板块下的构造及地幔动力学

Tectonics beneath plates and mantle dynamics

最新的全球地幔地震层析资料揭示了岩石圈板片可以俯冲到核幔边界,超地幔羽可以从核幔边界上升到地壳上部形成热点。在大陆板块汇聚边界,地幔地震层析图像不仅显示了岩石圈板片的超深俯冲,还保存了拆沉的岩石圈“化石”残片的重要信息。从地幔深部所获取的新资料为全地幔“单层对流“的新模式提供了依据。在介绍上述全球构造研究新动向的基础上,本文强调了研究岩石圈板块必须了解板块下的构造,探索岩石圈板块的驱动力应该从“岩石圈动力学“升华到“地幔动力学“,并提出了大陆板块汇聚边界地幔动力学研究的新思考。

The latest global mantle seismic tomographic data have revealed tectonics beneath plates:the lithospheric slab may be subducted to the core-mantle boundary and the superplume may rise from the core-mantle boundary to the upper crust to form a hot spot.The mantle“single-layer convection”model challenges the mantle“double-layer convection”model.Through the introduction of the aforesaid new hy-pothesis and new model,this paper emphasizes that to study the lithospheric plate is necessary to gain knowledge of the tectonics beneath the plate and that to explore the driving force of the lithospheric plate“lithosphere dynamics”should be sublimated into“mantle dynamics”.