贾湖史前人类迁移行为的初步研究——锶同位素分析技术在考古学中的运用

位于河南省舞阳县的贾湖遗址是一处著名的新石器时代遗址,距今7800～9000年。遗址中出土了大量的人和动物的骨骼与牙齿,这为研究史前时期中国中部地区人类的迁移情况提供了很好的材料。在本次研究中,共分析了26个人和动物样品,包括12个人体骨密质样品、9个人牙釉质样品和5个猪牙釉质样品。测定了每个样品的锶同位素浓度和87Sr/86Sr比值,结果表明猪牙釉质的锶同位素浓度（平均值为196±51ppm,n=5,1σ）高于人牙釉质的浓度（平均值为110±61ppm,n=9,1σ）,人骨骼的锶同位素浓度（平均值为444±173ppm,n=12,1σ）明显地高于人牙釉质的浓度。根据5个猪牙釉质样品87Sr/86Sr平均值±2倍的标准偏差确定的当地锶同位素比值范围（0.712205～0.712420）,发现14个人类个体中有5个是外来迁入的,并且从第1期到第3期人口的迁移率有增加的趋势。这是在国内首次利用锶位素分析方法对古人类的迁移现象进行研究,同时也表明此方法可以很好地判断古人类迁移行为。

PRELIMINARY STUDY OF PREHISTORIC HUMAN MIGRATION BASED ON Sr ISOTOPE ANALYSIS FROM JIAHU RELICS

Isotope analysis technology could better reveal latent information of archaeological remains.It is an important component of archaeometry,also the frontier and focus of current international archaeological research.Archaeologists have used this method to investigate human migration on some archaeological sites worldwide and demonstrated that it's a practical method.This paper is on human migration based on strontium analysis on samples from the Jiahu relics.The strontium isotope ratios from an individual person have been confirmed to directly reflect the isotopic ratios of the geological region in which that person lived,with the ratios in human bone reflecting those of the region around the time of human death and ratios in tooth enamel reflecting those of the region when the person lived as a child.A migration activity can thus be identified when the same person has different strontium isotope ratios in his/her bones and teeth.The Jiahu relics in Wuyang County,Henan Province is a famous Neolithic site from 9000aB.P.to 7800aB.P.The richness of excavated bones and teeth of both human beings and animals presents us a good opportunity to probe the prehistoric human mobility during the Neolithic period in central China.In this study,we have analyzed 26 samples of human beings and animals,including 12 human bone samples,9 human tooth enamel samples,and 5 pig tooth enamel samples.We measured strontium isotope concentration and 87Sr/86Sr ratio of each sample.The results show that strontium concentration in pig enamel（the average concentration of Sr=196±51ppm,n=5,1σ）is higher than in human enamel（the average concentration of Sr=110±61ppm,n=9,1σ）and the strontium concentration in human bones（the average concentration of Sr=444±173ppm,n=12,1σ）is significantly higher than in human enamel.According to the local strontium isotope ratio range determined by the mean 87Sr/86Sr ratios ±2 s.d.of pig enamel samples（0.712205～0.712420）,we find out that 5 of the 14 individuals in the study might be immigrants.A trend was also found out that the frequency of migration was increasing during that period.This is the first attempt to apply strontium isotope analysis to Chinese archaeology,which has been shown as a powerful method to identify prehistoric population mobility.