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近些年,宇宙成因核素暴露年代、光释光和放射性碳埋藏年代等方法在第四纪冰碛物的年代测定中已经取得显著进展.但对于第四纪冰川沉积物10万年甚至百万年以上的冰碛物样品的埋藏年代和暴露年代,由于方法自身问题或沉积物后期地质地貌过程的改造,使上述方法存在定年方面的挑战.而电子自旋共振(ESR)广泛的测年范围,使其在第四纪样品的测年中发挥着不可替代的作用.目前,石英ESR信号的衰退特征已有许多研究进展,但是对于冰碛物中的ESR信号的研究还很少.ESR测年方法由于缺乏测年机理的研究,西方学者和国内一些测年学者对这种方法的定年存有疑虑.因此,我们在典型冰川区开展对冰碛物中石英砂ESR信号变化的机理研究,得到人工研磨可以使ESR信号强度下降到原来值的53%~69%,但并不能使ESR信号完全归零.如果在以后的研究中能够找出这些残留信号值大小,并予以扣除,将会大大提高ESR冰碛物测年精度.在今后的研究中应探求其测年机理,提高测试样品的石英纯度,增强ESR测年信号的精度,使这种方法成为冰碛物交叉测年中独立可信的测年方法之一,为第四纪冰川研究中的老冰碛物的定年提供准确的年代依据.
In recent years, methods such as age of cosmic nuclide exposure, age of light-emitting and radiocarbon burial have made remarkable progress in the dating of Quaternary moraines, but for the Quaternary glacial sediments of 100,000 or even 100 In the years of burial and exposure of the samples of moraines above 10,000 years, the above methods have the challenges of dating because of their own problems or the modification of the geological and geomorphological processes of the sediments, whereas the ESR has a wide range of dating Range so that it plays an irreplaceable role in the dating of Quaternary samples.At present, there have been many studies on the decline characteristics of quartz ESR signals, but few studies have been done on ESR signals in moraines.ESR Due to the lack of dating mechanism, Western scholars and some Chinese dating scholars have doubts about the dating of this method, so we studied the mechanism of ESR change in quartz sand in moraines in a typical glacial region , Artificial grinding can reduce the ESR signal strength to 53% ~ 69% of the original value, but it can not completely zero the ESR signal.If we can find out the residual signal value in later research, And will be deducted, will greatly improve the ESR moraine dating accuracy in future research should explore its dating mechanism to improve the purity of the test sample of quartz, ESR dating signal to enhance the accuracy of this method to become a moraine One of the credible dating methods in cross dating dating provides an accurate chronological basis for the dating of old moraines in Quaternary glaciers.