引言近来关于压缩和拉张状态的探讨,提出低角度断层有可能切入大陆地壳深部。地震剖面上发现在地壳的中间深度存在明显的低角度反射层,这对上述认识无疑是个鼓舞。在某些情况下,这些反射层的分布与大断层带的地面轨迹伴生,而且可能与之相关。如美国怀俄明州温德河和拉勒米山脉的莫因逆掩断层以及塞维尔沙漠挤离构造的情形正是如此。还有一些反射层可以解释为深部的大断层。所有这些反射层在横向上往往是连续的,而且可以进 INTRODUCTION Recent discussions of compression and tension states suggest that low-angle faults may cut into the deep part of the continental crust. There is a clear low-angle reflection layer on the seismic profile at the mid-depth of the crust, which undoubtedly encouraged this understanding. In some cases, the distribution of these reflective layers is associated with, and may be related to, the ground track of a large fault zone. This is the case with the Maine thrusting fault of the Wyder River and the Laramie Mountains of Wyoming, USA, and the Sever Desert formation. Still other reflective layers can be interpreted as deep, large faults. All of these reflective layers tend to be laterally continuous and advanced