【摘要】 位于准噶尔盆地南缘西段的托斯台背斜经历了强烈的构造变形,地表出露丰富的断层相关褶皱现象,是北天山山前典型的断层相关褶皱及其叠合的复杂构造单元。笔者从过托斯台背斜地震剖面的构造分析入手,以地表和钻井揭示的构造现象为约束条件,配合基于断层相关褶皱几何变形的数值模拟,建立了与实际数据吻合的构造几何模型,将构造解释的多解性限制在合理的范围内,并通过正演平衡地质剖面制作,再现了托斯台构造几何变形的运动学过程。分析表明准噶尔盆地南缘山前西段存在多期次的构造逆冲推覆与叠加,侏罗纪至白垩纪期间,构造活动以向地表逆冲推覆为主,形成垂向叠加的双重构造;喜山晚期,则以隐伏逆冲为主,形成现今的托斯台断坡背斜,推覆位移量达12km。更多还原

【Abstract】 The Tuositai Anticline,which locates in the western section of the southern Junggar Basin foreland,has been strongly deformed.It is a complex superimposed fault-related fold in the piedmont of the northern Tianshan Mountains with rich fault-related folding marks exposed on the surface.Basing on geometric analyzing of a 2-D seismic line through the Tuositai Anticline constrained by the surface data and the well information,the present paper established the reasonable structural geometric model of the Tuositai Anticline.And then,a geometric numeral simulation cooperated with the geometry of the fault-related folding was developed,and its kinematics are also reconstructed by constructing a series of forward balanced geological cross-sections.The study results indicates that the Tuositai Anticline is a superimposed fold,and its thrusting and corresponding structural overlapping has been experienced several times.During the Jurassic to the Cretaceous,two southern dipping thrust faults had developed at the southern limb of the Tuositai Anticline,which forming a duplex structure,with the Jurassic and the Pre-Jurassic formations were thrust from south to the surface.After that,during the late Himalayan orogeny,another south dipping blind thrust have developed under the pre-existing duplex Tuositai Anticline,thus forming the present Tuosital Anticline with a total 12 km displacements.更多还原