Prologue to Uses of Chemical Residues to Make Statements About Human Activities

Soil chemistry provides the potential for interpreting the archaeological record without necessarily resorting to artifacts, historical documents, ethnoarchaeological observations, or experiments. The range of studies incorporating new technological developments, such as mass spectrometry and multi-element analyses, for analyzing and interpreting the chemical residues found at archaeological sites or modern contexts are increasing in the literature. However, the dilemmas of interpretation concentrate on evaluating the advantages and disadvantages of different techniques. Analytical approaches to how scientists make use of chemical residues to make statements about the past, discussed here, expand the potential of the breadth of techniques to investigate daily life activities and further our understanding of the materiality of social life.     

Kaleidoscopes,Palimpsests, and Clay: Realities and Complexities in Human Activities and Soil Chemical/Residue Analysis

The following article presents a new approach to the spatial and chemical analysis of residues left by the cycle of activities that interweave specialized clay griddle production with other domestic tasks at two house lots located in the Mexican town of Cuentepec, Morelos. Based upon multivariate spatial statistics and image analysis techniques, this analytical approach allows for a more robust definition of activity areas across multiple data domains. These patterns, and the general approach by which they were created, provide a framework for evaluating the potential of applying social theories in archaeology for the interpretation of chemical residue analysis.     

Chemical Residues as Anthropic Activity Markers. Ethnoarchaeology,Experimental Archaeology and Archaeology of Food Production and Consumption

ABSTRACT

Chemical residues preserved in floors can be considered anthropic activity markers. In fact, residues are strictly related to the activities performed and reflect their spatial distribution. We present a synthesis of the work carried out over the last few decades in Mexico and Italy related to the study of chemical residues in floors. Residues can be identified performing specific chemical analyses both of plastered or earthen floors samples. We outline a methodological approach concerning the use of the markers of the activities to interpret food production and consumption in the archaeological record, based upon evidence from experimental, ethnoarchaeological and archaeological examples. Here we point out the advantages and problems of such an approach, mainly related to equifinality, of the use of spot tests and gas chromatography coupled with mass spectrometry techniques using examples from different sites in the world.     

The Study of Archaeological Floors: Methodological Proposal for the Analysis of Anthropogenic Residues by Spot Tests,ICP-OES,and GC-MS

The identification of chemical activity residues on archaeological surfaces requires the analysis of large numbers of samples, which can be costly and time consuming. Researchers wishing to apply sediment chemistry often are confronted with a dilemma of which technique to use and how to accommodate sediment chemistry into their budget. We propose an approach to the identification of chemical activity residues in which semiquantitative spot tests, which are cheap, quick, and easy to apply, are employed as an initial phase of analysis in order to leverage the results of more time-consuming and costly instrumental techniques. Three examples that pair spot tests with gas chromatography-mass spectroscopy and inductively coupled plasma-optical emission spectrometry analysis show that spot tests successfully identify areas of interest. This approach can save both time and research funds.     

Identifying domestic functional areas. Chemical analysis of floor sediments at the Classical-Hellenistic settlement at Düzen Tepe (SW Turkey)

For over a decade, multi-element chemical analysis of floor sediments in archaeological contexts has been a tool to identify and interpret anthropogenic chemical residues and activities. For the current study, a multi-element chemical analysis was applied to floor samples from a Classical-Hellenistic courtyard building at Düzen Tepe (SW Turkey). Among a series of 19 elements analyzed, K, Mg, Fe, P and Sr are thought to directly reflect anthropogenic chemical residues. The elements Cr, Mg, Ni, Pb and Ti are considered to reflect the geological background of the site, yet their contents seem to vary over different chemical residue zones, making them a suitable tool for delineating activity areas. Overall, the sampling and analysis techniques applied at Düzen Tepe – mild acid sample extraction and ICP-OES analysis – have proven to be fit for this kind of study. The analyses allow human activity zones within the study area to be identified and interpreted and deliver insights into the archaeological contexts that could not be obtained by archaeological research alone.     

