泥河湾盆地三棵树遗址ESR年代学

ESR chronology of the Sankeshu Paleolithic site in the Nihewan Basin,North China

泥河湾盆地因发育良好的晚新生代湖相地层、丰富的旧石器遗址和哺乳动物化石而广受关注。盆地内已发现旧石器遗址100余处,被学术界称为"东方奥杜韦(Olduvai)峡谷"。由于缺乏合适的年代测定方法,许多重要的遗址,尤其是中更新世时间段的遗址缺乏年龄数据,如三棵树遗址,使得旧石器遗址研究少了时间轴合理的年代学框架。电子自旋共振(ESR)测年技术是上世纪60年代发展起来的一种测年技术,并在实践中得到了地质学界的广泛认可。对于中更新世遗址年龄的测定,ESR测年法具有明显的优势。本文利用石英Ti-Li心ESR法对三棵树遗址沉积物样品进行了独立年代测定,得到三棵树遗址文化层的年龄为599±70 kaBP。该年龄对于了解泥河湾盆地古人类的生存演化提供了必要的年代学依据。

The Nihewan Basin has attracted much attention owing to its well-developed late Mesozoic lacustrine strata and abundant Paleolithic sites and mammalian fossils.More than 100 Paleolithic sites have been found in the basin,which is known in academic circles as the“Olduvai canyon of the East”.Suitable dating materials are lacking;therefore,few independent ages are associated with Middle Pleistocene sites.Sankeshu Paleolithic site is one such example.This situation leaves the study of Paleolithic sites without a sound chronological framework.Electron spin resonance(ESR)dating technology is a dating technology developed in 1960s and has been widely recognized in geological circles.The ESR dating method has obvious advantages for the dating of the Middle Pleistocene sites,especially for the 400-780 kaBP which can not be dated by the Luminescence method.In this paper,we use quartz Ti-Li center ESR method to date four sediment samples at different depths of the Sankeshu site.The age of Sankeshu site is 599±70 kaBP,which provides a necessary chronological basis for understanding the survival and evolution of ancient humans in the Nihewan Basin.