Millet consumption in south Xinjiang during the 1st millennium BCE: Isotopic evidence from bone bioapatite at the Ji'erzankale site

Abstract

Although the Pamir Plateau in southern Xinjiang was likely a key route in the extensive transcontinental network of cultural exchange across Eurasia, little isotopic research has been conducted in this region. Here we present isotopic results of bioapatite (δ13C, δ18O) from humans and animals (n = 38) from the Ji'erzankale site (c. 400–600 years cal BCE) located in the Xinjiang Uyghur Autonomous Region of China. These results are combined with previously published collagen isotopic data from the same individuals to explore the possibility and extent of millet consumption in this area. The δ13C values of the sheep (−10.8 ± 0.7‰, n = 13) and humans (−13.7 ± 0.5‰, n = 24) were found to be higher than those of the wild hare (−14.9‰, n = 1). The humans consumed a predominately C3 diet, but the bioapatite-collagen δ13C spacing indicates that there was a minor input of C4 plants in the diet, likely millet. The inhabitants of the Ji'erzankale site were semi-nomadic pastoralists that likely supplemented their diet with the small scale consumption of millet. It is likely that the Pamir Plateau was a key area in the spread of millet agriculture between the East and the West during the 1st millennium BCE.