QUANTIFICATION AND DISTRIBUTION OF LIPID IN ARCHAEOLOGICAL CERAMICS: IMPLICATIONS FOR SAMPLING POTSHERDS FOR ORGANIC RESIDUE ANALYSIS AND THE CLASSIFICATION OF VESSEL USE

Organic residue analysis has been performed on 62 reconstructed vessels from a single archaeological site (Rounds, Northamptonshire, U.K.). In order to establish regions of lipid accumulation within a vessel, sherds were sampled from different parts of a vessel, for example base, body and rim, and submitted to lipid extraction procedures. The techniques of high-temperature gas chromatography (GC) and GC/mass spectrometry (GC/MS) were then used to analyse the sherd lipid extracts. The quantitative results obtained show differential accumulation and preservation of lipid in various parts of the same vessel. This latter observation has serious implications for the sampling of potsherds for organic residue analysis. Furthermore, the amount of absorbed lipid varies quite considerably between vessel types. On this basis, a new method is proposed for classifying vessel use by comparing the concentration of lipid present in different parts of individual vessels.     

A MULTI‐ANALYTICAL APPROACH FOR THE CHARACTERIZATION OF COMMODITIES IN A CERAMIC JAR FROM ANTINOE (EGYPT)*

This paper describes a multi‐analytical chemical study performed on the original, almost totally conserved, content of a small ceramic jar from the Antinoe archaeological site (fifth to seventh centuries ad, Roman Egypt) and now belonging to the archaeological collection of the Istituto Papirologico ‘Girolamo Vitelli’ (Florence, Italy). Scanning electron microscopy with an energy‐dispersive X‐ray spectrometer (SEM–EDX), Fourier transformed infrared spectroscopy (FTIR) and X‐ray diffraction (XRD) were all used to characterize the inorganic components of the archaeological material. The organic substances were analysed using FTIR, direct exposure mass spectrometry (DE–MS) and gas chromatography – mass spectrometry (GC–MS). The inorganic component essentially consisted of halite (NaCl). Among the NaCl crystals, lamellar elements were identified. They were chemically characterized by carbonato‐apatite and showed a concentric morphology typical of the scales of small fish. The most prevalent organic constituents of the sample were monocarboxylic acids, α,ω‐dicarboxylic acids, and cholesterol and its oxidation products. The organic material composition was consistent with the occurrence of lipids of animal origin. In addition, diterpenes related to pine pitch were also identified. The overall results suggest that the material recovered in the small ceramic jar found in Antinoe is a residue of fish‐based pickles such as garum, muria, allex and liquamen, which were commonly used in Roman times.     

EVIDENCE FOR THE MIXING OF FATS AND WAXES IN ARCHAEOLOGICAL CERAMICS

Lipid residues from two Late Saxon/early medieval ceramic vessels recovered from excavations at West Cotton, Raunds, Northamptonshire, U.K., have been investigated by high-temperature gas chromatography (GC) and GC/mass spectrometry (GC/MS). The solvent extracts of sherds sampled from different points on each vessel (i.e., base, body and rim) were analysed quantitatively and qualitatively and compounds were identified which were characteristic of beeswax and animal fat. Furthermore, by determining the sites of accumulation of the specific lipid types and their concentrations in different parts of the vessels it can be inferred that the beeswax was added to the vessels prior to the addition of the fat. It was concluded that the two vessels performed different functions in antiquity.     

NEOLITHIC ZOOMORPHIC VESSELS FROM EASTERN MACEDONIA,GREECE: ISSUES OF FUNCTION*

Five fragments of Late Neolithic clay zoomorphic vessels from northern Greece have been analysed for organic residues by gas chromatography – mass spectrometry. The results showed that the containers had been used in connection with a number of substances, in particular lower terpenoids, an oil or fat, possibly fossil fuel and in one case possibly beeswax. The paper considers likely interpretations of such combinations of materials in relation to possible functions of these symbolically enhanced artefacts. It appears that substances may have been used in the vessels because of their aromatic and/or medicinal and combustible properties, possibly in order to produce light, fragrance and/or smoke.     

