At the world's edge: Reconstructing diet and geographic origins in medieval Iceland using isotope and trace element analyses

Carbon, nitrogen and sulphur isotope data of archaeological fish and mammal bone collagen from Lithuania

Until relatively recently, stable sulphur isotope analysis of bone collagen was seldom undertaken in bioarchaeological research. With increasing frequency, its application has proven useful in reconstructing palaeodiets and palaeoecologies, as well as identifying potential migration and mobility patterns. Here, sulphur (δ³⁴S) isotope analysis, together with carbon (δ¹³C) and nitrogen (δ¹⁵N), was performed on six fish and 34 mammal bone collagen samples from 14 prehistoric sites in Lithuania dating from the Late Mesolithic (ca. 7000-5000 cal BC) to the Late Bronze Age (ca. 1100-500 cal BC). We present the first δ³⁴S data from Lithuania, including coupled δ¹³C and δ¹⁵N data, offering a crucial dataset for future research to explore spatial and temporal variability in the region and beyond.

Creating communities of care: Sex estimation and mobility histories of adolescents buried in the cemetery of St. Mary Magdalen leprosarium (Winchester, England)

Objectives

This study examines the biological sex and geographical origins of adolescents buried at the St Mary Magdalen leprosarium (Winchester, UK). The data are combined with archaeological and palaeopathological evidence to broaden the understanding of mobility and its relationship to leprosy and leprosaria in Medieval England.

Materials and Methods

Nineteen individuals (~10–25 at death) with skeletal lesions diagnostic of leprosy were analyzed using standard osteological methods. Amelogenin peptides were extracted from five individuals whose biological sex could not be assessed from macroscopic methods. Enamel samples were analyzed to produce ⁸⁷Sr/⁸⁶Sr and δ¹⁸O values to explore mobility histories.

Results

Amelogenin peptides revealed three males and two females. Tooth enamel samples provided an ⁸⁷Sr/⁸⁶Sr ratio range from 0.7084 to 0.7103 (mean 0.7090, ±0.0012, 2σ). δ¹⁸O_P values show a wide range of 15.6‰–19.3‰ (mean 17.8 ± 1.6‰ 2σ), with corresponding δ¹⁸O_DW values ranging from −9.7‰ to −4.1‰ (mean −6.3 ± 2.4‰ 2σ).

Discussion

Amelogenin peptide data reveal the presence of adolescent females with bone changes of leprosy, making them the youngest confirmed females with leprosy in the archaeological record. Results also show at least 12 adolescents were local, and seven were from further afield, including outside Britain. Since St. Mary Magdalen was a leprosarium, it is possible that these people traveled there specifically for care. Archaeological and palaeopathological data support the notion that care was provided at this facility and that leprosy stigma, as we understand it today, may not have existed in this time and place.

Silver Linings at the Dawn of a “Golden Age”

Nearly four decades after the first applications of strontium isotope analyses in archaeology and paleoecology research, it could be said that we are entering a “Golden Age”. Here, we reflect on major past developments and current strengths in strontium isotope research, as well as speculate on future directions. We review (1) the currently limited number of (but much needed) controlled feeding experiments, (2) recent advances in isoscape mapping and spatial assignment, and (3) the strength of multi-proxy approaches (including both the integration of strontium isotopes with other isotope systems and complementary techniques such as ancient DNA analyses). We also explore the integration of strontium isotope research with other types of paleoecological or archaeology data, as well as with evidence and interpretative frameworks from other fields (such as conservation ecology, conservation paleobiology or history). This blending is critical as we seek to advance the field beyond simply distinguishing local or relatively sedentary individuals from those that were non-local or highly mobile. We finish with a call for future research centered on balancing methodological developments and novel applications with critical self-reflection, deeper theoretical considerations and cross-disciplinarity.

Historical overview and new directions in bioarchaeological trace element analysis: a review

Given their strong affinity for the skeleton, trace elements are often stored in bones and teeth long term. Diet, geography, health, disease, social status, activity, and occupation are some factors which may cause differential exposure to, and uptake of, trace elements, theoretically introducing variability in their concentrations and/or ratios in the skeleton. Trace element analysis of bioarchaeological remains has the potential, therefore, to provide rich insights into past human lifeways. This review provides a historical overview of bioarchaeological trace element analysis and comments on the current state of the discipline by highlighting approaches with growing momentum. Popularity for the discipline surged following preliminary studies in the 1960s to 1970s that demonstrated the utility of strontium (Sr) as a dietary indicator. During the 1980s, Sr/Ca ratio and multi-element studies were commonplace in bioarchaeology, linking trace elements with dietary phenomena. Interest in using trace elements for bioarchaeological inferences waned following a period of critiques in the late 1980s to 1990s that argued the discipline failed to account for diagenesis, simplified complex element uptake and regulation processes, and used several unsuitable elements for palaeodietary reconstruction (e.g. those under homeostatic regulation, those without a strong affinity for the skeleton). In the twenty-first century, trace element analyses have been primarily restricted to Sr and lead (Pb) isotope analysis and the study of toxic trace elements, though small pockets of bioarchaeology have continued to analyse multiple elements. Techniques such as micro-sampling, element mapping, and non-traditional stable isotope analysis have provided novel insights which hold the promise of helping to overcome limitations faced by the discipline.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12520-020-01262-4.

At the world's edge: Reconstructing diet and geographic origins in medieval Iceland using isotope and trace element analyses

Objectives

A multi‐isotope study was conducted on individuals buried at Skriðuklaustur monastery (AD 1493–1554) to investigate their geographic origins and dietary composition. Comparative material from individuals excavated from Skeljastaðir, an inland farm site was also analyzed.

Materials and methods

Bone collagen was extracted from 50 humans (Skriðuklaustur and Skeljastaðir) and 25 animals (Skriðuklaustur) and analyzed for δ¹³C, δ¹⁵N, and δ³⁴S. Dental enamel samples from 31 individuals (Skriðuklaustur) were also analyzed for ⁸⁷Sr/⁸⁶Sr, δ¹⁸O, δ¹³C, and trace elements (Pb, Sr, Zn, Ba).

Results

The mean value determined from individuals from Skriðuklaustur (n = 36) was δ¹³C = −18.7 ± 0.8‰, δ¹⁵N = 12.8 ± 1.1‰, and δ³⁴S = 9.0 ± 1.6‰, whereas at Skeljastaðir (n = 14), it was δ¹³C = −20.5 ± 0.8‰, δ¹⁵N = 7.8 ± 0.9‰, and δ³⁴S = 9.4 ± 1.6‰. At Skriðuklaustur, human dental enamel samples (n = 31) provided a ⁸⁷Sr/⁸⁶Sr range of 0.7060–0.7088, δ¹⁸O_phosphate from 13.9 to 16.1‰ and δ¹³C_carbonate from −16.6 to −12.9‰. Inferred drinking water (δ¹⁸O_dw) values range from −12.3 to −8.9‰. Sr concentrations range from 25.8 to 156.7 ppm, Ba from 0.11 to 0.81 ppm, Zn from 43.8 to 145.8 ppm, and Pb from 0.13 to 9.40 ppm.

Discussion

A combination of results indicates that the people from Skriðuklaustur were born in Iceland, but some lived inland during childhood while others lived closer to the coast. Since Skriðuklaustur was a hospital, these individuals may have sought medical treatment at the monastery. The δ¹³C and δ¹⁵N values determined from bone collagen indicate that the people residing at Skriðuklaustur consumed a diet high in marine protein, while those residing at Skeljastaðir exhibit values more consistent with terrestrial resources.