Geochronometria最新文献_第7页

Luminescence chronology of fluvial and marine records from subsurface core in Kaveri delta, Tamil Nadu: Implications to sea level fluctuations 泰米尔纳德邦Kaveri三角洲地下岩心的河流和海洋记录的发光年代学:对海平面波动的影响

IF 1.2 4区地球科学

Geochronometria Pub Date : 2019-01-01 DOI: 10.1515/geochr-2015-0112

K. Goswami, Sivakumar Krishnan, A. Kumerasan, S. Sadasivam, Pankaj Kumar, M. Jaiswal

{"title":"Luminescence chronology of fluvial and marine records from subsurface core in Kaveri delta, Tamil Nadu: Implications to sea level fluctuations","authors":"K. Goswami, Sivakumar Krishnan, A. Kumerasan, S. Sadasivam, Pankaj Kumar, M. Jaiswal","doi":"10.1515/geochr-2015-0112","DOIUrl":"https://doi.org/10.1515/geochr-2015-0112","url":null,"abstract":"Abstract South-Eastern coastal plains of India experience some of the major delta formations of the Indian subcontinent majorly affected by fluctuations of the Indian summer monsoon (ISM) and sea level. Past shoreline signatures in the form of palaeo beach ridges in Kaveri delta (Tamil Nadu, India), suggest a wave-dominated delta and thus past sea-level variations affecting directly the sedimentary dynamics of the Kaveri river forcing the river to either aggrade or prograde. Chronostratigraphic and foraminiferal study of the 25 m deep sediment core taken 2.5 km onshore from Tamil Nadu coast, Kaveri delta shows evidence of changing coastline over the last 150 ka. Various units in the core reflect eight major phases of increased sea level (~3.4 ka, ~5.0 ka, 9–6 ka, 60–57 ka, 89–81 ka, ~102 ka,~121 ka and 143–140 ka) partly coinciding with the global climate cycles MIS 1, MIS 3, MIS 5, MIS 6 respectively during the late Quaternary period. During ~121 ka and 9–6 ka, direct signature of marine transgression is observed by the presence of foraminifera in the core location. The study also shows that the sea transgression during ~121 ka was much longer-lasting and higher than during 9–6 ka, even though not revealed in the Quaternary sea level curve given by previous authors. Depositional breaks are observed in the core during periods of lower sea levels as the river responded by incision. Total organic matter of the deposition between 9–6 ka was observed as high as 2.5–6% suggesting oxygen stressed conditions during the period.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"46 1","pages":"125 - 137"},"PeriodicalIF":1.2,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41893931","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

ESR dating of fossil teeth: In which extent the thickness of adjacent tissues should be taken into account in the external beta dose rate evaluation? 化石牙齿的ESR测年：在外部β剂量率评估中，应在多大程度上考虑相邻组织的厚度？

IF 1.2 4区地球科学

Geochronometria Pub Date : 2019-01-01 DOI: 10.1515/geochr-2015-0105

M. Duval, L. Martin

{"title":"ESR dating of fossil teeth: In which extent the thickness of adjacent tissues should be taken into account in the external beta dose rate evaluation?","authors":"M. Duval, L. Martin","doi":"10.1515/geochr-2015-0105","DOIUrl":"https://doi.org/10.1515/geochr-2015-0105","url":null,"abstract":"Abstract We used DosiVox to evaluate the impact of cement thickness on the dose effectively absorbed by the enamel layer. Until now, the thickness of the dental tissues adjacent to the enamel layer was not considered by any of the most widely used combined US-ESR dating programs (DATA and USESR). Instead, if adjacent tissues are present, their thickness is by default assumed to be sufficient to fulfill the infinite matrix conditions. Our result suggest that such an assumption may represent in first instance a fair approximation of the reality, as even with a thickness of only 1 mm, the cement contributes to at least 98% of the beta dose rate coming from the outer side of the enamel layer. However, when cement is < 1 mm thick, DATA or USESR would overestimate the external beta dose rate and the value should be corrected accordingly by considering the relative contribution of the sediment. The impact of this correction on the total dose rate may vary, as it is directly dependent on the radioactivity of the cement itself, as well as of the sediment or dentine. Our results show that a very thin cement layer (0.1 mm-thick) can significantly contribute to the beta dose rate and should therefore not be neglected. Consequently, based on these results, we recommend the systematic measurement of the thickness of the dental tissues adjacent to the enamel layer during sample preparation, in order to proceed to beta dose rate corrections if necessary. Although this work has been especially focused on the case of fossil teeth showing cement, the conclusions stand for any other geometry involving different dental tissues adjacent to the enamel layer dated by ESR.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"46 1","pages":"102 - 110"},"PeriodicalIF":1.2,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42049508","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

