Abstract: Based on the Maxwell′ s and Kelvln′ s rheological models,the deformation properties of the different layers in the crust and upper mantle are recongnized using an index called relaxation number,i. e.the ratio of the duration to the relaxation or retardation time.It is indicated that the asthenosphere is always viscous and the deformation properties of the overlying layers are as follows: the mantle lid, the lower crust,and,even, some of the upper crust are viscous in the long geological processes; the upper crust and mantle lid are elastic in the duration of a few decades; and, in general, the upper crust is elastic,while the lower crust and mantle lid are vis cons or anelastic/elasto-viscous in the duration as long as that between the above two situations.In addition, the problems of the flow in the mantle lid, the intraplate long-range transmis sion of driving force, etc. are discussed in terms of the recognition of the deformating properties.

Key words: Crust, Upper mantle, Elastic property, Viscosity, Rheological model, Relaxation number

摘要： 基于Maxwell和Kelvin流变模型,以延续时间与松弛期的比值,即松弛数,作为衡量指标,对地壳、上地幔不同层次的变形属性进行了判别。结果表明,除软流圈地幔主要为粘性流动外,其上各层的情况是：在漫长的地质过程中,不仅岩石圈地幔和下地壳属于粘性,上地壳也有可能处于粘性流动状态；在延续数十年的情况下,上地壳以及岩石圈地幔都可能呈弹性状态；延续时间介乎二者,通常上地壳为弹性,下地壳和岩石圈地幔为粘性或滞弹粘性。此外,还结合变形属性的判别,就岩石圈地幔的流动和板内的驱动力远程传递等问题进行了讨论。

关键词: 地壳, 上地幔, 弹性, 粘性, 流变模型, 松弛数