泛等时线法同位素定年的理论构想

Theoretical Supposition of Universal Isochron Dating

等时线法同位素定年是经典的地质年代学方法,并衍生出内部等时线和亚样品等时线等方法。根据等时线法的基本原理及前提条件,本文提出了泛等时线定年的理论构想。以Rb-Sr法为例,可以证明,用矿物+全岩构建的内部等时线与全岩等时线属于同一直线方程。用某一样品的单矿物外加其他若干全岩样品也能构成等时线。这种泛等时线可以结合不同等时线法定年的优点,避免其缺点,更有利于定年。

The isochron line geochronological dating is the classical method in geochronology, and minerals internal iso-chron and sub-sample isochron as the derivatives of this meth-od. Following the basic principle and precondition, this paper puts forward the universal isochron method for geochronology. Taking Rb-Sr isotopic system as a sample, it can be proved that the internal isochron equation of minerals and the whole rock is the same as that of the isochron line of some whole rocks. Some whole rocks and minerals from one another rock can also form one isochron line. This kind of universal isochron combines the advantages of internal isochron line and whole rocks line, and avoids the disadvantages. This method provides more choice to geochronological dating.