ESR牙齿珐琅质测年中不同拟合函数对古剂量测定的影响  

The influence of different fitting functions on paleodose determination in ESR dating of tooth enamel-Taking Longgupo tooth fossils as an example

作　　者：韩非[1,2] 尹功明[1] Jean-Jacques Bahain Tristan Garcia 刘春茹[1] 高璐[1] 李建平[1] 

机构地区：[1]中国地震局地质研究所,地震动力学国家重点实验室,北京100029 [2]法国国家自然历史博物馆史前部,1,rue Rene Panhard 75013,Paris,France [3]CEA,LISL Laboratoire National Henri Becquerel,Gif-sur-Yvette,F-91191,France

出　　处：《核技术》2011年第2期116-120,共5页Nuclear Techniques

基　　金：中央级公益性科研院所基本科研业务费(DF-IGCEA-0608-2-17);国家自然科学基金(40902051)资助

摘　　要：本文对单饱和指数(SSE)拟合函数、双饱和指数(DSE)拟合函数、指数加线性(EPL)拟合函数进行了讨论,并对重庆巫山龙骨坡早更新世遗址的8颗哺乳动物牙齿化石的古剂量作了对比研究。结果显示,SSE函数的古剂量拟合结果高于DSE和EPL函数,且拟合残差也较大。与已知参考剂量比较后发现,DSE函数拟合结果的相对偏差最小,SSE函数与参考值的偏差最大。实验说明,对于早期地点的牙齿化石样品采用SSE拟合函数会造成古剂量的高估,DSE的拟合结果更接近样品的真实古剂量。Paleodose determination is essential for ESR dating, and the DE value is influenced by the mathematical functions used for dose response data points fitting. At present, single saturation exponential （SSE） fitting is commonly used for ESR dating. It is valid when the number of trap sites is constant, but when the increasing irradiation dose induces new traps, the dose response curve will not follow a unique SSE function. In this study, in addition to SSE, the double saturation exponential （DSE） and exponential plus linear （EPL） functions were used to fit the ESR data of eight tooth fossil samples from Longgupo early Pleistocene site in Wushan, Chongqing. The results show that the DE values calculated by SSE fitting function are systematically higher than DSE and EPL, and the residual sum of square of SSE is larger than the other two. Compared with known reference dose value, we found that DSE has the smallest relative deviation among the three functions, and the SSE has the largest deviation. The study indicates that the SSE nction overestimates DE value of tooth fossil samples from old sites, while the DE value determined by DSE functions seems closer to the true value ofpaleodose.

关 键 词：古剂量 拟合函数 ESR测年 牙齿化石 龙骨坡 单饱和指数 双饱和指数 

分 类 号：P597.3[天文地球—地球化学]