Identifying biomolecular origins of solid organic residues preserved in Iron Age Pottery using DTMS and MVA

The chemical characterisation of solid organic residues found in ceramic vessels, can provide archaeologists with valuable information about ancient diets. Although several selective analytical techniques have been applied to the analysis of specific classes of compounds, such as extractable lipids, waxes, terpenoids and protein fragments, a non-selective analytical technique is required to characterise and categorise complete solid organic residues. In this study, Direct Temperature-resolved Mass Spectrometry (DTMS) is used for the characterisation of 34 solid residues situated on vessels recovered from an indigenous settlement from the Roman period at Uitgeest – Groot Dorregeest (The Netherlands). Sample preparation is limited to grinding very small samples (5–10 μg) and suspending them in water. DTMS analysis of aliquots (1–2 μL) of this suspension gave information about a broad range of organic compounds, such as lipids, polynuclear aromatic hydrocarbons, markers for residual proteins and polysaccharides, and for newly formed complex condensed polymers. Multivariate analysis of the DTMS spectra identified five different chemotypes: groups of residues with comparable chemical characteristics. The biomolecular origin of each of these chemotypes is identified by comparison with experimentally charred reference materials. The chemotypes A₁ and A₂ consist of charred residues identified as starch-rich foods (mixed with animal or plant products), chemotype C consists of protein-rich charred animal products without starch, chemotype B contains smoke condensates from wood fires, and chemotype D consists of special protein-rich and lipid-free foods or non-food products.     

Understanding residues of oil production: chemical analyses of floors in traditional mills

Oil production is an important aspect of ancient Mediterranean economy; therefore, archaeological studies on oil-producing installations using archaeometry and in particular the chemical analysis of absorbed residues is valuable in identifying the substances actually produced and to understand the spatial distribution of the activities carried out at oil mills.Modern contexts may provide a good reference for interpreting the archaeological chemical traces.This study examines the chemical traces in three abandoned oil mills in the Mediterranean: Polveraia (Tuscany, Italy), Martina Franca (Puglia, Italy) and Binibassi (Mallorca, Balearic Islands). To identify the residues released by the production of oil and absorbed by the floors, samples were taken from the floors of these installations and analysed using spot tests aimed at identifying the presence of fatty acids and phosphates. Some of the samples were analysed also with gas chromatography–mass spectrometry. The results of the analyses were plotted in the Geographic Information System (GIS) platform and interpolated with Inverse Distance Weighting (IDW) to determine the spatial distribution of the residues. Overall, the results show a large presence of fats in the analysed floors in all of the installations.     

Combining residue analysis of floors and ceramics for the study of activity areas at the Garum Shop at Pompeii

In this paper, we propose the application—for the first time in the Mediterranean area—of the combination of the study of chemical residues in floors and ceramics, with the aim of providing information about the activities carried out in archeological buildings. We chose the Garum Shop at Pompeii to test the method. In fact, due to the peculiarity of this archeological context, it provided an ideal case in which the activities performed are in part known, and the ceramic vessels recovered are still in situ. Floor samples were studied by means of spot tests developed in Mexico aimed at identifying the presence of phosphates, fatty acids, and protein residues, while the organic residues preserved in the ceramic matrix of amphorae, dolia, and other ceramic vessels were studied by gas chromatography coupled with mass spectrometry. Moreover, we integrated the data obtained with specific studies directed at better identifying the solid residues found inside two of the amphorae studied: botanical studies of fruit stones recovered in a Dressel 20 amphora and the characterization of the lime preserved in an African amphora. The research allowed for the identification of the traces of some of the activities performed, such as cooking and producing garum in the floors of the building, and the use and re-use of amphorae and dolia before the Vesuvian eruption.     

Analysis of DNA from Ethnoarchaeological Stone Scrapers

Analysis of DNA residues on stone tools provides a direct method of determining what the tools were used on. However, little is known about the taphonomy of DNA on tools. The discovery of present-day, stone-tool using hide workers in Ethiopia therefore provides a unique opportunity to study the survival and authenticity of DNA residues on stone tools. We collected stone scrapers from contexts ranging from excavated to confirmed use, as well as unused scrapers to test for the presence of DNA residues. We amplified segments of the mitochondrial genome with PCR to determine which animal species a tool was used on. We were able to recover authentic DNA from scrapers of known use and from a subset of excavated scrapers. We did, however, also obtain DNA unrelated to the use of the tools. Thus, caution must be used when interpreting results of DNA analysis of stone tools.     

