盐构造剖面的分层合并复原方法及应用

提出了盐构造区复原剖面制作的一种新方法——分层合并复原法,即将盐上、盐下和盐层分别复原,然后合并.与传统盐构造区复原剖面制作方法相比,该方法不需要进行均衡调整,减少了均衡调整计算中的误差,更符合实际变形情况.既可用于挤压区,也可用于伸展区;既可用于盐下复杂变形区,也可用于盐下简单变形区.理想情况下,还可通过对比两期复原剖面盐的面积,估算在此变形期间流入或流出剖面盐的面积.利用分层复原法制作的库车坳陷盐构造复原剖面反映出库车坳陷盐构造的发育经历了盐层及盐上层沉积期(65~23.3Ma)、盐构造初动期(23.3~1.64Ma)和盐构造定型期(1.64Ma以来)等3个发展阶段.

Layer-by-layer restoring technique of salt tectonics and its application

The restoration of deformed profiles is very important to tectonic analysis and basin simulation.In salt tectonics,the flowability property of salt makes the restoration of the deformed profiles very difficult.It is impossible to restore the original state of a deformed salt layer according to its original beddings because they are destroyed by the flowability of the salt in the process of the deformation.For this reason,a new restoring technique of salt tectonics is put forward,in which the salt layer,the overburdon of it and the subsalt layer are restored respectively,and then they are assembled.Compared with traditional restoring techniques of salt tectonics,the layer-by-layer restoring technique does not require isostatic adjustment,and so the restoring error is reduced.The method is not only suitable to compression salt tectonics but also extension salt tectonics;not only suitable to the complicated deformation subsalt layer but also to the simple deformation subsalt layer.Under ideal condition,using the method can estimate the salt area flowing in or out the profile by the comparison of the two restored sections before with after the deformation.The technique is applied to the restoration of the salt tectonics in the West Kuche Depression.The results show that the salt tectonics underwent three development stages:the sedimentation of the salt layer and its overburden (56～23.3 Ma),active salt tectonics (23.3～1.64 Ma) and salt tectonics formation (from 1.64 Ma).