件，用于分离羟基脯氨酸，使用另一种色谱柱，制备规模的Newcrom AH，它显示出有希望的潜力，作为常规分离和羟基脯氨酸的AMS定年-特别是接近年龄和质量限制的方法。
{"title":"ACHIEVING LOW BACKGROUNDS DURING COMPOUND-SPECIFIC HYDROXYPROLINE DATING: HPLC COLUMN EFFECTS","authors":"Bethan Linscott, Luke Spindler, Jamie Cameron, David Chivall, Rachel Wood","doi":"10.1017/rdc.2023.86","DOIUrl":"https://doi.org/10.1017/rdc.2023.86","url":null,"abstract":"ABSTRACT Accelerator mass spectrometry (AMS) radiocarbon ( 14 C) dating is central to the development of robust chronologies in archaeological and paleoenvironmental contexts spanning the last 50,000 years. For dates to be accurate, samples must be free of exogenous carbon contamination. At the Oxford Radiocarbon Accelerator Unit (ORAU), considerable advancements in the dating of bone collagen have been made through the development of a high performance liquid chromatography (HPLC) method for the dating of the amino acid hydroxyproline, which can mitigate the effects of carbon contamination. However, recent changes in ligand manufacturing methods for the mixed-mode column used in the ORAU protocol (Primesep A, SIELC Technologies; IL, USA) have resulted in unacceptably high analytical backgrounds. Prior to the manufacturing change, backgrounds of > 50k BP were achievable. Since the manufacturing change, a mean background of 32.5k BP has been measured. Due to column bleed, the Primesep A is therefore no longer suitable for 14 C measurement of hydroxyproline from older material. Here, we present background data and the chromatography conditions used to isolate hydroxyproline using an alternative column, a preparative-scale Newcrom AH, which shows promising potential as an alternative for the routine isolation and AMS dating of hydroxyproline—especially approaching the age and mass limits of the method.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"145 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135863111","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}
Tomas Rimkus, Berit Valentin Eriksen, John Meadows, Christian Hamann
ABSTRACT Bone points were one of the major hunting implements in northern European hunter-gatherer societies. They differ in shapes, types, and manufacturing techniques. In this paper, we investigate 22 bone points from the territory of Lithuania, by studying their morpho-technological characteristics, direct dates, and adhesive residues. The majority are isolated finds, but four points were selected from excavated archaeological sites dated between the 5th and 3rd millennia cal BC. Most of the points belong to the barbed points category, but six slotted points were also studied. Of the 22, 16 previously undated points were sampled for accelerator mass spectrometry radiocarbon (AMS 14 C) dating. The results of 10 successfully dated samples are discussed together with previously published 14 C dates of bone points from the same region. ATR-FTIR analysis of adhesive residues from six points suggest that birch bark tar was used to haft barbed points and lithic inserts. The results reveal the diversity of types of Early Holocene bone points in the territory of Lithuania, while the slotted and Kunda-type bone points fall into narrow timeframes.
