Pig diet in medieval York: carbon and nitrogen stable isotopes

This study investigates bone stable isotopes from pigs from medieval York, to characterise the pigs' diet and to explore their contribution to isotopic values from contemporary human bones. Pig bones from the Swinegate (N?=?9) and Coppergate (N?=?14) sites were used for carbon and nitrogen stable isotope analysis to test the hypothesis that the majority of pigs in medieval York were yard-kept and fed on scraps and fish waste, elevating their nitrogen ratios. The results show that the Swinegate and Coppergate pigs gave nitrogen isotope values similar to contemporary sheep and therefore that animal protein made little or no dietary contribution. One sample showed C and N results consistent with more animal protein in the diet, and we propose that this could have been a yard-kept pig consuming human refuse. The majority of the data indicate that the pigs were eating a largely herbivorous diet and that pigs in medieval York may have been raised in rural or woodland locations rather than in the city.     

The children of Kaminaljuyu: Isotopic insight into diet and long distance interaction in Mesoamerica

Known for its spectacular tombs and adobe talud–tablero architecture, the highland Guatemalan city of Kaminaljuyu is key to models of long distance interaction in Mesoamerica. We use stable isotopic data from human bone, dentine and tooth enamel to reconstruct Kaminaljuyu’s dietary history. Stable carbon isotope ratios and alkaline earth ratios of enamel carbonate indicate a decline in maize consumption from Preclassic to Classic periods, perhaps due to the desiccation of Lake Miraflores, which was used to irrigate Late Preclassic fields. Stable oxygen and strontium isotope ratios in enamel shed light on the geographic origin of Early Classic skeletons, and show that the central skeletons in the tombs were local children. However, four decapitated skulls and two peripheral skeletons show enriched oxygen ratios, similar to Lowland Maya sites. Strontium isotope ratios indicate that most of these are from an area underlain by Cretaceous limestones; one is from a metamorphic region. Two individuals may have traveled to or from Central Mexico. The greater evidence for lowland individuals among the tomb skeletons implies that political connections with the Maya area were more significant to elites at Kaminaljuyu than was direct contact with Central Mexico.     

Modern and early-middle Holocene shells of the freshwater mollusc Unio, from Çatalhöyük in the Konya Basin, Turkey: preliminary palaeoclimatic implications from molluscan isotope data

Carbon and oxygen isotope ratios in the shells of the freshwater Unio mollusc yield information on the isotopic composition of the water in which the shell was formed, which in turn relates to climatic conditions prevailing during the bivalves’ life span. Here we analysed shells from one modern Unio, from a modern lake shore in Anatolia, and 4 subfossil Unio shells from Çatalhöyük (dated between 7200 BC and 5000 BC, Neolithic and Chalcolithic periods). Sequential carbon and oxygen isotope analysis along the surface of the shells provides information on seasonal or shorter-term variability of lake waters during the lifetime of the organisms. δ¹⁸O values of the modern shell are consistent with it being collected from a dammed portion of the Seyhan River that does not undergo intensive summer evaporation. This is in contrast to many of the surface water bodies in Anatolia which suffer extensive evaporation in the arid summers. δ¹⁸O values of the subfossil shells from the Çatalhöyük middens indicate that the bivalves came from lakes which evaporated extensively during the summer months but were replenished by high winter rainfall, suggesting that the subfossil shells lived in relatively small lakes or ponds. Stable isotope analysis along the growth of freshwater bivalves is one of the few methods for investigating seasonal water fluctuations in the past. These results may alter current interpretations on the environment of Çatalhöyük during the Neolithic, although more work is needed to confirm these initial findings.     

