自从1969年Wasserburg等把计算技术应用于同位素质谱分析以后,使同位素分析精度和同位素地质学得到迅速发展。第二年,还是Wasserburg及其同事以高精度的锶同位素分析,得到了Colomera铁陨石的年龄,同时得到了一个等于0.698990±0.000047的宇宙中~(87)Sr/~(86)Sr的初始比,称为BABI(Basaltic Achondrite Best Initial)。几年之后,地质年代学家们 Since 1969 Wasserburg and other computational techniques applied to isotope mass spectrometry analysis, the rapid development of isotope analysis accuracy and isotope geology. The following year, Wasserburg and his colleagues analyzed the age of the Colomera meteorites using high-precision strontium isotope analysis and obtained an initial ratio of ~ (87) Sr / ~ (86) Sr in the universe equal to 0.698990 ± 0.000047 , Known as BABI (Basaltic Achondrite Best Initial). A few years later, geochronology geologists