Demography and ethnic continuity in the Tlailotlacan enclave of Teotihuacan: the evidence from stable oxygen isotopes

Mechanisms for the maintenance of Zapotec ethnicity in Tlailotlacan, an enclave of Teotihuacan, Mexico, are reconstructed using oxygen-isotope analyses of bone and enamel phosphate. The data indicate continual interaction among the enclave inhabitants, their Oaxacan homeland, and other diaspora colonies, with no dominant post-marital residence pattern. There is no apparent association between social status and place of origin, and individual agency is indicated by variable acceptance of Teotihuacan traditions. Striking patterns of movement include the sojourning of children in other regions and the relocation of breastfeeding women. These segments of the population would have played major roles in the social and political articulation of diaspora colonies. Foreign signatures in primary burials indicate that some immigrants died shortly after their arrival in Tlailotlacan. Data from secondary burials indicate the transportation of dead relatives or ancestors to Teotihuacan for burial. We conclude that the behaviour of immigrants in ancient and modern cities is analogous in many ways.     

Provenance of glass shards in archaeological lime plasters by LA-ICP-MS: implications for the ancient routes from the Gulf of Mexico to Teotihuacan in Central Mexico

We present the chemical characteristics of samples collected from the central courtyard of Teopancazco, a neighbourhood centre in Teotihuacan (Mexico), the most important classic Mesoamerican city. The rhyolitic glass shards used as aggregates have a composition comparable to the glass material sourced from the magmatic system of Altotonga (located along the route to the Gulf Coast). People travelling from the Gulf Coast may have transported the glass shards to Teotihuacan during the Xolalpan phase (350–550 AD). However, the reasons for using glass shards as a construction material remain unknown. These new data confirm the close relationship between inhabitants of Teopancazco and the Gulf Coast already revealed by previous archaeological and archaeometric studies.     

Chronologies in wood and resin: AMS C dating of pre-Hispanic Caribbean wood sculpture

This paper establishes a chronological framework for selected pieces of Caribbean (Taíno/Lucayan) wooden sculpture, enabling previously ahistoric artefacts to fit back into the wider corpus of pre-colonial material culture. Seventy-two ¹⁴C AMS determinations from 56 artefacts held in museum collections are reported, including 32 ceremonial duhos, or seats. Far from being constrained to the last few centuries prior to contact, the dates for these objects extend back to ca. AD 250, and include the artistic legacies of various cultures. Duhos in both low and high back styles are present from about AD 600, if not earlier, in a distribution that spans the Antillean island chain from Trinidad to Cuba. Complex, drug-related paraphernalia and elaborate ancestral reliquaries are in evidence by AD 1000, as are some distinctive regional styles – such as the unique iconography from the Bahamas and Turks and Caicos islands. This paper explores relevant methodological issues – from the challenges of working with museum pieces (e.g., uncertain provenance, discrete sampling techniques, impact of previous conservation treatments on dating results), to dealing with potential ‘in-built’ age in tropical hardwoods.     

The wood in the pits of terracotta figures and its architectural application

Ever since the pits of terracotta warriors and horses in China were discovered and opened to the public, a number of questions remained unsolved: what kinds of wood were selected for building the pits, how the wood was used in the pits' architecture and where was the giant volume of wood collected from? In this study, twenty pieces of charcoal specimens from Pit 1 and Pit 2 were examined with the Scanning Electron Microscope and identified as Abies, Tusga, Picea (all three genera in Pinaceae) and Phoebe (Lauraceae) woods. With the former works, it is concluded that the woods in the pits were mainly from the group of gymnosperms (95%) and few from that of angiosperms (5%). It is deduced that the wood in the pits was probably collected from the areas nearby.     

