Stable carbon and nitrogen isotopes of human dental calculus: a potentially new non-destructive proxy for paleodietary analysis

Fifty-eight dental calculus samples from medieval and post-medieval skeletons from Vitoria, Spain, and a single sample from an Alaskan Inuit were tested for stable carbon and nitrogen isotope compositions. There was sufficient carbon and nitrogen concentrations to obtain δ¹³C and δ¹⁵N values, and the samples from Spain produced results that were replicable and comparable to European isotope values based on bone collagen collected from literature sources. The Alaskan Inuit calculus sample yielded a δ¹⁵N value of +17.5‰, well beyond the range of the Spanish samples, but consistent with literature data for modern Greenlandic Inuit consuming a diet rich in marine food. There are several potential sources for carbon and nitrogen in calculus. The results of this study yield stable isotope values consistent with those obtained from other biomaterials used as isotope proxies for paleodietary research, including bone collagen, hair, and fingernails, although further work is necessary to verify the fidelity of calculus as an isotope proxy. Many studies in bioarchaeology are precluded by curatorial concerns regarding the destructive analysis of primary biomaterials. However, calculus is an “add-on”, or secondary biomaterial, that is not an integral part of the dental or skeletal system. Hence, its consumption during analysis is technically not destructive. Therefore, isotope analysis of dental calculus may provide a potential new avenue for paleodietary analysis where the use of other primary biomaterials is precluded.     

Paleonutritional and paleodietary survey on prehistoric humans from Las Cañadas del Teide (Tenerife,Canary Islands) based on chemical and histological analysis of bone

The aim of the present study is to perform a paleodietary and paleonutritional survey on 17 individuals buried in accordance with the prehispanic ritual in the central plateau of the island Tenerife, called Las Cañadas del Teide. We recorded hydrogen, nitrogen and carbon isotope compositions of human bone collagen, bone barium and strontium, and histomorphometrically assessed trabecular bone mass (TBM). Bone trace elements and TBM were compared with reference data derived from a modern sample consisting of 13 individuals. In addition, δ¹⁵N and δ¹³C values were determined in several modern indigenous plants, bone collagen of prehistoric domestic animals (goat and pig), and prehistoric wild animals (a giant lizard, Gallotia goliath and a giant rat, Canaryomis bravoi), which represent food sources potentially consumed by the prehistoric population of the Island. The carbon stable isotope composition of bone collagen ranged between ?20.5 and ?18.6‰ (VPDB), indicating a diet based on C₃ plants. Nitrogen isotope values ranged from 8.2 to 12.4‰ (AIR), suggesting a general meat-enriched diet, most likely domestic goats, of higher level consumers. Hydrogen isotope values ranged from ?18 to +4‰, whereas log Ba/Sr was greater than ?0.40 in the vast majority of cases. TBM showed a tendency to osteoporosis in 30% of the individuals analyzed. C-14 dating showed that two burial sites, including 5 individuals, belonged to the post-conquest era (after the 15th century), despite a fully “prehispanic” burial ritual, which lends credenceto the oral tradition that some of the prehispanic population fled to the highlands at the time of the Spanish conquest, and lived there during decades or even centuries. These individuals showed lower δD, δ¹³C and δ¹⁵N, and higher log Ba/Sr values than those buried before the Spanish conquest, suggesting dietary differences between the two groups. Also, women showed a trend to a higher consumption of vegetables than men.     