Distinguishing sheep and goats using dental morphology and stable carbon isotopes in C4 grassland environments

Distinguishing between sheep and goats in C₄ grass environments using new dental morphology criteria and enamel bioapatite stable carbon isotope ratios (δ¹³C) was tested on 35 modern individuals from the Central Rift Valley of Kenya. Two morphological criteria on the second and third lower molars, one of which had been previously partially described by Halstead et al. [Journal of Archaeological Science 29 (2002) 545], were found to be highly reliable in this population. Identification of species using carbon isotope ratios is made possible in some circumstances by differences in the feeding behavior of sheep, which are mainly grazers, and goats, which are mainly browsers. In environments where C₄ grasses predominate, sheep include a higher proportion of C₄ plants in their diet, and thus have higher δ¹³C values than goats. In the present study, the annual range and seasonal variation of carbon isotope ratio of diet of sheep and goats was measured from intra-tooth sequential analysis. Although the ranges of goat and sheep δ¹³C values overlap, those higher than −3.4‰ all belong to sheep; values lower than −5.2‰ all belong to goats. There is no overlap of the mean δ¹³C values by tooth, which range from −11.8‰ to −4.2‰ for goats, and from −3.1‰ to −1.3‰ for sheep. These results suggest that carbon isotope analysis of bone collagen and/or apatite will also distinguish sheep from goats in tropical C₄ grasslands. Application of the δ¹³C criteria to archaeological material must be restricted to C₄-dominated environments, and where potential access to C₃ plants (mobility, foddering) can be assessed. The utility of these morphological and isotopic criteria for differentiating sheep and goat breeds in other regions remains to be evaluated.     

Isotopic analysis of the ecology of herbivores and carnivores from the Middle Pleistocene deposits of the Sierra De Atapuerca,northern Spain

Carbon and oxygen isotope values reveal resource partitioning among the large mammal fauna from three contemporaneous Middle Pleistocene hominid-bearing localities within the Sierra de Atapuerca (northern Spain). Carbon isotope values sampled from the tooth enamel of fauna present during Atapuerca Faunal Unit 6 show that a C₃-dominated ecosystem surrounded the area where fossils were preserved during this time. For the herbivores, Fallow deer isotope values are significantly different from Red deer and horses and show that this species did not forage in open environments at this locality. Red deer and horses show similar feeding strategies with less negative carbon values implying use of more open environments for these taxa. For the carnivores, carbon isotope values for Ursus deningeri are significantly different from either lions (Panthera leo) or foxes (Vulpes vulpes) and support the contention that this species is herbivorous. Special metabolic mechanisms involved in hibernation in U. deningeri might also have influenced its isotope values. The carbon isotope values of remaining carnivores were similar and suggest that each was typically a generalist carnivore, eating a wide variety of prey items. While the isotopic results generally correspond to ecology indicated by previous techniques, this study shows that isotope analyses can provide further insights that alternate techniques do not provide. Isotope analyses can help elucidate the ancient ecology of taxa present in the Sierra de Atapuerca during the Middle Pleistocene allowing for an accurate portrayal of the setting in which humans lived.     

Stable Isotope Record of Human and Sheep Enamel Carbonate from the Ancient Middle Euphrates Valley (Syria)

Stable isotope analyses of human tooth enamel have allowed us to reconstruct the isotope composition of dietary carbon, changes in the oxygen isotope composition of drinking water and the possible migration of humans in ancient Terqa and Tell Masaikh (SE Syria). δ¹⁸O_carbonate values of human tooth enamel from the interval comprising the Neo‐Assyrian to the modern Islamic periods (from 900 BC to AD 1949) generally mirror the isotope composition of Euphrates water, which is believed to have been a major drinking water source. Lower δ¹⁸O_carbonate values of human Bronze Age apatite are linked to a different hydrologic system that was present in the Middle Euphrates valley at that time (2650–1700 BC). Higher δ¹⁸O_carbonate values of some individuals in the Neo‐Assyrian (900–700 BC) and Islamic periods (AD 600–1200) may indicate human migration from the interior of the Near East. Low δ¹³C_carbonate values (−11.3 to −12.4‰) of human tooth enamel from the interval comprising the Early Bronze to the Islamic periods (from 2650 BC to AD 1200) indicate C₃ plants as a predominant source of dietary carbon. Changes in human dietary customs in SE Syria (with inferred usage of C₄ plants) occurred in the modern Islamic period only (AD 1850–1949). Oxygen and carbon isotope data of sheep enamel show the usage of water bodies characterised by an enhanced evaporation rate during the Neo‐Assyrian time (900–700 BC) and grazing sheep herds on drier areas during the Islamic and the modern Islamic periods (after AD 600). Copyright © 2015 John Wiley & Sons, Ltd.     