Morphological,chemical and physical changes during charcoalification of wood and its relevance to archaeological contexts

Wood exposed to a heat source can be transformed into charcoal if subject to conditions of carbonisation (in the absence of air) or charring (in restricted air). Charcoal recovered from archaeological sites can yield fundamental information to our understanding of human economic and cultural development over time and (ecological) setting. This work describes the morphological (anatomy, degree of shrinkage), physical (reflectance) and chemical (elemental, molecular composition) properties of charcoal in relation to heat source and wood variables. In this study charcoal and charcoal fuel were experimentally produced whereby temperature (160–1200 °C), time of exposure (2–1440 min), heating rate (high and low) and wood type (angiosperm and conifer) were varied. The results show that charcoal, often described as an inert, black material, has different chemical and physical properties in relation to the investigated variables. By using these different properties it is possible to distinguish between the different types of fires (domestic and industrial) exploited by humans in the past. Morphological analyses and reflectance measurements are effective tools for this purpose and can be used in wood exposed to temperatures of 300 °C and above—temperatures which are relevant to archaeological research. Angiosperm and conifer wood react in different ways when exposed to heat and thus the taxonomic identity of archaeological material needs to be known. Chemical analyses can be used for wood exposed to temperatures below 400 °C whereas elemental analyses of the carbon content can be used for wood exposed to temperatures up to a maximum of 650 °C.     

New trials in the consolidation of waterlogged archaeological wood with different acetone-carried products

Some acetone-carried consolidants for waterlogged archaeological wood were tested in order to evaluate treatments able to save time and energy. In details, colophony (rosin), two esterified colophonies (Rosin 100^® and Rosin 459^®), a mixture of colophony with PEG 3400 and a vinyl acetate - vinyl versate copolymer (Vinavil 8020S^®) were tested. The treatments were carried out at temperatures of 20 and 35 °C on waterlogged maritime pine, elm, oak and beech. The materials came from the archaeological site of the ancient ships of Pisa (Tuscany, Italy) and were dated back to VII cent. BC – II cent. AD. To evaluate the processes, equilibrium moisture content and dimensional stability of treated wood samples at different relative humidity, and retention of impregnating products were measured; moreover macroscopic and microscopic examination were also run to respectively assess the shape and appearance of treated wood and the way of deposition of consolidants. The results highlighted that natural and modified colophony treatments gave the most satisfactory results both in the maintenance of shape and dimensions of samples and in the stabilization with respect to RH variations. Moreover, the equilibrium moisture contents of samples treated with R100 and R459 were much reduced in comparison to the other consolidants and to untreated archaeological wood. This fact was related to the high retention values of those products that occluded most of the porosity including the microporosity of cell walls. Therefore, in terms of higroscopicity treated wood was more similar to impregnating substances rather than to decayed wood. This fact was considered helpful in contrasting the moisture-related negative effects in cases of eventual faults in the climate control during e.g. exhibition and in protecting treated wood from the risks of new fungal attacks.     

Reasoned use of chemical parameters for the diagnostic evaluation of the state of preservation of waterlogged archaeological wood

Waterlogged archaeological wood undergoes decay processes that depend on both the burial conditions and the constituting species, and which cause the depletion of the structural components of wood cells. To quantitatively assess the state of preservation of the decayed material, specific parameters are usually measured by means of both chemical and physical analyses. In this paper an innovative approach in the use of the data obtained from these kinds of measurements is developed. A series of 132 archaeological wood samples of different wood species, burial times and states of preservation, and coming from different sites in Italy, was analysed. Their residual chemical composition, maximum water content and basic density were measured, and a reasoned use of these parameters was carried out through their elaboration, with the aim of both evaluating eventual incongruence or anomalies in the raw physical and chemical data (which has never been accomplished so far) and directly comparing in a reliable way the analytical results obtained from archaeological samples with very different states of preservation. This approach allowed defining the effective values of chemical parameters related to wood decay according to a same reference basis of calculation among the various data. By this way, it was possible to state that lignin can be also attacked by the agents causing biotic decay, and that in hardwoods its decay is more related to the burial conditions than to the wood species. Instead, the mechanism of polysaccharide depletion is diversified: conifers showed a uniform behaviour whereas hardwoods were more species-dependent. Moreover, in addition to the chemical composition, also anatomical factors influence the carbohydrate rate of decay in waterlogged wood.     

