The luminescence characteristics of feldspar from Nigeria were investigated. Without preheat treatment, the TL glow curve exhibited two peaks at 136°C and 175°C. When preheated to a temperature of 200°C...The luminescence characteristics of feldspar from Nigeria were investigated. Without preheat treatment, the TL glow curve exhibited two peaks at 136°C and 175°C. When preheated to a temperature of 200°C only one peak was observed at 240°C. The highest net IRSL intensity was obtained for a stimulation temperature of 250°C. The TL signal is reduced by IR stimulation, and the longer the stimulation the more pronounced the effect. The dose response curves for both the TL and the IRSL showed a linear relationship for the doses considered in the study. Dose recovery test performed using the SAR method showed consistency with given dose for both TL and IRSL.展开更多
The northern Liulengshan piedmont fault is located along the southern margin of the Yangyuan basin and represents a dip-slip normal fault,generally NEE-trending and NNW-dipping.Landforms offset by the fault are fairly...The northern Liulengshan piedmont fault is located along the southern margin of the Yangyuan basin and represents a dip-slip normal fault,generally NEE-trending and NNW-dipping.Landforms offset by the fault are fairly developed and well preserved in the Dushanpu area of Yangyuan County,Hebei Province.Two trenches were excavated in front of a scarp of the northern Liulengshan piedmont fault at Dushanpu and two paleoseismic events were revealed in the trenches,from which several samples were collected for dating.The samples were dated using the IRSL dating technique.The preliminary result shows the possible ages of the two paleoseismic events.展开更多
A possible approach to assess the fine grain OSL dating is discussed through comparison of equivalent dose (DE) values and ages obtained by IRSL and GLSL of fine grains for 31 sediment samples from North China. The IR...A possible approach to assess the fine grain OSL dating is discussed through comparison of equivalent dose (DE) values and ages obtained by IRSL and GLSL of fine grains for 31 sediment samples from North China. The IRSL and GLSL were measured with the same aliquots for each sample, i.e. shine-down was by 100 s of IRSL (880 nm) followed by 100 s of GLSL (514 nm) on the same discs. The DE values and ages found by IRSL are in good agreement with those by GLSL within 1-2σ for 80% samples, especially for aeolian loess samples. Considering that IRSL from feldspar differs obviously from GLSL dominated from quartz in dose response, thermal stability and optical bleaching characteristic, the agreement between the DE values may be taken as evidence that the two clocks of IRSL and GLSL had been well reset during deposition. The consistent ages of IRSL and GLSL, in turn, may be referred to an indicator to evaluate the fine grain OSL dating of sediments.展开更多
文摘The luminescence characteristics of feldspar from Nigeria were investigated. Without preheat treatment, the TL glow curve exhibited two peaks at 136°C and 175°C. When preheated to a temperature of 200°C only one peak was observed at 240°C. The highest net IRSL intensity was obtained for a stimulation temperature of 250°C. The TL signal is reduced by IR stimulation, and the longer the stimulation the more pronounced the effect. The dose response curves for both the TL and the IRSL showed a linear relationship for the doses considered in the study. Dose recovery test performed using the SAR method showed consistency with given dose for both TL and IRSL.
基金The research was supported by the Joint Earthquake Science Foundation of China. Contribution No. 96B0028, Institute of Geology, SSB, China
文摘The northern Liulengshan piedmont fault is located along the southern margin of the Yangyuan basin and represents a dip-slip normal fault,generally NEE-trending and NNW-dipping.Landforms offset by the fault are fairly developed and well preserved in the Dushanpu area of Yangyuan County,Hebei Province.Two trenches were excavated in front of a scarp of the northern Liulengshan piedmont fault at Dushanpu and two paleoseismic events were revealed in the trenches,from which several samples were collected for dating.The samples were dated using the IRSL dating technique.The preliminary result shows the possible ages of the two paleoseismic events.
基金the National Natural Science Foundation of China (Grant No. 49872062) by the Chinese Academy of Sciences (Grant No. KZ951-A 1-402-07).
文摘A possible approach to assess the fine grain OSL dating is discussed through comparison of equivalent dose (DE) values and ages obtained by IRSL and GLSL of fine grains for 31 sediment samples from North China. The IRSL and GLSL were measured with the same aliquots for each sample, i.e. shine-down was by 100 s of IRSL (880 nm) followed by 100 s of GLSL (514 nm) on the same discs. The DE values and ages found by IRSL are in good agreement with those by GLSL within 1-2σ for 80% samples, especially for aeolian loess samples. Considering that IRSL from feldspar differs obviously from GLSL dominated from quartz in dose response, thermal stability and optical bleaching characteristic, the agreement between the DE values may be taken as evidence that the two clocks of IRSL and GLSL had been well reset during deposition. The consistent ages of IRSL and GLSL, in turn, may be referred to an indicator to evaluate the fine grain OSL dating of sediments.
