沂沭断裂带的运动特征及构造碎屑的形变测量

沂沭断裂带是几个地体的推覆拼贴带.本文根据对5375个断裂碎屑进行的三度空间和其表面形迹测量报取得的近3万个数据,阐述了断裂形成的碎屑在运动中的状态和特点.反演出两盘地体的某些活动特征,总结了两种形变,圈定了形变中心,为进一步研究沂沭断裂带开阔了思路.本文在构造地质学中具有一定的意义,对地震地质学的研究有积极的作用.

THE MOVEMENT CHARACTERS OF YISHU FAULT BELT AND DEFORMATION MEASURE OF STRUCTURAL FRAGMENT

During tectonization process, fragments of fault took colliding and extruding one another, which caused structural features in different direction existing on the fault surface and fragment got smaller and smaller. Superposition of structure effects also on fragment surface. Usually, long axis of the fragment is parallel with movement direction, while short axis indicate advancing direction, which is different with boulder that controlled by run-off water with open environment on the earth surface. Fragment of the fault was affected by ground stress under the confining environment. Since the direction of moverment is different, usually, slickenside has angle with the long axis existing on the fragment surface. With the well-preserved fragment surface, we can determine sixteen to seventeen new structural movements and measure their pitch directions. Fragment of fault movement is also with rolling style and jumping style. The antithetic slickenside with equidistance formed during the intermittent of pulse movement. Gravel stronge deformation takes slump style movement as the key, which reflect exactly the direction of new tectonization. The deformation of fragment of fault includes psephicitying and flattening. Flattening can be divided into five levels according to the psephicitying: level zero to one is of low level psephicitying. level two is characteristiced by subedge angle fragment, level three to four take cylindrical and elliptic fragment, level five is called for rounded fragment. Flattening can be divided into six levels according to long and short axis of fragment. It is easy to distinguish the fragments base on the camber and curve of fragment. As mentioned above, author pinpointed the deformation/centers on Yishu fault belt which occurred 20 to 40 km wide and 320 km long, which makes a good foundation for researching the characteres of the fault movement and earthquake.