Evidence of Nd isotope for unhomogeneity and origin of upper mantle of North China platform

Based on isptopic age of Sm-Nd and its initial composition and its evolutio n obtained during the recent years of archean metamorphic magnesio-ferro th e vocanics of upper mantle of the North China platform, it is concluded tha t the isotopic composition of Archean upper mantle of the North China platf orm is not homogeneous, and values of I-Nd don not change regularly through the whole Archean; in contrast, they present obvious differences in differ ent regions. All this demands that the unhomogeneity of Archean upper mantl e of the North China platform inherits initial unhomogeneity of origin, and the origin of the North China platform should contribute to uneven accumul ation of planetesimals.