State policy,institutional framework and technical monopoly in early modern Spain: invention patents in the Crown of Aragon during the seventeenth century

This paper examines invention patents in the Crown of Aragon during the seventeenth century. Patents were granted by the Council of Aragon, the Royal Council responsible for political and legal issues arising in the Spanish territories belonging to the Crown of Aragon. The Council's functions in the area of patents arose out of the monarchy's interest in extending the validity of royal patents from Castile to Aragon in order to enhance its control over technical discoveries and developments, and to raise fresh revenues for the treasury. Both foreign and Castilian inventors applied for patents, which were immediately applicable, but the privileges they entailed were accepted only with difficulty by the Aragonese institutions. This reluctance severely curtailed the number of applications. Meanwhile, the Council's desire to cooperate with the monarchy led it eventually to define criteria for the grant of patents. However, the legal and institutional structure of the Crown of Aragon made it difficult for inventors to enforce and defend their rights. The lack of new patent applications to the Council in the later seventeenth century illustrates how the existence of a separate jurisdiction obstructed the consolidation of a patents system in the Crown of Aragon, hindering the spread of technical progress in Spain.     

Palaeodiet at Eton College Rowing Course, Buckinghamshire: isotopic changes in human diet in the Neolithic, Bronze Age, Iron Age and Roman periods throughout the British Isles

Through isotopic investigations of directly dated human remains recovered from the Eton College Rowing Course, we examine changes in diet from the Neolithic to the Roman period. The human isotope signatures point to a diet based on C₃ terrestrial resources. A significant correlation is visible between human ??¹³C values and time, but no such trend is observed in ??¹⁵N. The animal isotope data from Eton are unevenly distributed, making it difficult to determine if the human values mirror the animal values. To assess whether the results from Eton are typical, we compare our results to isotope data from other British sites dating from the Neolithic to the Roman period. Across this time period, we see a strong correlation between the mean ??¹⁵N of the humans and that of the main domesticated herbivores, with an offset of ??4.5?? between the two. Thus, the changes in the human isotope values are likely linked to changes in the isotopic signatures of the herbivores rather than changes in the protein composition of human diets. By contrast, no clear temporal relationship is observed between the mean ??¹³C of the humans and that of the main domesticated herbivores, with an offset of ??1.4?? between the two. There is, however, a weak correlation observed between the mean ??¹³C of the humans and that of the cattle, which may account for some of the variation in human ??¹³C values between sites. The absence of a strong correlation between mean human and animal ??¹³C suggests that the primary factor influencing human ??¹³C values between sites is dietary composition. The lack of co-variation between ??¹³C and ??¹⁵N is likely to reflect the different representation of dietary macronutrients. Given that the nitrogen results suggest that the animal protein consumption patterns are similar across sites, the human ??¹³C variation between sites is likely to reflect the plant portion of the diet.     

On the influence of climatic factors on the ratio between the cosmogenic isotope 14C and total carbon in the atmosphere in the past

Radiocarbon ¹⁴C is a cosmogenic isotope, which is most extensively used by scientists from a wide variety of fields. Its rate of generation in the atmosphere depends on solar modulation and thus, studying ¹⁴C concentration in natural archives, one can reconstruct solar activity level in the past. The paper shows results of box-model calculations of generation of the ¹⁴C isotope in the atmosphere and its relative abundance during the time interval 1389–1800 AD, taking into account influence of changing climate. This interval includes the deep minimum of solar activity and period of significant change in atmospheric concentration of CO₂ and global temperature. The performed analysis showed that concentration of ¹⁴C in the atmosphere reflects not only variations of the galactic cosmic rays intensity but as well changes of temperature and atmospheric CO₂ concentration. It is shown that the decrease in CO₂ concentration in the atmosphere during 1550–1600 can be connected with absorption of CO₂ by the ocean surface layer. Thus, taking into account the climatic changes is an important condition for the reconstruction of solar activity in the past using data based on cosmogenic isotopes.     

Paleodiet in northern Chile through the Holocene: extremely heavy δN values in dental calculus suggest a guano-derived signature?

