华北与扬子克拉通早期相互关系的Nd同位素地球化学制约

对于前寒武纪、特别是中、上元古代、华北和扬子克拉通大地构造特征及其相互关系的认识是长期争议的问题之一，其核心在于两克拉通是否属于同一大陆央石圈板块，扬子克拉通及其北缘由于研究程度较低，部分地质体缺乏可靠地质年代数据，影响了研究工作的进一步深入，本文就扬子克拉通北缘汉中碑坝和西乡地区重要地质体的形成时代作了系统的Ｒｂ－Ｓｒ、Ｓｍ－Ｎｄ和部分颗粒锆石Ｐｂ同位素蒸发年龄方法的同位素年代学分析的Ｒｂ－Ｓｒ

THE Nd ISOTOPIC GEOCHEMICAL CONSTRAIN ON THE CONTINENTALLITHOSPHERE RELATIONSHIP IN THE EARLY HISTORY BETWEENYANGTZ AND NORTHERN CHINA CRATONS

It is debatad for a long time for the understanding of the regional tectonic and continental lithosphere relationship involving that,in Precarnbrian,especially in the Middle Proterozoic and Late Proterozoic, whether Yangtz and northern China cratons were shared a single continental lithosphere. Based on increased and improved available isotopic chronological datum from the northern margin of Yangtz craton, Xixiong and Beiba areas and the northern China craton, through systematic Rb-Sr,Sm-Nd and single zircon evaporating Pb analysis,this paper studies, by means of isotopic tracers,the properties,evolution features and differences of the upper mantle of two cratons,and come to a conclusion that two cratons should be developed from two different continental upper mantle systems in Precambrian by the constrain of Nd isotope.