Rheological structure of the 660 km discontinuity in the Earth's mantle

为了了解流变学性质（如660 km深度处的粘度差）在地球深部地幔物质行为中的作用，基于现场观测的高压高温变形实验，对地幔矿物流变学进行了研究。我们证明了粒度敏感蠕变的重要性，以及位错蠕变，在变形的上地幔橄榄石，在地幔过渡区的显着水弱化的wadsleyite，和分离的洋壳近660公里的深度是不太可能的，由于低粘度之间的对比ringwoodite和majorite。

To understand a role of rheological properties (such as viscosity contrast at 660 km depth) in material behaviors in the Earth's deep mantle, the rheology of mantle minerals were studied based on high-pressure and high-temperature deformation experiments with in situ observation. We demonstrated the importance of grain-size-sensitive creeps, as well as dislocation creep, in deformation of the upper mantle olivine, the significant water-weakening of wadsleyite in the mantle transition zone, and that separation of oceanic crust near 660 km depth is unlikely due to low viscosity contrast between ringwoodite and majorite.