摘要
恒山灰色片麻岩中变基性岩的微量锆石U－Pb方法测定结果为：（1850±2）Ma，应代表吕梁期变基性岩墙（脉）的形成时代。三个由不同时代变基性岩构成的Sm－Nd全岩混合等时线年龄结果没有地质意义，不能作为恒山灰色片麻岩中变基性岩包体的形成时代。
The U-Pb trace zircon isotope age (1850± 2 Ma) of metabasites from the Hengshangrey gneiss is interpreted as the formation age of metabasite dikes during the Luliang period. Analyses of two samples yield indistinguishable (within the limit of error ), concordant ages of 1850±4 Ma and 1 852± 5 Ma, respectively. Five analyses of the two samples define a linear array with anupper intercept at 1 849+4/-5 Ma and a lower intercept at 636+38/-74 Ma. A pooling of this upper intercept age with the two concordant ages gives an age of 1 850±2 Ma. Three Sin-Nd wholerock isochron ages yielded by the metabasites of various ages cannot be regarded as the formationage of metabasite enclaves from the Hengshan grey gneiss.
出处
《矿物学报》
CAS
CSCD
北大核心
1999年第3期262-266,共5页
Acta Mineralogica Sinica
基金
国家自然科学基金!49773187
