Research Laboratory for Archaeology and the History of Art

Oxford, United Kingdom

Research Laboratory for Archaeology and the History of Art

Oxford, United Kingdom
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Liang H.,Nottingham Trent University | Sax M.,The British Museum | Saunders D.,The British Museum | Tite M.,Research Laboratory for Archaeology and the History of Art
Journal of Archaeological Science | Year: 2012

Optical Coherence Tomography (OCT) is a non-invasive subsurface 3D imaging technique based on the Michelson interferometer. The non-invasive nature of OCT and its speed of acquisition makes it possible to image large volumes of intact objects to yield a complete overview of the microstructure. The production methods for ancient Egyptian faience were first investigated using scanning electron microscopy (SEM) imaging of the microstructure in polished sections and microprobe analysis of the composition of the glass phases. These studies were based on original Egyptian faience objects and laboratory reproductions of faience beads made using three different production methods. The microstructure of the same laboratory samples and the Egyptian faience objects from the British Museum Research Laboratory Collection are re-examined using OCT. It is found that OCT virtual cross-section images can be used to group ancient faience objects into three categories on the basis of the morphology of the surface glaze layer and the glaze/core interaction layer. The OCT images correspond well with SEM images of polished sections of ancient faience objects and laboratory reproductions. The virtual cross-sections produced by OCT are somewhat limited by the penetration depth, which is affected by the high absorption coefficient of the material and, therefore, cannot always provide information on the presence or absence of interparticle glass that binds together the quartz particles in the core. Nevertheless, the top two layers are well imaged and since OCT images can be obtained rapidly and without the necessity of removing a sample, the method can be applied to a very much wider range of ancient faience objects than is possible by SEM examination of polished cross-sections. In summary, this paper examines to what extent OCT can assist the investigation of the production techniques of ancient Egyptian faience. © 2012 Elsevier Ltd.

Reynard L.M.,Harvard University | Pearson J.A.,University of Liverpool | Henderson G.M.,University of Oxford | Hedges R.E.M.,Research Laboratory for Archaeology and the History of Art
Archaeometry | Year: 2013

The calcium isotope ratios (δ44/42Ca) in milk-consuming infants and juveniles are compared to adults at two archaeological sites to test whether milk consumption is detectable in the skeleton using calcium isotopes. At Aşi{dotless}kli{dotless} Höyük, δ44/42Ca is correlated with δ15N and differs significantly between juveniles and adults, suggesting that δ44/42Ca is responding to dietary milk input. However, at Christ Church, Spitalfields, no correlation between δ44/42Ca and δ15N or age is noted. At this site, δ44/42Ca of adult females is not related to the minimum number of births, and we conclude that the maternal skeleton is not sufficiently isotopically perturbed for this signal to remain throughout her lifetime. Growth may result in an increase in very young infants' δ44/42Ca, in contrast to an expected decrease due to milk consumption, complicating the interpretation of the data. We conclude that milk consumption does not always result in a change in skeletal δ44/42Ca, or is masked by other effects. © 2012 University of Oxford.

Park S.D.E.,IdentiGEN | Magee D.A.,University College Dublin | Magee D.A.,University of Connecticut | McGettigan P.A.,University College Dublin | And 17 more authors.
Genome Biology | Year: 2015

Background: Domestication of the now-extinct wild aurochs, Bos primigenius, gave rise to the two major domestic extant cattle taxa, B. taurus and B. indicus. While previous genetic studies have shed some light on the evolutionary relationships between European aurochs and modern cattle, important questions remain unanswered, including the phylogenetic status of aurochs, whether gene flow from aurochs into early domestic populations occurred, and which genomic regions were subject to selection processes during and after domestication. Here, we address these questions using whole-genome sequencing data generated from an approximately 6,750-year-old British aurochs bone and genome sequence data from 81 additional cattle plus genome-wide single nucleotide polymorphism data from a diverse panel of 1,225 modern animals. Results: Phylogenomic analyses place the aurochs as a distinct outgroup to the domestic B. taurus lineage, supporting the predominant Near Eastern origin of European cattle. Conversely, traditional British and Irish breeds share more genetic variants with this aurochs specimen than other European populations, supporting localized gene flow from aurochs into the ancestors of modern British and Irish cattle, perhaps through purposeful restocking by early herders in Britain. Finally, the functions of genes showing evidence for positive selection in B. taurus are enriched for neurobiology, growth, metabolism and immunobiology, suggesting that these biological processes have been important in the domestication of cattle. Conclusions: This work provides important new information regarding the origins and functional evolution of modern cattle, revealing that the interface between early European domestic populations and wild aurochs was significantly more complex than previously thought. © 2015 Park et al.

