Review and assessment of the potential of post-IR IRSL dating methods to circumvent the problem of anomalous fading in feldspar luminescence

Quartz has been the main mineral used for optically stimulated luminescence (OSL) dating of sediments over the last decade. The quartz OSL signal, however, has been shown to saturate at relatively low doses of ～200–400 Gy, making it difficult to be used for dating beyond about 200 thou-sand years (ka), unless the environmental dose rate is low. The infrared stimulated luminescence (IRSL) from feldspars has been shown to continue to grow to higher dose levels than quartz OSL. The application of IRSL dating of feldspars, however, has long been hampered by the anomalous fading effect. Recent progress in understanding anomalous fading of the infrared stimulated luminescence (IRSL) signals in potassium-feldspar has led to the development of post-IR IRSL (pIRIR) protocols and also a multiple elevated temperature (MET) stimulation (MET-pIRIR) protocol. These procedures have raised the prospect of isolating a non-fading IRSL component for dating Quaternary deposits containing feldspars. In this study, we review the recent progress made on (1) overcoming anomalous fading of feldspar, and (2) the development of pIRIR dating techniques for feldspar. The potential and problems associated with these methods are discussed.     

Study and restudy of curated skeletal collections in bioarchaeology: A perspective on the UK and the implications for future curation of human remains

This paper considers the bioarchaeological study and restudy of human skeletal remains in museums and other institutions that curate human remains from archaeological sites. Papers published from 1990 to 2009 in the Journal of Archaeological Science, Journal of Paleopathology, American Journal of Physical Anthropology and International Journal of Osteoarchaeology were considered and contributions dealing with skeletal remains from UK archaeological sites were assessed. There were 258 papers published that matched these criteria and 352 instances when a skeletal collection had been analysed. Seventy‐nine per cent of the papers were based on skeletal samples curated in five geographic areas, London, Bradford, Portsmouth, Canterbury and York; the two sites that were most used were those of Wharram Percy, North Yorkshire, curated in Portmouth at English Heritage, and Christ Church, Spitalfields, curated at the Natural History Museum, London. Reasons for this concentration of research are suggested. It is recommended that the ‘use load’ should be better and more evenly spread around skeletal samples in other geographic areas of the UK in order that knowledge is not limited just to a few skeletal collections, and that a centralised database of skeletal collections curated by different institutions would contribute to this aim. Copyright © 2010 John Wiley & Sons, Ltd.     

Interpretations of Prehistoric Boat Remains

The simple assembly methods and long-unpractised boatbuilding and seamanship skills waiting to be discovered from those few shattered remains of British prehistoric boats make practical interpretation of their original form and function both a fascinating mental exercise and a quagmire for any tempted to publish their thoughts. Some contemporary views are reconsidered and in the spirit of scientific exploration others are offered to promote further debate.
© 2005 The Author     

New ages for the post-Howiesons Poort,late and final Middle Stone Age at Sibudu,South Africa

Optically stimulated luminescence (OSL) measurements are reported for single grains of quartz from deposits within Sibudu rock shelter. Such measurements enable rejection of unrepresentative grains and application of the finite mixture and central age models to obtain the most reliable age estimates. Three types of single-grain equivalent dose (D_e) distributions were observed: one sample represented a single dose population, three samples indicated mixing between Iron Age (IA) and Middle Stone Age (MSA) deposits, and 10 samples (in addition to the three mixed samples) showed scattered distributions. The latter type resulted from differences in the beta dose received by individual grains. For these samples, the beta doses were modelled and adjusted accordingly. Ages for the 14 samples collected from MSA deposits post-dating the Howiesons Poort (HP) resulted in three age clusters, which are stratigraphically consistent with the three informally named cultural phases at Sibudu: namely, the post-HP, late MSA and final MSA. Weighted mean ages of 58.5 ± 1.4 ka, 47.7 ± 1.4 ka and 38.6 ± 1.9 ka were calculated for these phases, respectively. The three phases were separated by two occupational hiatuses with durations of 10.8 ± 1.3 ka and 9.1 ± 3.6 ka. We hypothesise that the punctuated presence of humans at Sibudu was determined by large-scale fluctuations in climate during oxygen isotope stage (OIS) 3, which resulted in alternating wet and dry periods. Phases of occupation correspond to wet periods when fresh water was available in the Tongati River, whereas intervals of site abandonment correspond to dry periods when people were forced to migrate in search of a reliable source of fresh water. Where people migrated to, remains unresolved.     

Moving Towards Transformative Democratic Action Through Archaeology

Archaeologists have explored how politics affect the way we see the past. They have investigated how constructions of the past naturalize present political conditions, and have explored uses of the past in current politics. Few have examined how politics in archaeology can relate to the future. In this article I develop ideas on a transformational politics in archaeology that focuses on critiquing oppressive relations in the past and present, and works towards building more just relations for the future. I examine how we can achieve this through building more democratic relations in the places we work.     

‘Black Economic Empowerment’, Business and the State in South Africa

‘Black Economic Empowerment’ (BEE) has been a major policy thrust of the democratic governments in South Africa since 1994 in attempting to redress the effects of apartheid. In this article, we explore the historical precedents to BEE in South Africa, review the different steps taken in promoting it, and assess some of its outcomes to date. We argue that BEE can take only limited forms because of the economic policy constraints in which it has been incorporated. Moreover, these forms have an increasingly managerial logic that further restricts what can be achieved. Short of a major shift in conceptions of — and policy for — BEE, meaningful ‘empowerment’ is unlikely to take place.     

Molluscan calendars: The use of growth-line analysis to establish seasonality of shellfish collection at the Mesolithic site of Morton,Fife

The technique of growth-line analysis is used to examine seasonal growth patterns in modern specimens of the edible cockle, Cerastoderma edule L. The modern control work provides a basis for the interpretation of seasonal collection in archaeological cockles, and is applied to shells from the Mesolithic site of Morton, Fife. The seasonal use of the site is shown to be clearly related to site function.