Long-term fault slip rates are fundamental to active tectonic studies,as they provide direct constraints on earthquake recurrence,seismic hazard assessment,and risk mitigation.However,slip-rate estimates in northeaste...Long-term fault slip rates are fundamental to active tectonic studies,as they provide direct constraints on earthquake recurrence,seismic hazard assessment,and risk mitigation.However,slip-rate estimates in northeastern Iran remain limited due to sparse independent chronological constraints on displaced geomorphic markers.Moreover,few studies have tested whether quartz optically stimulated luminescence(OSL)dating yields slip-rate estimates consistent with terrestrial cosmogenic nuclide(TCN)and geodetic data in arid fluvial settings.The Abr and Khij faults,major strands of the Shahrud fault system in northeastern Iran,accommodate significant left-lateral strike-slip motion within the Arabia–Eurasia collision zone.In this study,we measured cumulative offsets of 331±7 m(Abr)and 193±4 m(Khij)from displaced alluvial-fan and erosional-surface deposits.Quartz OSL dating of four sediment samples-supported by dose recovery tests,decay curve analyses,and equivalent dose distribution modeling-yielded depositional ages of 111.0±8.6 ka(Abr)and 118.4±6.9 ka(Khij),providing maximum estimates for surface formation.Using these data,we calculated slip rates of 3.00±0.24 mm/yr and 1.63±0.11 mm/yr for the Abr and Khij faults,respectively.These rates fall within or slightly below previous estimates from TCN dating(Abr:3-4 mm/yr;Khij:1-3 mm/yr),indicating overall methodological agreement while highlighting the importance of refining displacement and age constraints.The complementary use of OSL and TCN dating offers a robust chronological framework that reconciles depositional and exposure histories,thereby refining slip-rate estimates for active faults in northeastern Iran.Together,the Abr and Khij faults accommodate~4.4 mm/yr of left-lateral slip,consistent with regional geodetic strain estimates from InSAR and GPS.This result supports the active tectonic role of the eastern Alborz Mountains within the Arabia-Eurasia collision zone.The study further demonstrates the reliability of quartz OSL dating in arid,fluvial depositional contexts,where weak luminescence signals,early saturation,partial bleaching,and sediment mixing are common challenges.The measured slip rates underscore the key role of the Abr and Khij faults in accommodating Arabia-Eurasia plate convergence and provide new constraints on strain partitioning across northeastern Iran.Our findings also have important implications for seismic hazard assessment and for refining fault activity rates in other transpressional orogenic settings.展开更多
The timing of Palaeolithic human activities in South China is still controversial because of the lack of a reliable chronology of archaeological sites.The Longdengshan Palaeolithic site(LPS),located close to the Wuyi ...The timing of Palaeolithic human activities in South China is still controversial because of the lack of a reliable chronology of archaeological sites.The Longdengshan Palaeolithic site(LPS),located close to the Wuyi Mountain of South China,represents the first discovered and scientifically excavated Middle Palaeolithic site in the Fujian Province.This site is of considerable significance for studying the diffusion and cultural connotation of early Homo sapiens in southern China.In this study,we present optically stimulated luminescence(OSL)ages obtained from medium-grained quartz collected at the LPS.The single-aliquot regenerative-dose measurements of red soil deposits collected at the same site yielded internally and stratigraphically consistent ages and similar errors,indicating a potential ability of the technique,and also reflecting the influence of various sedimentary facies on the test results.Our results indicate that the 38–63µm quartz grains were generally partially-bleached and had large values of over-dispersion in the palaeo-reticulated laterites of west Fujian.Some samples yielded unsatisfactory results,suggesting that the degree of bleaching of diluvial and alluvial deposits should be properly assessed before dating.We did not detect any enrichment/depletion of U,Th and radioactive disequilibrium.The effect of chemical weathering on the dose rate estimation was negligible.Therefore,we used a central age model and the maximum age model to calculate the age of two samples,respectively,and the minimum age model to calculate the ages of the rest of the samples.The OSL ages of the samples ranged from 27.09±2.30 ka to 54.65±7.39 ka for the 38–63µm quartz size fraction,and roughly corresponded to the Marine Isotope Stage 3.In addition,three ages out of five are based on the calculation of minimum ages in this research,which needs to be further verified by other dating methods.展开更多