Molina G.,Polytechnic University of Catalonia | Tite M.S.,Research Laboratory for Archaeology and the History of Art | Molera J.,University of Vic | Climent-Font A.,Autonomous University of Madrid | Pradell T.,Polytechnic University of Catalonia
Journal of the European Ceramic Society | Year: 2014

Lustre is a decoration consisting of a few hundreds of nanometres thick surface layer of silver and copper metal nanoparticles incorporated into the glaze. Polychrome lustreware with several combinations of colours and shines was produced in Abbasid Iraq in the 9th century AD. Three colour combinations, black plus red, white-silvery plus red-coppery and yellow-golden plus red-coppery, have been studied, and the materials and methods of production determined. Two separated firings the first for the copper and the second for the silver lustre were performed. The black, white, yellow and green colours of the silver lustres are associated with the different sizes of the nanoparticles and to their distribution in the layer. Although the addition of lead and tin in the initial mixture is demonstrated, their incorporation in the glaze has been found to be the key factor in the production of the red-coppery and yellow-golden lustre. © 2014 Elsevier Ltd.

Brown A.G.,University of Southampton | Basell L.S.,Research Laboratory for Archaeology and the History of Art | Toms P.S.,University of Gloucestershire | Bennett J.A.,University of Exeter | And 2 more authors.
Quaternary Science Reviews | Year: 2010

This paper presents the first systematic chronostratigraphic study of the river terraces of the Exe catchment in South West England and a new conceptual model for terrace formation in unglaciated basins with applicability to terrace staircase sequences elsewhere. The Exe catchment lay beyond the maximum extent of Pleistocene ice sheets and the drainage pattern evolved from the Tertiary to the Middle Pleistocene, by which time the major valley systems were in place and downcutting began to create a staircase of strath terraces. The higher terraces (8-6) typically exhibit altitudinal overlap or appear to be draped over the landscape, whilst the middle terraces show greater altitudinal separation and the lowest terraces are of a cut and fill form. The terrace deposits investigated in this study were deposited in cold phases of the glacial-interglacial Milankovitch climatic cycles with the lowest four being deposited in the Devensian Marine Isotope Stages (MIS) 4-2. A new cascade process-response model is proposed of basin terrace evolution in the Exe valley, which emphasises the role of lateral erosion in the creation of strath terraces and the reworking of inherited resistant lithological components down through the staircase. The resultant emergent valley topography and the reworking of artefacts along with gravel clasts, have important implications for the dating of hominin presence and the local landscapes they inhabited. Whilst the terrace chronology suggested here is still not as detailed as that for the Thames or the Solent System it does indicate a Middle Palaeolithic hominin presence in the region, probably prior to the late Wolstonian Complex or MIS 6. This supports existing data from cave sites in South West England. © 2009 Elsevier Ltd. All rights reserved.

Bonneau A.,Bordeaux Montaigne University | Bonneau A.,Laval University | Bonneau A.,Research Laboratory for Archaeology and the History of Art | Brock F.,Research Laboratory for Archaeology and the History of Art | And 3 more authors.
Radiocarbon | Year: 2011

The dating of South African rock art using radiocarbon is a considerable challenge and only 1 direct date has so far been obtained, on black pigments from Sonia's Cave Upper, Boontjieskloof. The main problem with direct dating these paintings is the presence of calcium oxalates behind, on, and within the pigment layers. Calcium oxalates are formed through lichen and bacterial action on the rock face. These reactions can sometimes take place over long periods and can incorporate carbon of a younger age into the pigments. This study aims to date black pigments from a rockshelter, RSA TYN2 (Eastern Cape, South Africa), by removing the calcium oxalate contamination. Two different protocols were tried: density separation and acidification. The latter successfully removed calcium oxalates and was therefore applied to 3 black pigment samples from the rockshelter. After acid pretreatment, accelerator mass spectrometry (AMS) dating was undertaken on the remaining residues. Three results were obtained (2072 ± 28 BP, 2100 ± 40 BP, and 2083 ± 32 BP), which constitute the oldest results so far obtained for direct dates on South African rock art. The most likely calibrated date range for the painting at this site is between 2120 and 1890 cal BP. The ages are in close agreement with each other and this consistency suggests that our preparation protocol has successfully removed the majority of the carbon contaminants. © 2011 by the Arizona Board of Regents on behalf of the University of Arizona.

Guerin G.,French National Center for Scientific Research | Mercier N.,French National Center for Scientific Research | Nathan R.,Research Laboratory for Archaeology and the History of Art | Adamiec G.,Silesian University of Technology | Lefrais Y.,French National Center for Scientific Research
Radiation Measurements | Year: 2012

The infinite matrix assumption is commonly used to derive dose rates in the field of paleodosimetric dating methods. The update of nuclear data allowed calculating new dose rate conversion factors and attenuation factors for taking account of grain size. The relevance of the infinite matrix assumption was found to be limited to specific cases and a discussion of potential errors in estimating dose rates to natural dosimeters in sedimentary media is proposed. A new set of geometric features is shown to be of paramount importance for estimating dose rates in sedimentary media. To quantify these effects, Monte Carlo modelling was applied and the architecture of the programmes is described. It is also shown that proper characterization of sediment samples, coupled to the modelling of radioactivity in these sediments may provide more accurate dose rates to quartz grains, down to the single grain scale. © 2012 Elsevier Ltd. All rights reserved.

