用化石生长线–日长推定地层年龄的方法：以元古界和新生界为例

A Dating Method by Fossil’s Growth Line and Day-Long: Examples from Some Proterozoic and Cenozoic Datings

摘要: 地史期间地球的自转速度一直处于逐渐减慢的状态，导致地球1年的天数变少(化石生长线清楚地记录了这个事实)，日长(1天有多少小时)增加。构建起地球年龄、地层时代和自转速度(日长)这三者的函数关系后，即可用化石生长线记录的日长推定化石赋存地层的年龄。本文概要介绍了新提出的生长线–日长定年法的立论思路和计算方法。对前人研究过的元古界及新生界的若干实例用生长线–日长定年法进行计算并比较两者的结果，证明本方法可作为同位素定年法的验证和补充。

Abstract: The rotational velocity of the earth had been becoming slower and slower during all the geohistorical process. It results in the day numbers in one year being fewer and fewer, which is recorded clearly by the growth lines on the fossils. Correspondingly, the day-long (hours in one day) had been becoming shorter and shorter during the geohistory. To make up a function relation among three variables, namely, the earth’s age, the stratigraphic chronology and the day-long, we can calculate the age of fossil-bearing strata by the data of day-long indicated by the fossil’s growth lines. The paper introduces, briefly, the theoretical thoughts and calculating formulas of the “growth line-day-long dating method” presented by the paper. Some Proterozoic and Cenozoic examples worked by the predecessors are re-dated by the new method, and the comparative study between the both demonstrates that the new method could act as a verification and supplement for the isotopic dating method.