Radiocarbon最新文献_第3页

RADIOCARBON VARIATIONS IN ANNUAL TREE RINGS WITH 11-YEAR SOLAR CYCLES DURING 1800–1950 1800-1950 年间树木年轮中放射性碳的变化与 11 年太阳周期的关系

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-04-30 DOI: 10.1017/rdc.2024.37

Pavel P Povinec, Ivan Kontuľ, Ivo Svetlik

引用次数: 0

14C GIRI SAMPLES IN AMS GOLDEN VALLEY: GRAPHITE PREPARATION USING AGE-3 AND ABSORPTION-CATALYTIC SETUP 美国航天局黄金谷的 14c giri 样品：利用 age-3 和吸收催化装置制备石墨

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-04-29 DOI: 10.1017/rdc.2024.46

E V Parkhomchuk, A V Petrozhitskiy, M M Ignatov, D V Kuleshov, A I Lysikov, A G Okunev, K A Babina, V V Parkhomchuk

引用次数: 0

Insights into growth, ring formation and maximum ages of Brazil nut trees (Bertholletia excelsa) using 14C dating and tree-ring analysis 利用 14C 测年和树环分析了解巴西坚果树（Bertholletia excelsa）的生长、年轮形成和最大树龄

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-04-29 DOI: 10.1017/rdc.2024.39

Victor L Caetano Andrade, Charles R Clement, David Herrera-Ramírez, Thomas Larsen, Flavia Durgante, Nicole Boivin, Jochen Schöngart, Susan Trumbore, Patrick Roberts

{"title":"Insights into growth, ring formation and maximum ages of Brazil nut trees (Bertholletia excelsa) using 14C dating and tree-ring analysis","authors":"Victor L Caetano Andrade, Charles R Clement, David Herrera-Ramírez, Thomas Larsen, Flavia Durgante, Nicole Boivin, Jochen Schöngart, Susan Trumbore, Patrick Roberts","doi":"10.1017/rdc.2024.39","DOIUrl":"https://doi.org/10.1017/rdc.2024.39","url":null,"abstract":"The Brazil Nut tree (Bertholletia excelsa, Lecythidaceae) is a species of considerable historical, economic and ecological importance in South America. Radiocarbon dating indicates some individuals can live from hundreds to more than 1000 years, which means they have the potential to reconstruct deep time growth patterns and their relationship to anthropogenic management or climate change from pre-colonial to present times. However, age estimates vary considerably amongst trees dated with different methods (i.e. tree-ring analysis, radiocarbon-dating, and repeated diameter measurements). Here we analyze living Brazil Nut trees growing in four distinct regions across the Brazilian Amazon using two dating methods: tree-ring counting and radiocarbon dating. Our results show that the congruence between the two methods varies amongst regions, and the highest congruence is found at the site of Tefé, Amazonas. This region features archaeological sites with anthropogenic Terra Preta soils, and is known for its long-term human forest management. This management likely enhanced light and nutrient availability, which possibly enabled the trees to grow at higher rates and form annual rings. Our findings highlight the need for better understanding of the growth of Brazil Nut trees for ecological research, but also the potential of dendrochronology for exploring climate change and human-forest interactions in the Amazon Basin.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140811509","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

Comparing MICADAS gas source, direct carbonate, and standard graphite 14C determinations of biogenic carbonate 比较 MICADAS 气体源、直接碳酸盐和标准石墨对生物碳酸盐的 14C 测定结果

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-04-29 DOI: 10.1017/rdc.2024.45

Jordon Bright, Chris Ebert, Carola Flores, Paul G Harnik, John Warren Huntley, Michał Kowalewski, Roger W Portell, Michael Retelle, Edward A G Schuur, Darrell S Kaufman

