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Faculty of Science, Medicine and Health - Papers: part A

2011

K

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Full-Text Articles in Social and Behavioral Sciences

Luminescence Dating Of K-Feldspar From Sediments: A Protocol Without Anomalous Fading Correction, Bo Li, Sheng-Hua Li Jan 2011

Luminescence Dating Of K-Feldspar From Sediments: A Protocol Without Anomalous Fading Correction, Bo Li, Sheng-Hua Li

Faculty of Science, Medicine and Health - Papers: part A

A protocol for optical dating of potassium-rich feldspar (K-feldspar) is proposed. It utilizes the infrared stimulated luminescence (IRSL) signal measured by progressively increasing the stimulation temperature from 50 to 250 °C in step of 50 °C, so-called multi-elevated-temperature post-IR IRSL (MET-pIRIR) measurements. Negligible anomalous fading was observed for the MET-pIRIR signals obtained at 200 and 250 °C. This was supported by equivalent dose (De) measurements using the IRSL and MET-pIRIR signals. The De values increase progressively from 50 °C to 200 °C, but similar De values were obtained for the MET-pIRIR signal at 200 and 250 °C. Measurement of modern …


Thermal Stability Of Infrared Stimulated Luminescence Of Sedimentary K-Feldspar, Bo Li, Sheng-Hua Li Jan 2011

Thermal Stability Of Infrared Stimulated Luminescence Of Sedimentary K-Feldspar, Bo Li, Sheng-Hua Li

Faculty of Science, Medicine and Health - Papers: part A

The thermal stability of the infrared stimulated luminescence (IRSL) signal measured at 50 °C as a function of IR stimulation time was investigated using KF grains extracted from sediments from central China. A dependence of thermal stability of IRSL signal on IR stimulation time and stimulation temperature were observed in pulse annealing studies. Relatively lower thermal stability is given by the initial part of the IRSL measured at 50 °C, than the later part of IRSL curve. Based on these observations, the thermal stability of the post-IR IRSL signal stimulated at elevated temperatures (100–200 °C) was also investigated. It was …


Reply To Comment By Huntley On "Isochron Dating Of Sediments Using Luminescence Of K-Feldspar Grains", Bo Li, Sheng-Hua Li, Hui Zhao Jan 2011

Reply To Comment By Huntley On "Isochron Dating Of Sediments Using Luminescence Of K-Feldspar Grains", Bo Li, Sheng-Hua Li, Hui Zhao

Faculty of Science, Medicine and Health - Papers: part A

In our isochron studies using grains of different sizes, we observed that the IRSL ages obtained from K‐feldspar without correction for fading show an increase with increasing grain size [Li et al., 2007, 2008]. Huntley [2011a] argued that this result was caused by different fading rates for grains of different sizes or by different source materials for different sizes of grains. We replied to his comment [Li et al., 2011], suggesting that the phenomenon could be explained by there being different fading rates for the IRSL signals produced by natural and laboratory irradiation [Li et al., 2007, 2008]. Instead of …


Infrared Stimulated Luminescence Measurements Of Single Grains Of K-Rich Feldspar For Isochron Dating, Bo Li, Sheng-Hua Li, Geoffrey A. T Duller, Ann G. Wintle Jan 2011

Infrared Stimulated Luminescence Measurements Of Single Grains Of K-Rich Feldspar For Isochron Dating, Bo Li, Sheng-Hua Li, Geoffrey A. T Duller, Ann G. Wintle

Faculty of Science, Medicine and Health - Papers: part A

This paper explores the use of single grain luminescence measurements in isochron dating of K-rich feldspars. The thermal stability of individual feldspar grains was investigated using pulse annealing methods, which appears to distinguish between K-rich and Na-rich feldspars. A good isochron fit was obtained using synthetic aliquots produced from the single grain data set and the age obtained based on an assumed K content of 13 ± 1% was in good agreement with that obtained using single aliquot measurements (and with other age control).


Anomalous Fading: A Reply To The Comment By Huntley On "Isochron Measurements Of Naturally Irradiated K-Feldspar Grains", Bo Li, Sheng-Hua Li, Ann G. Wintle, Hui Zhao Jan 2011

Anomalous Fading: A Reply To The Comment By Huntley On "Isochron Measurements Of Naturally Irradiated K-Feldspar Grains", Bo Li, Sheng-Hua Li, Ann G. Wintle, Hui Zhao

Faculty of Science, Medicine and Health - Papers: part A

We are pleased that Huntley (this issue) has put forward another explanation for the data that we obtained when we measured the equivalent doses (De) of potassium (K) feldspar grains of different diameters using their infrared stimulated luminescence (IRSL) signals (Li et al., 2007). We also measured the fading rates for the IRSL signals from grains of different size and concluded that the fading rates were independent of grain size. Huntley is concerned that the fading rates (g-values) that we obtained had relatively large errors and that these could have masked any minor differences in the g-values; a small systematic …