Pub Date : 2021-01-01DOI: 10.2478/geochr-2020-0034
Manping Sun, Yongjuan Sun, E. ChongYi, G. Hou, Jing Zhang, Yunkun Shi
Abstract As a daily utensil and artefact, the presence of ceramic at an archaeological site is direct evidence of human activity. While ceramics have been found at numerous sites on the Qinghai-Tibetan Plateau (QTP), most have been aged using conventional methods such as typology or radio-carbon dating of associated charcoal and bone. In this study, five sand-tempered grey ceramics from Talitaliha in the Qaidam Basin were dated using quartz and K-feldspar OSL. The reliability of the ceramic OSL ages was determined using six independent radiocarbon samples, three charcoal and three bone, from the same cultural layer. Six additional OSL ages were determined on sandy loess sediments at the Talitaliha site to provide upper and lower limits for the ceramic ages. The ceramic luminescence dating results are in good agreement with the 14C ages and are within the constraints of the stratigraphic OSL ages, suggesting that OSL dating of ceramics has great potential for archaeological research on the QTP. The determined age range for the Talitaliha site was between 3400–2800 cal BP; this fits well with Nuomuhong culture dates from other locations in the Qaidam Basin that range between 3400–2450 cal BP.
{"title":"Luminescence Dating of Nuomuhong Culture Ceramics at Talitaliha Site on the Northeastern Qinghai-Tibetan Plateau","authors":"Manping Sun, Yongjuan Sun, E. ChongYi, G. Hou, Jing Zhang, Yunkun Shi","doi":"10.2478/geochr-2020-0034","DOIUrl":"https://doi.org/10.2478/geochr-2020-0034","url":null,"abstract":"Abstract As a daily utensil and artefact, the presence of ceramic at an archaeological site is direct evidence of human activity. While ceramics have been found at numerous sites on the Qinghai-Tibetan Plateau (QTP), most have been aged using conventional methods such as typology or radio-carbon dating of associated charcoal and bone. In this study, five sand-tempered grey ceramics from Talitaliha in the Qaidam Basin were dated using quartz and K-feldspar OSL. The reliability of the ceramic OSL ages was determined using six independent radiocarbon samples, three charcoal and three bone, from the same cultural layer. Six additional OSL ages were determined on sandy loess sediments at the Talitaliha site to provide upper and lower limits for the ceramic ages. The ceramic luminescence dating results are in good agreement with the 14C ages and are within the constraints of the stratigraphic OSL ages, suggesting that OSL dating of ceramics has great potential for archaeological research on the QTP. The determined age range for the Talitaliha site was between 3400–2800 cal BP; this fits well with Nuomuhong culture dates from other locations in the Qaidam Basin that range between 3400–2450 cal BP.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"48 1","pages":"391 - 401"},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46068453","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}
Pub Date : 2021-01-01DOI: 10.2478/geochr-2020-0033
G. Yin, Chun-ru Liu, R. Yuan, Fei Han, R. Ding, J. Bahain
Abstract Carbonated rocks constitute one of the main lithologies of the southeastern Tibet area, China, a tectonically very active zone. However, due to the lack of suitable dating materials, it is difficult to carry out chronological studies of the local tectonic evolution in such carbonate areas. In the present study, electron spin resonance (ESR) method had been applied on the dating of carbonates heated during fault activity of the Lijiang-Xiaojinhe (LX) Fault, an important active fault located in the northwest of Yunnan Province. Clear displaced landforms show that the fault has undergone strong late-Quaternary activity. During the fault activity, the heat produced by friction lead to the melting of the frictional surface of the rocks, and the melting can attenuate or zero the ESR dating signal of carbonate. The aim of the present paper was to check the ability of carbonate use to chronologically identify fault activity using electron spin resonance (ESR) method. The results showed the last fault activity of the LX fault was dated by ESR about 2.0±0.2 ka ago, in agreement with historical and radiocarbon data. Hence ESR can be if necessary a practicable dating alternative method for the study of fault activity chronology in carbonate rock area.