{"title":"Comparing MICADAS gas source, direct carbonate, and standard graphite 14C determinations of biogenic carbonate","authors":"Jordon Bright, Chris Ebert, Carola Flores, Paul G Harnik, John Warren Huntley, Michał Kowalewski, Roger W Portell, Michael Retelle, Edward A G Schuur, Darrell S Kaufman","doi":"10.1017/rdc.2024.45","DOIUrl":"https://doi.org/10.1017/rdc.2024.45","url":null,"abstract":"Northern Arizona University, Flagstaff, Arizona, USA, recently installed a MIni CArbon DAting System (MICADAS) with a gas interface system (GIS) for determining the 14C content of CO2 gas released by the acid dissolution of biogenic carbonates. We compare 48 paired graphite, GIS, and direct carbonate 14C determinations of individual mollusk shells and echinoid tests. GIS sample sizes ranged between 0.5 and 1.5 mg and span 0.1 to 45.1 ka BP (n = 42). A reduced major axis regression shows a strong relationship between GIS and graphite percent Modern Carbon (pMC) values (m = 1.011; 95% CI [0.997–1.023], R2 = 0.999) that is superior to the relationship between the direct carbonate and graphite values (m = 0.978; 95% CI [0.959-0.999], R2 = 0.997). Sixty percent of GIS pMC values are within ±0.5 pMC of their graphite counterparts, compared to 26% of direct carbonate pMC values. The precision of GIS analyses is approximately ±70 14C yrs to 6.5 ka BP and decreases to approximately ±130 14C yrs at 12.5 ka BP. This precision is on par with direct carbonate and is approximately five times larger than for graphite. Six Plio-Pleistocene mollusk and echinoid samples yield finite ages when analyzed as direct carbonate but yield non-finite ages when analyzed as graphite or as GIS. Our results show that GIS 14C dating of biogenic carbonates is preferable to direct carbonate 14C dating and is an efficient alternative to standard graphite 14C dating when the precision of graphite 14C dating is not required.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140811829","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

Barrow Necropolis from the 3rd and 2nd Millennia BC in Western Ukraine. A Bayesian Modeling and Isotopic Study 乌克兰西部公元前三、二千年的荒冢墓地。贝叶斯建模和同位素研究

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-04-29 DOI: 10.1017/rdc.2024.40

Przemysław Makarowicz, Tomasz Goslar, Anita Szczepanek, Maryna Yahodynska, Vasyl Ilchyshyn, Aleksandra Kozak, Jan Romaniszyn, Jakub Niebieszczański, Vitalii Rud, Łukasz Pospieszny

{"title":"Barrow Necropolis from the 3rd and 2nd Millennia BC in Western Ukraine. A Bayesian Modeling and Isotopic Study","authors":"Przemysław Makarowicz, Tomasz Goslar, Anita Szczepanek, Maryna Yahodynska, Vasyl Ilchyshyn, Aleksandra Kozak, Jan Romaniszyn, Jakub Niebieszczański, Vitalii Rud, Łukasz Pospieszny","doi":"10.1017/rdc.2024.40","DOIUrl":"https://doi.org/10.1017/rdc.2024.40","url":null,"abstract":"This article discusses the absolute chronology of burials from the 3rd and 2nd millennia BC discovered under the mounds of three barrows in the Kordyshiv cemetery in western Ukraine. Its aim is to create a chronological model of the burials by modeling 27 AMS 14C dates obtained from 21 individuals buried in single and collective graves. Dietary analysis of stable carbon (δ13C) and nitrogen (δ15N) isotope values are presented. The Bayesian modeling of the 14C dates from the three Kordyshiv barrows revealed the extremely important role of these monuments as long-term objects used for ritual purposes. At the end of the 3rd millennium BC, the epi-Corded Ware Culture (epi-CWC) community erected a mound over the central burial in Barrow 2, then interred the graves of three additional deceased. After several hundred years Barrow 2 was reused by Komarów Culture (KC) communities from the Middle Bronze Age (MBA) who interred their deceased in the existing mound. The oldest monument with MBA burials was Barrow 3, in which the dead were buried in a two-stage sequence before and after the mid-2nd millennium BC. The youngest dated grave was Burial 1 in Barrow 1, comprising a collective burial that was interred between 1400 and 1200 BC. The additional analyses of carbon and nitrogen isotopes show significant differences in the diet of epi-CWC individuals buried in Barrow 2 from the individuals representing the KC.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140811485","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

Estimation of groundwater residence time using radiocarbon and stable carbon isotope ratio in dissolved inorganic carbon and soil CO2 利用溶解无机碳和土壤二氧化碳中的放射性碳和稳定碳同位素比值估算地下水的停留时间

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-04-29 DOI: 10.1017/rdc.2024.43

Rahul Kumar Agrawal, Ranjan Kumar Mohanty, Ajayeta Rathi, Shreya Mehta, M G Yadava, Sanjeev Kumar, Amzad H Laskar

