论文部分内容阅读
现有资料已经证明 ,岩石圈及其以下相当深度的岩石表现为固体性质 ,因此 ,应该按固体内应力状态测算深度 ;岩石力学实验证明围压越大 ,岩石的抗张、抗剪强度越高 ,在持续增高围压的条件下 ,岩石抗压强度几乎是无限的 ,Sibson提出 1 0～ 1 5km左右之下岩石逐渐由脆性转变为韧性 .韧性岩石仍是具有弹性的固体 ,并不处于静流体压力状态 .在目前缺乏反映流变程度数据的情况下 ,当已经测得不可忽略的差应力时 ,暂用弹性固体模型代替静止流体模型可以求算较准确的深度 .由弹性模型进一步发展为粘弹性模型将是一种进步 ,而如果从弹性模型又回到静流体模型则不能认为是一种前进 .构造应力场中大于差应力一个数量级的各向等正应力叠加在重力附加静压力之上 ,能够引起超高压变质作用 .
The available data have proved that rocks in the lithosphere and below are solid in nature. Therefore, the depth should be measured according to the solid internal stress state; rock mechanics experiments prove that the greater the confining pressure, the higher the tensile and shear strength of the rock. The compressive strength of rock is almost limitless under conditions of continuous increase in confining pressure. Sibson proposed that the rock gradually changes from brittle to ductile at about 10 to 15 km. The ductile rock is still an elastic solid and is not static. Fluid pressure conditions. In the absence of current rheological data, when a non-negligible differential stress has been measured, a more accurate depth can be calculated by temporarily using an elastic solid model instead of a stationary fluid model. The elastic model is further developed to The viscoelastic model will be an improvement, and if the elastic model is returned to the static fluid model, it cannot be considered as an advance. The isotropic stress equal to an order of magnitude greater than the differential stress in the tectonic stress field is superimposed on the static pressure added by gravity. On, can cause ultra-high pressure metamorphism.