动态部分熔融作用及其地球物理意义

本文着重阐述了上地幔动态部分熔融动力学的几个基本问题:(1)初始熔融物的产生;(2)渗透和萃取;(3)运移和聚集;(4)研究方法、内容及其地球物理意义。笔者强调指出,在初始熔融阶段,两面角是控制上地幔熔融物的几何分布、渗透性和连通性能的关键参数,少量熔融物(2%~5%)不仅会使软流圈中地震波速下降、导电率增加,而且还引起上地幔非弹性衰减现象。

DYNAMICAL PARTIAL MELTING AND ITS GEOPHYSICAL SIGNIFICANCES

Dynamical partial melting has great significances in understanding the movement of plate tectonics, transportation of deep heat energy, formation of primary magma and mechanism migration of melts. At the stage of initial melting, the distribution geometry of primary melts is characterized by different dihedral angles which control the permeability of the mantle and connectivity of melts in the unmelting matrix. A small melt fraction(2%-5%) not only decreases seismic wave velocity, but also increases electrical conductivity. Melts cause profound anelastic attenuation in the asthenosphere. In this paper, some basic problems of dynamic melting are introduced to attract attention to this new research field.