Dental calculus extracted from the teeth of 28 prehistoric human skeletons from coastal and valley archaeological sites in northern Chile that date from the Archaic period (∼2300 BC) to the Late Intermediate period (AD 1476) was analyzed for stable isotope (δ¹⁵N, δ¹³C) compositions. δ¹⁵N compositions were extremely heavy (+17.8 to +33.1‰), but comparable to some studies using conventional human biomaterials (hair, nail, muscle) at other prehistoric sites in northern Chile. There was a negative correlation between δ¹⁵N and δ¹³C for coastal sites, but a positive correlation for valley sites. Results for the valley sites point to a diet that was influenced by marine resources throughout all time periods. The unusually heavy δ¹⁵N values for the coastal sites require a dietary component with a δ¹⁵N composition significantly heavier than that of marine resources. The hyper-aridity at the study area (mean annual rainfall of 0.5–0.6 mm/year) is a likely contributing factor to the production of heavy δ¹⁵N values, but is unlikely to account for the heaviest δ¹⁵N values (>+30‰). One possible explanation for the heaviest δ¹⁵N values is that dietary components were impacted by isotopically-heavy guano, which is abundant in the region. Guano may have been used as a fertilizer during crop cultivation at the onset of the Formative period, continuing through the Historic period after Spanish contact. The indirect impact of guano from abundant bird habitats in the region may have influenced wild foodstuffs harvested throughout the pre-agricultural period. Results provide support for the utility of dental calculus as a proxy for obtaining stable carbon and nitrogen isotope signatures for use in paleodietary studies.     

STABLE ISOTOPIC RECONSTRUCTION OF DIET AND RESIDENTIAL MOBILITY IN A POSTBELLUM AFRICAN AMERICAN COMMUNITY IN RURAL GEORGIA

Abstract

Despite popular belief, the Great Migration following the Civil War was not a singular event but a long-term demographic phenomenon marked by freed African Americans returning to their natal communities or establishing new communities elsewhere and was presaged by smallerscale movements of African Americans between different regions of the Emancipation-era South. This study analyzes carbon and oxygen (δ¹³C, δ¹⁸O) stable isotope ratios in enamel carbonate from 34 individuals recovered from the Avondale Burial Place, an Emancipation-era cemetery, in Macon, Georgia, in order to reconstruct residential origin and early-life diet and examine whether these individuals immigrated to the site from elsewhere in the South. Carbon isotope results suggest mixed C₃/C₄ agro-pastoral subsistence rather than a reliance on C₄ products such as corn and corn-fed livestock as suggested by historical accounts. Oxygen isotope results suggest that the majority of individuals buried in the Avondale Burial Place were likely born in the area as well; in comparison with other isotopic studies from postbellum contexts, these results support the interpretation that the Great Migration was a gradual process with varying impacts in different areas. Interestingly, a sex-based divergence in both carbon and oxygen isotope values during childhood suggests differences in diet and water consumption possibly related to divergent gender roles. Overall, these results indicate that despite continued hardships, the members of this community consisted of local residents, and they do not indicate the presence of migrant individuals; this isotopic analysis, therefore, contributes to a growing body of bioarchaeological research reconstructing the lost and varied histories of postbellum African American communities.     

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.     

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.     

Strontium isotope evidence of migration and diet in relation to ritual tooth ablation: a case study from the Inariyama Jomon site,Japan

Ritual tooth ablation was extensively practiced among Jomon (Japanese Neolithic) societies in their final phase (ca. 3000-2300 BP). This tradition includes two different tooth ablation patterns, type 4I and type 2C, referring to extraction of the mandibular incisors and canines, respectively. However, the reason for this difference is unclear. Previous carbon and nitrogen stable isotope analysis of human remains from the Inariyama shell mound revealed that type 4I individuals were more dependent on terrestrial resources and type 2C individuals on marine resources. To test this hypothesis, we performed strontium (Sr) isotope (⁸⁷Sr/⁸⁶Sr) analyses on the same skeletal remains and on modern plants around the site. Because Sr isotope ratios of plants differ according to the local geology and seawater has a consistent Sr isotope ratio, the Sr isotope ratios of tooth enamel can reveal both migration and diet. Comparing Sr isotope ratios in plants and seawater with those of tooth enamel, we identified four possible immigrants. Type 4I locals had significantly higher Sr isotope ratios than type 2C locals. The ratios of the type 4I and type 2C locals were close to those of terrestrial plants and seawater, respectively, suggesting that type 4I locals had incorporated much Sr from terrestrial resources and type 2C locals from marine resources. These results support the hypothesis that ritual tooth ablation reflects dietary differences throughout an individual’s life, and they suggest possible occupational differentiation among the Jomon people.     