{"title":"BONE POINTS IN TIME: DATING HUNTER-GATHERER BONE POINTS IN THE TERRITORY OF LITHUANIA","authors":"Tomas Rimkus, Berit Valentin Eriksen, John Meadows, Christian Hamann","doi":"10.1017/rdc.2023.97","DOIUrl":"https://doi.org/10.1017/rdc.2023.97","url":null,"abstract":"ABSTRACT Bone points were one of the major hunting implements in northern European hunter-gatherer societies. They differ in shapes, types, and manufacturing techniques. In this paper, we investigate 22 bone points from the territory of Lithuania, by studying their morpho-technological characteristics, direct dates, and adhesive residues. The majority are isolated finds, but four points were selected from excavated archaeological sites dated between the 5th and 3rd millennia cal BC. Most of the points belong to the barbed points category, but six slotted points were also studied. Of the 22, 16 previously undated points were sampled for accelerator mass spectrometry radiocarbon (AMS 14 C) dating. The results of 10 successfully dated samples are discussed together with previously published 14 C dates of bone points from the same region. ATR-FTIR analysis of adhesive residues from six points suggest that birch bark tar was used to haft barbed points and lithic inserts. The results reveal the diversity of types of Early Holocene bone points in the territory of Lithuania, while the slotted and Kunda-type bone points fall into narrow timeframes.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"149 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135869307","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}
Natalia Piotrowska, Marzena Kłusek, Piotr Boroń, Ewelina Imiołczyk, Mateusz Budziakowski, Adrian Poloczek, Agata Poloczek-Imielińska, Marian Jaksik
ABSTRACT We present case studies on three objects of high importance for cultural heritage in southern Poland, dated in years 2018–2022 at the Gliwice 14 C and Mass Spectrometry Laboratory with radiocarbon ( 14 C) and dendrochronology methods. The first was a richly ornamented wooden cane, discovered during excavations on the market in Bytom city. The cane can be associated with medieval court proceedings. The archaeological context indicates the 13th century AD, and the 14 C result corresponds perfectly with this time, confirming that it is the oldest object of this type in Poland. The second was a 4-m-tall oak column from St. Leonard Church in Lipnica Murowana, a UNESCO heritage site. The local story said it was previously devoted to Światowid, a pagan deity. Our analysis excluded the pre-Christian age, as the tree was felled no earlier than the late 15th century, which is in agreement with historical records. The third was a wooden Saint Lawrence Church in Bobrowniki. The presbytery was covered with up to five layers of polychromic paintings, some of high artistic value. We dated three samples from the original wooden board, and by wiggle-matching, the calibrated age interval was narrowed to 1731–1754 cal AD.
{"title":"DATING OF WOODEN HERITAGE OBJECTS IN THE GLIWICE <sup>14</sup>C AND MASS SPECTROMETRY LABORATORY","authors":"Natalia Piotrowska, Marzena Kłusek, Piotr Boroń, Ewelina Imiołczyk, Mateusz Budziakowski, Adrian Poloczek, Agata Poloczek-Imielińska, Marian Jaksik","doi":"10.1017/rdc.2023.91","DOIUrl":"https://doi.org/10.1017/rdc.2023.91","url":null,"abstract":"ABSTRACT We present case studies on three objects of high importance for cultural heritage in southern Poland, dated in years 2018–2022 at the Gliwice 14 C and Mass Spectrometry Laboratory with radiocarbon ( 14 C) and dendrochronology methods. The first was a richly ornamented wooden cane, discovered during excavations on the market in Bytom city. The cane can be associated with medieval court proceedings. The archaeological context indicates the 13th century AD, and the 14 C result corresponds perfectly with this time, confirming that it is the oldest object of this type in Poland. The second was a 4-m-tall oak column from St. Leonard Church in Lipnica Murowana, a UNESCO heritage site. The local story said it was previously devoted to Światowid, a pagan deity. Our analysis excluded the pre-Christian age, as the tree was felled no earlier than the late 15th century, which is in agreement with historical records. The third was a wooden Saint Lawrence Church in Bobrowniki. The presbytery was covered with up to five layers of polychromic paintings, some of high artistic value. We dated three samples from the original wooden board, and by wiggle-matching, the calibrated age interval was narrowed to 1731–1754 cal AD.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"25 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135813892","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}
M H Garnett, R Pereira, C Taylor, C Murray, P L Ascough
ABSTRACT Sample materials such as sediments and soils contain complex mixtures of different carbon-containing compounds. These bulk samples can be split into individual fractions, based on the temperature of thermal decomposition of their components. When coupled with radiocarbon ( 14 C) measurement of the isolated fractions, this approach offers the advantage of directly investigating the residence time, turnover time, source, or age of the different components within a mixed sample, providing important insights to better understand the cycling of carbon in the environment. Several laboratories have previously reported different approaches to separate radiocarbon samples based on temperature in what is a growing area of interest within the research community. Here, we report the design and operation of a new ramped oxidation facility for separation of sample carbon on the basis of thermal resistance at the NEIF Radiocarbon Laboratory in East Kilbride, UK. Our new instrumentation shares some characteristics with the previously-reported systems applying ramped oxidation and/or ramped pyrolysis for radiocarbon measurement, but also has several differences which we describe and discuss. We also present the results of a thorough program of testing of the new system, which demonstrates both the reproducibility of the thermograms generated during sample combustion, and the reliability of the radiocarbon measurements obtained on individual sample fractions. This is achieved through quantification of the radiocarbon background and analysis of multiple standards of known 14 C content during standard operation of the instrumentation.