Locating Land Use at Neolithic Çatalhöyük,Turkey: The Implications of 87Sr/86Sr Signatures in Plants and Sheep Tooth Sequences

We evaluate local versus distant land‐use models at Neolithic Çatalhöyük, central Anatolia, using strontium isotope analysis of sheep tooth enamel and charred plant remains. Interpretation of strontium in sheep tooth sequences is constrained by previous oxygen isotope work, which largely excludes summer movement to the mountains but cannot distinguish between herding on the plain and the closest upland‐zone, Neogene limestone terraces. We establish a baseline contrast in modern plant strontium values between the plain and terraces and infer predominant herding on the plain from seven sheep tooth sequences. Archaeobotanical plant strontium values exclude the use of the terraces for cultivation and foraging. Relatively local crop and sheep management, plausibly intensive and integrated to some degree, given limited dry ground, appears likely on the basis of this pilot study.     

Evidence of early medieval trade and migration between Wales and the Mediterranean Sea region

Imported Mediterranean pottery recovered from 5th–7th century settlement sites along the south Wales coast indicates that trade and contact between Wales and Byzantium continued following the collapse of the Roman Empire in the early-5th century. It is hypothesised that people as well as pottery continued to travel to Wales from Byzantium, some of whom subsequently settled amongst the local communities. Strontium and oxygen isotope analysis was undertaken on human remains (n = 33 individuals) from four early medieval cemeteries from south Wales. The study identified individuals who may not have been local to the British Isles, thus demonstrating that the isotopic analysis of human remains from Wales can further our understanding of migration to Britain during the early medieval period.     

Isotopic analysis of archaeobotanicals to reconstruct past climates: Effects of activities associated with food preparation on carbon,hydrogen and oxygen isotope ratios of plant cellulose

The cellulose fraction of botanicals recovered from archaeologically defined strata may be suitable for stable isotope-based palaeoclimatology in much the same manner as cellulose from tree rings has been utilized. However, manipulation by humans is a distinct possibility with such specimens and constitutes a potential source of isotopic alteration early in the post-mortem history of the samples. We studied the susceptibility of plant cellulose to isotopic alteration caused by manipulations related to food processing to determine if discarded plant foods recovered from archaeological contexts are suitable substrates for isotopic palaeoclimatic studies. The carbon and hydrogen isotope ratios of cellulose nitrate and the oxygen isotope ratios of cellulose were determined for Zea mays cobs, Helianthus annus seeds, Agave americana leaves, Pachyrrhizus erosus tubers and a cellulose standard before and after a variety of treatments, including boiling, roasting, fermentation, liming, molding and carbonization. The oxygen and hydrogen isotope ratios (which are climatically sensitive in all plants) and the carbon isotope ratios (which reflect climate only in certain plants) of all samples, except for Agave, were conserved during various food-processing steps. Thus, it appears that the isotope ratios of cellulose and cellulose nitrate prepared from many archaeological food plants, whether processed or uncooked, will reflect in vivo values and can be used to reconstruct aspects of palaeoclimate. Such isotopic palaeoclimatic studies will extend the utility and value of existing collections of ecofacts by opening a unique window for the study of the relationships among climate, plants and man.     

Inter-site variability in the season of shellfish collection on the central coast of British Columbia

High-resolution stable oxygen isotope analysis of the bivalve Saxidomus gigantea from shell midden sites was applied to identify seasonal patterns of resource procurement on the central coast of British Columbia, Canada. A total of 90 archaeological shells were examined from eight distinct sites spanning a 4500-year period. Combining micro-growth pattern analysis with high-resolution stable oxygen isotope sampling allows for a precise season of collection to be determined in estuarine bivalves recovered from archaeological sites. The results of the stable oxygen isotope analysis provide insights into seasonally structured harvest of S. gigantea (butter clam), which is associated with different types of sites. The results show a variety of patterns, including multi-seasonal collection, intensive seasonal harvesting and casual, supplemental use of butter clams at different locations.     

