Analysis of adhering organic residues of two “coupes-à-socles” from the Neolithic funerary site “La Hougue Bie” in Jersey: evidences of birch bark tar utilisation

The “coupes-à-socle” (footed cups) are ceramics which can be found in domestic Neolithic contexts in Brittany (Castellic, Auzay-Sandun), but more generally in non-domestic areas. Their ceremonial function has often been evoked, in particular as a perfume burner. The analysis by GC and GC/MS of two samples from the “Hougue Bie” (Jersey) passage graves showed the presence of vegetable fatty acids, degraded n-alkanes and terpenoïds, biomarkers of birch bark tar. The presence of such substances could be explained either by the use of the “coupes-à-socle” for burning birch bark tar as an odoriferous product or their use as an everyday vessel for heating and increasing tar plasticity. However, the limited occurrence of this type of ceramic in habitat sites supports the former utilisation. This first report of the presence of birch bark tar in “coupes-à-socle” thus suggests use of this tar as an odoriferous product, in addition to its numerous, previously recognised, more technical uses.     

Small things in perspective: the contribution of our blind tests to micro-residue studies on archaeological stone tools

Our blind tests are distinctive for they were conducted on replicated stone tools used for a variety of tasks that included the processing of animal remains and plants. The analyst was required to differentiate an array of residues from microscopic morphological characteristics, using light microscopy. The original aim of our first tests was to assess the analyst's ability to identify a variety of plant and animal residues, but issues and problems that arose during the testing process made it clear that greater value might be gained from the lessons that we learnt about methodology and the direction for future micro-residue research. We show that problems identified during our first tests stimulated research. Amongst other things, we learnt to distinguish plant and animal remains more confidently than previously. Our residue analyses are firmly embedded in wider archaeological research and our tests help to explain why there are sometimes contradictions between the evidence from archaeologically recovered remains and residues on stone tools. A further outcome of the tests is that we have adopted a multi-stranded approach that provides a cautious, but secure strategy for identifying and interpreting use-residues. Our studies of contaminants through replications have also been invaluable for distinguishing incidental residues from use-related residues.     

A short note on starch and xylem of Ipomoea batatas (sweet potato) in archaeological deposits from northern New Zealand

This study examines preservation of microfossils identified as introduced Ipomoea batatas in soils from northern New Zealand. Starch grains and xylem cells showed highly variable preservation, from good to extremely poor. For starch grains, the latter included brown-staining, expansion and distortion of the grain and vacuole, loss of the Maltese cross, pitting, cracking, fragmentation and disintegration. Degraded xylem showed similar brown-staining, occasional cracking, cross-wise fragmentation, with wall pits becoming progressively less visible or showing distortion, expansion and coalescence.     

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.     

Molecular and isotopic traces of cooking and consumption of fish at an Early Medieval manor site in eastern middle Sweden

This paper is a presentation of a comparison between prehistoric food culture signals obtained through analyses of lipid food residues in pottery, i.e. pottery-use, from settlement remains on one hand and bone chemical analyses of human skeletal remains from an adjacent and contemporary cemetery on the other. The materials derive from the Early Medieval site Tuna in Alsike par., Uppland, Sweden. The results show a discrepancy between the two food signals and it is argued that pottery-use do not by necessity reflect everyday diet. But it is also argued that the integration of several food signals together with contextual archaeological data is a fruitful way to begin to understand the complexity of prehistoric cultures of food.     

Assessing the reliability of pRIA for identifying ancient proteins from archaeological contexts

The use of immunological techniques for identifying the origin of proteins and inferring foodstuffs exploited by prehistoric occupations has been conducted for several decades. Cases of experimental laboratory and archaeological studies have shown the potential of these techniques for reliable results. However, very few of these case studies employ archaeological sites that have excellent preservation and high-resolution spatial contexts between identifiable faunal remains, features, and stone tools. We present an assessment of the identification reliability of one immunological technique, protein radioimmunoassay (pRIA), using faunal remains and stone tools from two sites from arctic and subarctic contexts. The results of this research indicate that, even in contexts with excellent preservation, the identifications produced by the pRIA technique are subject to misidentification and cross-reactions due to diagenetic alteration of proteins. We propose a higher minimum reaction value (percent binding of labeled antibody) that mitigates these effects, and renders the pRIA results more reliable for ancient, poorly preserved organic remains.     