Prehistoric land use at an archaeological hot-spot (the rock art park of Campo Lameiro,NW Spain) inferred from charcoal,synanthropic pollen and non-pollen palynomorph proxies

Pollen, non-pollen palynomorphs and charcoal from a colluvial soil surrounded by prehistoric petroglyphs (Campo Lameiro, NW Spain) were studied in order to assess the nature of human activities and their impact on Holocene vegetation patterns. Several phases of anthropogenic impact were observed. (i) Between 7.6 and 6.5 ka cal BP, synanthropic taxa (Urtica dioica type, Plantago lanceolata type) and coprophilous fungi (e.g. Sporormiella-type) are indicative of early (pre-agricultural) creation of small patches of pasture using fire, possibly for incipient animal husbandry or as part of a deliberate strategy to improve game availability. Such activities only had a minor effect on the deciduous Quercus-dominated forest established earlier during the Holocene Thermal Maximum. (ii) Between 5.9 and 4.8 ka cal BP a more intense signal indicative of pastoral activity was detected, corresponding to the Neolithic period. (iii) Between 4.8 and 3.4 ka cal BP, which fits within the hypothetical timeframe of petroglyph creation, the synanthropic and humidity (e.g. Cyperaceae, Mougeotia) indicators diminished while charcoal concentration increased, which can be explained by Mid-Holocene cooling/drying (Neoglaciation) in combination with reduced human impact, or by non-pastoral activities in the area possibly in association with the development of the rock art culture, converting pasture to protected open ground through anthropogenic fires. (iv) During the Late Bronze Age and Early Iron Age (3.4–2.5 ka cal BP), grazing pressure and fire regime intensity are high, coinciding with evidence of regional forest regression, despite an amelioration in climate. (v) Later phases, not corresponding to prehistoric rock art contexts, include a phase of heavy grazing and reduced fire frequency (from ca. 2.5 to 1.2 ka cal BP) as well as the near complete elimination of the deciduous woodland, the expansion of ericaceous shrubland and the evidence of local agriculture and afforestation. These results are consistent with earlier studies in the area and highlight the spatial heterogeneity in the vegetation especially during periods of prehistoric anthropogenic interference.     

The use of forest resources in central Iberia during the Late Iron Age. Insights from the wood charcoal analysis of Pintia,a Vaccaean oppidum

Charred woods may be used to effectively reconstruct past wood acquisition strategies. We used anthracological data from the pre-Roman settlement of Pintia (Padilla de Duero, Valladolid) to examine the use of forest resources at the local scale. Palaeoecological data revealed heterogeneous landscapes in the inland northern meseta with environments that offered diverse sources of wood for the inhabitants of Pintia, one of the first cities of inland Iberia. Pines (Pinus pinea/pinaster and Pinus sylvestris/nigra) and both evergreen and deciduous Quercus L. and Juniperus L. were the main taxa identified as both fuelwood and construction elements, but the assemblages and frequencies of these taxa differed depending on their use. We also examined the potential of models from human ecology by considering the frequency, handling time and the relative technological value of each taxon to model how people gathered wood resources. The results suggest that although local availability affected the forest resources that were used by the Vaccaei people, specific taxa were positively selected for specific uses.     

Stable carbon and oxygen isotopic compositions of wood ash: an experimental study with archaeological implications

Wood ash, composed mainly of the mineral calcite, is an important component in many archaeological sites. Identification of wood ash in the archaeological record is often difficult due to mixing of ash with other calcitic components of geogenic origin and/or due to diagenetic changes. A recent empirical study using the stable isotope compositions of carbon (δ¹³C) and oxygen (δ¹⁸O) in wood ash enabled the identification of mixtures of wood ash with geogenic calcite and to follow diagenetic changes due to partial dissolution and re-precipitation of ash in two prehistoric cave sites in Israel. Little however is known about the processes responsible for the isotopic compositions of wood ash in relation to formation at various temperatures and the influence on isotopic composition of ash from a variety of plant species. Here we present an experimental study of wood ash formed by burning three C3 tree species and one C4 desert bush at different temperatures. The results indicate that there are significant differences in the isotopic compositions of carbon and oxygen between wood ash that forms by combustion at a relatively low temperature (500 °C) and at a higher temperature (900 °C). In addition, we show that the isotopic composition of carbon and oxygen in high temperature wood ash approaches equilibrium over a period of several months and that the carbon isotopic composition of low temperature wood ash may reflect the photosynthetic pathway of the burnt woody species. Lastly, we show that the isotopic compositions obtained from wood ash prepared at different temperatures do not reflect a temperature dependent fractionation process, but a mixing line between calcite that formed by low temperature combustion and calcite formed by high temperature combustion which later underwent re-carbonation with atmospheric CO₂. In addition, we suggest that exchange processes may possibly occur during combustion between decomposing calcium-oxalate and atmospheric O₂, CO₂ and CO. The archaeological implications of this study are discussed in relation to identification of wood ash in the archaeological record, identification of fuel sources and burning temperatures, and diagenetic changes expected in karstic cave environments. The method presented here can be applied at any archaeological site.     

