【摘要】 变换构造分析对于研究伸展断陷盆地的构造格局与油气分布具有重要的意义。在前人研究成果和近年来渤海湾盆地大量地震反射剖面解释的基础上,讨论了变换构造研究中一些有争议和有意义的问题。(1)对变换构造研究中采用的术语,诸如分段构造、变换构造、传递带、调节带和转换带重新进行了定义,并阐述了其基本概念。(2)根据侧列控凹主断层之间连接方式的不同,提出了一个新的分类方案,首先将变换构造划分为传递带、调节带和转换带3类,而后考虑每类变换构造特有的标志细分为若干亚类。(3)传递带和调节带的形成机制一般与侧列的控凹断层位移量沿其走向均匀变化有关。在断层中段位移量最大,在其末端,位移量减至最小。传递带和调节带形成于断层末端,然而,由于侧列断层叠覆程度的差异、位移量是否守恒、断层的倾向状况以及平面上侧列断层末端之间的横向距离等诸多因素,从而产生传递带或者是调节带以及与之有关的多种多样的变换构造样式。与传递带和调节带不同,转换带以连接不同伸展构造段的转换断层为特征,推测其形成是由于地壳伸展速率的巨大差异所致。更多还原

【Abstract】 Analysis of transform structures is important to study regional structural setting and hydrocarbon occurrence in extensional fault depressions.Based on previous studies and recent explanation of extensive seismic reflection survey in Bohai Bay Basin,some controversial and interesting problems of the transform structures are discussed in this paper.(1) We redefine the technical terms of the transform structures used in previous studies,such as segmentation structrure,transform structure,transfer zone,accommondation zone and transform zone,and illustrate its fundamental concepts.(2)According to different modes of the transform structures,which links two relay master faults and related fault depressions,a new scheme of classification is presented.First,the transform structures can be classified as three major types:transfer zone,accommondation zone and transform zone,and than,considering its special criteria,each type of the tranform structures is subdivided further into some subtypes.(3)Formation mechanism of transfer zone and accommondation zone is closely related with regular change of displacement along fault strike.The maximum displacement occurs in center segment of fault and gradually reduced to minimum toward fault termination,at which the transfer zone and accommondation zone are developed.However,because of difference in some controlling factors,such as overlapping degree of relay faults,keeping or not keeping constant displacement,attitude of relay faults dip and transverse distance between the ends of relay faults in plane view,either transfer zone or accommondation zone and a wide variety of its related structure styles are formed.Differing from the transfer zone and accommondation zone,the transform zone is characterized by transform fault which links different segments of extensional structural domains.It is suggested that the transform zone is formed due to difference in crustal extensional rate.更多还原