{"title":"ESR Chronology of Bedrock Fault Activity in Carbonate Area: Preliminary Results from the Study of the Lijiang-Xiaojinhe Fault, Southeastern Tibet, China","authors":"G. Yin, Chun-ru Liu, R. Yuan, Fei Han, R. Ding, J. Bahain","doi":"10.2478/geochr-2020-0033","DOIUrl":"https://doi.org/10.2478/geochr-2020-0033","url":null,"abstract":"Abstract Carbonated rocks constitute one of the main lithologies of the southeastern Tibet area, China, a tectonically very active zone. However, due to the lack of suitable dating materials, it is difficult to carry out chronological studies of the local tectonic evolution in such carbonate areas. In the present study, electron spin resonance (ESR) method had been applied on the dating of carbonates heated during fault activity of the Lijiang-Xiaojinhe (LX) Fault, an important active fault located in the northwest of Yunnan Province. Clear displaced landforms show that the fault has undergone strong late-Quaternary activity. During the fault activity, the heat produced by friction lead to the melting of the frictional surface of the rocks, and the melting can attenuate or zero the ESR dating signal of carbonate. The aim of the present paper was to check the ability of carbonate use to chronologically identify fault activity using electron spin resonance (ESR) method. The results showed the last fault activity of the LX fault was dated by ESR about 2.0±0.2 ka ago, in agreement with historical and radiocarbon data. Hence ESR can be if necessary a practicable dating alternative method for the study of fault activity chronology in carbonate rock area.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"48 1","pages":"215 - 221"},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42200752","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}
Pub Date : 2021-01-01DOI: 10.2478/geochr-2021-0008
N. K. Pawlak, A. Timar-Gabor, A. Chruścińska
Abstract Trapped charge dating method using electron spin resonance (ESR) of quartz is progressively used for sediment dating. ESR signals can be used for accurate age estimation only when these signals are zeroed by sunlight exposure before the layer creation or when one knows their ESR residual level (the part of the signal that is not bleached). It is well known that the ESR signal related to the Al-hole centres in quartz used for sediment dating has a significant residual signal. From the point of view of luminescence models, as a hole trap, the Al-hole centre is considered as a recombination centre in quartz. Recently, it was demonstrated experimentally that the ESR signal of the Al-hole centre is dependent on the total dose absorbed by the quartz sample in the past. The same effect was confirmed by simulations of the charge transport processes for a model including two recombination centres. Here, the dependence of residual hole concentration (RHC) in the recombination centres on the total dose absorbed by a sample in the past is studied in detail by computer simulations for a wide range of model parameters. The impact that the various relations of centre parameters have on the dependence of the residual as a function of dose is investigated and the implications for the dating practice are discussed.
{"title":"Residual Hole Concentration in Recombination Centres after Bleaching","authors":"N. K. Pawlak, A. Timar-Gabor, A. Chruścińska","doi":"10.2478/geochr-2021-0008","DOIUrl":"https://doi.org/10.2478/geochr-2021-0008","url":null,"abstract":"Abstract Trapped charge dating method using electron spin resonance (ESR) of quartz is progressively used for sediment dating. ESR signals can be used for accurate age estimation only when these signals are zeroed by sunlight exposure before the layer creation or when one knows their ESR residual level (the part of the signal that is not bleached). It is well known that the ESR signal related to the Al-hole centres in quartz used for sediment dating has a significant residual signal. From the point of view of luminescence models, as a hole trap, the Al-hole centre is considered as a recombination centre in quartz. Recently, it was demonstrated experimentally that the ESR signal of the Al-hole centre is dependent on the total dose absorbed by the quartz sample in the past. The same effect was confirmed by simulations of the charge transport processes for a model including two recombination centres. Here, the dependence of residual hole concentration (RHC) in the recombination centres on the total dose absorbed by a sample in the past is studied in detail by computer simulations for a wide range of model parameters. The impact that the various relations of centre parameters have on the dependence of the residual as a function of dose is investigated and the implications for the dating practice are discussed.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"48 1","pages":"415 - 427"},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48082947","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}
Pub Date : 2021-01-01DOI: 10.2478/geochr-2021-0004
P. Sierpień, J. Pawlak, H. Hercman, P. Pruner, N. Zupan Hajna, A. Mihevc, P. Bosák
Abstract Establishing a chronology of events is a critical step in reconstructing the palaeoclimate and it is important for all types of environmental records, including speleothems. Here, we analysed a unique series of flowstones deposited between 3.2 Ma (marine isotope stage (MIS) Km3) and 0.08 Ma (MIS 5). The studied flowstones are located in a classic karstic environment, the Račiška Pečina Cave in south-western Slovenia. Further, a detailed chronology of events was constructed based on oxygen isotope stratigraphy (OIS), combined with magnetostratigraphy and U-series dating. Two curves were selected as reference records where the LR04 record was used as the global curve and a Mediterranean record was used as the regional curve. The Račiška Pečina profile was divided into two segments separated by a principal disconformity. The lower segment correlated better with the regional Mediterranean curve, while the upper segment was with the global LR04 curve. These findings suggest that the main factors controlling environmental conditions in the cave area changed between 3.2 and 0.8 million years ago.