A NEW METHOD FOR EXTRACTION,ISOLATION AND TRANSESTERIFICATION OF FREE FATTY ACIDS FROM ARCHAEOLOGICAL POTTERY

This paper presents evidence for increased recovery of organic residues from archaeological pottery through use of a microwave‐assisted liquid chromatography protocol. C_16:0 and C_18:0 saturated fatty acids were obtained from archaeological potsherds recovered from nine Neolithic settlements in the Middle East dating between 4700 and 7300 cal bc , including materials that had not produced evidence for the survival of any lipid species through use of ‘conventional’ solvent extraction techniques. Compound‐specific isotopic analyses of C_16:0 and C_18:0 fatty acids in potsherd extracts subsequently revealed δ¹³C/δ¹²C compositions consistent with modern subcutaneous fats of wild boar and goats pastured on lands adjacent to the Jordan Valley, and residues from a modern pottery vessel used in the manufacturing of butter, cheese and yogurt in central Turkey. These results are presented as an illustration of capabilities of the microwave‐assisted recovery protocol. The reclamation of saturated and unsaturated fatty acids from archaeological pottery fragments recovered from a number of the earliest ceramic horizons in the Middle East is herewith reported, and the extraction methods and instrumental analytical techniques are described.     

Lipid Residues from Low‐Fired Pottery

This paper assesses the fate of lipids associated with low‐temperature and pit‐fired pottery to determine to what degree organic compounds persist or are removed during short‐firing episodes below 800 °C. Three different types of clay were fired using contrasting techniques including at 400 °C for 4 h in a muffle furnace, and pit‐firing in which pottery was fired to higher temperatures but for shorter periods of time. Total lipid extracts obtained by solvent extraction of test sherds were screened using gas chromatography‐flame ionization detection (GC‐FID) to determine the lipid concentrations and gas chromatography–mass spectrometry (GC–MS) to identify the organic compounds present. The results showed that firing of clay removes all naturally occurring alkyl lipids; however, during pit‐firing, diterpenoid lipids were introduced into the clay as a condensate from pine ( Pinus spp.) wood used as fuel. These results confirm that alkyl lipids, e.g., fatty acids, can be reliably associated with the use of vessels, although caution is required when interpreting the origins of lipids that might derive from fuel used in firing.     

ON THE AGE AND CONTENT OF JAR‐35—A SEALED AND INTACT STORAGE JAR FOUND ON THE SOUTHERN PLATEAU OF QUMRAN*

An intact and sealed storage jar known as Jar‐35 was found in 2004, south of the Qumran settlement. A previous study identified tartrate in the deposit of the jar, indicating the possible past presence of wine ( Buti et al. 2006 ). However, we cannot confirm this finding. Using liquid and gas chromatography with mass spectrometric detection, no trace of tartaric acid or salts thereof could be detected in our samples. We show that the major component of the deposit is gypsum. No other organic compounds were identified with the methods that we have applied. Both radiocarbon dating of charcoal in the deposit and thermoluminescence dating of the ceramic jar show that it dates to the main period of habitation at Qumran (c. 100 bc to ad 70).     

RECONSTRUCTING ANCIENT YEMENI COMMERCIAL ROUTES DURING THE MIDDLE AGES USING STRUCTURAL CHARACTERIZATION OF TERPENOID RESINS*

Following the discovery of items that look like resins at the medieval site of Sharma (Hadramawt coast, Yemen, c. 11th century ad ), chemical investigations were carried out in order to determine their nature and geographic origin. By combining visual observation, infrared spectroscopy, direct inlet electron ionization – mass spectrometry (DI EI–MS) and pyrolysis gas chromatography – mass spectrometry (Py GC–MS) or gas chromatography – mass spectrometry (GC–MS) analyses, it was demonstrated that 84% of the samples were harvested from Hymenaea trees growing in Madagascar and East Africa. Contrary to what was thought previously, frankincense, identified with certainty in only two samples, was thus not the main resin exploited at Sharma. These results are of prime importance for reconsidering the trading routes of resins passing through Sharma, a site that was obviously strongly connected with Africa during the Middle Ages.     

THE STUDY OF NABATAEAN ORGANIC RESIDUES FROM MADÂ’IN SÂLIH,ANCIENT HEGRA,BY GAS CHROMATOGRAPHY – MASS SPECTROMETRY*

Four Nabataean samples collected in some of the monumental tombs of Madâ’in Sâlih, ancient Hegra, in Saudi Arabia, have been studied by gas chromatography coupled with mass spectrometry. These samples are textile fragments that are either covered with a black layer or bound together with some black amorphous substance. Fatty acids and triterpenoic compounds were detected. Eight triterpenic compounds were identified: ursa‐9(11),12‐dien‐3‐ol, ursa‐9(11),12‐dien‐3‐one, olean‐9(11),12‐dien‐3β‐ol, β‐amyrone, β‐amyrin, α‐amyrone, α‐amyrin and lupeol. The resinous chemical composition and these pentacyclic alcohols, in considerable proportion, indicate a resin of the Burseraceae family, possibly of the genus Canarium.     

