Radiocarbon最新文献_第6页

SOIL CARBON STOCKS NOT LINKED TO ABOVEGROUND LITTER INPUT AND CHEMISTRY OF OLD-GROWTH FOREST AND ADJACENT PRAIRIE 土壤碳储量与老林和邻近草原的地上垃圾输入量和化学性质无关

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-02-13 DOI: 10.1017/rdc.2024.5

Karis J McFarlane, Stefania Mambelli, Rachel C Porras, Daniel B Wiedemeier, Michael W I Schmidt, Todd E Dawson, Margaret S Torn

{"title":"SOIL CARBON STOCKS NOT LINKED TO ABOVEGROUND LITTER INPUT AND CHEMISTRY OF OLD-GROWTH FOREST AND ADJACENT PRAIRIE","authors":"Karis J McFarlane, Stefania Mambelli, Rachel C Porras, Daniel B Wiedemeier, Michael W I Schmidt, Todd E Dawson, Margaret S Torn","doi":"10.1017/rdc.2024.5","DOIUrl":"https://doi.org/10.1017/rdc.2024.5","url":null,"abstract":"The long-standing assumption that aboveground plant litter inputs have a substantial influence on soil organic carbon storage (SOC) and dynamics has been challenged by a new paradigm for SOC formation and persistence. We tested the importance of plant litter chemistry on SOC storage, distribution, composition, and age by comparing two highly contrasting ecosystems: an old-growth coast redwood (Sequoia sempervirens) forest, with highly aromatic litter, and an adjacent coastal prairie, with more easily decomposed litter. We hypothesized that if plant litter chemistry was the primary driver, redwood would store more and older SOC that was less microbially processed than prairie. Total soil carbon stocks to 110 cm depth were higher in prairie (35 kg C m−2) than redwood (28 kg C m−2). Radiocarbon values indicated shorter SOC residence times in redwood than prairie throughout the profile. Higher amounts of pyrogenic carbon and a higher degree of microbial processing of SOC appear to be instrumental for soil carbon storage and persistence in prairie, while differences in fine-root carbon inputs likely contribute to younger SOC in redwood. We conclude that at these sites fire residues, root inputs, and soil properties influence soil carbon dynamics to a greater degree than the properties of aboveground litter.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"12 9 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139754330","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}

引用次数: 0

GEOCHRONOLOGY OF PHREATOPHYTIC MOUNDS ON THE ATMUR EL KIBIESH, EGYPT: WITH DESCRIPTIONS OF PLANTS COLLECTED DURING THE EXPEDITION TO THE EASTERN SAHARA, EGYPT, AND SUDAN (APPENDIX I) 埃及 atmur el kibiesh 上的植被丘的地质年代：附东萨哈拉、埃及和苏丹考察期间采集的植物描述（附录 I）

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-02-13 DOI: 10.1017/rdc.2024.1

C Vance Haynes, Loutfy Boulos, Anthony B Muller

引用次数: 0

CHARACTERIZATION AND SELECTION OF MORTAR SAMPLES FOR RADIOCARBON DATING IN THE FRAMEWORK OF THE MODIS2 INTERCOMPARISON: TWO COMPARED PROCEDURES 在 modis2 互比框架内确定和选择用于放射性碳年代测定的灰泥样本：两种比较程序

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-02-13 DOI: 10.1017/rdc.2024.3

G Artioli, S Barone, M Fedi, A Galli, L Liccioli, M Martini, F Marzaioli, F Maspero, L Panzeri, I Passariello, G Ricci, M Secco, F Terrasi