{"title":"Flowstones from the Račiška Pečina Cave (SW Slovenia) Record 3.2-Ma-Long History","authors":"P. Sierpień, J. Pawlak, H. Hercman, P. Pruner, N. Zupan Hajna, A. Mihevc, P. Bosák","doi":"10.2478/geochr-2021-0004","DOIUrl":"https://doi.org/10.2478/geochr-2021-0004","url":null,"abstract":"Abstract Establishing a chronology of events is a critical step in reconstructing the palaeoclimate and it is important for all types of environmental records, including speleothems. Here, we analysed a unique series of flowstones deposited between 3.2 Ma (marine isotope stage (MIS) Km3) and 0.08 Ma (MIS 5). The studied flowstones are located in a classic karstic environment, the Račiška Pečina Cave in south-western Slovenia. Further, a detailed chronology of events was constructed based on oxygen isotope stratigraphy (OIS), combined with magnetostratigraphy and U-series dating. Two curves were selected as reference records where the LR04 record was used as the global curve and a Mediterranean record was used as the regional curve. The Račiška Pečina profile was divided into two segments separated by a principal disconformity. The lower segment correlated better with the regional Mediterranean curve, while the upper segment was with the global LR04 curve. These findings suggest that the main factors controlling environmental conditions in the cave area changed between 3.2 and 0.8 million years ago.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"48 1","pages":"31 - 45"},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45300846","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}
Pub Date : 2021-01-01DOI: 10.2478/GEOCHR-2020-0009
Minqiang Bu, A. Murray, Myungho Kook, J. Buylaert, K. Thomsen
Abstract In this study, we explored the potential of a NaI(Tl) scintillator-based gamma spectrometer for the accurate determination of burial dose rates in natural geological samples using a full spectrum analysis (FSA) approach. In this method, an iterative reweighted least-square regression is used to fit calibration standard spectra (40K, and 238U and 232Th series in equilibrium) to the sample spectrum, after subtraction of an appropriate background. The resulting minimum detection limits for 40K, 238U, and 232Th are 4.8, 0.4 and 0.3 Bq·kg−1, respectively (for a 0.23 kg sample); this is one order of magnitude lower than those obtained with the three-window approach previously reported by us, and well below the concentrations found in most natural sediments. These improved values are also comparable to those from high-resolution HPGe gamma spectrometry. Almost all activity concentrations of 40K, 238U, and 232Th from 20 measured natural samples differ by ≤5% from the high resolution spectrometry values; the average ratio of dose rates derived from our NaI(Tl) spectrometer to those from HPGe spectrometry is 0.993 ± 0.004 (n=20). We conclude that our scintillation spectrometry system employing FSA is a useful alternative laboratory method for accurate and precise determination of burial dose rates at a significantly lower cost than high resolution gamma spectrometry.