Evidence for Birch Bark Tar Use as an Adhesive and Decorative Element in Early Iron Age Central Italy: Technological and Socio‐Economic Implications

Archaeological excavations carried out in Early Iron Age Vetulonia (northern Tuscany, Italy) brought to light a funerary urn particularly noteworthy for the presence of an unusual decoration obtained by plastering the vase surface with an organic dark grey substance, on which metal strips were originally fixed. In order to reveal the origin of such coating, it was chemically studied by gas chromatography coupled with mass spectrometry (GC/MS). Chemical analysis not only revealed that birch bark tar was used as coating/adhesive material for the manufacture of the urn, but also allowed us to discuss the significance of the vessel in terms of eco‐technological knowledge and possible cultural connections on a large geographical scale.     

IDENTIFICATION OF AN ADHESIVE USED TO REPAIR A ROMAN JAR

A combination of micro-analytical techniques, including thin layer chromatography (TLC), gas chromatography (GC), and combined gas chromatography/mass spectrometry (GC/MS), was employed to study the lipid composition of an adhesive used to repair an Ecton ware jar, recovered from Roman sediments of the River Nene at West Cotton (Rounds, Northamptonshire, U.K.). GC of the total lipid extract of the adhesive showed a complex pattern which was difficult to interpret. TLC was used to fractionate the extract. The fractions were then trimethylsilylated and submitted to GC and GC/MS. Betulin, lupeol, lupenone, allobetul-2-ene, and several other pentacyclic triterpenoid compounds were shown to be present in the ancient material. The similarities between the lipid compositions of the adhesive and of contemporary birch bark tar and a birch bark total lipid extract led to the conclusion that the adhesive was derived largely from birch bark, thus providing the first firm evidence for the use of birch bark tar in ancient Britain.     

GC–MS ANALYSIS OF LIPIDS IN PREHISTORIC ROCK PAINTS AND ASSOCIATED OXALATE COATINGS FROM THE LOWER PECOS REGION,TEXAS*

The presumption that lipids were used as binders/vehicles in pictograph paints from southwestern Texas was tested using gas chromatography–mass spectrometry (GC–MS). A one‐step transesterification/derivatization procedure was used to convert bound and unbound fatty acids to fatty acid methyl esters for the analysis. Approximately 30 organic compounds were detected in the natural rock coating that encapsulates the paints, but there were no compounds unique to the paints. Moreover, the C_16:0 and C_18:0 concentrations in the paint samples were similar to the concentrations of these fatty acids in the rock coating, indicating that the compounds are native to the patina. Thus, lipid binders were either not used in the original paint mixture or have since degraded.     

CHEMICAL COMPOSITION OF A BOG BODY ADIPOCERE

Chemical analyses were carried out on adipocere obtained from a bog body recovered from a peat bog at Meenybradden, County Donegal, Ireland. Chromatographic (thin-layer chromatography and gas chromatography) and mass spectrometric analyses, combined with microanalytical chemical transformations, have yielded detailed compositional information. An absence of intact triacylglycerols, diacylglycerols and monoacylglycerols indicates that hydrolysis is complete. Consequently the adipocere is composed mainly of fatty carboxylic acids. The high proportion of palmitic and stearic acids, together with depleted oleic acid content, indicates that extensive reduction and, possibly, β-oxidation have occurred during burial in the peat bog. Hydration of the double-bond in oleic acid has also occurred, as is shown by the formation of 10-hydroxystearic acid. The monoenoic fatty carboxylic acids that are present, composed mainly of C₁₈ and C₁₆ compounds, comprise a mixture of positional isomers. The results are compared and contrasted with those obtained from previous studies of the lipid composition of other adipoceres and cadavers of archaeological interest.     

PHYSICOCHEMICAL COMPOSITIONAL ANALYSIS OF CERAMICS: A CASE STUDY IN KENTING,TAIWAN*

The composition of ceramics does not just reflect the component of some specific, unprocessed, geological, raw material source, but also certain forms of human behaviour involved in its manufacture. The purpose of this research project is to apply the acid‐extraction chemical method, complemented by a thin‐section petrographic study, to the compositional analyses of certain local ceramic collections (mainly from several sites in the southern Taiwan area). The results present the raw materials that the ceramic manufacturers of the two cultural traditions (O‐laun‐pi Phase II and Phase III–IV), which overlapped temporally, used. These materials came from the same sources, but the ceramics were manufactured in different ways. Particularly, the people of O‐laun‐pi Phase III–IV also procured certain materials from either local sources or from somewhere in eastern Taiwan to make their pots. The results also indicate that there might have been a variation in terms of their manufacture among sites of the same cultural tradition.     