{"title":"A NEW RAMPED OXIDATION-<sup>14</sup>C ANALYSIS FACILITY AT THE NEIF RADIOCARBON LABORATORY, EAST KILBRIDE, UK","authors":"M H Garnett, R Pereira, C Taylor, C Murray, P L Ascough","doi":"10.1017/rdc.2023.96","DOIUrl":"https://doi.org/10.1017/rdc.2023.96","url":null,"abstract":"ABSTRACT Sample materials such as sediments and soils contain complex mixtures of different carbon-containing compounds. These bulk samples can be split into individual fractions, based on the temperature of thermal decomposition of their components. When coupled with radiocarbon ( 14 C) measurement of the isolated fractions, this approach offers the advantage of directly investigating the residence time, turnover time, source, or age of the different components within a mixed sample, providing important insights to better understand the cycling of carbon in the environment. Several laboratories have previously reported different approaches to separate radiocarbon samples based on temperature in what is a growing area of interest within the research community. Here, we report the design and operation of a new ramped oxidation facility for separation of sample carbon on the basis of thermal resistance at the NEIF Radiocarbon Laboratory in East Kilbride, UK. Our new instrumentation shares some characteristics with the previously-reported systems applying ramped oxidation and/or ramped pyrolysis for radiocarbon measurement, but also has several differences which we describe and discuss. We also present the results of a thorough program of testing of the new system, which demonstrates both the reproducibility of the thermograms generated during sample combustion, and the reliability of the radiocarbon measurements obtained on individual sample fractions. This is achieved through quantification of the radiocarbon background and analysis of multiple standards of known 14 C content during standard operation of the instrumentation.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"37 20","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135814218","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}
Sylwester Czopek, Marek Krąpiec, Jacek Pawlyta, Tomasz Tokarczyk
ABSTRACT The Early Iron Age hillfort in Chotyniec (SE Poland) is the westernmost permanent settlement of the Scythian cultural circle. Recognizing the construction of the fortified settlement’s ramparts and their chronology was considered one of the priorities of the systematic research conducted since 2016. Based on 18 radiocarbon dated samples from different parts of the rampart, a chronological model of its functioning was made. It indicates that the construction of this monumental fortifications protecting the settlement in Chotyniec should be dated to between 651–595 or 531–409 BC. This dating synchronizes well with the chronology of the most important ritual and ceremonial object within the Chotyniec settlement—the so-called zolnik and other Scythian settlements from the East European forest-steppe zone.
