GC–MS ANALYSIS AND FATTY ACID RATIOS OF ARCHAEOLOGICAL POTSHERDS FROM THE WESTERN GREAT BASIN OF NORTH AMERICA*

The study of organic residues in archaeological pottery has focused on fatty acids due to their relative stability and longevity. However, even these compounds are subject to degradation, which makes assignment of residues to original foods problematic. This paper suggests that the use of ratios of fatty acids that degrade at roughly the same rate can be useful to identify very general categories of foods. It compares independent information on pot function based on ethnography and engineering/technological studies to that reconstructed based on extracted fatty acid ratios. The results support the notion that Great Basin pots were used primarily to boil seeds and that pot shape and pot function were related.     

A COMPARISON OF METHODS FOR ESTABLISHING FATTY ACID CONCENTRATION GRADIENTS ACROSS POTSHERDS: A CASE STUDY USING LATE BRONZE AGE CANAANITE AMPHORAE*

Canaanite amphorae fragments in fabrics believed to be associated with the bulk transport of vegetable oils from the fourteenth‐century BC site of Amarna, Egypt, have been examined. A comparison is made between solvent extraction, saponification and the use of TMTFTH (m‐trifluoromethylphenyl)trimethylammomum hydroxide, used here for the combined extraction and derivatization of ceramic‐absorbed organic residues. Extracts were studied using gas chromatography and gas chromatography‐mass spectrometry. The extraction of fatty acids from small ceramic samples has established concentration gradients of absorbed organic matter from the inner to the outer surfaces of the sherds.     

Evidence for Varying Patterns of Exploitation of Animal Products in Different Prehistoric Pottery Traditions Based on Lipids Preserved in Surface and Absorbed Residues

The excavation of a barrow at Upper Ninepence, Walton in the Welsh Borderlands, U.K., revealed two phases of occupation associated with two different ceramic traditions, namely Grooved Ware (2500bc) and Peterborough Ware (3000bc). The Grooved Ware and Peterborough Ware pits seem to have a mutually exclusive distribution on the site. Screening of the sherds for lipid residues has revealed the presence of remnant fats in a remarkably well-preserved state considering the age of the finds. Investigations of various chemical characteristics of the remnant fats from absorbed and carbonized residues have enabled distinctions to be drawn between fats from non-ruminant (e.g. porcine) and ruminant (e.g. ovine or bovine) origins. Significantly, both ruminant and non-ruminant fats are found associated with the Grooved Ware whereas only ruminant fats are found associated with the Peterborough Ware. The assignments are based upon the distributions of solvent-extractable lipid components and the compound-specific stable carbon isotope values of the major n -alkanoic acids. The results reveal differences in vessel use and indicate possible changes in patterns of animal exploitation or dietary preferences between the two phases of occupation. The results illustrate the importance of residue analysis in archaeological investigations, particularly at prehistoric sites where evidence from faunal remains is limited or absent.     

PINE RESINS AND POTTERY SEALING: ANALYSIS OF ABSORBED AND VISIBLE POTTERY RESIDUES FROM CENTRAL NEW YORK STATE*

Analysis was performed on absorbed and visible residues from 21 New York State prehistoric pottery sherds dating from 2905 ± 35 bp (Intcal04) (1256–998 cal bc ) to 425 ± 40 bp (Intcal04) (1417–1626 cal ad ). The use of pine resin was detected in 10 of 12 absorbed residue samples and 11 of 17 sherds subjected to visible residue analysis. It seems likely that the pots were resin‐sealed to make them more impermeable, constituting the first chemical evidence of extensive resin‐sealing in North America. A comparison of the results of absorbed and visible residues from eight of the sherds indicates that the two kinds of residue provide complementary evidence of vessel use.     

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.     

The Application of Steroidal Biomarkers to Track the Abandonment of a Roman Wastewater Course at the Agora (Athens,Greece)*

A subterranean, stone‐built, sediment‐filled culvert discovered during excavations at the Agora (Athens, Greece) was dated to the Roman period on the basis of its characteristic construction and associated finds, including coins. The location of the culvert relative to other adjacent watercourses and an ancient river bed suggested that the structure was a sewer. This was confirmed through a multi‐molecular biomarker approach based on analysis of the bile acids associated with sediment filling the sewer, using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The acid fraction contained predominantly deoxycholic and lithocholic acids, while the neutral steroid fraction comprised a complex mixture of Δ⁵ sterol and 5β‐ and 5α‐stanols, dominated by coprostanol, suggesting the presence of faecal matter of predominantly human origin. The concentrations of neutral and acidic faecal biomarkers were observed to vary in tandem, with the highest concentrations being found in the sediment at the base of the fill in the culvert. A reduction in concentration occurred with decreasing depth of the fill, with concentrations in the uppermost samples being little different from control samples of sediment taken beyond the confines of the culvert. The enhanced concentration of bile acids relative to 5β‐stanols compared with fresh human faeces must reflect the enhanced diagenetic stability of the former, thereby making bile acids the possibly preferred biomarker for this type of study. The quantitative data obtained suggest that the culvert fell rapidly out of use, possibly coinciding with the Slavic incursion in AD 582–3.     