FIELD AND LABORATORY MULTI‐TECHNIQUE ANALYSIS OF PIGMENTS AND ORGANIC PAINTING MEDIA FROM AN EGYPTIAN COFFIN (26TH DYNASTY)

This paper describes the physico‐chemical analyses performed on an Egyptian wood coffin on the occasion of its restoration in the hall of the National Archaeological Museum of Parma (Italy), with the aim of investigating the pigments and organic materials originally used. Pigment determination was performed both in situ by a portable energy‐dispersive X‐ray fluorescence (EDXRF) spectrometer and in the laboratory using a micro‐Fourier‐transform‐infrared (micro‐FTIR) and a Fourier‐transform (FT) Raman spectrometer. The identification of organic materials was performed through gas chromatography – mass spectrometry (GC–MS) and micro‐FTIR analysis. Amongst the pigments, special attention was paid to the green, which appeared to be severely degraded and was examined using powder X‐ray diffraction (XRD) and scanning electron microscopy – energy‐dispersive X‐ray (SEM–EDX) in addition to the above‐cited techniques. Other materials used in the polychromatic decorations are Egyptian blue, cinnabar and possibly orpiment, while calcium carbonate was used for the ground layer. The organic materials were identified as beeswax, mastic and gum arabic, sometimes as mixtures.     

Adhesive Production and Pottery Function During the Iron Age at the Site of Grand Aunay (Sarthe,France)*

A combination of elemental, functional and molecular analyses performed on amorphous organic residues dating from the Iron Age was developed in order to identify these remains and to understand their relationship with ceramic vessels in which some of them were found. These analyses made it possible to distinguish between ceramic vessels used for the production or storage of adhesive materials, mainly birch bark tar, and those dedicated to the preparation of culinary commodities, which contained animal fats. The organization of the production of adhesives is described and the addition of beeswax to birch bark tar is reported for the first time. The use of birch bark tar for coating ceramic vessels is also discussed.     

The Preservation and Identification of Piñon Resins by GC‐MS in Pottery from the Western Great Basin

Gas chromatography — mass spectrometry analysis of a sherd from the Nevada Test Site revealed a high quantity of terpenes, including sesquiterpenoids and diterpenoids, demonstrating that piñon resins were prepared in the pot in prehistoric times. The presence of these biomarkers allowed for a very specific identification of the products prepared in the pot, a level of detail not often achieved in lipid residue analysis. That the terpenes are relatively unoxidized demonstrates that they are quite stable over long periods of time. The study also shows that sherds on the surface of archaeological sites can preserve lipids and terpenes and are amenable to organic residue analysis.     

CHARACTERIZATION OF NATURAL PRODUCTS ON NATIVE AMERICAN ARCHAEOLOGICAL AND ETHNOGRAPHIC MATERIALS FROM THE GREAT BASIN REGION,U.S.A.: A PRELIMINARY STUDY

Although documentary evidence provided by ethnographers makes reference to the source of adhesives, sealants, dyestuffs and medicines used by the communities of the Great Basin, much of it is sporadic and unspecified. However, observations of amorphous deposits surviving on stone tools, ceramics, basketry and wooden artefacts have prompted an investigation of their identity, procurement and use. The aim initially is to study samples from a number of archaeological and ethnographic contexts from the region. Comparative material includes higher plant and insect resins. The study provides a unique opportunity to document use patterns in plant and animal resources in the Great Basin region.     

The Preservation of Invertebrates in 16th‐Century Cesspits at St Saviourgate,York*

The taphonomy of invertebrates from 16th‐century cesspits at St Saviourgate, York, was investigated. Earthworms, fly larvae and puparia are preserved through replication in calcium phosphate, a process facilitated by acidic cesspit pore water and by the presence of abundant organic matter, bones and shells. Features preserved by mineralization include muscles, blood vessels and setae. Non‐mineralized invertebrate remains include puparia and beetles. Py–GC/MS (flash pyrolysis–gas chromatography/mass spectrometry) revealed a very high level of preservation of structural biomolecules, with all the protein and chitin markers that are evident in the living forms still being detectable in the divalent remains.     

How Did Mississippians Prepare Maize? The Application of Compound‐Specific Carbon Isotope Analysis to Absorbed Pottery Residues From Several Mississippi Valley Sites

A newly developed compound‐specific stable carbon isotope technique allows the detection of maize in absorbed organic pottery residues. This method was applied to absorbed organic residues from a variety of Mississippi Valley potsherds, and successfully identified maize components. Maize was cooked in sampled vessels less often than expected, but otherwise fitted expected patterns of maize use derived from stable carbon isotope analysis of human bone from the region. Absorbed organic pottery residue analysis is useful in determining pottery use, particularly in concert with other analytical methods.