地质力学认为,当地壳中不同大小,不同形状的任何部分发动运动的时候,作用于它周围的各项力的分布情况,一般是复杂的、多样的、不平衡的。它们的合力,除在特殊情况下,不通过该部分的质量中心(重心)。这样,该部分作为具有一定刚性的整体,就不免有转动的趋向。在弥满岩石的空间,岩块或地块不可能自由转动,只能让它自身对周围的岩石发生旋扭运动,以致产生旋卷构造。 Geomechanics holds the view that the distribution of forces acting around it in the movement of any part of different sizes and shapes in the earth’s crust is generally complex, diverse and unbalanced. Their resultant, except under exceptional circumstances, does not pass the quality center (center of gravity) of that part. In this way, the part as a whole with a certain rigidity can not help but have a tendency to rotate. In a space full of rocks, rocks or parcels can not freely rotate, but only allow themselves to twist and twist the surrounding rocks, resulting in a convoluted structure.