{"title":"The Application of Full Spectrum Analysis to NaI(Tl) Gamma Spectrometry for the Determination of Burial Dose Rates","authors":"Minqiang Bu, A. Murray, Myungho Kook, J. Buylaert, K. Thomsen","doi":"10.2478/GEOCHR-2020-0009","DOIUrl":"https://doi.org/10.2478/GEOCHR-2020-0009","url":null,"abstract":"Abstract In this study, we explored the potential of a NaI(Tl) scintillator-based gamma spectrometer for the accurate determination of burial dose rates in natural geological samples using a full spectrum analysis (FSA) approach. In this method, an iterative reweighted least-square regression is used to fit calibration standard spectra (40K, and 238U and 232Th series in equilibrium) to the sample spectrum, after subtraction of an appropriate background. The resulting minimum detection limits for 40K, 238U, and 232Th are 4.8, 0.4 and 0.3 Bq·kg−1, respectively (for a 0.23 kg sample); this is one order of magnitude lower than those obtained with the three-window approach previously reported by us, and well below the concentrations found in most natural sediments. These improved values are also comparable to those from high-resolution HPGe gamma spectrometry. Almost all activity concentrations of 40K, 238U, and 232Th from 20 measured natural samples differ by ≤5% from the high resolution spectrometry values; the average ratio of dose rates derived from our NaI(Tl) spectrometer to those from HPGe spectrometry is 0.993 ± 0.004 (n=20). We conclude that our scintillation spectrometry system employing FSA is a useful alternative laboratory method for accurate and precise determination of burial dose rates at a significantly lower cost than high resolution gamma spectrometry.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"48 1","pages":"161 - 170"},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46006528","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}
Pub Date : 2021-01-01DOI: 10.2478/geochr-2021-0005
D. Brezeanu, A. Avram, A. Micallef, S. Cintă Pinzaru, A. Timar-Gabor
Abstract The applicability of the single-aliquot regenerative-dose (SAR) protocol, by using the optically stimulated luminescence (OSL) signal of quartz as well as the post-infrared–infrared (pIRIR) signals of polymineral fine grains, namely pIRIR225 and pIRIR290, was assessed for dating loess in New Zealand South Island. OSL signals of quartz grains displayed low sensitivity. However, the application of repeated irradiation/bleaching cycles did not result in an increase in sensitivity; annealing in the 300–500°C temperature range generated the sensitisation of both the 110°C thermoluminescence (TL) peak as well as the OSL signal, likely by activation of yet unidentified luminescence centres. After heating, the quartz signal is comparable to that of ideal samples, but the annealing is precluding successful dating. On the other hand, feldspar infrared-stimulated signals displayed satisfactory properties, allowing estimation of ages ranging from 14 ± 1–29 ± 3 ka for the investigated deposit. It was shown that pIRIR225 and pIRIR290 methods have potential for dating loess in the South Island of New Zealand, based on the following observations: (i) Dose recovery tests were successful with recovered-to-given dose ratios with a <10% deviation from unity, (ii) constant residual values of about 4 Gy and about 10 Gy were obtained after exposures for 48 h in the case of pIRIR225 signals and 96 h in the case of pIRIR290 signals, respectively, (iii) while a slight dose-dependence of the residual was reported, and for a dose as large as 1600 Gy the residual values are ≅9 Gy and ≅19 Gy for pIRIR225 and pIRIR290 signals, respectively.
