Geochronometria最新文献_第9页

The history of the sedimentation processes and heavy metal pollution in the Central Danube Delta (Romania) 罗马尼亚多瑙河三角洲中部沉积过程和重金属污染的历史

IF 1.2 4区地球科学

Geochronometria Pub Date : 2018-05-08 DOI: 10.1515/geochr-2015-0090

R. Begy, S. Kelemen, H. Simon, C. Tănăselia

{"title":"The history of the sedimentation processes and heavy metal pollution in the Central Danube Delta (Romania)","authors":"R. Begy, S. Kelemen, H. Simon, C. Tănăselia","doi":"10.1515/geochr-2015-0090","DOIUrl":"https://doi.org/10.1515/geochr-2015-0090","url":null,"abstract":"Abstract The aim of this study was to investigate the effects of the Iron Gates (IG) hydroelectric power station on the Danube Delta sediment dynamics, and to assess the heavy metal concentrations and pollution in a typical Central Danube Deltaic lake. Eight sediment cores were analysed. The total 210Pb content was measured with 210Po using alpha spectrometry, and the supported 210Pb (226Ra) and 137Cs were measured by gamma spectrometry. The age depth model was derived by applying the 210Pb dating method, and for the calculation of the ages and the sedimentation rates the CRS model was used. The sedimentation rates can be divided into four periods:1940–1972, 1972–1980, 1972–1989 and 1989–2013. In the case of Lake Iacob in the first period, the average sedimentation rate was 0.418 g/cm2y, while in the second it slowly decreased to 0.376 g/cm2y. In the third period, the sedimentation fell to 0.209 g/cm2y, which means the retention of 27.3% of the sediment by the IG dam. In the case of Lake Isac the changes were more visible: in the first period the average sedimentation rate was 0.446 g/cm2y, while in the second it decreased to 0.197 g/cm2y, which means a 42.35% retention of sediment. In the last period, in both cases, a high increase in the sedimentation rate is shown: 0.677 g/cm2y for Lake Iacob and 0.715 g/cm2y for Lake Isac. The heavy-metal concentrations for As, Co, Cr and Ni show decreasing and Hg increasing tendencies, while Cd and Pb show constant values of 310 ± 12 ppb and 9 ± 1 ppm respectively.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2018-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43580653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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: 7

Identifying the degree of luminescence signal bleaching in fluvial sediments from the Inner Mongolian reaches of the Yellow River 黄河内蒙古河段河流沉积物发光信号漂白程度的识别

IF 1.2 4区地球科学

Geochronometria Pub Date : 2018-04-10 DOI: 10.1515/geochr-2015-0087

Fuqiang Li, B. Pan, Z. Lai, Hongshan Gao, Xianjiao Ou

{"title":"Identifying the degree of luminescence signal bleaching in fluvial sediments from the Inner Mongolian reaches of the Yellow River","authors":"Fuqiang Li, B. Pan, Z. Lai, Hongshan Gao, Xianjiao Ou","doi":"10.1515/geochr-2015-0087","DOIUrl":"https://doi.org/10.1515/geochr-2015-0087","url":null,"abstract":"Abstract The partial bleaching of the luminescence signal prior to deposition results in age overestimation, and can be a problem in delineating fluvial evolution within an OSL chronological framework. The Inner Mongolian reaches of the Yellow River are characterised by a high sediment load and complex sources of sediments. To test the incomplete bleaching occurring in this type of environment, the residual doses and the luminescence signal characteristics of different particle size fractions from 14 modern fluvial sediment samples were investigated. Furthermore, 26 OSL ages derived from drilling cores were compared with 11 radiocarbon ages. Our results show that the residual equivalent doses principally range between 0.16 and 0.49 Gy for silt grains, and between 0.35 and 3.72 Gy for sand grains of modern samples. This suggests that medium-grained quartz has been well bleached prior to deposition, and is preferable to coarse-grained quartz when dating fluvial sediments in this region. The results also show that the De values of coarse-grained fractions display a stronger correlation with distance downstream. In addition, a comparison of OSL and radiocarbon ages from drilling cores establishes further confidence that any initial bleaching of these sediments was sufficient. As a result, we believe that the studied fluvial samples were well bleached prior to deposition.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2018-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49593829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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: 5