Source of ore fluids at the Kalahari Goldridge deposit, Kraaipan greenstone belt, South Africa: evidence from Sr, C and O isotope signatures in carbonates

The Kalahari Goldridge deposit is located in the Archaean Kraaipan greenstone belt in the north-west province of South Africa. Gold mineralization in this deposit is hosted within banded iron formation which is flanked by a mafic schist in the footwall and clastic metasedimentary units in the hanging wall. Data from carbonate minerals from mineralized veins and bulk rock from the A and D zone ore bodies have helped to define the ultimate origin of the ore-forming fluids and their migration history. Carbon isotope ratios of carbonates from both the A and D zone ore bodies have tight clustering from −7.6 to −5.3‰ that indicates a unique origin for the ore-forming fluids associated with the mineralization at Kalahari Goldridge. The δ¹⁸O values of the carbonates have been influenced by temperature gradients and variable degrees of fluid–rock interaction promoting oxygen isotope exchange between ore fluid and host rocks. Minimum ⁸⁷Sr/⁸⁶Sr ratio values of 0.70354 in mineralized veins are most consistent with ore-forming fluids being relatively pristine with a mantle origin. Strontium and the corresponding ore-forming fluids were most likely derived from mantle-derived magmatic rocks probably represented by the meta-basaltic rocks that underlie the ferruginous package in the Kraaipan greenstone belt. Strontium isotopic composition of vein carbonates show considerable variation in ⁸⁷Sr/⁸⁶Sr ratios ranging from 0.70354 to 0.73914. This is consistent with an ore fluid composition that has been modified by the addition of radiogenic Sr possibly during passage of fluid through siliciclastic country rock concomitant with the observed hydrothermal alteration.     

Paleoenvironment of Australopithecus anamensis at Allia Bay,East Turkana,Kenya: evidence from mammalian herbivore enamel stable isotopes

Carbon (¹³C:¹²C) and oxygen (¹⁸O:¹⁶O) stable isotope ratio analysis was performed on well-preserved tooth enamel carbonate from fossil fauna recovered from a single excavation at the early hominid site of Allia Bay, East Turkana, Kenya. These data show greater enrichment in both ¹²C and in ¹⁶O than expected, based on the oxygen isotope composition of the middle Pliocene ocean, and on today’s ecology. The pattern of these data argues against a diagenetic explanation for the enrichment. The carbon stable isotope data of known browsers suggest a more extensive canopy cover during the middle Pliocene than today’s environments. The presence of browsing pig genera, hippo genera, deinotheres, and giraffes with δ¹³C values more negative than today’s all argue for woodland habitats. The presence of several grazing genera point to the presence of grasslands as well. The oxygen stable isotope ratios indicate that the site was better-watered than today, although the source, seasonal pattern, and actual amount of water cannot be determined from these data. The overall mosaic of environments suggested by these data, in combination with reports of exotic trees recovered in nearby deposits, indicate that woodlands were present in the region 3.9 my, unlike today. Such a setting matches expectations for the selective advantages of nut-eating, bipedal hominids over other hominoids.     

