Dual Energy Computed Tomography for the Non‐destructive Analysis of Ancient Ceramics

Ceramics are usually the most common artefact found on any ancient archaeological site. Compositional analysis of this pottery, and characterization of the clay fabrics from which they are made, has the potential to pinpoint sources of manufacture as well as identify trade routes and consumption patterns in the ancient world. Currently, most analytical techniques require the partial or total destruction of the ceramic sample. This research investigates the use of dual energy computed tomography (DECT) to analyse Black Gloss and Vesuvian Sigillata from Pompeii. The results indicate that DECT may be a viable adjunct or alternative to conventional analytical techniques. Importantly, unlike traditional methods, DECT is totally non‐destructive, a highly significant factor when analysing irreplaceable artefacts.     

Identification of Suspected Horn from the Queen Anne's Revenge (1718), North Carolina,USA

Infrared spectroscopy can be a valuable tool for conservators and archaeologists to help identify archaeological artefacts. We present a case‐study on the identification of an artefact recovered by North Carolina Department of Cultural Resources (NCDCR) Underwater Archaeology Branch from an early‐18th‐century shipwreck (31CR314). The wreck is assumed to be the remains of Queen Anne's Revenge, which sank off the North Carolina coast in 1718. A sample of the artefact was analysed by infrared spectroscopy to identify it. Prior to spectroscopic analysis it was speculated that the sample could be animal horn or leather. © 2011 The Authors     

Clues to Stone Tool Function Re-examined: Comparing Starch Grain Frequencies on Used and Unused Obsidian Artefacts

The identification of plant residues observed on prehistoric stone artefacts has often been used to inform on tool function without adequate consideration of potential contamination due to post-depositional processes. The paper redresses this balance by proposing a methodology which combines use-wear and residue analyses with systematic testing of depositional context to distinguish residues formed during tool use from accidental contamination. A case study involving obsidian artefacts from an open site in Papua New Guinea is used to illustrate the new approach. Starch grains, a class of residue which has had little attention outside Australia, were chosen as the focus of study because of their abundance at this site. The frequency of starch grains extracted from residues on stone artefacts was compared with those in sediments adhering to and adjacent to the artefact. A use-wear study conducted as a blind test provided an independent measure of whether the artefacts had been used. The frequency of starch grains was shown to be significantly correlated with used artefacts and not correlated with unused artefacts or the sediments. The case study demonstrates the importance of testing for contamination and also illustrates the benefit of studying starch grains as a class of plant residue.     

A novel and non-destructive approach for ZooMS analysis: ammonium bicarbonate buffer extraction

Bone collagen is found throughout most of the archaeological record. Under experimental conditions, collagen is apparently preserved as an intact molecule, with amino acid compositions and isotopic profiles only changing when almost all of the protein is lost. The ubiquity of collagen in archaeological bone has lead to the development of the use of collagen peptide mass fingerprints for the identification of bone fragments—Zooarchaeology by Mass Spectrometry (ZooMS). We report a novel, but a simple method for the partial extraction of collagen for ZooMS that uses ammonium bicarbonate buffer but avoids demineralisation. We compared conventional acid demineralisation with ammonium bicarbonate buffer extraction to test ZooMS in a range of modern and archaeological bone samples. The sensitivity of the current generation of mass spectrometers is high enough for the non-destructive buffer method to extract sufficient collagen for ZooMS. We envisage that a particular advantage of this method is that it leaves worked bone artefacts effectively undamaged post-treatment, suitable for subsequent analysis or museum storage or display. Furthermore, it may have potential as a screening tool to aid curators in the selection of material for more advanced molecular analysis—such as DNA sequencing.     

Defining an indicator package to allow identification of ‘cesspits’ in the archaeological record

This paper summarises the insect, plant macrofossil and other environmental evidence from a large number of deposits, thought to be cesspits, at a range of archaeological sites. A potential ‘indicator package’ (sensu Kenward and Hall, 1997), consisting of a range of biological materials and archaeological artefacts, is outlined which should allow a more accurate identification of cesspits in the archaeological record enhancing further studies of the rich evidence often preserved in them.     

The Removal of Protein from Mineral Surfaces: Implications for Residue Analysis of Archaeological Materials

Although there has been great interest and controversy concerning the detection of proteins in archaeological residues, very few studies have considered the effect of different extraction methods. Using well-defined control materials, this study compares the extraction efficiency of a number of different extraction reagents. Immunological and spectrophotometric assays are used to assess the amount of protein removed by each extraction method and the effectiveness is reported with reference to previous work. None of the previously reported methods were found to be effective at removing the protein from the mineral surface. We conclude that proteins are very strongly bound to the surface probably via short-range bonds. Although this may be encouraging for the long-term preservation of proteins in this context, extraction methods will have to be re-evaluated in order to achieve efficient recovery.     