Optically stimulated luminescence techniques applied to the dating of the fall of meteorites in Morasko 光学刺激发光技术应用于莫拉斯科陨星的年代测定

IF 1.2 4区地球科学

Geochronometria Pub Date : 2018-03-20 DOI: 10.1515/geochr-2015-0088

P. Moska, W. Stankowski, G. Poręba

引用次数: 1

Method validation for the determination of fraction of modern (F14C) in wood samples using conventional method 用常规方法测定木材样品中现代（F14C）成分的方法验证

IF 1.2 4区地球科学

Geochronometria Pub Date : 2018-02-21 DOI: 10.1515/geochr-2015-0080

R. Baydoun, O. Samad, B. Nsouli, G. Younes

{"title":"Method validation for the determination of fraction of modern (F14C) in wood samples using conventional method","authors":"R. Baydoun, O. Samad, B. Nsouli, G. Younes","doi":"10.1515/geochr-2015-0080","DOIUrl":"https://doi.org/10.1515/geochr-2015-0080","url":null,"abstract":"Abstract The radiocarbon laboratory at the Lebanese Atomic Energy Commission is undertaking environmental studies, in order to determine the anthropogenic impact of technologies on the ecosystem through the determination of radiocarbon content in tree leaves and plants. Thus, it was important to validate the method used to demonstrate that the applied procedure gives reliable results. Method validation is universally applied in analytical laboratories as an essential part of quality assurance system and as a basic technical requirement of the ISO 17025 standard. The conventional method used for determination of Fraction Modern (F14C) is a standard method issued by the American Society for Testing and Materials in 2011 with a code ASTM-D 6866-11 Method C. According to Eurachem guide, internal validation was expressed in terms of accuracy that was evaluated by trueness and precision. Trueness was expressed in terms of relative bias, while for precision ten consecutive replicates were carried out to under repeatability conditions and five duplicates were analyzed under reproducibility conditions. The limit of detection and the minimum detectable activity (MDA) were calculated. Uncertainty sources were defined and their relative standard uncertainties were calculated in order to determine the combined standard uncertainty. Five reference samples of different matrices were analyzed; calculated z score values were acceptable as being between –2 and +2. The calculation and results are presented in this work.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2018-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44006191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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

Environmental dose rate determination using a passive dosimeter: Techniques and workflow for α-Al2O3:C chips 使用被动剂量计测定环境剂量率：α-Al2O3：C芯片的技术和工作流程

IF 1.2 4区地球科学

Geochronometria Pub Date : 2018-02-21 DOI: 10.1515/geochr-2015-0086

S. Kreutzer, Loïc A. Martin, G. Guérin, C. Tribolo, P. Selva, N. Mercier

{"title":"Environmental dose rate determination using a passive dosimeter: Techniques and workflow for α-Al2O3:C chips","authors":"S. Kreutzer, Loïc A. Martin, G. Guérin, C. Tribolo, P. Selva, N. Mercier","doi":"10.1515/geochr-2015-0086","DOIUrl":"https://doi.org/10.1515/geochr-2015-0086","url":null,"abstract":"Abstract In situ dosimetry (active, passive dosimeters) provides high accuracy by determining environmental dose rates directly in the field. Passive dosimeters, such as α-Al2O3:C, are of particular interest for sites with desired minimum disturbance (e.g., archaeological sites). Here, we present a comprehensive approach obtaining the environmental cosmic and γ-dose rate using α-Al2O3:C chips. Our procedure consists of (1) homemade field containers, (2) a homemade bleaching box, (3) a rapid measurement sequence and (4) software based on R to process the measurement results. Our validation steps include reproducibility, irradiation time correction, cross-talk evaluation and source calibration. We further simulate the effect of the container against the infinite matrix dose rate, resulting in attenuation of ca. 6%. Our measurement design uses a lexsyg SMART luminescence reader equipped with green LEDs. The irradiation is carried out under the closed β-source. The minimum dose that can be determined was estimated with ca. 10 μGy. However, we also show that for the equipment used, an irradiation time correction of ca. 2.6 s is needed and irradiation cross-talk should be taken into account. The suggested procedure is cross-checked with four reference sites at Clermont-Ferrand showing a good γ-dose rate for three out of the four sites. Finally, an application example, including needed analytical steps, is presented for dosimeters buried at the archaeological site of the Sierra de Atapuerca (Spain).","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2018-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46943374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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: 17

