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总结我国扬子地块南缘新元古代—早中生代沉积岩目前已发表的Ｎｄ同位素资料发现，这些沉积岩具有随时间变化而其Ｎｄ同位素组成发生漂移的现象。在绝大多数时间里，它们具有２０００Ｍａ左右的Ｎｄ模式年龄，但在１０００～７００Ｍａ的新元古代和＜４００Ｍａ的晚古生代—早中生代时间段中，Ｎｄ同位素模式年龄急剧降低，反映在此时间段内，新生地幔物质已经进入沉积物的物源区。１０００～７００Ｍａ期间的Ｎｄ同位素变化归因于晋宁期的碰撞造山作用而晚古生代－早中生代沉积岩的Ｎｄ同位素变异起因于海盆发育阶段洋壳的出现。即扬子地块南缘在晚古生代—早中生代期间曾经存在过洋壳，且该洋盆可能是古特提斯大洋分支的一部分。
The present Nd isotope data of Neoproterozoic-Early Mesozoic sedimentary rocks in the southern margin of the Yangtze block in China are summarized. They show that these sedimentary rocks have a shift in their Nd isotope composition with time. In most of the time, they have the age of about 2000Ma Nd mode, but in the Neoproterozoic of 1000 ~ 700Ma and <400Ma of the Late Paleozoic - Early Mesozoic age, Nd isotope pattern age dramatically decreased, reflected in this time period The Neozoic mantle material has entered the provenance area of sediments. The changes of Nd isotope during 1000-700 Ma are attributed to the collision orogeny of Jinning Period and the Nd isotopic variation of late Paleozoic-Early Mesozoic sedimentary rocks is attributed to the appearance of oceanic crust during the development of the basin. That is, the southern margin of the Yangtze block had existed during the Late Paleozoic-Early Mesozoic and the oceanic basin was probably a part of the paleo-Tethys Oceanic Branch.