Photographic methods to detect colourants in archaeological textiles

Protocols for photography of archaeological textiles to detect components of differing chemistry that are indicative of colourants were developed. Parameters of light source, camera distance, filter type, film type, film speed, and aperture size were evaluated for visible, UV-reflectance, UV-fluorescence, and infrared photography. Using these techniques facilitates selective sampling for further analysis that maximizes critical data acquisition while minimizing destruction of the artefact. Hence, forensic photography of archaeological perishable materials should be regarded as a precursor to destructive analytical methods.     

The decomposition of starch grains in soils: implications for archaeological residue analyses

Recent research involving starch grains recovered from archaeological contexts has highlighted the need for a review of the mechanisms and consequences of starch degradation specifically relevant to archaeology. This paper presents a review of the plant physiological and soil biochemical literature pertinent to the archaeological investigation of starch grains found as residues on artefacts and in archaeological sediments. Preservative and destructive factors affecting starch survival, including enzymes, clays, metals and soil properties, as well as differential degradation of starches of varying sizes and amylose content, were considered. The synthesis and character of chloroplast-formed ‘transitory’ starch grains, and the differentiation of these from ‘storage’ starches formed in tubers and seeds were also addressed. Findings of the review include the higher susceptibility of small starch grains to biotic degradation, and that protective mechanisms are provided to starch by both soil aggregates and artefact surfaces. These findings suggest that current reasoning which equates higher numbers of starch grains on an artefact than in associated sediments with the use of the artefact for processing starchy plants needs to be reconsidered. It is argued that an increased understanding of starch decomposition processes is necessary to accurately reconstruct both archaeological activities involving starchy plants and environmental change investigated through starch analysis.     

Assessing the effects of geomorphological processes on archaeological densities: a GIS case study on Zakynthos Island,Greece

While geomorphological processes are considered key factors in the distribution of archaeological surface finds, few studies have attempted to quantify the relationship between artefact dispersal and erosional/depositional patterns. This paper compares Unit Stream Power Erosion Deposition model (USPED) and Revised Universal Soil Loss Equation (RUSLE) and integrates the results in the archaeological finds’ density map of Zakynthos Archaeological Project. The study area (Palaiokastro), with artefacts dated from middle Paleolithic to medieval times, includes a steep terrain with a surrounding plain area, where the downslope erosion has considerably modified the distribution of archaeological remains. Through this study, it is possible to identify relationships between high artefact densities and stable/non-eroded surfaces, and on the other hand, low densities and eroded surfaces. However, the results indicate a degree of spatial variability, which modifies the predicted relationship. The consideration of the effects of these temporal and spatial patterns is crucial for developing effective sampling methods and accurately interpreting the archaeological record.     

Integrated geoarchaeological methods for the determination of site activity areas: a study of a Viking Age house in Reykjavik,Iceland

For over a decade, geoarchaeological methods such as multi-element analysis and soil micromorphology have been used to identify and interpret activity areas on archaeological sites. However, these techniques, along with others such as magnetic susceptibility, loss on ignition, and microrefuse, artefact and bone distribution analyses are rarely integrated in the study of a single site, even though they provide very different and potentially complementary data. This paper presents a comparative study of a wide range of geoarchaeological methods that were applied to the floors sediments of a Viking Age house at the site of Aðalstræti 16, in central Reykjavík, Iceland, along with more traditional artefact and bone distribution analyses, and a spatial study of floor layer boundaries and features in the building. In this study, the spatial distributions of artefacts and bones could only be understood in the light of the pH distributions, and on their own they provided limited insight into the use of space in the building. Each of the sediment analyses provided unique and valuable information about possible activity areas, with soil micromorphology proving to have the greatest interpretive power on its own. However, the interpretation potential of the geochemical methods was dramatically enhanced if they were integrated into a multi-method dataset.     