Recurrence interval of strong earthquakes in the se Altai, Russia revealed by tree-ring analysis and radiocarbon dating 由树木年轮分析和放射性碳定年揭示的俄罗斯阿尔泰东南部强震的复发间隔

IF 1.2 4区地球科学

Geochronometria Pub Date : 2018-01-24 DOI: 10.1515/geochr-2015-0083

R. Nepop, A. Agatova

{"title":"Recurrence interval of strong earthquakes in the se Altai, Russia revealed by tree-ring analysis and radiocarbon dating","authors":"R. Nepop, A. Agatova","doi":"10.1515/geochr-2015-0083","DOIUrl":"https://doi.org/10.1515/geochr-2015-0083","url":null,"abstract":"Abstract This paper presents the results of paleoseismogeological investigations including tree-ring analysis and radiocarbon dating in pleistoseist zone of the 2003 Chuya earthquake, SE Altai, Russia. Twenty-five radiocarbon dates of previously unknown evidences of prehistoric earthquakes along the fault bounders of the Chagan-Uzun massif, North Chuya and South Chuya ranges are reported. Perspectives of applying dendroseismological approach within the high mountainous seismically active southeastern part of Russian Altai are demonstrated. In addition to estimating the germination ages of trees growing on the bare surfaces of seismically triggered landslides, analysis of wood penetrating injuries in the individual tree ring series was applied for dating paleorock-falls. Analysis of distribution patterns of tree-ring anomalies and injured trees suggests a criterion of recognizing seismic origin of past rock-falls. Dendrochronologically obtained dates of abrupt intensifications of rock-falls can be considered as supposed dates of past earthquakes, which should be verified by alternative proxy data. Obtained results argue for the high regional seismicity in the second half of the Holocene. Strong earthquakes occurred here AD 1532, and 600–700, 1300–1500, 2400–2700, 3400–3700, 3800–4200 cal BP. This data clarifies the chronology of seismic events within the SE Altai. The specified recurrence interval of strong earthquakes is about 400 years during the last 4000 years.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2018-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/geochr-2015-0083","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46085173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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: 3

A review of radiometric analysis on soil erosion and deposition studies in Africa 非洲土壤侵蚀和沉积研究的辐射分析综述

IF 1.2 4区地球科学

Geochronometria Pub Date : 2018-01-24 DOI: 10.1515/geochr-2015-0085

Caroline W. Maina, J. Sang, B. Mutua, J. Raude

{"title":"A review of radiometric analysis on soil erosion and deposition studies in Africa","authors":"Caroline W. Maina, J. Sang, B. Mutua, J. Raude","doi":"10.1515/geochr-2015-0085","DOIUrl":"https://doi.org/10.1515/geochr-2015-0085","url":null,"abstract":"Abstract Soil erosion is one of the main soil degradation phenomena that threaten sustainable use of soil productivity thus affecting food security. In addition, it leads to reservoir storage capacity loss because of sedimentation. This not only affects water quantity but also water quality. Worldwide, annual loss in reservoir storage capacity due to sedimentation is 0.5 to 1%. Similarly, about 27% of land in Africa is largely degraded by erosion. As a result, there is need to minimize soil erosion and deposition through site specific estimation of soil erosion and deposition rates in the reservoirs. To achieve this, Fallout RadioNuclides (FRNs) are some of the methods in use. The most common radionuclides include; 137Cs, 210Pb and 7Be. Only few countries in Africa have exploited these FRNs. In these countries, 137Cs has been largely exploited but in some regions, it has been reported to be below minimum detection limit. Using 137Cs and 210Pb, maximum reference inventory in Africa is found to be 1450 and 2602 Bq/m2, respectively. However, there is minimal application of 7Be within the continent. Also, very little has been done in Africa to assess chronology and sedimentation rates of reservoirs using FRNs measured from sediment cores. In conclusion, a gap still exists on FRNs application in Africa in assessing soil erosion, deposition and reservoir sedimentation.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2018-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/geochr-2015-0085","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42901504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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: 5

Luminescence chronostratigraphy for the loess deposits in Złota, Poland 波兰Złota黄土矿床的发光年代地层