Investigation of the ‘canopy effect’ in the isotope ecology of temperate woodlands

Anomalously ¹³C-depleted carbon stable isotope values from closed forest ecosystems have been termed the ‘canopy effect’. Originally this was ascribed to recycling of depleted carbon from forest floor decomposition of organic material, although others have suggested that it is equally likely to be due to variations in leaf-level processes in response to increased shade. This depletion in the heavier carbon isotope is passed on to woodland herbivores feeding within the forest environments. A similar isotopic depletion has also been reported in the archaeological literature from more open temperate woodland settings, but no measurements have been made on the plants at the base of the food chain in order to quantify the effect. In this study we attempt this by examining the carbon and nitrogen stable isotopic values of different species of grasses from a range of open to closed habitat settings within Wytham Wood, Oxfordshire, UK. We find a strong relationship between carbon isotopic depletion of plant tissue and lowered light intensity with an up to 5‰ shift between grass grown in open and closed locations. In order to follow this up the food chain, we also report data on wool from sheep grazing in open pastures near the Wood, and on fallow deer living within the woodland, but which turn out not to show a strong canopy effect, probably related to their feeding strategies. We conclude that there is indeed a strong ‘canopy effect’ in temperate woodland, probably related to differential light levels, but that not all apparently woodland-dwelling mammals show such an effect. We also show considerable isotopic variation at the base of the food chain, which should counsel caution when attempting to interpret dietary isotopes using mixing models.     

Provisioning Inka feasts at Tiwanaku, Bolivia: the geographic origins of camelids in the Pumapunku complex

While political integration can be achieved by many means, here we focus on the use of feasting and statecraft in the Inka Empire of the Andean Late Horizon (c. AD 1400-1532) in South America. In order to examine Inka political integration of the Lake Titicaca Basin of Bolivia, we examine paleomobility and paleodiet through radiogenic strontium and stable oxygen and carbon isotope data in archaeological camelid remains from the site of Tiwanaku. Mean radiogenic strontium isotope values from all archaeological camelid enamel and bone samples is ⁸⁷Sr/⁸⁶Sr = 0.70998 ± 0.00179 (1σ, n = 48), mean stable oxygen isotope values from a sub-set of archaeological camelid enamel and bone samples is δ¹⁸O_{carbonate (VPDB)} = −10.0‰ ± 2.6‰ (1σ, n = 18) and mean stable carbon isotope values from a sub-set of archaeological camelid enamel and bone samples is δ¹³C_{carbonate (VPDB)} = −9.0‰ ± 1.7‰ (1σ, n = 18). While many camelids consumed in these feasting events were likely local to the Lake Titicaca Basin, others came from a variety of different geologic zones, elucidating our understanding of Inka statecraft and the role of feasting in political integration in empires in the past.     

Strontium and stable isotope evidence for diet and mobility in Roman Gloucester,UK

This paper presents the results of a multi-isotopic (oxygen, strontium, carbon and nitrogen isotopes) investigation of population and dietary diversity in Roman Gloucester, focusing on individuals found in a late 2nd century AD mass burial pit at London Road, and comparing them to those found in the nearby cemetery. There were no statistical differences in isotopic composition between mass grave and cemetery burials, suggesting, in agreement with the osteological evidence, that the mass burial was the result of a catastrophic event, probably an epidemic disease. Strontium and oxygen isotope analysis demonstrated considerable diversity in the origins of the Gloucester population, with evidence for both UK and non-UK individuals. Diet was predominately terrestrial and similar to that of other Romano-British populations. Elevated δ¹³C_dentine ratios in some individuals are correlated with raised δ¹⁸O_p values and are therefore probably due to childhoods spent in warmer climates, rather than dietary variation.     

Development and evaluation of geochemical methods for the sourcing of archaeological maize

Strontium (Sr)-isotope values on bone from deer mice pairs from 12 field sites in the Chaco Canyon area, New Mexico, were compared with isotope values of synthetic soil waters from the same fields. The data indicate that mice obtain Sr from near-surface sources and that soil samples collected at depths ranging from 25 to 95 cm contain Sr that is more accessible to the deep roots of maize; thus, synthetic soil solutions provide better data for the sourcing of archaeological maize. However, the Sr-isotope composition of mice may be more valuable in sourcing archaeological remains of animals such as rabbit, turkey, and deer.     