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.     

Evidence of early tobacco in Northeastern North America?

While tobacco use was a widespread and important social practice among Native Americans during the Historic Period, the prehistoric origins of the practice are poorly understood. Smoking pipes significantly predate botanical evidence of tobacco in Eastern North America. A promising technique for addressing this problem is gas chromatography/mass spectroscopy (GC/MS) analysis to identify nicotine or related compounds in smoking pipe residues. GC/MS analysis of a smoking pipe dating to approximately 300 B.C. from the Boucher Site, a Middlesex-complex site from Vermont, has produced evidence of nicotine decay products. This is interpreted as evidence for an Early Woodland Period origin for tobacco use in Eastern North America. The cultural and chronological implications of this finding are discussed.     

Sourcing archaeological bitumen in the Olmec region

Prehispanic Mesoamerican peoples collected, processed, and used bitumen for decoration, sealant, and adhesive. Among the earliest to do so were the Olmec (1200–500 b.c.) of Mexico's southern Gulf coastal lowlands. Geochemical analysis of bitumen from Olmec archaeological contexts as well as from seeps in the Olmec region reveals that seeps can be geochemically differentiated and can be correlated with archaeological samples. Groups of sites with chemically different archaeological bitumen indicate multiple procurement networks reflecting complex regional systems of exchange and interaction. Organic geochemical analysis of bitumen provides a new tool to study procurement strategies and exchange patterns in Mesoamerica.     

AN EVALUATION OF ANALYTICAL AND INTERPRETATIVE METHODOLOGIES FOR THE EXTRACTION AND IDENTIFICATION OF LIPIDS ASSOCIATED WITH POTTERY SHERDS FROM THE SITE OF SAGALASSOS,TURKEY*

Three lipid analysis methods were applied to extracts of archaeological potsherds from the ancient city of Sagalassos, south‐west Turkey. In the fatty acid methyl ester fraction, obtained by selective transesterification of acylglycerols, the ratio of methyl palmitate to methyl stearate was determined. Secondly, by means of gas chromatography– combustion–isotope ratio mass spectrometry (GC–C–IRMS), stable carbon isotope ratios were measured for the same methyl esters. Finally, triglyceride composition was determined via high‐performance liquid chromatography–mass spectrometry (HPLC–MS). All three methods can be used to trace the origin of animal fat. Agreement between them is reasonable, especially in recognizing ruminant adipose fat. One sample was found to be of dairy origin using both GC–C–IRMS and HPLC–MS. The advantages of the various methods are discussed. Variations in lipid composition were observed between samples from different periods and excavated in diverse areas within the city of Sagalassos.     

The contents of unusual cone-shaped vessels (cornets) from the Chalcolithic of the southern Levant

Cornets are cone-shaped ceramic vessels, characteristic of the Chalcolithic period (ca. 4700–3700 BC) in Israel and Jordan. Their contents and use are unknown. Gas chromatography with flame ionization and mass-selective detection, showed that extracts of cornets from five different sites with different related activities (domestic, habitation cave and a cultic complex) all contain the same assemblage of mainly n-alkanes adsorbed within their walls. This assemblage differs from those found in other types of ceramic vessels from the same sites, as well as from the residues found within the associated sediments. The assemblage of odd and even-numbered n-alkanes found in the cornets is almost identical to that found in the residues of beeswax heated on modern ceramic fragments, as well as in a beehive from the Iron Age IIA strata at Tel Rehov, Israel. Thus the cornets are most likely to have contained beeswax. The presence of beeswax in the cornets contributes to our understanding of the Chalcolithic period; a time when secondary products such as milk, olive oil and wine are thought to have come into use.     

Characterization of organic media in the wall-paintings of the “Palace of Nestor” at Pylos,Greece: evidence for a secco painting techniques in the Bronze Age

This paper presents the results of an investigation of organic binding media detected in samples from the Mycenaean wall-paintings at the “Palace of Nestor” in Pylos (Western Messenia, Greece): samples dated from the Late Bronze Age (ca. 1200 BC). This is the first scientific study to be conducted on organic binding media in Mycenanean painting, and it is a study that aims to contribute significantly towards our understanding of the original painting techniques used during the Bronze Age. The analytical procedures employed for the detection and characterization of the organic substances preserved within the paint layers (proteinaceous materials, lipids and plant gums), were based on chromatography/mass spectrometry techniques (PY–GC/MS, GC/MS). The most significant results, highlighting an a secco painting technique, are herein reported and discussed.     

