RHEOLOGICAL PROPERTIES OF DEEP SUBDUCTED OCEANIC LITHOSPHERE AND THEIR GEODYNAMIC IMPLICATIONS
  • 【摘要】

    According to the experimental studies on the rheology of two important mantle rocks (eclogite and harzburgite), the rheological properties of the deep subducted oceanic lithosphere are investigated by... 展开>>According to the experimental studies on the rheology of two important mantle rocks (eclogite and harzburgite), the rheological properties of the deep subducted oceanic lithosphere are investigated by assuming a simplified harzburgite type slab model with moderate thickness of basaltic layer. When the mantle convergence rate is small or the subducting slab has been trapped in the mantle for an enough long time, the strength profile of the slab is characterized by a strong subducting crustal component lying on a weak subducting upper mantle. However, if the convergence rate is large enough, the subducting slab will be featured only by a rigid cold center. Our study suggests that the detachment of the subducting crust component from the underlying upper mantle is only likely to happen in hot slow subducting slabs, but not the cold fast subducting lithosphere. Rheological properties of the harzburgitic and the eclogitic upper mantle vary with depths. The eclogitic upper mantle is stronger than the peridotitic upper mantle across the upper mantle. Transition zone is the high strength and high viscosity layer in the upper mantle except the lithosphere. 收起<<

  • 【作者】

    金振民  章军锋  H.W.GREEN II  金淑燕 

  • 【作者单位】

    FACULTY OF EARTH SCIENCES/FACULTY OF EARTH SCIENCES/INST. GEOPHYS. & PLANET. PHYS.

  • 【刊期】

    中国科学:地球科学(英文版) EI SCI 2002年11期

  • 【关键词】

    SUBDUCTION ZONE  MANTLE ROCK  HIGH P-T  DETACHMENT  RHEOLOGICAL LAYERING 

  • 【基金项目】

    国家重点基础研究发展计划(973计划)(G1999075501) THE USA NATIONAL SCIENCE FOUNDATION AND THE CRUST-MANTLE INTERACTION LABORATORY AT CHINA UNIERSITY OF GEOSCIENCES(WUHAN)