{"title":"CHARACTERIZATION AND SELECTION OF MORTAR SAMPLES FOR RADIOCARBON DATING IN THE FRAMEWORK OF THE MODIS2 INTERCOMPARISON: TWO COMPARED PROCEDURES","authors":"G Artioli, S Barone, M Fedi, A Galli, L Liccioli, M Martini, F Marzaioli, F Maspero, L Panzeri, I Passariello, G Ricci, M Secco, F Terrasi","doi":"10.1017/rdc.2024.3","DOIUrl":"https://doi.org/10.1017/rdc.2024.3","url":null,"abstract":"For several decades, many efforts have been dedicated to enhancing the accuracy of mortar radiocarbon dating and evaluating the reliability of the results concerning the typology of the examined specimens. Several assumptions that are fundamental for the application of the method may be in many cases not fulfilled, such as (a) complete primary limestone dissociation during calcination, (b) efficient separation of geogenic carbon contained in calcareous aggregates, (c) short carbonation time, and (d) absence of secondary calcite. Many laboratories all over the world have proposed different methods to select suitable fractions of mortar. The first intercomparison attempt, involving eight international laboratories, was organized in 2016 aiming at comparing and statistically treating the results obtained on the same materials by different laboratories with their own characterization and pre-treatment methods (Hajdas et al. 2017; Hayen et al. 2017). Following this first step, a new intercomparison experiment was proposed and set up in 2018 during the Mortar Dating International Meeting (Bordeaux, FR). A new set of three mortar samples was chosen, taking care of the selection of standardized materials (homogeneity, known mineralogical composition, absence of exogenous inclusions, known expected age). This work describes the results of two research teams involved in the intercomparison. The samples were characterized, selected, and dated depending on each laboratory strategy. The results stress the importance of the characterization of the raw material is to better understand the mineralogical and petrographical composition of the samples. Such information can support the choice of the most appropriate strategy for the extraction of CO2 and then for data interpretation.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"12 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139754459","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}

引用次数: 0

A SUMMARY OF RADIOCARBON MEASUREMENTS OF FLUVIAL AND COLLUVIAL DEPOSITS IN CATCHMENTS OF SOUTH-CENTRAL ONTARIO, CANADA 加拿大安大略省中南部集水区河流和冲积沉积物放射性碳测量概要

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-02-13 DOI: 10.1017/rdc.2024.2

William C Mahaney, Andrew M Stewart

{"title":"A SUMMARY OF RADIOCARBON MEASUREMENTS OF FLUVIAL AND COLLUVIAL DEPOSITS IN CATCHMENTS OF SOUTH-CENTRAL ONTARIO, CANADA","authors":"William C Mahaney, Andrew M Stewart","doi":"10.1017/rdc.2024.2","DOIUrl":"https://doi.org/10.1017/rdc.2024.2","url":null,"abstract":"Fluvial and colluvial deposits of Late Holocene age in South-Central Ontario catchments have provided few 14C dates, most by conventional methods registering century-old ages. Other young deposits, dated by conventional and accelerator mass spectrometry radiocarbon (AMS 14C), have yielded bomb-affected post-1950 ages over variable time limits. Attempts to date the base of Ah and lower-in-section soil horizons, in Early to Late Holocene stream terrace deposits, have yielded atomic bomb effects. Comparing bomb contamination in Late Holocene fluvial deposits, using both conventional and AMS methods, identifies a mix of bomb-affected beds juxtaposed with dated beds, the latter yielding ages with narrow standard deviations. Colluvial deposits overlying key glacial sections in the Rouge Catchment, while rare, yield bracketed AMS ages for an Ahbk horizon that refines weathering times relative to previously obtained conventional 14C dates. Bomb-affected sediment appears variably distributed within floodplain soils and in the ground soil of a colluvial section. Mass wasted deposits, with AMS 14C ages spread over the last few centuries, appear related to Little Ice Age (LIA) changes in climate, corroborated by pollen records. Further, these AMS-14C dated beds calibrate weathering of secondary Fe-Al oxihydroxides over the first half a millennium of weathering time.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"1 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139754494","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}

引用次数: 0

ADVANCING ANTARCTIC SEDIMENT CHRONOLOGY THROUGH COMBINED RAMPED PYROLYSIS OXIDATION AND PYROLYSIS-GC-MS 通过热解氧化和热解-气相色谱-质谱联用技术推进南极沉积物年代学研究