Potential misidentification of in situ archaeological tool-residues: starch and conidia

Microscopic identification of organic residues in situ on the surface of archaeological artefacts is an established procedure. Where soil components morphologically similar to use-residue types exist within the soil, however, there remains the possibility that these components may be misidentified as authentic residues. The present study investigates common soil components known as conidia, fungal spores which may be mistaken for starch grains. Conidia may exhibit the rotating extinction cross under cross-polarised light commonly diagnostic of starch, and may be morphologically indistinguishable from small starch grains, particularly at the limits of microscope resolution. Conidia were observed on stone and ceramic archaeological artefacts from Honduras, Palau and New Caledonia, as well as experimental artefacts from Papua New Guinea. The findings act as a caution that in situ analysis of residues, and especially of those less than 5 μm in size, may be subject to misidentification.     

Polarized Light Microscopy: An Old Technique Casts New Light on Māori Textile Plants

Understanding the composition of an artefact has ramifications for advancing human history and behaviour knowledge, providing cultural information about trade, agricultural practices and adaptation to new environments. However, accurate plant identification from artefacts is problematic, since textile production, age, dirt and/or conservation treatments obscure morphological features, and specimen size and/or ethical considerations hamper modern analytical methods. This study tested the efficacy of polarized light microscopy (PLM) in the identification of New Zealand plant species commonly used in Māori textiles, and demonstrates that morphological and birefringent features observed using PLM have the potential to distinguish between‐ and within‐plant genera.     

Starch residues on museum artefacts: implications for determining tool use

A sample of 11 museum artefacts was examined to assess the preservation of any adhering organic residues, particularly starch granules, and to assess the potential for the identification of cooked starchy foods. The primary aim was to examine starchy deposits, extract starch granules and examine their physical condition to increase our understanding of the taphonomy of starch granules and associated organic residues in archived material and archaeological deposits. The study shows that organic plant residues could be recovered from archived artefacts and makes a significant contribution to understanding the function of this material. Recovered starch granules showed an interesting pattern of varying organic preservation on the surface of stone and wooden artefacts. Some starch granules were found to be well preserved while others in the same sample appeared to have been affected by enzyme degrading micro-organisms. Recovered residues included fully gelatinised starch.     

Submerged Mesolithic Landscape Investigation,Eleven Ballyboes,Republic of Ireland

This paper reports on the first systematic attempt to conduct archaeological survey and excavation for submerged prehistory on the island of Ireland. Fieldwork was conducted in two small bays where Early Mesolithic flint artefacts washed ashore hinted at the presence of a submerged assemblage. Methods employed include non‐intrusive survey, hand coring and excavation. Together, these allowed identification of the artefact source, albeit reworked, in one bay and an early Holocene peat in the other. Though the subtidal assemblage is reworked and relatively small, it is significant in an Irish context and more widely illustrates the potential preservation of prehistoric sites and palaeo‐landscapes in high‐energy settings.     

Artefacts,archaeologists and American Indians

Abstract

Archaeologists traditionally have observed the style and technology of artefacts and used this to classify archaeological assemblages, describing the repeated association of artefact groups as a ‘Culture’. We continue to place overwhelming reliance on our ability to derive meaningful information about past culture from artefacts, yet the importance these objects had for the members of the cultural group (past and present) is not adequately considered. The typological approach sidelines the creative role of the artisans, we find out a little about their economy, gain momentary glimpses of their religion, but learn almost nothing about their humanity. Archaeologists tend to focus on the physical, technological or esoteric attributes of an artefact, while indigenous populations tend to focus on the object's ritual or social importance. This is most apparent in the treatment of funerary artefacts. Until recently, many American Indian tribal groups have seen no distinction between ‘grave robbing’ and ‘archaeological excavation’ it made no difference to them whether the dead were disturbed by looters or by qualified archaeologists. By involving indigenous populations in the design, practice and dissemination of archaeological research, we can add humanity to our study of the human past, and take a step toward a truly worldwide archaeology.     

New Data on the Exploitation of Obsidian in the Southern Caucasus (Armenia,Georgia) and Eastern Turkey,Part 1: Source Characterization

A large analytical programme involving both obsidian source characterization and obsidian artefact sourcing was initiated recently within the framework of the French archaeological mission ‘Caucasus’. The results will be presented in two parts: the first part, this paper, deals with the presentation and characterization of obsidian outcrops in the southern Caucasus, while the second presents some results obtained from a selection of artefacts originating from different Armenian sites dated to between the Upper Palaeolithic and the Late Bronze Age. The same analytical method, LA–ICP–MS (laser ablation inductively coupled plasma mass spectrometry), has been used to characterize all the studied samples (both geological and archaeological). This method is more and more widely used to determine the elemental composition of obsidian artefacts, as it causes minimal damage to the studied objects. We present in this first part new geochemical analyses on geological obsidians originating from the southern Caucasus (Armenia, Georgia) and eastern Turkey. These data enhance our knowledge of the obsidian sources in these regions. A simple methodology, based on the use of three diagrams, is proposed to easily differentiate the deposits and to study the early exploitation of this material in the southern Caucasus.     

