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Full-Text Articles in Social and Behavioral Sciences
A Single-Aliquot Luminescence Dating Procedure For K-Feldspar Based On The Dose-Dependent Met-Pirir Signal Sensitivity, Bo Li, Richard G. Roberts, Zenobia Jacobs, Sheng-Hua Li
A Single-Aliquot Luminescence Dating Procedure For K-Feldspar Based On The Dose-Dependent Met-Pirir Signal Sensitivity, Bo Li, Richard G. Roberts, Zenobia Jacobs, Sheng-Hua Li
Faculty of Science, Medicine and Health - Papers: part A
It has been shown previously that the ‘sensitivity’ of the post-infrared infrared stimulated luminescence (post-IR IRSL or pIRIR) signal—that is, the intensity of the test dose signal (Tx)—can retain a ‘memory’ of the pre-dose received in nature, but can be reset by sunlight bleaching. Based on this observation, we describe here a single-aliquot regenerative-dose (SAR) multiple elevated temperature (MET) pIRIR dating procedure for K-feldspar that differs in one important respect from the conventional SAR MET-pIRIR procedure. Instead of using a high temperature IR bleaching step between each SAR cycle—as in the conventional procedure—our modified procedure uses a solar simulator bleach …
Extending The Age Limit Of Luminescence Dating Using The Dose-Dependent Sensitivity Of Met-Pirir Signals From K-Feldspar, Bo Li, Zenobia Jacobs, Richard G. Roberts, Sheng-Hua Li
Extending The Age Limit Of Luminescence Dating Using The Dose-Dependent Sensitivity Of Met-Pirir Signals From K-Feldspar, Bo Li, Zenobia Jacobs, Richard G. Roberts, Sheng-Hua Li
Faculty of Science, Medicine and Health - Papers: part A
We investigated the sensitivity change of multiple-elevated-temperature (MET) stimulated post-infrared infrared-stimulated luminescence (MET-pIRIR) signals as a response to irradiation, sunlight bleaching and heating using samples from the Mu Us Desert, central China. A strong dose dependence of MET-pIRIR signal sensitivity was observed. The intensity of the test-dose signals (Tx) increase with the pre-dose received. Furthermore, the signal sensitivity can be reset by sunlight bleaching or heating. This suggests that both the electron traps and hole centres in K-feldspar can be bleached by sunlight, and can, therefore, be used for dating. Using the test-dose signal as a monitor for sensitivity change, …
On The Dose Dependency Of The Bleachable And Non-Bleachable Components Of Irsl From K-Feldspar: Improved Procedures For Luminescence Dating Of Quaternary Sediments, Bo Li, Richard G. Roberts, Zenobia Jacobs
On The Dose Dependency Of The Bleachable And Non-Bleachable Components Of Irsl From K-Feldspar: Improved Procedures For Luminescence Dating Of Quaternary Sediments, Bo Li, Richard G. Roberts, Zenobia Jacobs
Faculty of Science, Medicine and Health - Papers: part A
The infrared (IR) stimulated luminescence (IRSL) and post-IR IRSL (pIRIR) signals from K-feldspar can, for convenience, be divided into two components, bleachable and ‘non-bleachable’, where the latter corresponds to the ‘residual’ signal observed in sunlight-bleached samples. In this paper, we examine the non-bleachable component of IRSL of K-feldspar for several sedimentary samples from across Eurasia. We observed a large variability in the residual doses among these samples after prolonged exposure to sunlight. By employing multiple elevated temperature (MET) IR stimulations at 50–300 °C, we show that the residual dose increases systematically with stimulation temperature, attaining values as high as ∼50 …
The Effect Of Band-Tail States On The Thermal Stability Of The Infrared Stimulated Luminescence From K-Feldspar, Bo Li, Sheng-Hua Li
The Effect Of Band-Tail States On The Thermal Stability Of The Infrared Stimulated Luminescence From 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 from a sedimentary K-feldspar was investigated using isothermal decay study. It is observed that the isothermal decay of IRSL signal cannot be described using a first-order exponential decay function. Instead, the decay can be well described by considering the presence of band-tail states. Based on the isothermal decay results, a trap depth of ∼1.92 eV was obtained for the IRSL stimulated at 50 °C and the width of the band-tail states was found to be ∼0.37 eV below the conduction band edge. Deeper trap depths (up to ∼2.06 eV) were …
Lowland River Responses To Intraplate Tectonism And Climate Forcing Quantified With Luminescence And Cosmogenic 10be, J D. Jansen, G C. Nanson, T J. Cohen, T Fujioka, D Fabel, J R. Larsen, A T. Codilean, D M. Price, H H. Bowman, J.-H May, L A. Gliganic