Dietary reconstruction in Migration Period Central Germany: a carbon and nitrogen isotope study

This study presents bone collagen carbon and nitrogen isotope data from the Migration Period cemeteries (fifth/sixth century AD) of Obermöllern and Rathewitz in Central Germany. The human average δ ¹³C ratios of ?19.8?±?0.3 ‰ and δ ¹⁵N ratios of 9.6?±?0.9 ‰ (n?=?43) reflect a mixed diet in a temperate C3-based ecosystem without significant difference between the two sites. The average offset between human and faunal δ ¹³C and δ ¹⁵N values indicates a significant contribution of plant food to the human diet that has different isotope ratios from the forage of the animals. It furthermore suggests the influence of land management on the δ ¹⁵N values. One adult male from Obermöllern stands out due to his elevated nitrogen isotope ratio, body height, grave goods, and burial position. The collagen isotope data of this study are comparable with data from other central European sites and confirm rather stable communities with moderate variation in the environmental conditions of arable land.     

Applying new approaches to modeling diet and status: isotopic evidence for commoner resiliency and elite variability in the Classic Maya lowlands

Classic Maya states were characterized by a high degree of socioeconomic stratification. This paper investigates the degree to which status, as defined by grave goods and tomb construction, influenced dietary patterns of elites and commoners throughout the Classic Period (200–900/1000 AD) of the southern lowlands. We compile a database (N = 102) of previously-published stable isotope ratios (δ¹³C collagen, δ¹³C apatite, and δ¹⁵N collagen) from Maya bone mineral and collagen, and interrogate these data through two new isotopic modeling techniques: a simple carbon isotope model ( Kellner and Schoeninger, 2007; Froehle et al., 2010) and a multivariate isotope model ( Froehle et al., 2012). We find that Maya elite diet varied significantly through time in terms of maize consumption and trophic level, while commoner diet remained remarkably stable. These findings provide new information relevant to studies of ancient Maya class structure and to studies of subsistence strategies of the pre-Columbian Americas.     

A strontium isotope analysis on the relationship between ritual tooth ablation and migration among the Jomon people in Japan

Distinct patterns can be discerned in the extensive ritual tooth ablation found among the human skeletal remains of the Late–Final Jomon period (ca. 3200–2800 cal BP) in Japan. Based on comparative observations of sex and grave patterns in the skeletal remains, two major patterns in ritual tooth ablation, termed type 4I and type 2C, have been assigned to locals and immigrants, respectively. In order to test this hypothesis, strontium (Sr) isotope (⁸⁷Sr/⁸⁶Sr) analyses were performed on human skeletal remains from the Yoshigo shell mound in Aichi Prefecture, central Japan. Plants in the surrounding area were also examined to illustrate the geographic ⁸⁷Sr/⁸⁶Sr distribution. The Sr isotopic variation in human tooth enamel (⁸⁷Sr/⁸⁶Sr = 0.70868–0.71028) was greater than that in human bones (⁸⁷Sr/⁸⁶Sr = 0.70871–0.70943). Individuals with higher Sr isotope ratios in their tooth enamel than seawater Sr values of 0.7092 can be identified as immigrants (36% of population). The presence of these isotopically identified immigrants between both type 2C and type 4I individuals does not support the previous hypothesis. The intra-population ⁸⁷Sr/⁸⁶Sr distribution of tooth enamel of type 2C individuals showed a significantly higher mean ratio than that of type 4I individuals, suggesting a higher proportion of immigrants among the former.     

