| Behavior of natural polycrystalline rocks | |||||||||
| Flow laws for steady-state creep: High-stress regime Power-law creep implies that at 500ºC olivine would only deform at unrealistically high stresses. A better description of the behavior of olivine at high-stress regime (> 200MPa) is given by the Dorn's law, a relationship that is not as temperature dependent as the power law, in which Qd is an activiation energy, σd a critical stress that must be exceeded, and εd is the critical strain rate. |
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| Sensitivity of Flow Curves to Thermo-Dynamical Parameters and Chemical Environment Confining Pressure and Temperature Confining pressure prevents the sample from falling apart. It is therefore not surprising that increasing confining pressure increases the amount of deformation a sample can accumulate before failure (bottom left figure) and allows for larger differential stress to be supported. Temperature enhances the ductility of material. Under high temperature material can therefore accumulate more strain but they can do so for a smaller amount of differential stress. |
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| Courtesy Mervyn Paterson (ANU) | |||||||||
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