The Quaternary sediments in the Yili Basin can serve as archives for studying the Cenozoic basin-mountain relationship. In this study, based on typical natural sections and boreholes, the surficial sediments of the Hu...The Quaternary sediments in the Yili Basin can serve as archives for studying the Cenozoic basin-mountain relationship. In this study, based on typical natural sections and boreholes, the surficial sediments of the Huocheng area were studied, and their sedimentary ages were obtained using the optically stimulated luminescence(OSL) and electron spin resonance(ESR) dating methods. These dates, combined with changes in the sedimentary facies, provided details of the neotectonic movement in the Yili Basin and adjacent areas. By dating sediments from five sections and three boreholes, we determined that the surficial sediments of the Huocheng area were mainly formed in the Late Pleistocene, with scattered instances of Holocene sediments. The surficial sediments mainly consisted of alluvial fan facies, fluvial facies, lacustrine facies, and desert facies. Based on the activity on the Hongshanzui fault and the northern margin fault of the Wusun Mountains, the Huocheng area was uplifted synchronously with the Tianshan Mountains during the last stage of the Late Pleistocene, causing the desert facies sediments to be superimposed on the former paleo-lake sediments.展开更多
常规的OSL(open short load)校准方法具有简便易行的特点 ,被广泛应用于单端口测量的测试夹具的校准 .在本文中 ,OSL方法被首次扩展应用于双端口夹具的校准 ,并消除该方法带来的相位不确定问题 .通过实验证明这种方法与SOLT(short open ...常规的OSL(open short load)校准方法具有简便易行的特点 ,被广泛应用于单端口测量的测试夹具的校准 .在本文中 ,OSL方法被首次扩展应用于双端口夹具的校准 ,并消除该方法带来的相位不确定问题 .通过实验证明这种方法与SOLT(short open load thru)展开更多
为了研究光释光(OSL)技术,设计了OSL剂量探测系统。采用Landauer单点剂量片作探测器,敏感材料为Al2O3:C,并在CW-OSL模式下对系统进行了本底评估、剂量线性和最小可探测剂量(MDD)测试。实验结果表明,该系统本底控制在150 cps的较低...为了研究光释光(OSL)技术,设计了OSL剂量探测系统。采用Landauer单点剂量片作探测器,敏感材料为Al2O3:C,并在CW-OSL模式下对系统进行了本底评估、剂量线性和最小可探测剂量(MDD)测试。实验结果表明,该系统本底控制在150 cps的较低水平,处于国内领先水平;探测器经60Co标准源辐照后,在1~100 m Gy剂量范围内具有良好的线性响应;MDD为1μGy。展开更多
摘要Long-term fault slip rates are fundamental to active tectonic studies,as they provide direct constraints on earthquake recurrence,seismic hazard assessment,and risk mitigation.However,slip-rate estimates in northeastern Iran remain limited due to sparse independent chronological constraints on displaced geomorphic markers.Moreover,few studies have tested whether quartz optically stimulated luminescence(OSL)dating yields slip-rate estimates consistent with terrestrial cosmogenic nuclide(TCN)and geodetic data in arid fluvial settings.The Abr and Khij faults,major strands of the Shahrud fault system in northeastern Iran,accommodate significant left-lateral strike-slip motion within the Arabia–Eurasia collision zone.In this study,we measured cumulative offsets of 331±7 m(Abr)and 193±4 m(Khij)from displaced alluvial-fan and erosional-surface deposits.Quartz OSL dating of four sediment samples-supported by dose recovery tests,decay curve analyses,and equivalent dose distribution modeling-yielded depositional ages of 111.0±8.6 ka(Abr)and 118.4±6.9 ka(Khij),providing maximum estimates for surface formation.Using these data,we calculated slip rates of 3.00±0.24 mm/yr and 1.63±0.11 mm/yr for the Abr and Khij faults,respectively.These rates fall within or slightly below previous estimates from TCN dating(Abr:3-4 mm/yr;Khij:1-3 mm/yr),indicating overall methodological agreement while highlighting the importance of refining displacement and age constraints.The complementary use of OSL and TCN dating offers a robust chronological framework that reconciles depositional and exposure histories,thereby refining slip-rate estimates for active faults in northeastern Iran.Together,the Abr and Khij faults accommodate~4.4 mm/yr of left-lateral slip,consistent with regional geodetic strain estimates from InSAR and GPS.This result supports the active tectonic role of the eastern Alborz Mountains within the Arabia-Eurasia collision zone.The study further demonstrates the reliability of quartz OSL dating in arid,fluvial depositional contexts,where weak luminescence signals,early saturation,partial bleaching,and sediment mixing are common challenges.The measured slip rates underscore the key role of the Abr and Khij faults in accommodating Arabia-Eurasia plate convergence and provide new constraints on strain partitioning across northeastern Iran.Our findings also have important implications for seismic hazard assessment and for refining fault activity rates in other transpressional orogenic settings.