The effect of charring and burial on the biochemical composition of cereal grains: investigating the integrity of archaeological plant material

Stable isotope analysis of charred archaeobotanical cereal grains has the potential to provide direct evidence of crop growing conditions in the past and to refine palaeodietary predictions. If isotope values of archaeobotanical material are to be considered robust, it is necessary to characterise the compositional changes associated with their charring and burial. This study used a suite of analytical techniques, including FT-IR and solid state ¹³C NMR, to characterise changes in the biochemical composition of modern einkorn grains with heating at 230 °C for 2 h, 4 h, 8 h and 24 h, encompassing conditions that replicate their undistorted ancient counterparts. The biochemical composition of archaeobotanical charred einkorn grains was also investigated by FT-IR and solid state ¹³C NMR in order to assess the changes in composition which occur during burial. Results of FT-IR and solid-state ¹³C NMR show that heating of modern einkorn grains resulted in Maillard reactions between cereal proteins and starch, forming high molecular weight melanoidins, which contain both alkyl and aromatic carbon. Loss of low molecular weight carbon and nitrogen-containing volatiles resulted in a slight but non-systematic increase in the δ¹³C values and a systematic increase of 0.8‰ in the δ¹⁵N values of the charred einkorn grains. Solid-state ¹³C NMR shows that the ancient charred einkorn grains consisted entirely of aromatic carbon and retained a similar proportion of nitrogen to their modern 24 h charred counterparts, despite a significantly lower concentration of amino acids. This indicates that the amino acid nitrogen in the ancient charred grains was retained in the stable melanoidins whose polymeric structure makes them resistant to subsequent degradation.     

Application of boron isotopes to the understanding of fluid–rock interactions in a hydrothermally stimulated oil reservoir in the Alberta Basin, Canada

Boron isotope ratios of reservoir minerals and fluids can be a useful geothermometer and monitor of fluid–rock interactions. In Cold Lake oil sands of northern Alberta, there is a large variation in δ¹¹B of the produced waters generated during steam injection and recovery of oil and water. The higher temperature waters (～ 200 °C) have isotopically light δ¹¹B values (+ 3‰ to + 14‰) and high B contents (～150 p.p.m.). It is inferred that the range of δ¹¹B values of the hydrothermal fluids results from reaction with the reservoir rock, and is a function of the temperature of the fluid–rock interaction. The distinct B geochemistry of the produced waters can be used to show that there is no detectable mixing of the oil recovery waters with the regional formation waters or shallow groundwater aquifers containing potable water. Examination of B isotope ratios of reservoir minerals, before and after steam injection, allows the evaluation of sources of B in the reservoir. The only significant phase containing B is pumice. It shows generally positive δ¹¹B values before steam injection and negative values after steam, with δ¹¹B as low as ? 28‰. Other possibly reactive phases include clay minerals and organic matter, but their abundance is not great enough to impact on the isotopic composition of the produced waters. This information makes it possible to evaluate the boron isotope fractionation equation derived from experimental data ( Williams LB (2000) Boron isotope geochemistry during burial diagenesis. PhD Dissertation. The University of Calgary, Alberta, Canada; Williams LB, Hervig RL, Holloway JR, Hutcheon I (2001a) Boron isotope geochemistry during diagenesis: Part 1. Experimental determination of fractionation during illitization of smectite. Geochimica et Cosmochimica Acta, in press). The results show that the fractionation curve predicts the difference between δ¹¹B of the pumice and hydrothermal fluids in the Cold Lake reservoir. This not only indicates that the reservoir fluids have approached boron isotope equilibrium with the reservoir rock, but also shows that B isotopes provide a useful geothermometer for hydrothermally stimulated oil reservoirs.     

