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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
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
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
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
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
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 …
Expectations Of Scatter In Equivalent-Dose Distributions When Using Multi-Grain Aliquots For Osl Dating, Alastair C. Cunningham, Jakob Wallinga, Philip S. J Minderhoud
Expectations Of Scatter In Equivalent-Dose Distributions When Using Multi-Grain Aliquots For Osl Dating, Alastair C. Cunningham, Jakob Wallinga, Philip S. J Minderhoud
Faculty of Science, Medicine and Health - Papers: part A
In the OSL dating of sediment, the scatter in equivalent dose (D e) between grains is almost always larger than would be expected due to counting statistics alone. Some scatter may be caused by insufficient (partial) bleaching of some of the grains prior to deposition. In order to date partially bleached sediment, it is essential to estimate the amount of scatter caused by other processes (e.g. grain-to-grain variability in the natural dose rate). Measurements of such scatter are performed at the single-grain level; by contrast, most OSL dating is performed on multi-grain subsamples, for which grain-to-grain scatter is reduced through …
Extracting Storm-Surge Data From Coastal Dunes For Improved Assessment Of Flood Risk, Alastair C. Cunningham, Marcel A. J Bakker, Sytze Van Heteren, Bert Van Der Valk, Ad J. F Van Der Spek, Dennis R. Schaart, Jakob Wallinga
Extracting Storm-Surge Data From Coastal Dunes For Improved Assessment Of Flood Risk, Alastair C. Cunningham, Marcel A. J Bakker, Sytze Van Heteren, Bert Van Der Valk, Ad J. F Van Der Spek, Dennis R. Schaart, Jakob Wallinga
Faculty of Science, Medicine and Health - Papers: part A
Future changes in climate and sea level are likely to increase the threat from storm surges in many coastal regions. Mitigation of this threat requires an understanding of storm surge magnitude and frequency, and the relationship of these variables to climate parameters. This understanding is currently limited by the brevity of instrumental records, which rarely predate the twentieth century. However, evidence of former storm surges can be recorded in coastal dunes, because the dune topography may trap high-magnitude deposits at elevated locations. Here we combine a range of techniques to extract storm-surge data from coastal dune sediment. The sediment is …
Commentary On Farbstein, R. "Technologies Of Art", Katherine Szabo
Commentary On Farbstein, R. "Technologies Of Art", Katherine Szabo
Faculty of Science, Medicine and Health - Papers: part A
Chaîne opératoire, as both an analytical approach and a sociotechnical perspective, has had a presence in material culture literature for some considerable time. However despite the longevity of the concept, its full potential for the comparative study of material culture production and consumption has not really been realized within archaeology. Here, Farbstein explores this area through looking at the production of mobiliary art in a range of raw materials at Pavlovian Upper Paleolithic sites.
Un Hombre De San Juan: Aproximación Facial En Antropología, Susan Hayes
Un Hombre De San Juan: Aproximación Facial En Antropología, Susan Hayes
Faculty of Science, Medicine and Health - Papers: part A
Within both anthropology and forensic identification, a facial approximation (also known as "facial reconstruction") is often presented as an accomplished fact, with minimal, or no evidence of the research and methods used to achieve the result. This paper presents a detailed overview of the research and methods used for a 2D computer graphic facial approximation of a prehistoric man unearthed in the Jachal Valley, San Juan Province, Argentina. Understood to be a member of the extinct Huarpe, this individual's skull displays many of the morphological features that are consistent with what is known about this group of early Amerindian farmers. …
Observation Of Unstable Fast Component In Osl Of Quartz, Anchuan Fan, Sheng-Hua Li, Bo Li
Observation Of Unstable Fast Component In Osl Of Quartz, Anchuan Fan, Sheng-Hua Li, Bo Li
Faculty of Science, Medicine and Health - Papers: part A
Optically stimulated luminescence (OSL) dating has been applied to quartz grains extracted from a sedimentary layer containing stone tools from the bank of Salawusu River, Mu Us desert in central China. Severe age underestimation was observed by applying the single-aliquot regenerative dose (SAR) dating method when compared with the isochron infrared stimulated luminescence (iIRSL) dating results using potassium-rich feldspar grains of different grain sizes. Preheating plateau and dose recovery tests suggest that the SAR protocol is robust for this sample. Component resolving indicates that the OSL signals were dominated by the fast component. However, the fast component is thermally unstable …
Isochron Dating Of Sand-Loess-Soil Deposits From The Mu Us Desert Margin, Central China, Bo Li, Sheng-Hua Li, Jimin Sun
Isochron Dating Of Sand-Loess-Soil Deposits From The Mu Us Desert Margin, Central China, Bo Li, Sheng-Hua Li, Jimin Sun
Faculty of Science, Medicine and Health - Papers: part A
A sand-loess-soil sequence from the margin of the Mu Us Desert was studied using the isochron infrared stimulated luminescence (IRSL) dating method utilizing K-feldspar grains extracted from sediments. Although the IRSL ages measured with the conventional method showed underestimation as a result of anomalous fading, the isochron results are broadly consistent with independent ages based on stratigraphic correlation in a glacial/interglacial scale over the last 250 ka. For samples older than 250 ka, the IRSL signals approached in field saturation and the isochron dating gave ambiguous results, suggesting an age limit for the method.