Ancient Maya wood selection and forest exploitation: a view from the Paynes Creek salt works,Belize

Ancient building construction wood preserved in a peat bog below the seafloor in a shallow mangrove lagoon in Paynes Creek National Park, Belize, provides an exceptional record of Classic Maya wood use. Identifications of construction wood at Early Classic Chan B'i, and Late Classic Atz'aam Na, are reported and discussed to assess forest exploitation and species selection over time. Black mangrove (Avicennia germinans) dominates the Early Classic assemblage. The Late Classic assemblage is characterized by greater variability and an absence of mangrove species. When considered in the environmental context, identified species conform to principles of optimal foraging. The change in the wood assemblage over time suggests overexploitation of forest resources, resulting in deforestation of the local landscape and subsequent adaptation of foraging behavior. Deforestation is linked to the wider social context in which growing inland populations created demand for salt, putting greater pressure on the forest resources exploited by the Paynes Creek salt works for fuel and timber.     

Archaeobotanical inference of Bronze Age land use and land cover in the eastern Mediterranean

Charcoal and charred seeds at five Bronze Age archaeological sites discern ancient land use in the eastern Mediterranean. Seed frequencies of orchard crops, annual cereals and pulses, and wild or weedy plants are used to characterize plant utilization at different archaeological sites on the island of Cyprus, in the Rift Valley of Jordan, and in the Jabbul Plain and along the upper Euphrates River valley in Syria. Seed to charcoal ratios provide proxies to determine the relative usage of dung versus wood for fuel across the ancient Mediterranean landscape. Greater charcoal and lower charred seed values are interpreted to represent a wooded environment, while higher amounts of charred seeds and minimal wood charcoal suggest a much great use of dung as a fuel source. Interestingly, Politiko-Troullia (Cyprus, Cypriot archaeological sites are, by convention, named for the nearest modern village (Politiko), followed by an italicized toponym (Troullia) referring to the plot of land that incorporates the site) has the lowest seed to charcoal ratio, suggesting its residents primarily burned wood and that the landscape surrounding Troullia remained relatively wooded during the Bronze Age. In contrast, villagers at Tell el-Hayyat (Jordan) utilized a mixture of wood and dung, in contrast to Tell Abu en-Ni’aj (Jordan), and especially Umm el-Marra and Tell es-Sweyhat (Syria), where inhabitants relied solely on dung fuel. Comparative analysis and interpretation of seed and charcoal evidence thus illustrates the variety of fuel use strategies necessitated by the dynamic and diverse Bronze Age landscapes of the Eastern Mediterranean.     

On the provenience of wood used in the manufacture of snuff trays from San Pedro de Atacama (Northern Chile)

The consumption of hallucinogenic substances is a long-standing tradition in the Americas. San Pedro de Atacama (SPA) in Northern Chile is the archaeological zone with the highest incidence of snuffing implements in the world. Snuff trays from SPA have been studied under a variety of prisms but their provenience, in particular that of the wood used in their manufacture, has not yet been addressed. The delicate nature of trays and their excellent state of preservation call for the use of non-invasive analytical methods. Wood density was used to demarcate a possible range of species and hence as a broad provenience marker, and its value determined for 169 trays from the museum at San Pedro de Atacama. The results showed that although some of the SPA snuff trays studied may have been manufactured with local wood, most of them used exogenous wood as raw material. At this point, it is not possible to ascertain the precise origin of such wood, but Bolivia and NWA appear as likely candidates. Three distinct styles have been defined for SPA trays: Tiwanaku, San Pedro, and Circumpuneño (encompassing the area around the Puna de Atacama and including SPA). The effect of style on density points to different sources of wood in Tiwanaku style trays and trays in San Pedro and Circumpuneño styles. As expected from geographically and temporally dynamic patterns of interaction of SPA with neighboring regions, diachronic differences in wood density distributions were found. Tray manufacturing technique was not dependent on wood density, suggesting that the skill of artisans and the quality of their tools allowed them to use any type of wood for their art work, independent of its complexity.     

