Luminescence characteristics and dose distributions for quartz and feldspar grains from Mumba rockshelter,Tanzania

Mumba rockshelter is a key archaeological site for the Middle and Later Stone Age occupation of East Africa, but its chronology has remained unresolved. We report the results of a dating study, focussing on the characterisation of the optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL) properties of quartz- and potassium-rich feldspar grains. Quartz has previously proven troublesome for dating in East Africa. We identified five general types of quartz grain behaviour, based on the shapes of their OSL decay and dose–response curves. Dose recovery experiments and measurement of the natural samples revealed particular problems with quartz grains that had hyperbolic dose–response curves, low characteristic saturation doses and anomalously large changes in sensitivity between regenerative-dose cycles. The use of pulsed irradiation during measurement and standard and additional quality-assurance criteria during data analysis reduced the number of grains that suffered from these problems. We applied these procedures to individual grains of quartz from eight samples and, using appropriate statistical models, identified post-depositional mixing in three samples. The remaining samples had scattered equivalent-dose distributions typical of quartz grains that had received variable beta dose rates during burial. Stratigraphically consistent OSL ages were obtained for all but the deepest sample. Feldspar ages were estimated for the latter sample and three other samples, using the elevated temperature IRSL signal that exhibited low rates of anomalous fading. Fading-corrected feldspar ages for the latter three samples are consistent with their single-grain quartz ages, but single-grain dating is needed to address problems of post-depositional mixing.     

Representation as work in ‘America's most historic city’

This paper examines how the practices of heritage tourism reproduce identities in and of Fredericksburg, Virginia. In particular, we focus on the everyday practices of tourism workers who are essential in the representation and reproduction of this heritage space. In so doing, we want to move away from research in geography that theorizes representation and embodiment as distinct realms of experience and inquiry. Instead, we argue that representation is work and within this very material process, city workers weave memory with history as they guide visitors through ‘America’s Most Historic City'. Through an examination of three of Fredericksburg's tourism work environments we show how representations succeed in reproducing heritage tourism spaces precisely because representation is work.     

New Perspectives on Spatial Patterns of Agrarian Reform: A Comparison of Two Russian Oblasts

The author, based on field work, interviews, and examination of local and regional literature and official statistical sources, compares the experience in agrarian reform in two disparate locations—KostToma Oblast, northeast of Moscow in the Noncher-nozem Region, and Rostov Oblast on Russia's Black Sea littoral in the fertile Chernozem (Black Earth) region. It examines both the reorganization of state and collective farms and the establishment of private peasant farms in the two oblasts, with particular emphasis on the latter. The sections on private farms represent an initial attempt, based on in-depth information for a limited sample population, to garner insights, at the rayon level, into factors that may be influencing regional variations in the number, size, and location of private farms across the Russian countryside. 2 maps, 6 tables, 53 references.