关键词: 电子自旋共振测年；金牛山古人类遗址的年代

Abstract: Our early work on Uranium-series dating had assigned an age range of 230--300 ka for the Palacoanthropological site of Jingniushan. In this work five more tooth samples from this site were dated with both clcctron--spin--resonance (ESR) and Uranium--series techniques.
Enamel layers were scparatcd for ESR dating. The accumulated dose(AD) was normalized with alaninc dosimeter. As the AD value based on the exponential extrapolation much depends on the highest irradiated dose, linear extrapolation going with high correlation coefficiants was implemented. A value of 0.23 for alpha-effectiveness has been empirically determined, which differs somehow from the commonly accepted value of 0.15. Tentative efforts were made to determine the radon emanation and moisture coefficients. To keep the necessary consistency with the U-dating method on the U-uptake assumption, the ESR ages were calculated on the basis of early U-uptakc model.
The closed-system assumption of the U-series dating was cheched and confirmcd by com-paring thc Th- -230/ U- -234and Pa--231 / U--235 activity ratios for every dentine sample.
The ESR ages, rànging from 197-241 ka, are in fairly good agreement with the U-datcsfor each of these samples. The average ESR age of these 5 samples is 229±28 (ka), which matches the lower end of the published U--scries age range.

Key words: Electron spin resonance dating; Jingniushan; Palaeoanthropology