北大别变质杂岩主要是一套英云闪长岩质片麻岩。以全岩样品测定得到 10 47± 44 .5 Ma的 Sm - Nd等时线年龄 ,εNd值 - 8.99,r=0 .998。 Nd同位素和 Pb同位素给出的模式年龄也显示这套灰色片麻岩的古老来源。同位素成分研究显示 ,岩石普遍具有较高的 Sr同位素 (>0 .70 7)和较低的 Nd同位素 (<0 .5 12 4)现代比值 ,所有岩石的现代 εNd值均 <0 ,Pb同位素明显偏低 ,这些特征可以与中 -下地壳的同位素成分对比。北大别灰色片麻岩源自一个活化的古老地壳 ,中 -下地壳物质重熔所生成的岩浆经分异形成了北大别灰色片麻岩 ,而它们的形成和演化过程与华北板块向杨子板块下俯冲作用密不可分 ,燕山期花岗岩浆的活动可能使它们经历了最后一次大规模的构造热事件 North Dabie metamorphic complex is mainly a set of diorite dioritic gneiss. The Sm-Nd isochron age of 1047 ± 44.5 Ma was obtained from whole-rock samples with εNd value of 8.99 and r = 0.998. The age of the patterns given by Nd isotopes and Pb isotopes also shows the ancient source of this set of gray gneisses. Isotope composition studies show that rocks generally have modern Sr isotopes (> 0.707) and lower modern ratios of Nd isotopes (<0.124), all modern εNd values ​​for all rocks are <0, and Pb isotopes are significantly Low, these features can be compared with the isotopic composition of the lower crust. The North Dabie gray gneiss originated from an activated ancient crust. The magma generated by remelting of the Middle-Lower crust was differentiated to form the North Dabie gray gneiss, and their formation and evolution are similar to those of the North China plate Subduction of the plate is inseparable from the Yanshanian granite magmatic activity may make them experienced the last large-scale tectonic thermal event