The Center for Archaeological Science, Sichuan University team reveals the dietary structure of Han and Jin Dynasty populations in the Lop Nur region.

Recently, XUEYE Wang, an associate researcher at the Center for Archaeological Science, Sichuan University, and others published a research paper titled 'Diet along the eastern Silk Roads: an isotopic case study of ancient humans and livestock from the Han-Jin Dynasties in the Lop Nur region, northwest China' in the international archaeological journal Archaeological and Anthropological Sciences. Collaborators came from the Institute of Geology and Geophysics of the Chinese Academy of Sciences, Jilin University, Xinjiang University, Xinjiang Institute of Cultural Relics and Archaeology, the Loulan Museum, Wuhan University, and the University of California, Santa Cruz. The study reconstructed the diet of the population at that time by analyzing carbon, nitrogen, and oxygen isotopes of human and animal teeth unearthed from tombs of the Han and Jin dynasties (Figure 1) in the Lop Nur region of the eastern Tarim Basin, Xinjiang.

Figure 1. Geographical location of the Lop Nur No. 1 Cemetery in 2015

The results show that the 未15N values of herbivores ranged from 10.2鈥� to 15.5鈥�, which is abnormally high, far higher than the previously published 未15N values of herbivores in the Eurasian steppes, Hexi Corridor, and northern Xinjiang (< 9鈥�). Combined with the local climatic conditions and the accumulation layers of animal manure in the site (Figure 2), it is speculated that the extremely arid climate and human fertilization behavior are possible reasons for the abnormally high nitrogen isotope values. The human diet was mainly composed of mixed C3/C4 foods, relying on animal products. In addition, a large number of tombs from the Han and Jin dynasties are preserved in the Lop Nur region, but there are obvious differences in the specifications of the tombs. Considering the possible social stratification at that time, this study preliminarily infers that the "village population" consumed more millet foods than the "city population" by comparing the isotope data of human bone remains from tombs of different specifications.

Figure 2. Accumulation layers of animal manure preserved in the sites of the Han and Jin dynasties in the Lop Nur region

The SIBER (Stable Isotope Bayesian Ellipses in R) isotope niche model analysis in this study shows that the dietary diversity of the Loulan people in the Han and Jin dynasties was much higher than that of the Xiaohe and Gumugou people in the Bronze Age, and the consumption of C4 foods increased significantly (Figure 3). The differences in isotopic niche width between different periods reflect the diversification of agricultural practices and the expansion of dietary choices in the Lop Nur region during the Han and Jin dynasties.

Figure 3. SIBER analysis of human bone isotopes in the Lop Nur region and archaeological sites of the same period in Northwest China

This study was carried out relying on the scientific investigation project (2014FY210500) of the National Basic Research Program of the Ministry of Science and Technology, which was undertaken by the Institute of Geology and Geophysics of the Chinese Academy of Sciences and four other units. In addition, this study was also supported by the National Natural Science Foundation of China (42072210 & 42207508), the Independent Deployment Project of the Institute of Geology and Geophysics of the Chinese Academy of Sciences (IGGCAS-201905), and the Youth Fund Project for Interdisciplinary Research of the Center for Archaeological Science, Sichuan University.