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-02-08 DOI: 10.1017/rdc.2023.116

Catherine E Ginnane, Jocelyn C Turnbull, Sebastian Naeher, Brad E Rosenheim, Ryan A Venturelli, Andy M Phillips, Simon Reeve, Jeremy Parry-Thompson, Albert Zondervan, Richard H Levy, Kyu-Cheul Yoo, Gavin Dunbar, Theo Calkin, Carlota Escutia, Julia Gutierrez Pastor

{"title":"ADVANCING ANTARCTIC SEDIMENT CHRONOLOGY THROUGH COMBINED RAMPED PYROLYSIS OXIDATION AND PYROLYSIS-GC-MS","authors":"Catherine E Ginnane, Jocelyn C Turnbull, Sebastian Naeher, Brad E Rosenheim, Ryan A Venturelli, Andy M Phillips, Simon Reeve, Jeremy Parry-Thompson, Albert Zondervan, Richard H Levy, Kyu-Cheul Yoo, Gavin Dunbar, Theo Calkin, Carlota Escutia, Julia Gutierrez Pastor","doi":"10.1017/rdc.2023.116","DOIUrl":"https://doi.org/10.1017/rdc.2023.116","url":null,"abstract":"Radiocarbon (14C) dating of sediment deposition around Antarctica is often challenging due to heterogeneity in sources and ages of organic carbon in the sediment. Chemical and thermochemical techniques have been used to separate organic carbon when microfossils are not present. These techniques generally improve on bulk sediment dates, but they necessitate assumptions about the age spectra of specific molecules or compound classes and about the chemical heterogeneity of thermochemical separations. To address this, the Rafter Radiocarbon Laboratory has established parallel ramped pyrolysis oxidation (RPO) and ramped pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) systems to thermochemically separate distinct carbon fractions, diagnose the chemical composition of each fraction, and target suitable RPO fractions for radiocarbon dating. Three case studies of sediment taken from locations around Antarctica are presented to demonstrate the implementation of combined RPO-AMS and Py-GC-MS to provide more robust age determination in detrital sediment stratigraphy. These three depositional environments are good examples of analytical and interpretive challenges related to oceanographic conditions, carbon sources, and other factors. Using parallel RPO-AMS and Py-GC-MS analyses, we reduce the number of radiocarbon measurements required, minimize run times, provide context for unexpected 14C ages, and better support interpretations of radiocarbon measurements in the context of environmental reconstruction.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"42 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139754500","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}

引用次数: 0

RADIOCARBON AND URANIUM PROFILES IN MARINE GASTROPODS AROUND THE JAPANESE ARCHIPELAGO 日本列岛周围海洋腹足类动物的放射性碳和铀剖面图

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-02-06 DOI: 10.1017/rdc.2023.122

Shoko Hirabayashi, Takahiro Aze, Yosuke Miyairi, Hironobu Kan, Yusuke Yokoyama

{"title":"RADIOCARBON AND URANIUM PROFILES IN MARINE GASTROPODS AROUND THE JAPANESE ARCHIPELAGO","authors":"Shoko Hirabayashi, Takahiro Aze, Yosuke Miyairi, Hironobu Kan, Yusuke Yokoyama","doi":"10.1017/rdc.2023.122","DOIUrl":"https://doi.org/10.1017/rdc.2023.122","url":null,"abstract":"In this study, we investigate the distribution of radiocarbon and uranium in the calcified opercula of Turbo sp. collected from Ryukyu region and Chiba, Japan, to explore the potential of U/Th dating using mollusks collected from the Japanese archipelago. We acquired high-resolution radiocarbon and uranium concentration measurements using single-stage accelerator mass spectrometry and laser ablation−inductively coupled plasma−mass spectrometry. Our results show that uranium in the opercula of modern Turbo sp. is unevenly distributed at concentrations 1000 times less than those in coral skeletons. Radiocarbon found in the calcified opercula samples record ambient seawater radiocarbon values as well as coral skeletons. Uranium in the calcified opercula of Holocene Turbo marmoratus were also unevenly distributed and concentrated within the opercula in a different manner than observed in modern samples, suggesting uranium exchange after death. Our results suggest variable uptake of uranium isotopes into mollusk shells and highlights the need for rigorous sample selection criteria when choosing mollusks species for U/Th dating around Japan.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"22 1","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139754323","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}