{"title":"Investigations on the Luminescence Properties of Quartz and Feldspars Extracted from Loess in the Canterbury Plains, New Zealand South Island","authors":"D. Brezeanu, A. Avram, A. Micallef, S. Cintă Pinzaru, A. Timar-Gabor","doi":"10.2478/geochr-2021-0005","DOIUrl":"https://doi.org/10.2478/geochr-2021-0005","url":null,"abstract":"Abstract The applicability of the single-aliquot regenerative-dose (SAR) protocol, by using the optically stimulated luminescence (OSL) signal of quartz as well as the post-infrared–infrared (pIRIR) signals of polymineral fine grains, namely pIRIR225 and pIRIR290, was assessed for dating loess in New Zealand South Island. OSL signals of quartz grains displayed low sensitivity. However, the application of repeated irradiation/bleaching cycles did not result in an increase in sensitivity; annealing in the 300–500°C temperature range generated the sensitisation of both the 110°C thermoluminescence (TL) peak as well as the OSL signal, likely by activation of yet unidentified luminescence centres. After heating, the quartz signal is comparable to that of ideal samples, but the annealing is precluding successful dating. On the other hand, feldspar infrared-stimulated signals displayed satisfactory properties, allowing estimation of ages ranging from 14 ± 1–29 ± 3 ka for the investigated deposit. It was shown that pIRIR225 and pIRIR290 methods have potential for dating loess in the South Island of New Zealand, based on the following observations: (i) Dose recovery tests were successful with recovered-to-given dose ratios with a <10% deviation from unity, (ii) constant residual values of about 4 Gy and about 10 Gy were obtained after exposures for 48 h in the case of pIRIR225 signals and 96 h in the case of pIRIR290 signals, respectively, (iii) while a slight dose-dependence of the residual was reported, and for a dose as large as 1600 Gy the residual values are ≅9 Gy and ≅19 Gy for pIRIR225 and pIRIR290 signals, respectively.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"5 7","pages":"46 - 60"},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41269037","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}
Abstract Wuhan area located middle Yangtze River Basin, is dominated by East Asian Monsoon. Widely developed Holocene flu-lacustrine sediments are ideal materials for the reconstruction of paleoclimate change and geo-environment evolution, for which the chronology is a key issue. In this study, 20 luminescence dating samples were collected from a flu-lacustrine sequence and the reliability of the quartz OSL dating to these samples were checked by using luminescence characteristics of dose recovery test and thermos transfer test. Our results indicate that different grain size fraction of 4∼11 μm, 38∼63 μm, and 90∼125 μm were well-bleached before burial. Dating results show that all these ages range from 0.8 ± 0.1 to 7. 9 ± 0.7 ka between 4.25 and 38.55 m, and most of them follow the stratigraphic sequence and other climatic recorder within the normal range of error. Disordered OSL ages may be caused by complicated transport-deposit processes. As a consequence, OSL dating method of SAR-SGC protocol could provide a significant chronology for Holocene flu-lacustrine sediment in large river depo-system.
{"title":"Holocene OSL Chronology of Flu-Lacustrine Sediments in Yangtze River Basin, Wuhan Area, China","authors":"Chuanyi Wei, Huasong Zhang, Chang’an Li, Yufen Zhang, Yawei Li, Mingming Jia, Guo-Qiang Li, Yonghui Leng","doi":"10.2478/GEOCHR-2020-0012","DOIUrl":"https://doi.org/10.2478/GEOCHR-2020-0012","url":null,"abstract":"Abstract Wuhan area located middle Yangtze River Basin, is dominated by East Asian Monsoon. Widely developed Holocene flu-lacustrine sediments are ideal materials for the reconstruction of paleoclimate change and geo-environment evolution, for which the chronology is a key issue. In this study, 20 luminescence dating samples were collected from a flu-lacustrine sequence and the reliability of the quartz OSL dating to these samples were checked by using luminescence characteristics of dose recovery test and thermos transfer test. Our results indicate that different grain size fraction of 4∼11 μm, 38∼63 μm, and 90∼125 μm were well-bleached before burial. Dating results show that all these ages range from 0.8 ± 0.1 to 7. 9 ± 0.7 ka between 4.25 and 38.55 m, and most of them follow the stratigraphic sequence and other climatic recorder within the normal range of error. Disordered OSL ages may be caused by complicated transport-deposit processes. As a consequence, OSL dating method of SAR-SGC protocol could provide a significant chronology for Holocene flu-lacustrine sediment in large river depo-system.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"48 1","pages":"284 - 293"},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47543125","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}
Pub Date : 2021-01-01DOI: 10.2478/geochr-2020-0016
Zhaojing Ding, Lupeng Yu, Z. Lai, Ping An, Xiaodong Miao, Ruru Xu, Zengqi Liu
