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

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.

Bone collagen was extracted from 50 humans (Skriðuklaustur and Skeljastaðir) and 25 animals (Skriðuklaustur) and analyzed for δ¹³ C, δ¹⁵ N, and δ³⁴ S. Dental enamel samples from 31 individuals (Skriðuklaustur) were also analyzed for ⁸⁷ Sr/⁸⁶ Sr, δ¹⁸ O, δ¹³ C, and trace elements (Pb, Sr, Zn, Ba).

The mean value determined from individuals from Skriðuklaustur (n = 36) was δ¹³ C = -18.7 ± 0.8‰, δ¹⁵ N = 12.8 ± 1.1‰, and δ³⁴ S = 9.0 ± 1.6‰, whereas at Skeljastaðir (n = 14), it was δ¹³ C = -20.5 ± 0.8‰, δ¹⁵ N = 7.8 ± 0.9‰, and δ³⁴ S = 9.4 ± 1.6‰. At Skriðuklaustur, human dental enamel samples (n = 31) provided a ⁸⁷ Sr/⁸⁶ Sr range of 0.7060-0.7088, δ¹⁸ O_phosphate from 13.9 to 16.1‰ and δ¹³ C_carbonate from -16.6 to -12.9‰. Inferred drinking water (δ¹⁸ O_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.

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 δ¹³ C and δ¹⁵ N 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.