摘要
本文通过对分馏引起的Sm-Nd模式年龄扰动与源岩Sm-Nd模式年龄对比发现,两者模式年龄差值远大于由Nelson和DePaolo(1985)给出的Sm-Nd分馏所致的模式年龄误差公式计算出的值。经重新推导,发现原公式有误,正确的Sm-Nd分馏模式年龄误差计算公式应为:
Comparing the Sm-Nd model ages of the fractionation product to those of source rocks, the authors found that the differences between them are much larger than those calculated through the error equation of Nelson and DePaolo (1985). After rederiving, it is proven that the error e-quation of Nelson and DePaolo (1985) lost a mutiple factor-1/(?). The correct error equa-tion of the Sm-Nd model age caused by fractionation is given: Err tDM Be-cause difference between the model ages of fractionated product and its source rocks is larger than what Nelson and DePaolo expected, the significance of granitoid model ages should be considered deeply, which might not represent the real time of crust -mantle fractionation.
出处
《地质论评》
CAS
CSCD
北大核心
1997年第1期52-57,共6页
Geological Review
关键词
岩石
钐
钕
模式年龄
误差
估计公式
fractionation of Sm-Nd, model age, error equation