Abstract The Qaidam Basin preserves the largest Yardang field on Earth, and yardangs are intriguing landforms for studies of the paleo-environment and aeolian processes. Formation of yardangs involved both the initial lacustrine deposition and the subsequent wind-erosion processes. However, the timings of both processes in the Qaidam Basin are still controversial due to limited age data and unsuitable dating methodology. In this paper, we first compared two optical dating methods to determine the suitable one for the study area, then investigated the geomorphic processes based on the new ages. Two-step post-IR IRSL (pIRIR) and multi-elevated-temperature pIRIR (MET-pIRIR) methods of feldspar, were applied to date lacustrine sediments on the top parts of yardangs to decipher the transition time from depositional to an erosional environment. Comparisons of the two methods demonstrated that the influence from anomalous fading was very minimal thus negligible for MET-pIRIR method, as proved by the De plateau between MET-pIRIR250 and MET-pIRIR290; while the pIR50IR250 signals suffered from fading obviously, which was difficult to be corrected due to the high De close to saturation. Consequently, the chronology in this study was based on the MET-pIRIR250 method, potentially offering reliable ages of over 200 ka. Seven MET-pIRIR250 ages of 201–336 ka suggested that a mega-Qaidam Lake (>2714 m a.s.l. on Google Earth) maintained until Marine Isotopic Stage (MIS) 7. The absence of sediments since ca. 200 ka implied wind-erosion and yardang formation since MIS6. This transition from lacustrine to a wind-erosion environment was interpreted as a response to the glacial-interglacial scale climatic changes.
{"title":"Post-IR Irsl Chronology of Paleo-Lacustrine Sediments from Yardangs in the Qaidam Basin, NE Tibetan Plateau","authors":"Zhaojing Ding, Lupeng Yu, Z. Lai, Ping An, Xiaodong Miao, Ruru Xu, Zengqi Liu","doi":"10.2478/geochr-2020-0016","DOIUrl":"https://doi.org/10.2478/geochr-2020-0016","url":null,"abstract":"Abstract The Qaidam Basin preserves the largest Yardang field on Earth, and yardangs are intriguing landforms for studies of the paleo-environment and aeolian processes. Formation of yardangs involved both the initial lacustrine deposition and the subsequent wind-erosion processes. However, the timings of both processes in the Qaidam Basin are still controversial due to limited age data and unsuitable dating methodology. In this paper, we first compared two optical dating methods to determine the suitable one for the study area, then investigated the geomorphic processes based on the new ages. Two-step post-IR IRSL (pIRIR) and multi-elevated-temperature pIRIR (MET-pIRIR) methods of feldspar, were applied to date lacustrine sediments on the top parts of yardangs to decipher the transition time from depositional to an erosional environment. Comparisons of the two methods demonstrated that the influence from anomalous fading was very minimal thus negligible for MET-pIRIR method, as proved by the De plateau between MET-pIRIR250 and MET-pIRIR290; while the pIR50IR250 signals suffered from fading obviously, which was difficult to be corrected due to the high De close to saturation. Consequently, the chronology in this study was based on the MET-pIRIR250 method, potentially offering reliable ages of over 200 ka. Seven MET-pIRIR250 ages of 201–336 ka suggested that a mega-Qaidam Lake (>2714 m a.s.l. on Google Earth) maintained until Marine Isotopic Stage (MIS) 7. The absence of sediments since ca. 200 ka implied wind-erosion and yardang formation since MIS6. This transition from lacustrine to a wind-erosion environment was interpreted as a response to the glacial-interglacial scale climatic changes.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"48 1","pages":"313 - 324"},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69208303","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}
Pub Date : 2021-01-01DOI: 10.2478/geochr-2020-0011
N. Meriç, E. Şahiner, G. Kitis, G. Polymeris
Abstract The present study aimed at quantifying the relationship between TL and either CW-OSL or LM-OSL using commercially available magnesium oxide. The samples were bleached at two different temperatures, and a component-resolved analysis on the integrated signals was performed. According to the data of the present study, each one among the five observed LM-OSL component receives electrons from at least two different TL peaks. Two different fast OSL components were resolved in the LM-OSL curves, both accumulating electrons from all TL glow peaks with Tmax>150°C. Component C3 is very well correlated with the TL peaks at 102, 135 and 194°C, while components C4 and C5 are related to the TL glow peaks of 292°C, 353°C and 464°C. We note that for CW-OSL the resolution is good when two or more components differ in intensity by an order of magnitude. Blue stimulation depletes substantially the first two TL peaks but not the third peak. Substantial depletion of the high-temperature TL peaks is achieved only by using the LM-OSL configuration. The results of the present study suggest that the traps that contribute to TL and OSL are the same, despite using different recombination pathways.
