Relation between radiocarbon,archaeological dating and sediment properties on the example of colluvial deposits (NE Poland)

This study focuses on the analysis of the structural and textural features of the colluvial (deluvial) deposits in the Suwałki Lake District (NE Poland) and their absolute age. The colluvium has a thickness of up to 150 cm. The dates of the peat under colluvium or lowermost fossil humus-rich horizons point to the ages from 5405±80 BP to 480 BP. Deposition of material at the footslope is a result of a denudation triggered by human action (surface water erosion and tillage erosion) and usually corresponds with the settlement stages. The ¹⁴C dating of deposited sediment sometimes indicated to older dates of colluvium then the archaeological evidence available for examined sites. Locally, the overlying fossil humic horizon was older then the lowermost one. The textural features of the colluvial deposits such as: the content of fine fraction, weak sorting and relationship between the mean grain-size (Mz) and the sorting index (σ₁) were used to recognize sediment redeposited from the upper part of the slope. Basing on the mineral composition and electrical conductivity of fossil humus horizon it is possible to say whether the soil was degraded or aggraded. These features of the humus-rich horizons occurring between colluvial sediments can be used to explain discrepancy between the radiocarbon dating and archaeological evidence.     

Beyond Metrics: Reappraising York’s Hungate “Slum”

Much of the excitement generated in Britain since 2007 by the York Archaeological Trust’s excavations of the city’s Hungate neighborhood, which Benjamin Seebohm Rowntree characterized as a “slum” in his pioneering poverty survey of 1901, derives from the unexpected volume and variety of material evidence uncovered about life in a poor community within a modern industrial city. Such material evidence and its often uncertain relationships to other historical data can enhance analysis by complicating understanding of the past, rather than echoing conventional wisdom. Findings from Hungate can thus contribute to nuanced understandings of urban social disadvantage not only at the neighborhood level in this one particular British city, but at the larger scales of analysis that encompass the growth of cities and interacting urban regions in Britain and around the world during the nineteenth and twentieth centuries. These understandings have contemporary relevance for a world in which over half of humanity now lives in urban areas, as misconceptions about “slums” continue to undermine efforts to reduce urban inequality.     

Constraints on the precision of SAR in equivalent dose estimations close to saturation in quartz

Difficulties in evaluating accurate equivalent doses for Late Quaternary sediments from the south coasts of Greece arose in the course of SAR measurements. Large scatter among apparent equivalent doses perplexed the evaluation of accurate mean estimates in circumstances where very large doses were involved. Besides, dose recovery experiments revealed that when intersection of the natural signal occurs onto the saturating segment of the growth curve, a distinct relationship between D_e and growth curve shape occurs. At very low slope angles, SAR tends to overestimate the recovered dose. The mechanism which controls the spread in equivalent dose estimation is investigated.     

Construction of a quartz OSL standardised growth curve (SGC) for aeolian samples from the Horqin dunefield in northeastern China

It has been suggested that the standardised growth curve (SGC) method can be used to de-terminate D_e accurately and reduce the measurement time. However, different opinions regarding the applicability of the SGC method exist. In this paper, we report the construction of quartz OSL SGC for 35 aeolian samples from different parts of the Horqin dunefield in northeastern China, and then test their applicability for D_e determination. Our results suggest that: 1) up to a regeneration dose of 80 Gy, the SGC of the Horqin dunefield can be fitted using the exponential plus linear equation, with the r² value of 0.97, and all the regeneration dose points closely stick to the fitting line, implying that all samples share a very similar dose-response curve; 2) for samples with Des ranging from 1 to 50 Gy, the ratios of SAR D_e to SGC D_e fall within the range of 0.9–1.1, and the average ratio of SAR D_e to SGC D_e is 1.01±0.01, close to unity. Therefore, the construction of SGC is correct, and the SGC is an effective procedure for accurate D_e determination for samples from the study area.     

Geoarchaeological studies on Roman time harbour sediments in Cologne — comparison of different OSL dating techniques

Due to the construction of a new North-South subway in Cologne, Roman time harbour sediments were exposed and were sampled for luminescence dating. A very good independent age control was given by the precise knowledge of the chronology of Roman activity and by radiocarbon ages of charcoal samples. Hence, different methodological approaches within luminescence dating were applied for Holocene heterogeneously bleached fluvial samples and were compared to the known ages. For one sample, optically stimulated luminescence (OSL) dating was applied to coarse-grained quartz using a single aliquot regenerative-dose (SAR) protocol. After D_e-measurements, different statistical approaches were tested (i.e. arithmetic mean, median, minimum age model, finite mixture model, leading edge method and the Fuchs and Lang approach). It is demonstrated that the Fuchs and Lang approach along with the leading edge method yielded the best matching OSL ages with respect to the known ages.     

The age of the subfossil trunk horizon in deposits of the Warta River valley (central Poland) based on <Superscript>14</Superscript>C dating

The present study focuses on investigations carried out in the Late Vistulian succession of the Warta River deposits (central Poland) in which a horizon of subfossil trees was excavated. Prelim-inary conclusions on time record and past environmental conditions of a forest existence determined from radiocarbon dating, pollen analyses and geological evidence appear promising with view of tree-ring chronologies.     

Taxonomic characterisation of fresh Dipterocarpaceae resins by gas chromatography–mass spectrometry (GC–MS): providing clues for identification of unknown archaeological resins

Plant and particularly non-wood forest products have played an important role in the evolution of human cultures all over the world, as source of food but also of raw substances fulfilling material, spiritual, and medicinal requirements. Plant exudates and particularly dammar resins (Dipterocarpaceae family) were widely used in the past in Asia notably as waterproofing and caulking materials. This study focuses on the GC–MS chemical characterisation of freshly collected dammars and establishes new molecular parameters enabling discrimination between dammars and other types of plant resin, whatever their botanical origin. Such analyses provide clues for a precise identification (taxonomy, occurrence of other material in addition to the resin, alteration state) of unknown resinous material discovered in archaeological contexts. The value of our approach is illustrated by the taxonomic characterisation of two samples collected in jars from the Brunei wreck and a Chinese junk lost more than 40 km off the Sultanate of Brunei during the end of the fifteenth century or the early beginning of the sixteenth century.     

Consuming Citizenship? The Archaeology of Mexican Immigrant Ambivalence in Early Twentieth-Century Los Angeles

In late nineteenth- and early twentieth-century America, the consumption of American-made goods was seen as an expression of one’s patriotism and loyalty to the nation. According to a number of historical archaeological case studies, racialized groups, such as African Americans and Chinese Americans, used consumption as a way of gaining access to the full benefits of American citizenship typically reserved for individuals deemed “white” by law. The material culture of Mexican immigrants living in early twentieth-century Los Angeles tells a slightly different tale. Despite being ascribed a legal whiteness, archaeological and documentary data suggest that Mexican immigrants expressed ambivalence toward their consumption of American goods and outright rejected the notion that exerting such buying power would lead to a broader acceptance in Anglo American society.