Application of 239,240 Pu, 137Cs and heavy metals for dating of river sediments 239,240 Pu, 137Cs和重金属在河流沉积物测年中的应用

IF 1.2 4区地球科学

Geochronometria Pub Date : 2019-01-01 DOI: 10.1515/geochr-2015-0111

D. Ciszewski, E. Łokas

{"title":"Application of 239,240 Pu, 137Cs and heavy metals for dating of river sediments","authors":"D. Ciszewski, E. Łokas","doi":"10.1515/geochr-2015-0111","DOIUrl":"https://doi.org/10.1515/geochr-2015-0111","url":null,"abstract":"Abstract The periodical nature of overbank sediment accumulation makes their detailed dating much more difficult than dating sediments in water reservoirs. To improve the commonly used dating with 137Cs, we combined this method with Pu isotopes and heavy metals in order to date sediments of the Chechło River (southern Poland), which was polluted by a lead-zinc mine. We analyzed 137Cs, Pu isotopes and heavy metal concentrations in three profiles of overbank sediments and in two profiles of subsidence basins in the lower river reach. The results indicate a lower accuracy and higher uncertainty of the overbank than the dating of reservoir sediments. The application of plutonium isotopes provided very important information validating caesium peaks or providing the principal information regarding horizons dated with heavy metals. The obtained dates give the earliest possible age of particular horizons with the actual sediment deposition delayed by several to a dozen years. This investigation shows that using plutonium radioisotopes can be a useful tool for dating, particularly of the youngest overbank sediments where numerous sedimentation gaps cause uncertainties in the application of other methods, e.g. radiocaesium and heavy metals.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"46 1","pages":"138 - 147"},"PeriodicalIF":1.2,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45836326","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

Temporal variation of prehistoric human settlement recorded in the oxbow lake deposits of San river (Sandomierz Basin, SE Poland) 波兰东南部桑多米日盆地圣河牛轭湖沉积物史前人类住区的时间变化

IF 1.2 4区地球科学

Geochronometria Pub Date : 2019-01-01 DOI: 10.1515/geochr-2015-0119

P. Gębica, A. Michno, M. Sobucki, S. Czopek, K. Trybała-Zawiślak, A. Wacnik

引用次数: 4

A new method for constructing Pb-210 chronology of young peat profiles sampled with low frequency 一种构建低频采样泥炭年轻剖面Pb-210年表的新方法

IF 1.2 4区地球科学

Geochronometria Pub Date : 2019-01-01 DOI: 10.1515/GEOCHR-2015-0101

J. Sikorski

{"title":"A new method for constructing Pb-210 chronology of young peat profiles sampled with low frequency","authors":"J. Sikorski","doi":"10.1515/GEOCHR-2015-0101","DOIUrl":"https://doi.org/10.1515/GEOCHR-2015-0101","url":null,"abstract":"Abstract The paper presents the results of measurements the specific concentration of lead-210 for six peat profiles representing four peat bogs from two regions of Poland and the problem of creating age-depth models. For the construction of age-depth models, it is proposed to use mathematical functions, the best fit to the measured activity. The F-statistics were used as a measure of the match quality. The obtained models are visualized in two ways – showing the age calculated on the basis of direct measurements of activity and indicating points that are the results of the used approximation. Such visualization is important to clearly distinguish the places of the age-depth model that result from the measurements of activity from those places that are the result of the approximation used. This paper proposes and tests the application of activity modelling for the cores shorter than the range of the lead method. The paper also outlines the limitations and potential dangers related to the interpretation of core dating results i) obtained by using the activity approximation resulting in the smoothing of the age-depth profile, and ii) for the cores of a length smaller than the depth of the presence of the unsupported lead. Additionally, the proposed models were compared with the models obtained by using SIT, Mod-Age, OxCal, Clam, and Bacon programs.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"46 1","pages":"1 - 14"},"PeriodicalIF":1.2,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42174231","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

Interpretation of soil erosion in a Polish loess area using OSL, 137Cs, 210Pbex, dendrochronology and micromorphology – case study: Biedrzykowice site (s Poland) 使用OSL、137Cs、210Pbex、树木年代学和微形态学解释波兰黄土地区的土壤侵蚀——案例研究：Biedrzykowice遗址（波兰）