Provenance analysis of Olivella biplicata shell beads from the California and Oregon Coast by stable isotope fingerprinting

While Olivella beads are a common component of archaeological sites in California, and were widely traded in prehistory, no method has been developed to trace individual beads to a point of origin. This study examines the potential of stable carbon and oxygen isotopes to source Olivella beads from the Pacific coast. The study shows that 1) the oxygen isotopic composition of modern Olivella biplicata shells faithfully varies with ambient sea surface temperature and local upwelling, lending themselves to sourcing studies; 2) oxygen isotope ratios in modern shells can be used to identify shells that grow north versus south of Point Conception, California; and 3) shell carbon isotope ratios may further subdivide these two regions into more spatially restricted source zones. Analyses on a small sample of 10 beads found at various archaeological sites within the interior of California suggest that all were made in southern California.     

EXAMINING CHILDHOOD DIETS AT KAMINALJUYU,GUATEMALA, THROUGH STABLE ISOTOPIC ANALYSIS OF SEQUENTIAL ENAMEL MICROSAMPLES*

Stable carbon and oxygen isotope ratios of tooth enamel provide a means to examine nutritional changes during childhood. To date, such studies have used large enamel samples, often spanning the developmental period of the tooth. This paper reports the results of small samples drilled from first molars and premolars of human teeth from Kaminaljuyu, a Classic period city in highland Guatemala. Carbon isotopes show considerable increase between cuspal and cervical enamel for both teeth, indicating an increase in maize consumption during childhood. Oxygen isotope trends are more variable, and suggest some seasonal fluctuation. While the oxygen isotope data confirm the identification of foreign skeletons among the samples, they illustrate a need for caution when sampling teeth due to variable δ¹⁸O composition of enamel within a tooth.     

Isotopic evidence for the reconstruction of diet and mobility during village formation in the Early Middle Ages: Las Gobas (Burgos,northern Spain)

Strontium, carbon, and nitrogen isotopes of human bone and tooth remains have been used to reconstruct residential mobility and diet of early medieval populations at Las Gobas from the sixth to eleventh centuries. Most non-local individuals correspond to the tenth to eleventh centuries and were mostly women and infants. This residential mobility coincided with the formation of Laño village and the abandonment of artificial cave settlement. Carbon and nitrogen isotope ratios of bone collagen indicate an omnivorous homogenous diet based on terrestrial plant resources, with few animal-derived proteins from livestock. Millet consumption was restricted to an earlier period of time (seventh to ninth centuries); and in later periods (tenth to eleventh centuries), mainly C₃ plants such as wheat and barley were consumed. In general, there were no dietary differences between individuals according to sex or age. Sex-related dietary differences have only been observed in the tenth to eleventh centuries, when females consumed a more vegetarian diet and less animal protein. The higher δ ¹⁵N values in infants reflect the weaning effect, while the differences in δ ¹⁵N values between young adult men and young adult women can be explained as a physiological factor related to pregnancy or different origins. In a comparison with contemporaneous medieval populations in the northern Iberian Peninsula, both δ ¹³C and δ ¹⁵N values suggest similar foodstuff resources and diet among Christian and Muslim populations.     

Addressing data comparability in the creation of combined data sets of bioapatite carbon and oxygen isotopic compositions

Before amalgamating published isotope data, comparability should be demonstrated. This paper compares carbon and oxygen isotopic compositions of 30 enamel samples measured by two laboratories. The aims were to see what, if any, isotopic variation was observed, to determine the causes as needed and to correct if possible. Bioapatite was acidified at 90°C in 2006 and at 26°C in 2017, while δ values were corrected via one‐point normalization in 2006 and by two‐point normalization in 2017. One case (of the 30) produced different δ values between the analysis dates, suggesting contamination. Repeated carbon isotope ratio measurements were not meaningfully different. Repeated oxygen isotope ratio measurements were significantly different, even following correction for acid‐carbonate fractionation at different temperatures and the renormalization of 2017 δ values using one point; however, differences were not meaningful for interpretations. Results were used to calculate real interpretative differences (RIDs) for comparing enamel bioapatite as 0.6‰ for δ¹³C values and as 1.6‰ for δ¹⁸O values.