Stable Isotopes and Oral Tori in Greenlandic Norse and Inuit

Palatine (PT) and mandibular torus (MT) have long been of interest to dental researchers and anthropologists, but their aetiology remains unresolved. Some combination of genetic and environmental factors influences their expression, but the relative role of each remains contentious. Previous research has shown that the Greenlandic Norse exhibit exceptionally high frequencies and pronounced expressions of PT and MT. In this regard, they are significantly different from genetically related medieval Scandinavian populations, so environmental factors have to be considered. An earlier study that estimated stable carbon and nitrogen isotope compositions for a Greenlandic Norse sample makes it possible to compare directly PT and MT expression with the relative degree of marine protein intake. For comparative purposes, parallel observations were made on a Greenlandic Inuit sample. Some researchers suggest the intake of marine resources could impact bone development, including torus expression, but our analysis found no significant correlation between PT or MT expression and δ¹³C and δ¹⁵N values in the Norse. In the Inuit, PT expression also showed no relationship to stable isotope compositions. MT size in the Inuit did, however, show a significant inverse relationship with δ¹³C and δ¹⁵N values. As MT size goes up, stable isotope compositions go down. Compared with contemporary European populations, the Greenlandic Norse show very positive isotope compositions, but the Inuit, with their high protein‐high fat diet, show significantly higher δ¹³C and δ¹⁵N values than the Norse. It is unclear how this relates to the contrasting findings for MT size and stable isotope values. Copyright © 2016 John Wiley & Sons, Ltd.     

Iron mineralization and dolomitization in the Paran Fault zone,Israel: implications for low‐temperature basinal fluid processes near the Dead Sea Transform

Petrography, Eh‐pH calculations and the stable isotope composition of oxygen are used to interpret geochemical processes that occurred during iron oxide mineralization and dolomitization along the Menuha Ridge segment of the Paran Fault, southern Israel, adjacent to the Dead Sea Transform (DST). Iron mineralization is strongly localized in the fault zone as ferruginous lenses, whereas Fe dolomitization spreads laterally into the Cenomanian‐Turonian carbonate host rock as stratabound beds. The average oxygen isotope fractionation between syngenetic quartz and iron oxides in the ferruginous lenses gives a temperature of 50 ± 10°C and δ¹⁸O SMOW water = ?3.5‰; consistent with an origin from metalliferous groundwater flow in the sedimentary basin. Ferroan dolomite initially formed under strongly reducing conditions, but this was followed by oxidation and pseudomorphic replacement of the dolomite by a mesh of fine‐grained iron oxides (simple zoned dolomites). This cycle of ferroan dolomite formation and replacement by iron oxides was repeated in complex zoned dolomites. Dolomite oxygen isotope compositions fall into two groups: a high δ¹⁸O group corresponding to the simple zoned dolomites and non‐ferroan dolomites and a low δ¹⁸O group corresponding to the complex zoned dolomites. Water‐rock calculations suggest that the epignetic dolomites formed under fluid‐buffered conditions: the high δ¹⁸O group are indicated to have formed at temperatures of ca. 25°C for waters with δ¹⁸O = ?4 to 0‰; the low δ¹⁸O complex zoned dolomites at 50–75°C for waters with the same isotopic composition. A kinetic calculation for a complex zoned dolomite‐bearing bed indicates that dolomitization must have occurred at high values of the dolomite saturation index. This requirement for high Mg supersaturation and the indication that epigenetic dolomitization is more protracted in stratigraphically deeper formations located closer to the DST is consistent with models proposing that Mg‐rich solutions originated in the Dead Sea Rift.     