Scientific investigation of the paint and adhesive materials used in the Western Han dynasty polychromy terracotta army,Qingzhou, China

A royal tomb of early period of the Western Han dynasty (206 B.C–8 A.D) was excavated by archaeologists in Qingzhou County, Shandong Province in 2006. Over 2000 polychromy terracotta soldiers, horses, chariots, servants etc. were unearthed from the tomb. All the terracotta figures are one quarter or one sixth as large as the livings, most of them were painted with well designed patterns. In order to gain complete information about the materials and techniques used for the polychromy on the terracotta army, five samples from the painted areas were taken. In addition, one sample from the area to adhere one leg to the ploychromy horse body was also obtained. The analytical techniques applied include XRF, FTIR, Py-GC/MS and GC/MS. Chinese purple, cinnabar, lead red and ochre were used as pigments, while animal glue was identified as binding medium and adhesive in the polychromy terracotta army in the Han Dynasty. The results definitely will provide new evidence about the materials and technologies used in Han Dynasty. Especially, the binding medium identified is different in comparison with Qin Shihuang's terracotta army (259–210 BC).     

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.     

The 9th‐Century‐AD Belitung Wreck,Indonesia: analysis of a resin lump

The 9th‐century‐AD Belitung wreck was discovered in 1998 in the Java Sea. Construction techniques rapidly confirmed that it was unlike any known Chinese or Southeast Asian vessel. The uncertainty about its origins was resolved in 2008 by timber identifications: it was constructed in the Middle East (probably Oman or Yemen). This paper, on the characterization of a dammar resin lump collected in the vicinity of the wreck, supplies additional evidence confirming the probable re‐stitching of the vessel somewhere in Asia. © 2010 The Authors     

Potential vegetation markers – analytical pyrolysis of modern plant species representative of Neolithic SE Spain

A selection of plant species that may have been relevant for the Neolithic in the SW Mediterranean have been characterised with pyrolysis gas chromatography mass spectrometry (pyrolysis–GC/MS) in search for molecular vegetation markers. Roots and aerial parts were analysed separately for the following species: Anthyllis cytisoides, Asphodelus cerasiferus, Brachypodium retusum, Cistus albidus, Cistus clusii, Dorycnium pentaphyllum, Ephedra fragilis, Juniperus oxycedrus, Juniperus phoenicea, Olea europaea, Phillyrea angustifolia, Pinus halepensis, Pistacia lentiscus, Quercus coccifera, Rhamnus lycioides, Rosmarinus officinalis, Smilax aspera and Stipa tenacissima; furthermore domesticated plants were analysed, including wheat (Triticum aestivum, Triticum dicoccum, Triticum monococcum, Triticum timopheevi and Triticum turgidum), barley (Hordeum vulgare and H. vulgare Hulled) and legumes (Lathyrus cicera, Lathyrus sativus, Lens culinaris, Pisum sativa, Vicia ervilia, Vicia faba and Vicia sativa). This resulted in 290 potential markers. In addition, the organic matter of surface soils under different vegetation cover has been analysed to test the presence of the potential markers in the soil. Forty-six of the potential markers were detected in the soil organic matter, of which part have not been reported before. The results may be useful for interpretation of the organic matter composition of soils and plant remains, which can be valuable in archaeology.     

The painting of the Etruscan “Tomba della Quadriga Infernale” (4th century BC), in Sarteano (Siena, Italy): technical features

This work presents the results of an investigation of the painting technique used in the Etruscan tomb “Tomba della Quadriga Infernale”. This tomb was discovered in Sarteano (Siena, Italy) in October 2003 and dated back to the second half of the 4th century BC. Red, dark red, pink, yellow, white, black, and grey colours were used in the tomb in order to create paintings, which now represent a very precious record of the Etruscan art of wall painting in a hypogeal environment. The technical features of the painting were revealed by stratigraphy using optical and electronic microscopy. The components and preparatory layers of the painted areas were characterized using Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray microanalysis (SEM-EDS), X-ray diffraction (XRD), and gas chromatography/mass spectrometry (GC/MS). XRD, SEM-EDS, and optical microscopic techniques were also used for mineralogical analysis of the rock substrate. The SEM-EDS and FTIR analyses showed that red and yellow ochre, calcite, and vegetable charcoal were used to paint the walls of the tomb: the pigments, either alone or mixed together, were utilized to produce pure colours (red, yellow, white, and black) and intermediate tonalities (pink, dark red, and grey). SEM-EDS, FTIR, and XRD highlighted that the painting was made on a preparatory layer of calcite, applied onto a levelling material made up of calcite, clay minerals, quartz, and iron oxides. GC/MS analyses revealed that egg was used as an organic binder to disperse the pigments.     

The meals in a Tuscan building yard during the Middle Age. Characterization of organic residues in ceramic potsherds

The characterization of organic residues found in ceramics objects coming from the Carmine Convent in Siena (Central Italy), probably built in the second half of the 13th century, is described. The nine objects analyzed in this study are pots, casseroles, and lids and they were used as filling material of the vault of one room of the convent.