引用次数: 0

14C PREPARATION PROTOCOLS FOR ARCHAEOLOGICAL SAMPLES AT THE LMC14, SACLAY, FRANCE 14C 法国萨克雷 LMC14 考古样本制备规程

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-01-24 DOI: 10.1017/rdc.2023.119

J-P Dumoulin, C Moreau, E Delqué-Količ, I Caffy, D Farcage, C Goulas, S Hain, M Perron, A Semerok, M Sieudat, B Thellier, L Beck

引用次数: 0

“APPROXIMATE” WIGGLE-MATCH DATING APPLIED TO EARLY AMERICAN MUSEUM OBJECTS 应用于美国早期博物馆藏品的 "近似 "触发匹配年代测定法

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-01-23 DOI: 10.1017/rdc.2023.127

Carla S Hadden, Katharine G Napora, Brent W Tharp

引用次数: 0

14C IN TREE RINGS IN THE VICINITY OF THE RBMK REACTOR NUCLEAR POWER PLANT RBMK 反应堆核电站附近树木年轮中的 14c

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-01-23 DOI: 10.1017/rdc.2023.125

Evgeniy I Nazarov, Alexander V Kruzhalov, Maxim E Vasyanovich, Alexey A Ekidin, Maria D Pyshkina, Vladimir V Kukarskikh, Ekaterina V Parkhomchuk

{"title":"14C IN TREE RINGS IN THE VICINITY OF THE RBMK REACTOR NUCLEAR POWER PLANT","authors":"Evgeniy I Nazarov, Alexander V Kruzhalov, Maxim E Vasyanovich, Alexey A Ekidin, Maria D Pyshkina, Vladimir V Kukarskikh, Ekaterina V Parkhomchuk","doi":"10.1017/rdc.2023.125","DOIUrl":"https://doi.org/10.1017/rdc.2023.125","url":null,"abstract":"The paper presents the results of radiocarbon (14C) concentration measurements in tree rings in the vicinity of Kursk NPP (Russia) with four operating RBMK reactors. The sampling was carried out from the site with the highest expected accumulation of radiocarbon in vegetation. The site was determined with long-term meteorological data. The measurements of 14C concentration carried out with accelerator-mass spectrometer in Budker Institute of Nuclear Physics, Novosibirsk, Russia. The obtained results demonstrated the influence of exploitation of Kursk NPP to the concentration of 14C in tree rings. Based on the equilibrium between the 14C ratio in the tree rings and the surrounding air, retrospective estimates of the radiocarbon discharge and effective doses were made. Effective doses were calculated with two approaches: IAEA methodology and less conservative approach, considering the real food consumption in the Kursk region. The values of calculated doses by the second method (0.08–2.58 μSv) are more than 2 times less than IAEA approach (0.17–5.30 μSv). The highest difference between measured and background 14C in tree ring is 41.7 ± 5.8 pMC in 2014 during the restoration of graphite stack. The main contribution to 14С exposure in the considering period is caused by background – from 70 to 99%.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":"96 ","pages":""},"PeriodicalIF":8.3,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139556025","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}

引用次数: 0

CHRONOLOGICAL MODELING ON A CALIBRATION PLATEAU: IMPLICATIONS FOR THE EMERGENCE OF AGRICULTURE IN THE DUTCH WETLANDS 校准高原上的年代模型：对荷兰湿地农业出现的影响

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-01-22 DOI: 10.1017/rdc.2023.126

Merita Dreshaj, Daan Raemaekers, Michael Dee

引用次数: 0