{"title":"Estimation of groundwater residence time using radiocarbon and stable carbon isotope ratio in dissolved inorganic carbon and soil CO2","authors":"Rahul Kumar Agrawal, Ranjan Kumar Mohanty, Ajayeta Rathi, Shreya Mehta, M G Yadava, Sanjeev Kumar, Amzad H Laskar","doi":"10.1017/rdc.2024.43","DOIUrl":"https://doi.org/10.1017/rdc.2024.43","url":null,"abstract":"Estimation of residence time of groundwater, particularly in regions with inadequate surface waters are very important for formulating sustainable groundwater management policies. We developed a technique for extracting dissolved inorganic carbon (DIC) quantitatively from water for measuring its 14C contents and presented the analytical details here. We also measured stable carbon isotope ratio (δ13C) in soil CO2 and groundwater DIC to correct the groundwater 14C ages. In addition, 14C in soil CO2 were measured for making necessary correction in the initial activity of the recharging water. The corrected 14C contents in the groundwater samples were used to estimate their residence times employing Lumped Parameter Models (LPM), a set of mathematical models to account for the processes that take place during transport from the recharge to the sampling spots. We present a case study focused on the calculation of radiocarbon ages and residence times for a groundwater sample collected from the campus of Physical Research Laboratory in Ahmedabad, Gujarat, India. The study also includes estimations of groundwater residence times using previously measured 14C ages of groundwater samples from Gujarat, India. Various factors controlling the groundwater ages in the LPM and their applicability are discussed.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140812471","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 HOMEMADE SEMIAUTOMATIC GRAPHITIZATION DEVICE FOR AMS 14C DATING AT NTUAMS LAB 自制半自动石墨化装置，用于在 Ntuams 实验室进行 ams 14c 测定

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-04-29 DOI: 10.1017/rdc.2024.48

Tzu-Tsen Shen, Hong-Chun Li, Rick Qiu

{"title":"A HOMEMADE SEMIAUTOMATIC GRAPHITIZATION DEVICE FOR AMS 14C DATING AT NTUAMS LAB","authors":"Tzu-Tsen Shen, Hong-Chun Li, Rick Qiu","doi":"10.1017/rdc.2024.48","DOIUrl":"https://doi.org/10.1017/rdc.2024.48","url":null,"abstract":"A low-cost and computer-controlled graphitization system connected to an elemental analyzer (EA) has been designed and built at the NTUAMS Lab. This semiautomatic system equips 6-unit reactors for the graphitization of CO2 with H2 on the iron catalyst. The entire procedure takes about 7 hours for iron conditioning, sample combustion and loading, and graphitization. The system can produce good-quality graphite for samples containing 0.5–1.6 mg carbon mass, with the pressure yield of graphitization ranging from 57.7% to 87.1%. The average values of OXI and OXII agree well with the consensus value, but the result of ANU sucrose was observed to be slightly higher than the reported one. The background samples of anthracite over ten months yielded an average of 0.38±0.10 pMC (n=21) corresponding to a 14C age of 45 kyr BP. Intercomparison samples L and M of FIRI exhibit that the measured 14C ages are almost identical to the consensus values and have a small spread in these values. The system has been carrying out graphitization for total organic carbon (TOC) of peat samples, and providing a more efficient and convenient way for AMS 14C dating.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140811487","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 dates from the archaeological site of Sakas, Bihar, India 印度比哈尔邦萨卡斯考古遗址的放射性碳年代测定

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-04-29 DOI: 10.1017/rdc.2024.42

J Bates, V K Singh, R N Singh, Manisha Singh, Brij Mohan, Sudarshan Chakradhari, Abhay P Singh, Matthew Conte, Yongje Oh

引用次数: 0

SQUEAKY CLEAN CELLULOSE: COMPARING PRETREATMENT EFFECTIVENESS ON SINGLE TREE RINGS AND WOODEN LATHS 吱吱作响的洁净纤维素：比较单个树环和木板条的预处理效果

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-04-04 DOI: 10.1017/rdc.2024.20

Wendy Hlengiwe Khumalo, Helene Løvstrand Svarva, Damaris Zurbach, Marie-Josée Nadeau