The World's Oldest Stone Artefacts from Gona, Ethiopia: Their Implications for Understanding Stone Technology and Patterns of Human Evolution Between 2·6–1·5 Million Years Ago

The systematic archaeological and geological survey and excavations at Gona between 1992–1994 led to the discovery of well-flaked stone artefacts which are currently the oldest known from anywhere in the world. More than 3000 surface and excavated artefacts were recovered at 15 localities documented east and west of the Kada Gona river. Based on radioisotopic dating (⁴⁰Ar/³⁹Ar) and magnetostratigraphy, the artefacts are dated between 2·6–2·5 million years ago (Ma). EG10 and EG12 from East Gona are the most informative with the highest density, providing the best opportunity for characterizing the oldest assemblages and for understanding the stone working capability of the earliest tool makers. Slightly younger artefact occurrences dated to 2·4–2·3 Ma are known from Hadar and Omo in Ethiopia, and from Lokalalei in Kenya. Cut-marked bones dated to 2·5 Ma from Bouri in Ethiopia are now providing important clues on the function of these artefacts. In addition, Australopithecus garhi known from contemporary deposits at Bouri may be the best candidate responsible for the oldest artefacts. Surprisingly, the makers of the Gona artefacts had a sophisticated understanding of stone fracture mechanics and control similar to what is observed for Oldowan assemblages dated between 2·0–1·5 Ma. This observation was corroborated by the recent archaeological discoveries made at Lokalalei. Because of the similarities seen in the techniques of artefact manufacture during the Late Pliocene–Early Pleistocene, it is argued here that the stone assemblages dated between 2·6–1·5 Ma group into the Oldowan Industry. The similarity and simplicity of the artefacts from this time interval suggests a technological stasis in the Oldowan.     

Māori Textiles from Puketoi Station,Otago, New Zealand

Abstract

A group of Māori textile artefacts were discovered in a rock shelter in the southern South Island of New Zealand in 1895. The assemblage comprised a significant number of textile and textile-related artefacts including large and small bags, footwear and prepared leaf and fibre for textile production. The artefacts were privately owned until the 1920s when they were acquired by the Otago Museum, remaining there until new techniques made further investigation possible. This paper presents information from an interdisciplinary investigation of the Puketoi Station assemblage of textile artefacts, which examined artefact structure, form and function, and materials of construction. Interpretation of these artefacts using contemporary textile analysis methods, traditional weaving knowledge, and recent archaeological research, turns them from static objects into dynamic components of culture. The Puketoi Station artefacts embody and illustrate a unique material culture associated with the late prehistoric southern New Zealand Māori lifestyle.     

Early Imports in the Late Bronze Age of South‐Western Iberia: The Bronze Ornaments of the Hypogea at Monte da Ramada 1 (Southern Portugal)

The composition and manufacture of Late Bronze Age metallic artefacts from funerary and domestic contexts of southern inland Portugal was studied. The prevailing trend comprises binary bronzes (10.3 ± 2.1 wt% Sn) showing deformed equiaxial grains, annealing twins and slip bands. The alloy composition is somewhat independent of artefact type, while the manufacture seems to rely on artefact function and the skilfulness of the metallurgist. The technological characteristics were linked with archaeological and chronological features, disclosing some artefacts of uncommon composition, such as low‐tin bronze bracelets (4.3–7.1 wt% Sn) associated with ornaments of exotic materials (glass and Egyptian faience beads, and also ostrich egg shell beads). The assemblage testifies to an archaic trade with the Mediterranean region before the establishment of the first Phoenician colonies on the southern Iberian coast.     

Quantifying artefacts over time: Interval estimation of a Poisson distribution using the Jeffreys prior

This paper presents a new method for estimating the amount of an artefact class in use at a given moment in the past from a random assemblage of archaeological finds. The method is based on the use of simulation, since an analytical solution is computationally impractical. Estimating the number of artefacts in use at any time t is shown to follow a Poisson distribution, which allows for credible intervals to be established using the Jeffreys prior. This estimator works from minimal assumptions about the dating and duration of finds, as well as the intensity of collection, and is applied to coinage from four Roman‐period sites excavated by the Roman Peasant Project (2009–14). The result provides an estimation of the abundance of material according to an interval of certainty.