基金supported by National Natural Science Foundation of China(Grant Nos.41301012,42077407 and 41771020),Natural Science Foundation of Fujian Province,China(Grant No.2020J01185),and the Innovation Research Team Fund of Fujian Normal University(Grant No.IRTL1705).
摘要The timing of Palaeolithic human activities in South China is still controversial because of the lack of a reliable chronology of archaeological sites.The Longdengshan Palaeolithic site(LPS),located close to the Wuyi Mountain of South China,represents the first discovered and scientifically excavated Middle Palaeolithic site in the Fujian Province.This site is of considerable significance for studying the diffusion and cultural connotation of early Homo sapiens in southern China.In this study,we present optically stimulated luminescence(OSL)ages obtained from medium-grained quartz collected at the LPS.The single-aliquot regenerative-dose measurements of red soil deposits collected at the same site yielded internally and stratigraphically consistent ages and similar errors,indicating a potential ability of the technique,and also reflecting the influence of various sedimentary facies on the test results.Our results indicate that the 38–63µm quartz grains were generally partially-bleached and had large values of over-dispersion in the palaeo-reticulated laterites of west Fujian.Some samples yielded unsatisfactory results,suggesting that the degree of bleaching of diluvial and alluvial deposits should be properly assessed before dating.We did not detect any enrichment/depletion of U,Th and radioactive disequilibrium.The effect of chemical weathering on the dose rate estimation was negligible.Therefore,we used a central age model and the maximum age model to calculate the age of two samples,respectively,and the minimum age model to calculate the ages of the rest of the samples.The OSL ages of the samples ranged from 27.09±2.30 ka to 54.65±7.39 ka for the 38–63µm quartz size fraction,and roughly corresponded to the Marine Isotope Stage 3.In addition,three ages out of five are based on the calculation of minimum ages in this research,which needs to be further verified by other dating methods.
基金financial support of the Natural Science Foundation of China (No. 41772200)China Earthquake Administration teacher research Fund (No. 20140103)+1 种基金China Geological Survey Program (No. 121201011000150021, No.DD20190351)Innovation Leading Talents Program of Qingdao (19–3–2–19–zhc)
摘要The Quaternary sediments in the Yili Basin can serve as archives for studying the Cenozoic basin-mountain relationship. In this study, based on typical natural sections and boreholes, the surficial sediments of the Huocheng area were studied, and their sedimentary ages were obtained using the optically stimulated luminescence(OSL) and electron spin resonance(ESR) dating methods. These dates, combined with changes in the sedimentary facies, provided details of the neotectonic movement in the Yili Basin and adjacent areas. By dating sediments from five sections and three boreholes, we determined that the surficial sediments of the Huocheng area were mainly formed in the Late Pleistocene, with scattered instances of Holocene sediments. The surficial sediments mainly consisted of alluvial fan facies, fluvial facies, lacustrine facies, and desert facies. Based on the activity on the Hongshanzui fault and the northern margin fault of the Wusun Mountains, the Huocheng area was uplifted synchronously with the Tianshan Mountains during the last stage of the Late Pleistocene, causing the desert facies sediments to be superimposed on the former paleo-lake sediments.
摘要为了研究光释光(OSL)技术,设计了OSL剂量探测系统。采用Landauer单点剂量片作探测器,敏感材料为Al2O3:C,并在CW-OSL模式下对系统进行了本底评估、剂量线性和最小可探测剂量(MDD)测试。实验结果表明,该系统本底控制在150 cps的较低水平,处于国内领先水平;探测器经60Co标准源辐照后,在1~100 m Gy剂量范围内具有良好的线性响应;MDD为1μGy。