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We present here experimental study of the rheological properties of UHP eclogite from Dabie at a pressure of 3 GPa by utilizing the 5 GPa Griggs type piston cylinder apparatus. The rheological constitutive equation of eclogite is determined with a stress exponent of 3.4, an activation energy of 480 kJ/mol and a preexponential factor of 103.3. Our!study shows that: (1) As a typical two phase rock, the flow strength of eclogite depends on the proportions of the strong phase (garnet) and the weak phase (omphacite); (2) The plastic deformation of eclogite is dominated by dislocation creep; (3) Based on that eclogite has the same strength as the upper mantle harzburgite, our study suggests that the delamination of the subducting crust component from the underlying upper mantle is unlikely. Therefore, the stretching after the collision orogeny coupled with the upwelling of the upper mantle may play a more important role in the exhumation of UHP rocks.
We present here experimental study of the rheological properties of UHP eclogite from Dabie at a pressure of 3 GPa by utilizing the 5 GPa Griggs type piston cylinder apparatus. The rheological constitutive equation of eclogite is determined with a stress exponent of 3.4, an activation energy of 480 kJ / mol and a preexponential factor of 103.3. Our! Study shows that: (a) As a typical two phase rock, the flow strength of eclogite depends on the proportions of the strong phase (garnet) and the weak phase (omphacite) (2) The plastic deformation of eclogite is dominated by dislocation creep; (3) Based on that eclogite has the same strength as the upper mantle harzburgite, our study suggests that the demination of the subducting crust component from the underlying upper mantle is unlikely Thus, the stretching after the collision orogeny coupled with the upwelling of the upper mantle may play a more important role in the exhumation of UHP rocks.