{"title":"Component-Resolved Analysis Towards Correlation between Thermoluminescence and Optically Stimulated Luminescence in Commercial Magnesium Oxide","authors":"N. Meriç, E. Şahiner, G. Kitis, G. Polymeris","doi":"10.2478/geochr-2020-0011","DOIUrl":"https://doi.org/10.2478/geochr-2020-0011","url":null,"abstract":"Abstract The present study aimed at quantifying the relationship between TL and either CW-OSL or LM-OSL using commercially available magnesium oxide. The samples were bleached at two different temperatures, and a component-resolved analysis on the integrated signals was performed. According to the data of the present study, each one among the five observed LM-OSL component receives electrons from at least two different TL peaks. Two different fast OSL components were resolved in the LM-OSL curves, both accumulating electrons from all TL glow peaks with Tmax>150°C. Component C3 is very well correlated with the TL peaks at 102, 135 and 194°C, while components C4 and C5 are related to the TL glow peaks of 292°C, 353°C and 464°C. We note that for CW-OSL the resolution is good when two or more components differ in intensity by an order of magnitude. Blue stimulation depletes substantially the first two TL peaks but not the third peak. Substantial depletion of the high-temperature TL peaks is achieved only by using the LM-OSL configuration. The results of the present study suggest that the traps that contribute to TL and OSL are the same, despite using different recombination pathways.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"48 1","pages":"222 - 231"},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49654612","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}
Pub Date : 2021-01-01DOI: 10.2478/geochr-2021-0001
P. Moska, A. Bluszcz, G. Poręba, K. Tudyka, G. Adamiec, A. Szymak, A. Przybyła
Abstract The Gliwice Luminescence Laboratory (GLL) is a part of the Institute of Physics – Centre for Science and Education at the Silesian University of Technology, which has gradually evolved since the 1980s. To date, nearly 3500 samples have been dated using luminescence from materials such as ceramics, bricks, and sediments from archaeological and geological sites. Currently, the laboratory is equipped with four luminescence readers and three gamma spectrometers, allowing luminescence dating of approximately 300 samples annually for the needs of research projects. This article focuses on the laboratory procedures used in GLL to obtain luminescence ages. Recent improvements of the GLL's facilities and new equipment, as well as the performance spanning the Laboratory's 30 years of activity, are discussed in terms of obtained results and the involvement in national and international projects.
{"title":"Luminescence Dating Procedures at the Gliwice Luminescence Dating Laboratory","authors":"P. Moska, A. Bluszcz, G. Poręba, K. Tudyka, G. Adamiec, A. Szymak, A. Przybyła","doi":"10.2478/geochr-2021-0001","DOIUrl":"https://doi.org/10.2478/geochr-2021-0001","url":null,"abstract":"Abstract The Gliwice Luminescence Laboratory (GLL) is a part of the Institute of Physics – Centre for Science and Education at the Silesian University of Technology, which has gradually evolved since the 1980s. To date, nearly 3500 samples have been dated using luminescence from materials such as ceramics, bricks, and sediments from archaeological and geological sites. Currently, the laboratory is equipped with four luminescence readers and three gamma spectrometers, allowing luminescence dating of approximately 300 samples annually for the needs of research projects. This article focuses on the laboratory procedures used in GLL to obtain luminescence ages. Recent improvements of the GLL's facilities and new equipment, as well as the performance spanning the Laboratory's 30 years of activity, are discussed in terms of obtained results and the involvement in national and international projects.","PeriodicalId":50421,"journal":{"name":"Geochronometria","volume":"48 1","pages":"1 - 15"},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46526788","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}
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