Stable Carbon and Nitrogen Isotope Variability of Bone Collagen to Determine the Number of Isotopically Distinct Specimens

Journal of Archaeological Method and Theory - Archaeological and palaeontological excavations frequently produce large quantities of highly fragmentary bone. These bones can help to answer...     

Assessing stories before sites: identifying the tangible from the intangible

Despite a growing recognition that intangible heritage forms an important part of the significance of heritage sites, and that intangible values are intertwined with material resources and spaces, many procedures for the identification and management of heritage sites remain unchanged and fail to integrate these two sets of values. The conservation of heritage sites continues to be dominated by a process that first identifies a material site and then identifies the associated values that comprise its significance. This paper suggests that rather than identifying the physical expression of heritage as the initial point of heritage assessment, the stories (or intangible values) of a region or national history can form the primary mechanism for identifying physical heritage sites. Using the example of Australian government policies of Aboriginal segregation and assimilation, we suggest how national stories – or intangible values – might be used to identify representative sites.     

Access relative to need for community conservation funding in Australia

ABSTRACT

In a climate of scarce resources for heritage preservation, there is a need to develop principles and methodology for assessing and responding to inequity within the conservation sector. This paper focuses on spatial, or geographic, barriers as one factor determining the accessibility of conservation services. While the case study focuses on the conservation and management of collections of cultural material in Australia, the methodology is globally relevant for advancing the equitable distribution of heritage and conservation resources according to need. Using a statistical analysis of the spatial distribution of 1323 local heritage conservation projects that have been funded by the National Library of Australia’s Community Heritage Grants Program from 1994 to 2017, this study provides a measure of the spatial equality of conservation in Australia. Spatial distribution analysis indicates that the majority of projects funded are located in major cities, with fewer projects funded in regional, remote and very remote areas. An ‘access relative to need’ approach is proposed to counter the current centralisation of the conservation industry. Of particular relevance for international readers is the potential for this methodology to frame studies of the impacts on heritage resulting from climate change and extreme weather events.     

On the applicability of post-IR IRSL dating to Japanese loess

Recent work on infrared stimulated luminescence (IRSL) dating has focussed on finding and testing signals which show less or negligible fading. IRSL signals measured at elevated temperature following IR stimulation at 50°C (post-IR IRSL) have been shown to be much more stable than the low temperature IRSL signal and seem to have considerable potential for dating. For Early Pleistocene samples of both European and Chinese loess natural post-IR IRSL signals lying in the saturation region of the laboratory dose response curve have been observed; this suggests that there is no significant fading in nature. As a contribution to the further testing of post-IR IRSL dating, we have used 18 samples from two Japanese loess profiles for which quartz OSL and tephra ages up to 600 ka provide age control. After a preheat of 320°C (60 s), the polymineral fine grains (4–11 μm) were bleached with IR at 50°C (200 s) and the IRSL was subsequently measured at 290°C for 200 s. In general, the fading uncorrected post-IR IRSL ages agree with both the quartz OSL and the tephra ages. We conclude that the post-IR IRSL signal from these samples does not fade significantly and allows precise and accurate age determinations on these sediments.     

Attempts at thermoluminescence dating of fired materials from the Przeworsk Culture settlements

The thermoluminescence (TL) dating method has a significant measurement error margin reaching almost 10%. Due to this fact it could be considered as little effective in case of such sites from the Roman period as burial grounds with many artefacts useful for archaeological dating. However, for many settlements from this period, where pottery is the only kind of artefacts, the TL method can give notable results. The main purpose of the study was to make an attempt at TL dating of pottery and clay daub samples from the Nieszawa Kolonia and Kręcieszki sites and to compare the obtained dates with the results of archaeological dating of selected features from the Przeworsk Culture settlements. In the Kręcieszki site the fragments of burnt clay daub were dated by the TL method for the first time in the Lublin laboratory. It turned out that clay daub is an equally good dating material as pottery. It can be found that the TL dating of pottery from Nieszawa Kolonia confirms two stages of settlement. The first settlement stage is related to the phases B2-B2/C1-C1a of the Roman period, i.e. from the beginning of the 2^nd to the beginning of the 3^rd century. The second group of TL dates corresponds to the phases C2D that is to the second stage of settlement, from the second half of the 3^rd century to the half of the 5^th century AD. The results of TL dating of pottery and clay daub in the Kręcieszki site are rather similar and correspond to the phase B1/B2 of the period of Roman influence, determined from pottery style, but can also indicate the phase B2/C1.     

Preliminary results towards the equivalence of transformed continuous-wave Optically Stimulated Luminescence (CW-OSL) and linearly-modulated (LM-OSL) signals in quartz

The present paper presents a comparative experimental study of two commonly measured Optically Stimulated Luminescence (OSL) signals in quartz. The experimental study measures both the continuous wave OSL (CW-OSL) and the linearly modulated (LM-OSL) signals from the same quartz sample for a range of stimulation temperatures between 180 and 280°C, while the former is transformed to pseudo LM-OSL (ps LM-OSL). A computerized deconvolution curve analysis of the LM-OSL and ps LM-OSL signals was carried out, and the contributions of several OSL components to the initial OSL signal (0.1 s) were shown to be independent of the stimulation temperature used during the measurement. It was also found that the composite OSL (0.1 s) signal consists mainly of the first two OSL components present in the OSL curves. The equivalence of the ps LM-OSL (transformed CW-OSL) and of LM-OSL measurements was also examined by an appropriate choice of the experimental stimulation times, and of the stimulation power of the blue LEDs used during the measurement.     

Concordant <Superscript>210</Superscript>Pb and <Superscript>137</Superscript>Cs ages of black sea anoxic unconsolidated sediments

Two independent geochronologic radiometric methods: ¹³⁷Cs and ²¹⁰Pb were used to determine the sedimentation rate and subsequently to date the oldest sediments of a 50 cm core containing unconsolidated sediments collected at a depth of 600 m below sea surface in the anoxic zone of the Western Black Sea, off the Romanian town of Constanta. Both methods gave coincident value within experimental uncertainties of 0.42±0.20 mm·y⁻¹ for ¹³⁷Cs and 0.49±0.03 mm·y⁻¹ in the case of ²¹⁰Pb, within the Constant Initial Concentration model, which gave for the lower most sediments an age of 1.00±0.01 ka. The constant sedimentation model as well as the possible causes of observed discrepancy between experimental uncertainties are discussed.     

Dating mortar by optically stimulated luminescence: A feasibility study

Quartz is the datable component in mortar. Although its luminescence properties are very well studied, the problem of mortar dating arises from a low level of optical bleaching. In order to reduce the time consuming efforts for dating lime mortar in monuments by optically stimulated luminescence, we investigated the most suitable methods of dose and dose rate determination, and we explored tests which are suitable to predict the datability of a given material. Reverting to the large number of publications on sedimentary partially bleached quartz we found linear modulation techniques especially useful, equally we also recommend the determination of the level of optical depletion before starting analyses. Single grain analysis is regarded as an ultimate but infallible tool to date very poorly bleached quartz from mortar. Dose rate measurements need to take into account the radioactive equilibrium of the uranium decay and the short range inhomogeneity of the environmental gamma radiation field: gamma spectrometry and on-site TLD measurements are best suited.