IF 1.2 4区地球科学

Geochronometria Pub Date : 2018-01-24 DOI: 10.1515/geochr-2015-0073

P. Moska, G. Adamiec, Z. Jary, A. Bluszcz, G. Poręba, N. Piotrowska, M. Krawczyk, J. Skurzyński

{"title":"Luminescence chronostratigraphy for the loess deposits in Złota, Poland","authors":"P. Moska, G. Adamiec, Z. Jary, A. Bluszcz, G. Poręba, N. Piotrowska, M. Krawczyk, J. Skurzyński","doi":"10.1515/geochr-2015-0073","DOIUrl":"https://doi.org/10.1515/geochr-2015-0073","url":null,"abstract":"Abstract Loess formations in Poland display a close relationship with cooling and warming trends of the Northern Hemisphere during the Pleistocene. Loess sequences sensitively record regional palaeoclimatic and palaeoecological changes. The Złota loess profile (21°39’E, 50°39’N) provides a unique opportunity to reconstruct climate conditions in the past in this part of Poland. This continuous sequence of loess and palaeosol deposits allows to distinguish between warmer and more humid climate which is favourable for soil development and much colder and dry periods which are conducive to loess accumulation. The silty and sandy aeolian material originates mainly from weathered rock surfaces affected by frost shattering or from glaciofluvial/fluvial deposits of river flood plains. In Poland, loess and loess-like formations occur in the southern part of the country, mostly in the south polish uplands, i.e. in the Lublin, Sandomierz, and Cracow Uplands. We used different techniques to establish a chronological framework for this site. 21 samples for luminescence dating were collected from the investigated loess profile in Złota. Infrared post-IR IRSL dating method was applied to the polymineral fine grains (4–11µm). The dating results are accompanied by detailed analyses of the geochemical composition, organic carbon and carbonate. Also, analysis of magnetic susceptibility and grain-size distribution were investigated. Based on such a large stratigraphic dataset an age-depth model using OxCal has also been constructed for this site.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2018-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46171114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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: 17

Development of a Larix principis-rupprechtii tree-ring width chronology and its climatic signals for the southern Greater Higgnan Mountains 大希格南山脉南部华北落叶松年轮宽度年表的发展及其气候信号

IF 1.2 4区地球科学

Geochronometria Pub Date : 2018-01-24 DOI: 10.1515/geochr-2015-0082

Tongwen Zhang, Shulong Yu, Yu-jiang Yuan, Liping Huang, Shengxia Jiang

引用次数: 1

Comparison of beta (LSC) and gamma (HPGe) spectrometric methods for lead-210 in chronological study 年代研究中铅210的β（LSC）和γ（HPGe）光谱测定方法的比较

IF 1.2 4区地球科学

Geochronometria Pub Date : 2018-01-24 DOI: 10.1515/geochr-2015-0084

R. Mikalauskienė, J. Mažeika, R. Petrošius, P. Szwarczewski

{"title":"Comparison of beta (LSC) and gamma (HPGe) spectrometric methods for lead-210 in chronological study","authors":"R. Mikalauskienė, J. Mažeika, R. Petrošius, P. Szwarczewski","doi":"10.1515/geochr-2015-0084","DOIUrl":"https://doi.org/10.1515/geochr-2015-0084","url":null,"abstract":"Abstract The sediments of two lakes located in the Baltic Uplands, the western part of the East European Plain (East Lithuania and North East Poland), were studied. Activity concentration of 210Pb was determined using two nuclear analytical techniques: determination of 210Pb in equilibrium with its beta emitting daughter 210Bi using liquid scintillation counter (LSC), and direct determination of 210Pb (and other radionuclides) by low-background gamma-ray spectrometer with a well type HPGe detector. For the 210Pb determination by LSC the methodology of lead separation based on the anion exchange resin in Cl– form (Eichrom) was used. Several steps of radiochemical procedures and respective parameters were investigated additionally. The optimized procedures for LSC method were used for case study with two lake cores. The activity concentration of 210Pb in lake sediment samples based on both nuclear analytical techniques (LSC and HPGe) were compared. 210Pb dating of cores was performed according to Constant Rate of 210Pb Supply (CRS) model with some modifications. Both techniques in the range of uncertainties gave similar results. From two considered lakes, the more eutrophic one exhibited higher sediment mass accumulation rate (MAR) values.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2018-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44807974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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: 4