{"title":"ABSOLUTE CHRONOLOGY OF THE RAMPART OF THE EARLY IRON AGE HILLFORT IN CHOTYNIEC NEAR RADYMNO (SOUTHEASTERN POLAND) IN THE CONTEXT OF RADIOCARBON DATING","authors":"Sylwester Czopek, Marek Krąpiec, Jacek Pawlyta, Tomasz Tokarczyk","doi":"10.1017/rdc.2023.87","DOIUrl":"https://doi.org/10.1017/rdc.2023.87","url":null,"abstract":"ABSTRACT The Early Iron Age hillfort in Chotyniec (SE Poland) is the westernmost permanent settlement of the Scythian cultural circle. Recognizing the construction of the fortified settlement’s ramparts and their chronology was considered one of the priorities of the systematic research conducted since 2016. Based on 18 radiocarbon dated samples from different parts of the rampart, a chronological model of its functioning was made. It indicates that the construction of this monumental fortifications protecting the settlement in Chotyniec should be dated to between 651–595 or 531–409 BC. This dating synchronizes well with the chronology of the most important ritual and ceremonial object within the Chotyniec settlement—the so-called zolnik and other Scythian settlements from the East European forest-steppe zone.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136112649","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}
Maciej T Krajcarz, Mateusz Baca, Chris Baumann, Hervé Bocherens, Tomasz Goslar, Danijela Popović, Magdalena Sudoł-Procyk, Magdalena Krajcarz
ABSTRACT The paper focuses on the Pleistocene deposits in Perspektywiczna Cave, southern Poland, related to cave hyena (Crocuta crocuta). We used direct radiocarbon dating of hyena fossils supported by genetic and stable isotope analyses to infer the paleobiology of this population. Radiocarbon dating of 19 hyena remains suggests long inhabitation of the region during early MIS 3, around 50–34 ky cal BP. The youngest among our dates, 34,355–33,725 cal BP (1σ, combined of two dates for the same specimen) points out the latest appearance of a cave hyena north to Carpathians. Beside this long period of occupation, the Perspektywiczna Cave hyenas stayed ecologically stable, but their genetic structure changed. Two mtDNA haplogroups were present, one typical for other Late Pleistocene European populations and the other one known so far only from recent African populations.
摘要本文对波兰南部Perspektywiczna洞穴中与洞鬣狗(Crocuta Crocuta)有关的更新世沉积进行了研究。我们使用遗传和稳定同位素分析支持的鬣狗化石的直接放射性碳定年来推断该种群的古生物学。19具鬣狗遗骸的放射性碳定年表明，该地区在MIS 3早期(约50-34 kcal BP)长期居住。在我们的测年数据中，最年轻的是34,355-33,725 cal BP (1σ，同一标本的两个测年数据的组合)，表明喀尔巴阡山脉以北的洞穴鬣狗最晚出现。除了这段漫长的占领时期，Perspektywiczna洞穴鬣狗在生态上保持稳定，但它们的遗传结构发生了变化。有两个mtDNA单倍群存在，一个是其他晚更新世欧洲人群的典型，另一个是迄今为止只在最近的非洲人群中发现的。
{"title":"NEW INSIGHTS INTO LATE PLEISTOCENE CAVE HYENA CHRONOLOGY AND POPULATION HISTORY—THE CASE OF PERSPEKTYWICZNA CAVE, POLAND","authors":"Maciej T Krajcarz, Mateusz Baca, Chris Baumann, Hervé Bocherens, Tomasz Goslar, Danijela Popović, Magdalena Sudoł-Procyk, Magdalena Krajcarz","doi":"10.1017/rdc.2023.89","DOIUrl":"https://doi.org/10.1017/rdc.2023.89","url":null,"abstract":"ABSTRACT The paper focuses on the Pleistocene deposits in Perspektywiczna Cave, southern Poland, related to cave hyena (Crocuta crocuta). We used direct radiocarbon dating of hyena fossils supported by genetic and stable isotope analyses to infer the paleobiology of this population. Radiocarbon dating of 19 hyena remains suggests long inhabitation of the region during early MIS 3, around 50–34 ky cal BP. The youngest among our dates, 34,355–33,725 cal BP (1σ, combined of two dates for the same specimen) points out the latest appearance of a cave hyena north to Carpathians. Beside this long period of occupation, the Perspektywiczna Cave hyenas stayed ecologically stable, but their genetic structure changed. Two mtDNA haplogroups were present, one typical for other Late Pleistocene European populations and the other one known so far only from recent African populations.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"14 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136114609","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}
Laura E Beramendi-Orosco, Galia González-Hernández, Edith Cienfuegos, Francisco Otero