A palaeodietary investigation of carbon (C/C) and nitrogen (N/N) in human and faunal bones from the Copper Age cemeteries of Varna I and Durankulak,Bulgaria

Stable isotope analyses have been applied to human and faunal bone collagen from the Varna I and Durankulak cemeteries to explore palaeodietary adaptations in the Neolithic and Eneolithic (Copper Age). The results suggest both populations primarily utilised terrestrial, C₃-based diets, despite their proximity to the Black Sea. The wider δ¹⁵N range of the Durankulak humans likely indicates the differential utilisation of terrestrial meat sources, which is probably related to the degree to which primary and/or secondary ovicaprid products were consumed, particularly since ovicaprid δ¹⁵N values differ from other herbivores. The isotopic distribution of Varna I reflects a linear relationship between δ¹⁵N and δ¹³C, suggesting that a minority of individuals enriched in both isotopic parameters supplemented their diets with marine resources. These burials include the well known ‘chieftain’ (burial 43) and show notable material wealth by way of grave goods. At the population level, however, there is no significant correlation between stable isotope values and material wealth at Varna I, a fact with implications for theories regarding emergent social/economic hierarchies in Balkan prehistory. Five burials at Durankulak were found to have relatively enriched δ¹³C and δ¹⁵N values with respect to the rest of the population. These burials reflect a prominently marine-based or mixed terrestrial C₃-based diet that included C₄ inputs, possibly from millet, for which the limitations of stable isotope analysis on bulk collagen are not able to differentiate. AMS dating has shown that these burials belong to a much later period.     

Dietary adaptation during the Longshan period in China: stable isotope analyses at Liangchengzhen (southeastern Shandong)

Rice and millet were staple crops at Liangchengzhen, a late Neolithic Longshan site in Shandong, China, but the degree of dietary variation is not known. This study uses stable isotope analysis of human and faunal skeletal remains to quantitatively address the importance of these crops as well as terrestrial domesticates and aquatic resources in the diet at Liangchengzhen. Although no collagen could be extracted from the poorly preserved human bones, the δ¹³C stable isotope results for 2 apatite sample and 16 tooth enamel samples averaged −9.8‰ suggesting that diet was based on foods averaging from −24‰ to −18‰, with millet and millet-fed animals comprising at most approximately 25–30% of the diet. Pig faunal δ¹³C isotope values suggested that during the earlier Longshan period pigs were fed mainly millet with more C₃ foods such as rice included by the later Longshan period. Solid ceramic residues from two guan jar sherds produced δ¹³C values averaging −18‰ and δ¹⁵N values averaging +16‰, suggesting both vessels contained fish. The results of the study indicate that by the Longshan period, people in southeastern Shandong no longer relied as heavily on millet and that the agricultural crop of rice had increased in importance at Liangchengzhen. Unfortunately, without human collagen samples to provide nitrogen isotope results, we cannot estimate the relative contribution of aquatic and terrestrial protein to the diet of people at Liangchengzhen. In general, however, the pattern of a diverse agricultural system on the basis of the macrobotanical remains from Liangchengzhen is supported by the isotopic results.     

What has Iberia to do with Jerusalem? Crusade and the Spanish route to the Holy Land in the twelfth century

In spite of repeated papal injunctions forbidding them to abandon their homeland, Iberian Christians, like their co-religionists throughout Europe, were energised by a desire to participate in the Holy Land crusades. The most significant and creative attempt in the first half of the twelfth century to respond to this Spanish desire was the development of the idea of the iter per Hispaniam, which was fostered by Iberian archbishops and monarchs such as Diego Gelmírez of Santiago de Compostela and Alfonso I of Aragon. This Spanish route was intended to unite the conflicts in the peninsula and the Holy Land, forming a single Mediterranean-wide crusading theatre and thereby granting the Iberian conflict a deeper connection with the struggle for control of the holiest sites in Christendom. This article explores the development of crusading ideology in Spain and the difficulties of doing so in a venue outside of the Holy Land. Additionally, the development of the Spanish route idea provides a unique opportunity to contextualise recent historiographical discussions about the essence of the crusades and to highlight the way in which different perspectives helpfully offer insight into various aspects of peninsular crusading.