Plant processing strategies and their affect upon starch grain survival when rendering Peltandra virginica (L.) Kunth,Araceae edible

There is a long history of human interaction with plants of the Aroideae subfamily (Araceae). Despite these plants' chemical defenses against animal and vegetal predation, humans have targeted their starchy corms, tubers and rhizomes for dietary purposes. In the Eastern Woodlands of North America, early Europeans described the Native population as utilizing the highly acridic Peltandra virginica (arrow arum) for subsistence needs. In order to render this resource edible, however, the acridic principle first needs to be eliminated. Our study investigates the affect these processing activities have on the integrity of arrow arum starch grains. Findings from this study demonstrate that environmental variables specific to individual processing procedures may be more influential on starch grain survival than simply the temperatures reached during cooking.     

Ergosterol (5, 7, 22-ergostatrien-3β-ol) as a potential biomarker for alcohol fermentation in lipid residues from prehistoric pottery

In this paper we explore the potential use of ergosterol (5, 7, 22-ergostatrien-3β-ol) as a possible biomarker for yeast and alcohol fermentation, applying the analytical technique previously used routinely in Swedish archaeology for the analysis of lipid residue in prehistoric pottery. Taking note on the connection between brewing, baking and agriculture the frequency of vessels showing gas chromatography mass spectrometry traces of this compound in lipid residues from a clearly agricultural Bronze Age/Early Iron Age population was compared with the same signal in a clearly non-agricultural Neolithic foragers pottery population. The result shows a small but statistically significant difference between the two populations, indicating a connection between the presence of ergosterol in lipid residues from pottery and agriculture. The results are also discussed in terms of varying cleanliness, degradation, deposition conditions and contamination. Suggestions for future research include the use of a more sensitive analytical protocol in order to improve detection limits and to include materials from clear agricultural Neolithic vessel populations.     

Late Pleistocene to Early Holocene Plant Movements in Southern Kyushu, Japan

From the late Pleistocene to early Holocene in Japan, subtropical and temperate forest elements moved northwards. This affected human choices and access to food sources. More settled patterns of living spread northwards gradually, and northern hunting-gathering-fishing people began cultivating vegetables and cereal crops. This poster reports the presence of ancient starch residues on stone artefacts in Kagoshima Prefecture, southern Kyushu. The oldest residues recovered are dated by context to about 30,000 ¹⁴C yr BP. If such residues can be identified, it may be possible to detect a hypothesized early phase of tropical plant movement northwards during warmer climate peaks in the late terminal Pleistocene, as well as during the long period of Holocene warming that followed. As an initial step towards identification, the morphological characteristics and condition of the starch granules are described and compared to those of other sites in early Japan.     

Subsistence practices and pottery use in Neolithic Jordan: molecular and isotopic evidence

This paper presents direct evidence of subsistence practices and pottery use at a Late Neolithic site at al-Basatîn, northern Jordan. Measurable concentrations of C_16:0 and C_18:0 were recovered from 8 of 10 archaeological pottery fragments through use of a microwave-assisted silica gel and aminopropyl solvent protocol developed for the isolation and concentration of free fatty acids in marine sediments. Subsequent isotopic analysis of the surviving C_16:0 and C_18:0 saturated fatty acids revealed ∂¹³C ratios consistent with those of adipose fats of ruminant and non-ruminant animals pastured on lands adjacent to the Jordan Valley. The high recovery of diagnostic compounds from the al-Basatîn material is discussed in context of a wider examination of the initial development and use of pottery in the Fertile Crescent, and the emerging debate concerning the efficacy of stable carbon isotope values in characterizing organic residues embedded in pottery fragments recovered from the earliest ceramic horizons in the Middle East and Europe.