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  • CN 62-1070/P
  • ISSN 1000-694X
  • Bimonthly 1981
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Establishing Standard Growth Curve (SGC) for Optical Dating of K-feldspar by Least Square Method

  • Yang Hongyu ,
  • Zhao Hui ,
  • Wang Xingfan
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  • 1. Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China;
    2. College of Resources and Environment, University of Chinese Academy of Sciences, Benjing 100049, China

Received date: 2018-01-13

  Revised date: 2018-04-09

  Online published: 2019-02-14

Abstract

The standard growth curve (SGC) provides a possible method for obtaining the De value of the sample efficiently and quickly. However, due to the radiation dose rate, operating procedures and instrument error, etc., each laboratory should develop their own SGC which has unique parameters. In this study, SGC is a standard growth curve obtained by using the least squares method to standardize the test dose corrected signal Lri/Tri * De. It is used to quickly get the equivalent dose De value of the sample. The least square normalization process was realized by the R software; and the standard growth curve of K-feldspar was established at 50, 100, 150, 200, 250℃. It is found that the SGC has the best convergence at 250℃; and the signal fading rate is negligible at this temperature. Therefore, we estimate the equivalent dose of the sample by using the SGC function at 250℃. By comparing the consistency of 250℃ SGC De and 250℃ MET-pIRIR De, it is found that in the dose range of 0-500 Gy the obtained De values are well consistent by SGC and MET-pIRIR methods, which indicates the reliability of the SGC method in this range. There are obvious differences in the higher dose range (>600 Gy) compared to the MET-pIRIR results. The insufficient number of older samples used to fit SGC in this study leads to the function parameters is not accurate enough in the high dose region. On the other hand, 600 Gy is close to the saturation dose level of 844.5 Gy, so the De measured is likely to have a large deviation in the region of >600 Gy. It is necessary to gradually accumulate more samples to improve the SGC parameters in the future work.

Cite this article

Yang Hongyu , Zhao Hui , Wang Xingfan . Establishing Standard Growth Curve (SGC) for Optical Dating of K-feldspar by Least Square Method[J]. Journal of Desert Research, 2019 , 39(1) : 97 -104 . DOI: 10.7522/j.issn.1000-694X.2018.00040

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