断层相关褶皱的几何学模型及其应用

Geometric Models of Fault-related Folds and Their Application

在前陆盆地逆冲带中发育两种主要的断层相关褶皱构造样式:断层转折褶皱和断层传播褶皱。利用断层相关褶皱 的下伏断层和上覆褶皱之间的角度参数存在的函数关系,可以对自然构造横剖面的构造解释进行检验。由于在时间地震剖 面下的构造图形由于产生变形而与实际的自然构造有一定的偏差,这会影响几何学模型检验的有效性,因此在应用的过程中 需要进行校正。通过地震速度谱将时间地震剖面转化为深度地震剖面,然后利用几何学关系对断层相关褶皱的构造剖面进 行了检验。

There are two main types of fault-related folds in the foreland thrust belts, i. e. , fault-bending folds and fault-propagation-folds. Forthe brittle rock deformation, there exists quantitative geometric relationship between fault shape and fold shape. According to the specific angular function relationships of fault-related fold models, the natural geological structures and the interpretation of seismic sections can be analyzed and tested geometrically. Through examination of seismic-time sections it is found that the structure configurations always lose shapes from their natural structures, thus an effect on the validity of geometric tests will occur. The transformation from the seismic-time section into the seismic-depth section by seismic speed spectrum can be carried out to test the reasonabili-ty of the interpreted structures. The subsurface structure examples of the tests are given from the Tarim oil field in Kuqa basin. With the geometric analysis and tests of the subsurface structures, the authors have successfully interpreted and predicted the original existence of the fault-bending folds and fault-propagation folds in fault-related folds of Kuqa area.