Lowland River Responses To Intraplate Tectonism And Climate Forcing Quantified With Luminescence And Cosmogenic 10be, J D. Jansen, G C. Nanson, T J. Cohen, T Fujioka, D Fabel, J R. Larsen, A T. Codilean, D M. Price, H H. Bowman, J.-H May, L A. Gliganic
Faculty of Science, Medicine and Health - Papers: part A
Intraplate tectonism has produced large-scale folding that steers regional drainage systems, such as the 1600 km-long Cooper Ck, en route to Australia's continental depocentre at Lake Eyre. We apply cosmogenic 10Be exposure dating in bedrock, and luminescence dating in sediment, to quantify the erosional and depositional response of Cooper Ck where it incises the rising Innamincka Dome. The detachment of bedrock joint-blocks during extreme floods governs the minimum rate of incision (17.4±6.5 mm/ky) estimated using a numerical model of episodic erosion calibrated with our 10Be measurements. The last big-flood phase occurred no earlier than ∼112–121 ka. Upstream of the Innamincka …
Study Of The Relationship Between Infrared Stimulated Luminescence And Blue Light Stimulated Luminescence For Potassium-Feldspar From Sediments, Zhijun Gong, Bo Li, Sheng-Hua Li
Study Of The Relationship Between Infrared Stimulated Luminescence And Blue Light Stimulated Luminescence For Potassium-Feldspar From Sediments, Zhijun Gong, Bo Li, Sheng-Hua Li
Faculty of Science, Medicine and Health - Papers: part A
In luminescence measurements of potassium-feldspar (K-feldspar), both infrared (IR) and blue light (BL) can be used as stimulation sources. Component analysis suggests that the blue light stimulated luminescence (BLSL) measured at 60 °C from K-feldspar can be fitted using three components, namely fast, medium and slow. In order to explore the relationship between the origin of the infrared stimulated luminescence (IRSL) signal and the different components of the BLSL, five sets of experiments were conducted, namely post-IR BLSL (pIR-BLSL), post-BL IRSL (pBL-IRSL), pulse annealing tests, dose response and laboratory fading rate tests. It is observed that most of the IRSL …
Determining The Cooling Age Using Luminescence-Thermochronology, Bo Li, Sheng-Hua Li
Determining The Cooling Age Using Luminescence-Thermochronology, Bo Li, Sheng-Hua Li
Faculty of Science, Medicine and Health - Papers: part A
Luminescence technique has been shown to have great potential in low-temperature (< 100 °C) themochronology. This study investigates the kinetic process of luminescence in a cooling system. We present a new formula that can be used for determining the cooling age based on luminescence-thermochronology. The cooling rate can be obtained directly from a plot of luminescence age versus the present temperature. We show that the application and capacity of luminescence-thermochronology are significantly controlled by the saturation of luminescence and environmental dose rate.
Holocene Environmental Changes In Central Inner Mongolia Revealed By Luminescence Dating Of Sediments From The Sala Us River Valley, Sheng-Hua Li, Jimin Sun, Bo Li
Holocene Environmental Changes In Central Inner Mongolia Revealed By Luminescence Dating Of Sediments From The Sala Us River Valley, Sheng-Hua Li, Jimin Sun, Bo Li
Faculty of Science, Medicine and Health - Papers: part A
Luminescence dating of the fluvial and lacustrine sediments from the Sala Us River valley at the south edge of the Mu Us Desert, central Inner Mongolia, is reported. The study region lies in the northwestern marginal zone of the east Asian summer monsoon and is sensitive to climate change. The dating results combined with environmental proxies indicate that the Holocene Climate Optimum period, took place from 8.5 to 5 ka ago and was marked by lake development. After ~5 ka ago, the region became arid, as inferred from lake regression and fluvial activity. Deposition of fluvial sediments lasted from ~5 …
Luminescence Dating Of K-Feldspar From Sediments: A Protocol Without Anomalous Fading Correction, Bo Li, Sheng-Hua Li
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 …
Reply To Comment By Huntley On "Isochron Dating Of Sediments Using Luminescence Of K-Feldspar Grains", Bo Li, Sheng-Hua Li, Hui Zhao
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 …
Thermal Stability Of Infrared Stimulated Luminescence Of Sedimentary K-Feldspar, Bo Li, Sheng-Hua Li
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 …
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
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).