裕子 小池

Carbon and nitrogen stable isotope analysis using human bones and hair from Philippine burial sites

1n order to understand the diet of the past human population in the Philippines, we analyzed stable isotopic compositions of 61 individuals from five burial sites with different geographical locations, environmental conditions and subsistence strategies. The carbon stable isotope ratio (O13C) and nitrogen stable isotope ratio (O15N) of bone collagen and hair were used to estimate dietary protein resources of the population. The Batanes site is located at about 200 km north from the north coast of Luzon and about 150 km south from Taiwan, with the so・cal1edboat-shaped and jar burials (355土 70BP). Results of O13C (-16.6土1.3%0) and O15N (9. 8:t 1. 7%0) values for bone collagen from 21 individuals showed that dietary protein resources had more dependence on marine ecosystems than that on terrestrial resources. The isotopic values vary due to the burial types: both O13C and O15N values of the specimens from the boat-shaped and jar burials were higher than those from both the primer pit burial. In the Lal-lo site (N士 11) of Northern Luzon which is famous for its huge shell midden (3400-1000 years ago),δ13C and O15N values were -19土1.2%0 and 9.7 土1. 6~ゐ respectively. Resu1ts showed a diet more dependent on terrestrial resources than others, because freshwater shells indicared terrestrial values. Hair samples from the 13 centur・yold mummies (N = 3) at Kabayan in Benguet Mountain Province, northwest of Luzon had the average value of -17土1.0%0for O13C and 8.0:t 1. 0%0 for δ15N reflecting a diet dependent on both terrestrial and aquatic resources. The average value of the Santa Ana site (N = 8) in Manila (about 1095 AD) were -15.2土3.3協 forδ13C and 10.4土0.7克ofor O15N values, suggesting highest dependence on marine ecosystem among the 5 sites. Romblon site (N = 18) in Central Philippines (13 14 centuries) yielded the average O13C value of -17.4土2.3%0and O15N value of 10.1土1.lrooindicating protein resources dependent on both terrestrial and marine ecosystems. 1n al the sites, the δ13C and O15N values lack gender-based difference.