Open Access. Powered by Scholars. Published by Universities.®
Social and Behavioral Sciences Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 31 - 44 of 44
Full-Text Articles in Social and Behavioral Sciences
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.
Selection Of Integration Time Intervals For Quartz Osl Decay Curves, Alastair C. Cunningham, Jakob Wallinga
Selection Of Integration Time Intervals For Quartz Osl Decay Curves, Alastair C. Cunningham, Jakob Wallinga
Faculty of Science, Medicine and Health - Papers: part A
In quartz optically stimulated luminescence (OSL) dating protocols, an initial integral of the OSL decay curve is used in the calculation of equivalent dose, once a background integral has been subtracted. Because the OSL signal commonly contains a number of exponentially decaying components, the exact choice of time intervals used for the initial-signal and background integrals determines the composition of the net signal. Here we investigate which combination of time intervals will produce the net signal most dominated by the fast OSL component, while keeping an acceptable level of precision. Using a three-component model of OSL decay, we show that …
Optically Stimulated Luminescence Dating Of Young Quartz Using The Fast Component, Alastair C. Cunningham, Jakob Wallinga
Optically Stimulated Luminescence Dating Of Young Quartz Using The Fast Component, Alastair C. Cunningham, Jakob Wallinga
Faculty of Science, Medicine and Health - Papers: part A
have attempted to isolate the fast component of the quartz optically stimulated luminescence (OSL) signal using a curve-fitting procedure. By pre-determining the decay constants, the procedure is simple enough to be scripted, allowing a large number of aliquots to be processed. A Monte Carlo error routine is used, in which simulated decay curves are fitted with several exponentials, which vary in their decay rates according to the measured distributions of fast and medium component decay rates. The derived error term is closely related to the intensity of the fast component signal, but is also influenced by the degree of similarity …
Faces Of The Teouma Lapita People: Art, Accuracy And Facial Approximation, Susan Hayes, Frederique Valentin, Hallie Buckley, Matthew Spriggs, Stuart Bedford
Faces Of The Teouma Lapita People: Art, Accuracy And Facial Approximation, Susan Hayes, Frederique Valentin, Hallie Buckley, Matthew Spriggs, Stuart Bedford
Faculty of Science, Medicine and Health - Papers: part A
In 2008 we completed facial approximations of four individuals from the early Lapita Culture, a seafaring people who were the first to settle the islands of the Western Pacific circa 3000 years ago. Typically an approximation is performed as a 3D sculpture or using computer graphics. We chose to sketch what we have been able to determine from the remains because the artistic conventions of drawing work with visual perception in ways that are more complementary to the knowledge, theories and methods that make up the facial approximation of human remains.
New 14c Ages On Cellulose From Diprotodon Gut Contents: Explorations In Oxidation Chemistry And Combustion, Richard Gillespie, L Keith Fifield, Vladimir Levchenko, Rob Wells
New 14c Ages On Cellulose From Diprotodon Gut Contents: Explorations In Oxidation Chemistry And Combustion, Richard Gillespie, L Keith Fifield, Vladimir Levchenko, Rob Wells
Faculty of Science, Medicine and Health - Papers: part A
We report radiocarbon ages on cellulose isolated from the gut contents of a Diprotodon found at Lake Callabonna, South Australia. The maximum age obtained corresponds to a minimum age of >53,400 BP for this extinct giant marsupial. This is older than, and hence consistent with, the generally accepted Australian megafauna extinction window. We argue that dichromate and other strong oxidants are less selective than chlorite for lignin destruction in wood, and our results suggest that ages approaching laboratory background can be obtained using a repeated pretreatment sequence of chlorite-alkali-acid and measurement of the sometimes discarded 330 C combustion fraction.
Shell Artefact Production At 32,000-28,000 Bp In Island Southeast Asia: Thinking Across Media?, Katherine Szabo, Adam Brumm, Peter Bellwood
Shell Artefact Production At 32,000-28,000 Bp In Island Southeast Asia: Thinking Across Media?, Katherine Szabo, Adam Brumm, Peter Bellwood
Faculty of Science, Medicine and Health - Papers: part A
The evolution of anatomical and behavioural modernity in Homo sapiens has been one of the key focus areas in both archaeology and palaeoanthropology since their inception. Traditionally, interpretations have drawn mainly on evidence from the many large and well-known sites in Europe, but archaeological research in Africa and the Levant is increasingly altering and elaborating upon our understanding of later human evolution. Despite the presence of a number of important early modern human and other hominin sites in Southeast Asia, evidence from this region has not contributed to the global picture in any significant way. Indeed, the acknowledged simplicity of …
Sibudu Cave, Kwazulu-Natal: Background To The Excavations Of Middle Stone Age And Iron Age Occupations, Lyn Wadley, Zenobia Jacobs
Sibudu Cave, Kwazulu-Natal: Background To The Excavations Of Middle Stone Age And Iron Age Occupations, Lyn Wadley, Zenobia Jacobs
Faculty of Science, Medicine and Health - Papers: part A
Sibudu Cave excavations have yielded an Iron Age occupation directly overlying a long sequence of final Middle Stone Age (MSA) layers dating c. 61 000-26 000 years ago. Older, undated layers contain a Howiesons Poort Industry. A diverse animal population is represented in the final MSA. Proxy environmental data suggest cooler, drier conditions with a larger savanna component to the vegetation than at present.