Stable Carbon Isotopic Analysis of Human Skeletons
from Mawaki, Akaura and Kamiyamada

According to the ¹³C analysis of human bone collagen, the δ¹³C values for the three　samples from the Jomon period sites in the Hokuriku district are as follows: -17.0 per mil for the Mawaki Site, -17.3 per mil for the Akaura Shell Mound and 18.5 per mil　for the Kamiyamada Shell Mound. The most oceanic site of the three is the Mawaki producing numerous bones of dolphins at the entrance of Toyama Bay. The second is the Akaura Site mainly with salt-water fish bones and shells on the inside of Nanao Bay. The Kamiyamada facing Kahoku Lagoon, mainly with freshwater fish bones and shells, is most influenced by land water. The δ¹³C values for human bone collagen from these sites are mainly correlative with the two food chains: C3 plants with lower values and marine phytoplankton with higher values. In the case of fishing people closely affected by a chain of marine phytoplankton, theδ¹³C value becomes higher in proportion to their dependence on ocean animals, especially marine mammals. It is, therefore, a natural result that the values are arranged in the order of Mawaki, Akaura and Kamiyamada. However, there is little difference between these values against our expectations. Theδ¹⁵N values for Mawaki and Kamiyamada are respectively +12.0 per mil and +8.2 per mil; the graph of the δ¹³C and δ¹⁵N composition shows that Mawaki belong to a sub-group near the Hokkaido in the Honshu group.

(Revised for my web-site after Journal of the Anthropological Society of Nippon, Vol.99, No.2:194, 1991)