IF 1.2 4区地球科学

Geochronometria Pub Date : 2019-01-01 DOI: 10.1515/geochr-2015-0109

G. Poręba, Z. Śnieszko, P. Moska, P. Mroczek, I. Malik

{"title":"Interpretation of soil erosion in a Polish loess area using OSL, 137Cs, 210Pbex, dendrochronology and micromorphology – case study: Biedrzykowice site (s Poland)","authors":"G. Poręba, Z. Śnieszko, P. Moska, P. Mroczek, I. Malik","doi":"10.1515/geochr-2015-0109","DOIUrl":"https://doi.org/10.1515/geochr-2015-0109","url":null,"abstract":"Abstract Loess areas used for agriculture are susceptible to soil erosion. The intensive process of soil erosion in Polish loess areas began with the onset of the Neolithic and has continued intermittently until today. This work presents the results of soil erosion from simultaneous use of the 137Cs and 210Pbex methods on an agricultural field located on loess slope. Moreover, to establish the age of accumulated sediment connected with water slope erosion, OSL dating, selected physicochemical and micromorphological analyses were applied. The reference values of the 137Cs and 210Pbex fallout for the studied site (Biedrzykowice, the Proszowice Plateau, Małopolska Upland) equal 2627 (45% connected with Chernobyl) and 4835 Bq·m–2, respectively. The results of the 137Cs and 210Pbex inventories measured for the agricultural field range from 730 to 7911 and from 1615 to 11136 Bq·m–2, respectively. The mean soil erosion is about 2.1 kg·m–2·a–1 (about 1.4 mm·a–1). The accumulation of the colluvial sediments started in the Neolithic and drastically increased in the Middle Ages. The examined gully catchment in Biedrzykowice has probably developed quite rapidly as a result of increased erosion. This resulted in the abandonment of this area as farmland and, consequently, in the minimization of water erosion on the slope due to the entrance of woody vegetation in this area. Erosion processes were highly intensified during the last 70 years as a result of deforestation after World War II and intensive agricultural reuse of this area after a break, as indicated by isotope measurements and dendrochronology.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"46 1","pages":"57 - 78"},"PeriodicalIF":1.2,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49409573","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: 14

Carbon isotopes in wood combustion/pyrolysis products: experimental and molecular simulation approaches 木材燃烧/热解产物中的碳同位素:实验和分子模拟方法

IF 1.2 4区地球科学

Geochronometria Pub Date : 2019-01-01 DOI: 10.1515/geochr-2015-0110

H. Hercman, M. Szczerba, P. Zawidzki, A. Trojan

{"title":"Carbon isotopes in wood combustion/pyrolysis products: experimental and molecular simulation approaches","authors":"H. Hercman, M. Szczerba, P. Zawidzki, A. Trojan","doi":"10.1515/geochr-2015-0110","DOIUrl":"https://doi.org/10.1515/geochr-2015-0110","url":null,"abstract":"Abstract A series of laboratory experiments was performed to determine the carbon stable isotopic composition of different combustion/pyrolysis (B/P) products. Variation in the δ13C values of the products was observed, up to 4‰. The differences in the carbon isotopic compositions of the B/P products were dependent on temperature, time and wood type. Comparison of the results for fresh and fossil oak wood suggested that the δ13C differences were the effect of selective decomposition of some wood components during the fossilization process. The temperature dependence of the carbon isotopic composition was linked to variation in the carbon isotopic composition of the main wood components, which each had different levels of thermal stability. Isotopes exchange reactions in between different products can be also considered as possible source of variation of δ13C on temperature. Both these hypotheses were supported by molecular simulations of cellulose and lignin B/P. The results confirm that B/P should be treated as a continuous process, where the results depend on the degree of process development. Natural burning processes are dynamic and burning conditions change rapidly and it is necessary to take care when using combustion products as a paleoenvironmental proxy or as an isotopic characteristic for the identification of source material.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"46 1","pages":"111 - 124"},"PeriodicalIF":1.2,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44841932","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: 2

Optically stimulated luminescence dating of coastal sediments at Funing Bay, Southeastern China 东南抚宁湾海岸沉积物的光激发发光测年

