影响地下应力状态的构造作用

Tectonic Activities Affecting Ground Stress State

成岩成矿的外部条件中压力是很重要的因素。地下岩石所受的压力不仅来自上覆岩石的重力 ,而且来自构造力和热力及其它力。这些力合成一个三轴不等的应力状态 ,相当一个以最短轴为半径的球状应力迭加一个差应力。前者影响成岩成矿和变质作用 ,后者控制岩石变形和组构的变化。通过三维应变应力测量 ,这两部分力通过计算是可以区分开的 。

Underground pressure is an important factor for rock and mineral formation. It is derived not only from the gravity force caused by the overlying rocks but also from tectonic, thermal and other dynamic forces. All these forces construct a stress state with three differential axes. The stress state can be described by a sphere stress having the radius of the minimum axis with the superimposition of a differential stress between the maximum and the minimum axes. The spheric stress affects the rock and mineral formation and metamorphism, and the differential stress controls the deformation and the fabric variation of rocks.The spheric stress induced by tectonics is called an additional tectono-hydrostatic pressure,which is a basic of new method of measurement and calculation of fomation depth of geological actions.