The prehistoric pile-dwelling settlement of Stagno (Leghorn,Italy): wood and food resource exploitation

A pile-dwelling settlement, dated to the final Bronze–early Iron Age (XII–XI century BC), was excavated at Stagno, near Leghorn (Tuscany, Italy). The site presented a well-preserved portion of the wooden foundation structure buried by sediments rich in plant remains: both wood and plant remains were subjected to archaeobotanical investigation. The ultimate goal was to improve our knowledge on agricultural economy and wood usage in Tuscany during the prehistoric ages. The results pointed to a farming system based on Triticum spp. (wheat), Hordeum spp. (barley) and Leguminosae cultivation in addition to the gathering of wild fruits, such as Corylus avellana, Cornus mas, Prunus spp., Vitis spp. Many of these plant remains are associated to a wetland context. Mesohygrophilous trees, such as deciduous Quercus, Ulmus minor, Fraxinus cf. excelsior, and Sorbus were used for the construction of the pile-dwelling structures; the choice of these plants indicates a good knowledge of the technological characteristics of timber.     

Equivalent dose distributions from single grains of quartz at Sibudu,South Africa: context,causes and consequences for optical dating of archaeological deposits

Optical ages for 14 sediment samples collected from the post-Howiesons Poort, late Middle Stone Age (MSA) and final MSA deposits at Sibudu, KwaZulu-Natal, South Africa were reported in a companion paper (Jacobs, Z., Wintle, A.G., Duller, G.A.T., Roberts, R.G., Wadley, L. New ages for the post-Howiesons Poort, late and final Middle Stone Age at Sibudu, South Africa. Journal of Archaeological Science, 2008). These ages were based on equivalent dose (D_e) distributions that were overdispersed. In this paper, we investigate factors both internal and external to the grains that may contribute to such higher than expected overdispersion in single grain D_e values. Intrinsic factors accounted for some, but not all, of the observed scatter, and application of a set of rejection criteria filtered grains for which erroneous D_e values would otherwise be calculated. We investigated sediment mixing and differences in the beta dose received by individual grains in their burial environment as two likely reasons for the observed overdispersion. The scatter in D_e distributions for all the samples is best explained by grains that were deposited at the same time and which were well bleached, but that subsequently received a range of beta doses. A procedure is presented for adjusting the measured beta dose rate, and its associated error. We show that using a combination of single grain OSL measurements of D_e, the finite mixture model and adjustment of the beta dose rate, result in stratigraphically consistent ages. These ages are more consistent than the ages obtained from multiple grain aliquot D_e values and the average dose rates for each sample; the multiple grain ages are about 10% older, partly because of the variable dose rate and partly because these aliquots contained grains with undesirable OSL characteristics.