IF 1.2 4区地球科学

Geochronometria Pub Date : 2019-01-01 DOI: 10.1515/geochr-2015-0103

Jian-hui Jin, Yun-ming Huang, Zhi-zhong Li, Xue-chun Fan, Z. Ling, Zhi-xing Li, Xiao-ju Liu

{"title":"Optically stimulated luminescence dating of coastal sediments at Funing Bay, Southeastern China","authors":"Jian-hui Jin, Yun-ming Huang, Zhi-zhong Li, Xue-chun Fan, Z. Ling, Zhi-xing Li, Xiao-ju Liu","doi":"10.1515/geochr-2015-0103","DOIUrl":"https://doi.org/10.1515/geochr-2015-0103","url":null,"abstract":"Abstract The possible role of environmental change, especially sea level change, as a stimulus for the development of human residence and migration is poorly understood. We investigate this problem by showing a record of sea-level change and coastal transformation based on a sediment core (FN1 core) and a Neolithic site (Pingfengshan site) obtained from the Funing bay on the northeast coast of Fujian, China. The Funing bay coastal area represents a unique feature in China’s Neolithic cultures, comprising a silty beach dominated by quartz-rich sand and several important sites of Huangguashan cultural period. Samples from FN1 core and Pingfengshan site were taken for grain size ananlyses and for optically stimulated luminescence (OSL) dating. The blue-light stimulated OSL signals were measured by the single aliquot regenerative dose (SAR) protocol to determine the ages of of the samples. Samples from FN1 core yield OSL ages ranging from 49.9 ka to 0.8 ka, providing the systematic geochronological evidence for the sea level change of Funing bay. The comparison of sea level change and Neolithic cultural periods presents a good relationship in coastal area of Fujian, China since about 7 ka before present. In detail, the cultural types of Keqiutou culture and Huangguashan culture all belong to coastal mountainous culture, of which flourishing periods corresponds to the higher sea level periods of mid-late Holocene. Tanshishan culture belongs to estuarine coastal culture, and most sites of this period correspond to a lower sea level located at lower altitudes.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"46 1","pages":"15 - 24"},"PeriodicalIF":1.2,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43175743","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: 1

A 333-year record of the mean minimum temperature reconstruction in the Western Tianshan Mountains, China 中国西天山333年平均最低气温重建记录

IF 1.2 4区地球科学

Geochronometria Pub Date : 2019-01-01 DOI: 10.1515/geochr-2015-0104

L. Jiao, Sheng-jie Wang, Yuan Jiang, Xuerui Liu

{"title":"A 333-year record of the mean minimum temperature reconstruction in the Western Tianshan Mountains, China","authors":"L. Jiao, Sheng-jie Wang, Yuan Jiang, Xuerui Liu","doi":"10.1515/geochr-2015-0104","DOIUrl":"https://doi.org/10.1515/geochr-2015-0104","url":null,"abstract":"Abstract In this paper, a fragile ecological area in the Western Tianshan National Nature Reserve of China was selected as the research region, and Picea schrenkiana, which is sensitive to climate change, was selected as the research object. The mean minimum temperature in the growing season of the previous year (May to September) was the main limiting factor for tree radial growth based on an analysis of the relationship between chronological series and climatic factors during 1959–2012 (r = –0.792, p < 0.05). Moreover, the relationship was stable, which showed that tree rings can be used as alternative materials for climate reconstruction. Therefore, the mean minimum temperature of the previous year in 1680–2012 was reconstructed, and the explained variance of the reconstruction equation was 62.7% (R2adj = 62.0%, F = 85.8). The 31 dramatically altered years were found via characteristic year analyses, and extreme changes occurred most often under relatively warm conditions. The mean minimum temperature in the reconstruction shows a clear warming trend by the 11-year moving average of the reconstructive series since the 1950s (the temperature increase: 0.341°C/decade). The driving factors of the mean minimum temperature were influenced mainly by the interaction of solar activity and large-scale atmospheric–oceanic variability, especially the westerly circulations.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"46 1","pages":"37 - 48"},"PeriodicalIF":1.2,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43003154","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

Application of long time artificial optical bleaching of the E1’ centre to sediment ESR dating E1′中心长时间人工光学漂白在沉积物ESR定年中的应用

IF 1.2 4区地球科学

Geochronometria Pub Date : 2019-01-01 DOI: 10.1515/geochr-2015-0106

Chuanyi Wei, Chun-ru Liu, Chang‐An Li, G. Yin, Yufen Zhang, Wenpeng Li, Lu-Peng Yu

引用次数: 4