ABSTRACT We present atmospheric radiocarbon concentrations in CO 2 integrated samples taken between January 2019 and December 2021 in the Mexico City Metropolitan Area (MCMA) and explain the variations in terms of changes in emission sources associated with the COVID-19 lockdown restrictions imposed from March 2020. Δ 14 C values for samples collected during 2019 range between –44.15‰ and –13.17‰, with lower values during months with higher fossil fuels consumption and air stagnation, whereas higher values were found for periods with high number of fires around MCMA or wet months with higher contribution of heterotrophic respiration. For samples collected during 2020, Δ 14 C values range between –17.7‰ and 2.25‰, with an increasing trend immediately after the initial lockdown and higher values obtained for samples collected during lockdown phases 2 and 3 and the period of extremely high epidemic risk. This agrees with the 38% and 52% decrease in gasoline and diesel sales. Once essential activities gradually opened from July 2020, Δ 14 C follow a decreasing trend as vehicle traffic started to increase again. Δ 14 C values for samples collected during 2021 range from –32.89‰ to –10.27‰, with the higher value obtained during a period of extremely high epidemic risk with a 30% reduction in gasoline and diesel consumption. Despite the complexity of emission sources in MCMA, from Δ 14 C variations it was possible to identify changes in fossil CO 2 emissions resulting from the significant reduction in vehicle traffic due to the COVID-19 lockdown and the restrictions imposed to control transmission of the disease.
{"title":"CHANGES IN FOSSIL CO<sub>2</sub> EMISSIONS IN MEXICO CITY DURING THE COVID-19 LOCKDOWN DEDUCED FROM ATMOSPHERIC RADIOCARBON CONCENTRATIONS","authors":"Laura E Beramendi-Orosco, Galia González-Hernández, Edith Cienfuegos, Francisco Otero","doi":"10.1017/rdc.2023.76","DOIUrl":"https://doi.org/10.1017/rdc.2023.76","url":null,"abstract":"ABSTRACT We present atmospheric radiocarbon concentrations in CO 2 integrated samples taken between January 2019 and December 2021 in the Mexico City Metropolitan Area (MCMA) and explain the variations in terms of changes in emission sources associated with the COVID-19 lockdown restrictions imposed from March 2020. Δ 14 C values for samples collected during 2019 range between –44.15‰ and –13.17‰, with lower values during months with higher fossil fuels consumption and air stagnation, whereas higher values were found for periods with high number of fires around MCMA or wet months with higher contribution of heterotrophic respiration. For samples collected during 2020, Δ 14 C values range between –17.7‰ and 2.25‰, with an increasing trend immediately after the initial lockdown and higher values obtained for samples collected during lockdown phases 2 and 3 and the period of extremely high epidemic risk. This agrees with the 38% and 52% decrease in gasoline and diesel sales. Once essential activities gradually opened from July 2020, Δ 14 C follow a decreasing trend as vehicle traffic started to increase again. Δ 14 C values for samples collected during 2021 range from –32.89‰ to –10.27‰, with the higher value obtained during a period of extremely high epidemic risk with a 30% reduction in gasoline and diesel consumption. Despite the complexity of emission sources in MCMA, from Δ 14 C variations it was possible to identify changes in fossil CO 2 emissions resulting from the significant reduction in vehicle traffic due to the COVID-19 lockdown and the restrictions imposed to control transmission of the disease.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136209001","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}
ABSTRACT In-situ cosmogenic 10 Be (and 26 Al) concentrations in alluvial sediments provide a spatially averaged signal of the erosion rate of the catchment area. Catchmentwide erosion rates reflect the production rate of the entire basin, and their calculation requires knowledge of the complete production rate model. Available calculators determine production rates on a pixel-based approach and achieve computational efficiency by relying on a scaling method that ignores geomagnetic field strength variations. Here we introduce a new python-based tool that determines erosion rates based on the hypsometry of the catchment. The method relies on the fact that production rates are much more sensitive to changes in elevation than latitude. Our tool has two main advantages: (1) computation time is short (<30 seconds) and independent of the scaling method; there is no need to neglect magnetic field variations, and (2) because production rate scaling is performed by a widely used online calculator, the results are fully comparable to exposure ages or point-based erosion rates determined with the same calculator; future updates to production rate scaling are immediately effective for catchmentwide erosion rate calculation. We demonstrate in two case studies that (1) for similar scaling methods, our calculator reproduces pixel-based results within a few percent, and (2) erosion rates determined with different scaling methods may differ by >20%, differences can vary systematically with erosion rate, and using a time-constant scaling method may result in a bias in the interpretation of catchmentwide erosion rates.
