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在压力3GPa,温度1450～1600K,应变速率10-4～10-5s-1条件下,对深俯冲带和上地幔中两种重要岩石（榴辉岩和方辉橄榄岩）的流变性质进行了实验研究,获得了榴辉岩在超高压条件下的流变参数,应力指数为3.4,活化能为480kJ/mol,活化体积为12cm3/mol.实验结果表明具有中等石榴石含量榴辉岩的流变强度与方辉橄榄岩的流变强度在上地幔浅部条件下基本相当,是多晶绿辉石岩强度的2～3倍和多晶石榴石岩强度的一半.随榴辉岩中石榴石含量的逐步增加,岩石的整体流变强度也不断增大.在实验研究基础上,计算了不同板块汇聚速率条件下深俯冲大洋岩石圈在不同深度层次上的流变强度,以及橄榄岩和榴辉岩上地幔流变强度随深度的变化.研究表明,俯冲洋壳从下覆的上地幔拆离出来最有可能发生在缓慢俯冲的热俯冲带中;而快速俯冲的冷俯冲带,俯冲地壳与上地幔之间在强度上是耦合的,发生拆离的可能性不大.过渡带是上地幔中除岩石圈地幔外的高强度和高黏度层.
The rheological properties of two important rocks (eclogite and harzburgite) in the deep subduction zone and the upper mantle under the conditions of pressure 3 GPa, temperature 1450-1600K and strain rate 10-4-10-5s-1 The rheological parameters of the eclogites under ultrahigh pressure were obtained, and the stress exponent was 3.4, the activation energy was 480 kJ / mol and the activation volume was 12 cm3 / mol.The experimental results show that the eclogites with medium garnet content The rheological strength of the harzburgite is roughly equivalent to that of the karst rock in the shallow part of the upper mantle, which is about two to three times the intensity of the polychromasite and half the intensity of the polycrystal garnet. Garnet content gradually increased, and the overall rheological strength of rock also increased.On the basis of experimental study, the rheological strength of deep-subducted oceanic lithosphere at different depth levels under different plate convergence rates was calculated, and the peridotite And the variation of rheological strength with depth of mantle from eclogite.Research shows that the subduction of oceanic crust is most likely to occur in slow subducting hot subduction zone when detachment from the overlying upper mantle.The rapid subduction of cold subduction zone and subduction Between the crust and the upper mantle in strength is Bonded, detached unlikely occurrence. On the mantle transition zone is, in addition to a high strength rock mantle layer and the high viscosity.