Remains of the day-preservation of organic micro-residues on stone tools

Here I report on the decay processes of microscopic organic residues left on stone tool surfaces after their use. Residue analysis on ancient stone tools facilitates reconstruction of past activities. This study enables predictions about the circumstances under which ancient residues preserve. Experimental tool sets with modern residues were buried for a year in separate deposits at Sterkfontein, Sibudu (South Africa) and Zelhem (the Netherlands) whose pH and geomorphology varied, they were then analysed using light microscopy. Biological weathering mainly causes residue decay. In unstable environments rich in microbes and micro-organisms, residues decay quickly. From an archaeological perspective this means that sites that are stable, desiccated, waterlogged, extremely acidic or alkaline and extremely cold or hot sites. Different residue types have different preservation optima and this may lead to a preservation and perhaps interpretation bias. The preliminary predictive models presented in this paper could aid in the considered selection of sites and samples.     

ORGANIC RESIDUE ANALYSIS IN ARCHAEOLOGY: THE ARCHAEOLOGICAL BIOMARKER REVOLUTION*

Organic residue analysis utilizes analytical organic chemical techniques to identify the nature and origins of organic remains that cannot be characterized using traditional techniques of archaeological investigation (because they are either amorphous or invisible). The field is founded upon the principle that the biomolecular, or biochemical, components of organic materials associated with human activity survive in a wide variety of locations and deposits at archaeological sites. The archaeological information contained in organic residues is represented by the biomolecular components of the natural products that contribute to the formation of a given residue. By applying appropriate separation (chromatographic) and identification (mass spectrometric) techniques, the preserved, and altered, biomolecular components of such residues can be revealed. Once identified, the Archaeological Biomarker Concept can be applied, wherein the structure and even isotopic composition(s) of a given biomolecule or suite of biomolecules (the ‘chemical fingerprint’) can be related to the compositions of organisms exploited by humans in the past. As the organic residue field emerges from its pre‐paradigmatic phase, and the organic residue revolution gathers pace, the way is open for challenging many long‐held archaeological hypotheses and offering new perspectives on the study of human activity in the past.     

The Latest Objects from Silchester,Hants

THIS paper brings together for the first time a selection of medieval glass and pottery distilling-vessels from British sites. A discussion on the technical aspects of distilling by F. Greenaway (Part I) is followed by a report on two important groups of glass and pottery distilling-apparatus from Selborne and Pontefract priories of the middle and late 15th century respectively (Part II). Part III discusses pottery distilling-vessels from other finds in Britain. Two types of pottery alembic are distinguished and their use in association with bases of either furnace or bowl type is suggested; industrial bottles connected with distilling are also briefly considered. The survey has brought much information to light but has also left many problems unanswered. Coordination of documentary research into techniques, archaeological recognition of vessels, and the chemical analysis of residues is necessary before firm decisions can be made about the uses of the vessels and the types of unit required for specific operations. It is hoped that this paper will stimulate further work in this field.     

Geochemical analysis of Late Classic and Post Classic Maya marketplace activities at the Plazas of Cobá, Mexico

Abstract

Lines of evidence for ancient exchange plazas may include trade routes and trade artifacts, urban open space near public structures, and rock alignments denoting market stalls, but regular patterns in soil chemical concentrations also point to marketplace use. We applied geochemical and geospatial analysis of the floors of the main Plaza of Group B and Plazas A, H, and J of Group D at Cobá, Mexico, to discover the chemical residues of phosphorus (P) and metals associated with the exchange of foodstuffs and mineral workshop items that may have been marketed there. The patterns of chemical residues in the floor of the Group B Plaza suggest ritual activities while the linear, parallel patterns of elevated Mehlich phosphorus and chelate extractable zinc concentrations in Plaza A support the hypothesis of market exchange at that location. Plaza H is associated with several Postclassic buildings, including the Pinturas Structure D-33. During the Postclassic period, Cobá had lost much of its population, though chemical residues from Plaza H are congruent with marketing. We argue that Plazas A and H were not permanent marketplaces but rather multi-purpose locations that also hosted large ceremonies.     

Revealing the Monastic Kitchen: Chemical Analysis of the Soil Inside the Monastery of Cornellana (North‐West Spain)

The residues deposited on the floor of the kitchen of the monastery of Cornellana (Asturias, Spain), while it was still in use in the 18th century, have been analysed using different techniques, including the Kjeldahl method, phenol – sulphuric acid assay, FT–IR, SEM–EDX and LOI. This has allowed us to determine the areas of concentration of proteins, carbohydrates, fatty acids, phosphorus and carbonates, and thus approach the interpretation of the layout of the different areas of activity related to the treatment and cooking of foodstuffs in the kitchen. In any case, and regardless of the fact that this is the first time that these techniques have been applied to study a monastic kitchen in the Iberian Peninsula, the aim of this research is to demonstrate their applicability to other case studies of this integrated set of analytical techniques, some of which are not used very often in the analysis of concentrations of residues and analysis of areas of activity on archaeological soils.     