Raghavan M.,Research Laboratory for Archaeology and the History of Art | Raghavan M.,Copenhagen University | McCullagh J.S.O.,Chemistry Research Laboratory | Lynnerup N.,Copenhagen University | Hedges R.E.M.,Research Laboratory for Archaeology and the History of Art
Rapid Communications in Mass Spectrometry | Year: 2010

We report a novel method for the chromatographic separation and measurement of stable carbon isotope ratios (δ13C) of individual amino acids in hair proteins and bone collagen using the LCIsoLink system, which interfaces liquid chromatography (LC) with isotope ratio mass spectrometry (IRMS). This paper provides baseline separation of 15 and 13 of the 18 amino acids in bone collagen and hair proteins, respectively. We also describe an approach to analysing small hair samples for compound-specific analysis of segmental hair sections. The LC/IRMS method is applied in a historical context by the δ13C analysis of hair proteins and bone collagen recovered from six individuals from Uummannaq in Greenland. The analysis of hair and bone amino acids from the same individual, compared for the first time in this study, is of importance in palaeodietary reconstruction. If hair proteins can be used as a proxy for bone collagen at the amino acid level, this validates compound-specific isotope studies using hair as a model for palaeodietary reconstruction. Our results suggest that a small offset observed in the bulk δ13C values of the hair and bone samples may be attributed to two factors: (i) amino acid compositional differences between hair and bone proteins, and (ii) differential turnover rates of the tissues and the amino acid pools contributing to their synthesis. This application proposes that hair may be a useful complementary or alternative source of compound-specific paleodietary information. © 2010 John Wiley & Sons, Ltd.

Parker A.G.,Oxford Brookes University | Lee-Thorp J.,Research Laboratory for Archaeology and the History of Art | Mitchell P.J.,University of Oxford
Proceedings of the Geologists' Association | Year: 2011

The late Holocene environmental history of the Lesotho highlands, southern Africa, is poorly understood with few detailed studies to date. At Likoaeng, Senqu Valley, Lesotho, a 3m stratified sedimentary sequence from an open-air archaeological site records vegetation development for the period 3400-1070cal.BP. Phytolith analyses and bulk sediment organic matter δ 13C indicate that C 4 grassland dominated the lower part of the sequence until approximately 2960cal.BP when there was a switch to C 3 Pooid grassland (2960-2160cal.BP). Also noted was a change from hunting mainly bovids to a dominance of fishing at the site. The change in grassland type and archaeological subsistence strategies corresponds with an episode of neoglacial cooling and the expansion of Alpine sourgrasses into lower altitudes. From 2160 to 1600cal.BP grassland became a mix of C 3 and C 4 types and by 1600-1070cal.BP there was a return to C 4 dominated grassland. During this latter phase there was a reversal from fishing to hunting again (and eventually some keeping of domestic livestock) at the site. These data outline the vegetation response to latitudinal shifts of frontal systems, and relatively strong atmospheric circulation variability, perhaps underpinned by variations of polar water into the Benguela Current during the late Holocene. © 2010 The Geologists' Association.

Ramsey C.B.,Research Laboratory for Archaeology and the History of Art | Dee M.,Research Laboratory for Archaeology and the History of Art | Lee S.,Research Laboratory for Archaeology and the History of Art | Nakagawa T.,Northumbria University | Staff R.A.,Research Laboratory for Archaeology and the History of Art
Radiocarbon | Year: 2010

Calibration is a core element of radiocarbon dating and is undergoing rapid development on a number of different fronts. This is most obvious in the area of 14C archives suitable for calibration purposes, which are now demonstrating much greater coherence over the earlier age range of the technique. Of particular significance to this end is the development of purely terrestrial archives such as those from the Lake Suigetsu sedimentary profile and Kauri tree rings from New Zealand, in addition to the groundwater records from speleothems. Equally important, however, is the development of statistical tools that can be used with, and help develop, such calibration data. In the context of sedimentary deposition, age-depth modeling provides a very useful way to analyze series of measurements from cores, with or without the presence of additional varve information. New methods are under development, making use of model averaging, that generate more robust age models. In addition, all calibration requires a coherent approach to outliers, for both single samples and where entire data sets might be offset relative to the calibration curve. This paper looks at current developments in these areas. © 2010 by the Arizona Board of Regents on behalf of the University of Arizona.

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