{"title":"RIVERSAND: A NEW TOOL FOR EFFICIENT COMPUTATION OF CATCHMENTWIDE EROSION RATES","authors":"Konstanze Stübner, Greg Balco, Nils Schmeisser","doi":"10.1017/rdc.2023.74","DOIUrl":"https://doi.org/10.1017/rdc.2023.74","url":null,"abstract":"ABSTRACT In-situ cosmogenic 10 Be (and 26 Al) concentrations in alluvial sediments provide a spatially averaged signal of the erosion rate of the catchment area. Catchmentwide erosion rates reflect the production rate of the entire basin, and their calculation requires knowledge of the complete production rate model. Available calculators determine production rates on a pixel-based approach and achieve computational efficiency by relying on a scaling method that ignores geomagnetic field strength variations. Here we introduce a new python-based tool that determines erosion rates based on the hypsometry of the catchment. The method relies on the fact that production rates are much more sensitive to changes in elevation than latitude. Our tool has two main advantages: (1) computation time is short (<30 seconds) and independent of the scaling method; there is no need to neglect magnetic field variations, and (2) because production rate scaling is performed by a widely used online calculator, the results are fully comparable to exposure ages or point-based erosion rates determined with the same calculator; future updates to production rate scaling are immediately effective for catchmentwide erosion rate calculation. We demonstrate in two case studies that (1) for similar scaling methods, our calculator reproduces pixel-based results within a few percent, and (2) erosion rates determined with different scaling methods may differ by >20%, differences can vary systematically with erosion rate, and using a time-constant scaling method may result in a bias in the interpretation of catchmentwide erosion rates.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"0 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135830937","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}
Kari M Finstad, Erin E Nuccio, Katherine E Grant, Taylor A B Broek, Jennifer Pett-Ridge, Karis J McFarlane
ABSTRACT Microbial processing of soil organic matter is a significant driver of C cycling, yet we lack an understanding of what shapes the turnover of this large terrestrial pool. In part, this is due to limited options for accurately identifying the source of C assimilated by microbial communities. Laboratory incubations are the most common method for this; however, they can introduce artifacts due to sample disruption and processing and can take months to produce sufficient CO 2 for analysis. We present a biomass extraction method which allows for the direct 14 C analysis of microbial biomolecules and compare the results to laboratory incubations. In the upper 50 cm soil depths, the Δ 14 C from incubations was indistinguishable from that of extracted microbial biomass. Below 50 cm, the Δ 14 C of the biomass was more depleted than that of the incubations, either due to the stimulation of labile C decomposition in the incubations, the inclusion of biomolecules from non-living cells in the biomass extractions, or differences in C used for assimilation versus respiration. Our results suggest that measurement of Δ 14 C of microbial biomass extracts can be a useful alternative to soil incubations.