Phosphatic mineralization of seeds from archaeological sites

Recent investigations of botanical material from archaeological sites have provided seeds and plant remains exhibiting a crystalline or semi-crystalline appearance. X-ray diffraction and partial chemical analysis have revealed that the particular plant materials had been replaced by calcium phosphate. Using systematic sampling and retrieval techniques a significant body of data has been accumulated. Most mineralized botanical evidence has been recovered from faecal deposits, in particular cess pits and garderobes, and has provided an important source of information about aspects of diet of past populations.     

Chemical analyses of organic residues in archaeological pottery from Arbon Bleiche 3, Switzerland – evidence for dairying in the late Neolithic

Fatty acids distribution and stable isotope ratios (bulk δ¹³C, δ¹⁵N and δ¹³C of individual fatty acids) of organic residues from 30 potsherds have been used to get further insights into the diet at the Late Neolithic (3384–3370 BC) site of Arbon Bleiche 3, Switzerland. The results are compared with modern equivalents of animal and vegetable fats, which may have been consumed in a mixed ecology community having agrarian, breeding, shepherd, gathering, hunting, and fishing activities. The used combined chemical and isotopic approach provides valuable information to complement archaeological indirect evidence about the dietary trends obtained from the analysis of faunal and plant remains. The small variations of the δ¹³C and δ¹⁵N values within the range expected for degraded animal and plant tissues, is consistent with the archaeological evidence of animals, whose subsistence was mainly based on C₃ plants. The overall fatty acid composition and the stable carbon isotopic compositions of palmitic, stearic and oleic acids of the organic residues indicate that the studied Arbon Bleiche 3 sherds contain fat residues of plant and animal origin, most likely ruminant (bovine and ovine). In several vessels the presence of milk residues provides direct evidence for dairying during the late Neolithic in central Europe.     

Field Methods for the Analysis of Mud Brick Architecture

Recent research into mud brick architecture have established that the simple mud brick is a potential source of cultural information and can provide information about chronology, technology, identity, labor, resources, and environmental conditions. Some analytical techniques for the analysis of sun-dried mud bricks are dependent on the exportation of archaeological samples to foreign laboratories. Some countries severely restrict (or prohibit) the export or removal of archaeological materials making it essential to conduct analysis while in the field. This paper demonstrates the successful use of in-field procedures using a range of portable equipment to quantify basic mud brick characteristics, including particle size distribution through wet sieving, RGB color, magnetic susceptibility, and acid digestion to quantify calcium carbonate. Field and laboratory methods were compared on a single data set, specifically the assemblage from the Neolithic Anatolian site of Çatalhöyük. The results confirmed the accuracy of these methods and provide effective field techniques for mud brick analysis. This article provides an overview of recent research highlighting the importance of mud brick studies and provides procedures for in-field analysis of materials.     

Phosphate Analysis of Anthropic Soils

Abstract

The use of phosphate analysis in archaeology is possible because past human occupation and activities increased the amount of soil phosphorus in the areas occupied. The accumulated phosphorus in archaeological deposits tends to remain constant through time and is measurable through soil sampling and chemical analysis, thereby providing archaeology with a valuable tool, applicable to a wide variety of research situations. Phosphate analysis is especially useful in surveying large areas to locate and delimit sites.     

Identifying Chemical Activity Residues on Prehistoric House Floors: A Methodology And Rationale For Multi‐Elemental Characterization of a Mild Acid Extract of Anthropogenic Sediments

Archaeologists have employed sediment chemistry in site prospection for nearly a century. For example, phosphorus is a good indicator of human occupation, because it is a generic indicator of human activity. Recently, multi‐element studies of sediments have successfully identified specific activity areas by analysing other elements in addition to phosphorus. To reach its full potential, however, sediment chemistry must be undertaken with an understanding of how these residues are formed and of the chemical indicators that can be used to identify specific activities. Methodologies that optimize the extraction of specific residues must be employed. Not to do so is a naïve application of the technique.