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出 处:《地学前缘》1998年第1期17-39,共23页Earth Science Frontiers
摘 要:一些元素(K,Rb,Re,Sm,Lu,U和Th)的自然长寿命放射性同位素,衰变为另种元素稳定同位素的作用,广泛应用于岩石和矿物的年龄测定。这种测年提供了关于地球地质历史的信息,并已用于标定地质年代表。同位素测年的物理原理并不难理解,但所需要的测定技术,则要求同位素地球化学家利用地质人员采集的样品进行熟练精细的操作。对测年结果的解释也应由双方合作进行,并且在很大程度上依靠区域和地区的地质信息。笔者只介绍最广泛应用于测定岩浆岩和变质岩年龄的同位素方法,其余的一些方法只一提而过。The decay of naturally occurring long lived isotopes of certain elements (K, Rb, Re, Sm, Lu, U, and Th) to stable isotopes of other elements is widely used for dating rocks and minerals. Such dates provide information about the geologic history of the Earth and have been used to define the Geologic Timescale. The physical principles on which isotopic dates are based are not difficult to understand. However, the necessary measurements are best made by skilled isotope geochemists using samples collected by field geologists. The interpretation of the resulting dates should be done collaboratively, but depends critically on information of the local and regional geology. This paper presents only the most widely used isotopic methods of dating igneous and metamorphic rocks. Other methods that are only mentioned in passing are described in textbooks on isotope geology.
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