{"title":"RADIOCARBON ANALYSIS OF SOIL MICROBIAL BIOMASS VIA DIRECT CHLOROFORM EXTRACTION","authors":"Kari M Finstad, Erin E Nuccio, Katherine E Grant, Taylor A B Broek, Jennifer Pett-Ridge, Karis J McFarlane","doi":"10.1017/rdc.2023.80","DOIUrl":"https://doi.org/10.1017/rdc.2023.80","url":null,"abstract":"ABSTRACT Microbial processing of soil organic matter is a significant driver of C cycling, yet we lack an understanding of what shapes the turnover of this large terrestrial pool. In part, this is due to limited options for accurately identifying the source of C assimilated by microbial communities. Laboratory incubations are the most common method for this; however, they can introduce artifacts due to sample disruption and processing and can take months to produce sufficient CO 2 for analysis. We present a biomass extraction method which allows for the direct 14 C analysis of microbial biomolecules and compare the results to laboratory incubations. In the upper 50 cm soil depths, the Δ 14 C from incubations was indistinguishable from that of extracted microbial biomass. Below 50 cm, the Δ 14 C of the biomass was more depleted than that of the incubations, either due to the stimulation of labile C decomposition in the incubations, the inclusion of biomolecules from non-living cells in the biomass extractions, or differences in C used for assimilation versus respiration. Our results suggest that measurement of Δ 14 C of microbial biomass extracts can be a useful alternative to soil incubations.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135831084","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}
Yaroslav V Kuzmin, Sergey V Leshchinskiy, Vasily N Zenin, Elena M Burkanova, Elya P Zazovskaya, Aleksandra S Samandrosova
ABSTRACT A summary of the chronology for the key paleontological and archaeological site of Volchia Griva in the southern part of the West Siberian Plain is presented. Currently, 42 reliable 14 C values have been generated on animal bones (37 14 C dates) and charcoal (5 14 C dates). Three stratigraphic levels of animal bones are established. The 14 C ages of the fossils are as follows: the upper level—ca. 10,620–12,520 BP; the middle level—ca. 13,700–17,800 BP; and the lower level—ca. 18,230–19,790 BP. The majority of animal fossils and artifacts are associated with the lower level. Based on the results obtained, we suggest that Upper Paleolithic people occupied the Volchia Griva site during the second part of the Last Glacial Maximum (LGM), ca. 18,200–19,800 BP, and perhaps occasionally afterwards. It is obvious that these humans were well adapted to the cold and dry climate of the LGM, as well as numerous other populations in Siberia south of 58°N. It is noteworthy that the youngest 14 C values on woolly mammoth are of ca. 10,620–11,815 BP, and this makes the Volchia Griva one of the latest mammoth refugia in northern Eurasia outside of the Arctic.
{"title":"CHRONOLOGY OF THE VOLCHIA GRIVA MEGAFAUNAL LOCALITY AND PALEOLITHIC SITE (WESTERN SIBERIA) AND THE ISSUE OF HUMAN OCCUPATION OF SIBERIA AT THE LAST GLACIAL MAXIMUM","authors":"Yaroslav V Kuzmin, Sergey V Leshchinskiy, Vasily N Zenin, Elena M Burkanova, Elya P Zazovskaya, Aleksandra S Samandrosova","doi":"10.1017/rdc.2023.82","DOIUrl":"https://doi.org/10.1017/rdc.2023.82","url":null,"abstract":"ABSTRACT A summary of the chronology for the key paleontological and archaeological site of Volchia Griva in the southern part of the West Siberian Plain is presented. Currently, 42 reliable 14 C values have been generated on animal bones (37 14 C dates) and charcoal (5 14 C dates). Three stratigraphic levels of animal bones are established. The 14 C ages of the fossils are as follows: the upper level—ca. 10,620–12,520 BP; the middle level—ca. 13,700–17,800 BP; and the lower level—ca. 18,230–19,790 BP. The majority of animal fossils and artifacts are associated with the lower level. Based on the results obtained, we suggest that Upper Paleolithic people occupied the Volchia Griva site during the second part of the Last Glacial Maximum (LGM), ca. 18,200–19,800 BP, and perhaps occasionally afterwards. It is obvious that these humans were well adapted to the cold and dry climate of the LGM, as well as numerous other populations in Siberia south of 58°N. It is noteworthy that the youngest 14 C values on woolly mammoth are of ca. 10,620–11,815 BP, and this makes the Volchia Griva one of the latest mammoth refugia in northern Eurasia outside of the Arctic.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135830707","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}
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