Museum salvage: A case study of Mesoamerican artifacts in museum collections and on the antiquities market

Abstract

Museum salvage refers to critical studies of museum collections with little or no provenience information that seek to glean useful archaeological information from these artifacts and examine the nature of their origins and possible connections to the illicit antiquities trade and the art market. Our case study focuses on artifacts from Mesoamerica and objects from the ancient capital of Teotihuacan in particular. We take a multi-scalar approach, including a quantitative analysis of Sotheby’s auction records for Mesoamerican items from 1966 to 2010, a survey of Teotihuacan attributed items in U.S. museums, and a more detailed examination of Teotihuacan-style artifacts in the Denver Museum of Nature & Science collections. The study tracks and attempts to explain diachronic patterns in the Mesoamerican antiquities trade, connections to museum collecting practices, and looting behavior. The study illustrates the potential benefits of museum salvage, while also revealing the clear limitations of research on poorly documented archaeological material.     

Preservation,storage and display of waterlogged wood and wrecks in an aquarium: “Project Aquarius”

A test aquarium containing water and waterlogged historical wooden material was observed during a three-year period at Vänernmuseum, Sweden, to test the feasibility of preserving and exhibiting archaeological wood or shipwrecks in a way accessible to the public. Experiments were also set up in a laboratory environment, to provide information on single factors that could influence the long-term preservation state of wood, and other processes that may occur in the water.     

The ethnoarchaeology of firewood management in the Fang villages of Equatorial Guinea, central Africa: Implications for the interpretation of wood fuel remains from archaeological sites

In archaeological literature, the study of trees and wood remains is a topic of relatively marginal interest, especially compared to texts on crops and human–animal relations. However, charcoal is the most frequent botanical remain found in archaeological sites. Charcoal analysis can therefore play a major role in the development of studies in both landscape and palaeoethnobotanical reconstruction. The majority of the archaeological charcoal assemblages reflect the exploitation of wood as an energy source (fuel). The archaeological study of firewood selection has been predominantly developed from “eco-utilitarian” or “subsistence economy” perspectives, but has not yet considered fuel collection and use as one of the most enduring categories of human–environment interactions, nor has archaeology looked into its potential as a source of empirical information on past perceptions of, and interactions with, ancient landscapes. The aim of this paper is to expand previous archaeological work on the interpretation of charcoal macro-remains through the study of firewood collection as a historically constituted, socially mediated and archaeologically observable landscape practice. In order to achieve this, we present an ethnoarchaeological case study from the Fang society of Equatorial Guinea (central Africa) aimed at gaining a better understanding of the complex interactions between cultural, ecological and economic variables in firewood collection strategies.     

Reburial of shipwrecks in marine sediments: a long-term study on wood degradation

Historical shipwrecks in marine environments are continuously decomposed by wood-degrading organisms, adapted to this specific environment. To protect the wrecks from degradation and to preserve the unique remains for future generations, reburial of wrecks using various covering materials has been suggested as a long-term preservation method. The following experiment was carried out to study the bio-protective effect of sediment. Sound oak, pine, and birch samples were buried above and within marine sediment in Marstrand harbour, and retrieved for analysis after 6, 12, 24, and 36 months. Macroscopic as well as light-microscopic examinations were carried out on each occasion. Marine borers (shipworm, Limnoria), soft rot and tunnelling bacteria were wood degraders immediately above the seabed; soft rot, tunnelling bacteria, and erosion bacteria were active 10 cm below the seabed; erosion bacteria were the only degraders at a depth of 43 cm below the seabed. The wood species had different durability towards the decay agents. After 3 years, wood samples above the seabed were totally decomposed, whereas wood was highly protected at 43 cm depth in sediment. In the sediment, decay decreased significantly with depth of burial. The results suggest that reburial of shipwrecks in marine sediment can be recommended as a simple and efficient method for long-term preservation of the wooden cultural heritage.     

Selected physical parameters to characterize the state of preservation of waterlogged archaeological wood: a practical guide for their determination

Non-destructive and destructive methods for determining the physical parameters of waterlogged wood such as the porosity, the water content, the wet and dry bulk densities plus the density of the cell wall material are presented. Considerations in respect to determination of masses, volumes and sampling size are discussed.