{"title":"SQUEAKY CLEAN CELLULOSE: COMPARING PRETREATMENT EFFECTIVENESS ON SINGLE TREE RINGS AND WOODEN LATHS","authors":"Wendy Hlengiwe Khumalo, Helene Løvstrand Svarva, Damaris Zurbach, Marie-Josée Nadeau","doi":"10.1017/rdc.2024.20","DOIUrl":"https://doi.org/10.1017/rdc.2024.20","url":null,"abstract":"Obtaining accurate radiocarbon (14C) results from wood samples requires the extraction of cellulose. In the past, this has been done using different combinations of methods including acidified bleaching, acid-base-acid, and strong bases. This often becomes a time-consuming task in most analyses, especially when single ring isotope chronologies are needed from wood samples. Using 14C and Fourier-transform infrared spectroscopy (FTIR), we tested four different pretreatment methods to determine their ability to produce high quality cellulose. We then adjusted the best methods to determine a method for pretreating wood laths of multiple rings. A sequence of base-acid-base-acid-bleach + strong base (BABAB+) and BABAB produced the most accurate results when compared to the Bomb20 Northern Hemisphere Zone 1 curve with an average difference in Δ14C of 1.3‰ and 5.8‰ respectively. These methods were adjusted to pretreat an entire wood lath and a comparison of the FTIR results suggest that our adjusted BABAB+ and BABAB produced high quality cellulose comparable to that of an individually pretreated ring. The possibility to pretreat wood lath samples has the potential to more than double the number of tree rings which can be pretreated in a week. This is a significant reduction in time when creating long tree ring chronologies.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140559894","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 AGES OF PLANT REMAINS IN MASSIVE GROUND ICE AND UNDERLYING SEDIMENTS OF THE BARROW PERMAFROST TUNNEL, ALASKA 阿拉斯加巴罗永久冻土隧道块状地表冰和底层沉积物中植物遗骸的放射性碳年龄

IF 8.3 3区地球科学

Radiocarbon Pub Date : 2024-04-04 DOI: 10.1017/rdc.2024.25

Go Iwahana, Masao Uchida, Kazuho Horiuchi, Jody Deming, Hajo Eicken, Hiroshi Ohno, Kanako Mantoku, Toshiyuki Kobayashi, Kazuyuki Saito

{"title":"RADIOCARBON AGES OF PLANT REMAINS IN MASSIVE GROUND ICE AND UNDERLYING SEDIMENTS OF THE BARROW PERMAFROST TUNNEL, ALASKA","authors":"Go Iwahana, Masao Uchida, Kazuho Horiuchi, Jody Deming, Hajo Eicken, Hiroshi Ohno, Kanako Mantoku, Toshiyuki Kobayashi, Kazuyuki Saito","doi":"10.1017/rdc.2024.25","DOIUrl":"https://doi.org/10.1017/rdc.2024.25","url":null,"abstract":"Massive ground ice found in the Barrow Permafrost Tunnel at 3–7 m depths from the surface has been interpreted as an ice wedge and used to reconstruct early Holocene environmental changes. To better understand the development of this ground ice, we conducted radiocarbon dating for 34 samples of plant remains from the massive ground ice and underlying sediment layer. A significantly large gap in the measured radiocarbon ages (more than 24 ka) between massive ice and the underlying sediment layer throughout the tunnel profile suggested at least two possibilities. One is that the lower and older sediment layer had thrust upwards at the boundary between intruding ice wedge and adjacent sediment, and the growing ice had pushed the sediment sideways. Another is that erosional events had removed surface materials at about 12–36 ka BP (14–41 cal ka BP) before the overlaying sediment layer with massive ground ice developed. The overall distribution of radiocarbon ages from the massive ice supported the ice-wedge hypothesis as a formation mechanism, although our results showed several age inversions and large fluctuations. Dating of densely spaced samples revealed two ground-ice regions with similar ages around 11–11.5 and 10–10.5 ka BP divided by a relatively narrow region of transitional ages along the tunnel long-axis. This distribution may be explained by a possible misalignment between the sampling direction and the ice-wedge growth line or by intermittent ice growth with repeated cracking at more random locations than the classic ice-wedge growth model suggested.","PeriodicalId":21020,"journal":{"name":"Radiocarbon","volume":null,"pages":null},"PeriodicalIF":8.3,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140560348","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