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已有活动构造研究结果表明,天山北缘具有典型的大陆内部活动构造特征,表现为多排平行山体的背斜和逆断裂.为了研究乌鲁木齐坳陷区的地壳细结构、主要断裂展布和深、浅构造关系,2004年底,在乌鲁木齐西部的天山与准噶尔盆地之间的过渡带上,完成了一条近SN向的长度为78 km的深地震反射探测剖面.结果表明,该区地壳以双程走时9~10.5 s左右的强反射带为界分为上地壳和下地壳,上地壳厚约26~28 km,下地壳厚约23~25 km.双程走时5 s以上,反射层位丰富,构造形态清晰,且在剖面横向上具有明显不同的构造特征;在西山以南的区域,为一系列近东西向展布、南北向排列的逆冲背斜构造和一组自南向北逆冲的断裂,它们在深部均受到滑脱带的控制;在西山和王家沟一带,为一套向北陡倾的反射层系和一组沿层间滑动的断裂;剖面北部显示出了典型的沉积盆地图像,沉积盆地最深处约为10~12 km.双程走时6~9 s之间,为一些延续长度较短、反射能量较弱、且无规律可寻的凌乱反射,表明这部分地壳结构具有明显的“反射透明”性.Moho过渡带出现的时间位于双程走时14~17 s,对应壳幔过渡带厚度约为9~10 km.本区Moho面自北向南逐渐加深,剖面北部其深度约为50~52 km,在靠近北天山附近,其深度约为54~55 km.在剖面中部的西山附近,上、下地壳分界面反射和Moho过渡带反射变得模糊,且浅部地层还出现隆起和褶皱,推测与准噶尔盆地和天山的挤压过程有关.
The results of the active tectonics indicate that the northern margin of the Tianshan Mountains is characterized by typical continental intracontinental tectonics characterized by anticlines and reverse faults of multiple parallel mountains.In order to study the fine crustal structure of the Urumqi depression, , And a shallow tectonic relationship at the end of 2004. At the transitional zone between the Tianshan Mountains and the Junggar Basin in western Urumqi, a near-trending deep seismic reflection and sounding profile measuring 78 km in length was completed at the end of 2004. The results show that the crust of the area consists of two- The time interval of 9 ~ 10.5 s is divided into upper crust and lower crust. The upper crust is about 26-28 km thick and the lower crust is about 23-25 km. The double-way travel time is more than 5 s, and the reflection layer is rich. It is characterized by a clear tectonic pattern and distinctly different structural features in the transverse direction of the section. In the area south of the Xishan Mountains, it is a series of thrust distributions with near-EW distribution and north-south alignment and a group of NW- , Which are controlled by the detachment belt in the deep part. In the Xishan and Wangjiagou areas, they are a set of north-steep reflections and a set of faults that slide along the layers. The northern part of the profile shows typical sedimentary basins Image, most sedimentary basin Is about 10 ~ 12 km. Two-way travel time between 6 ~ 9 s, for some short continuation length, the reflection energy is weak, and irregular disorder can be found, indicating that this part of the crustal structure has obvious “reflection Transparent. ”The Moho transitional zone appears at a time of 14-17 s, with a corresponding crust-mantle transitional zone of about 9-10 km. The Moho surface in this area is gradually deepened from north to south with a depth of about 50 ~ 52 km, near the North Tianshan Mountains, with a depth of 54-55 km. Reflecting the upper and lower crustal interfaces and the Moho transitional zone near the western part of the profile, the reflections of the upper and lower crusts become blurred and the shallow formations also show uplift and Fold, speculated that the Junggar Basin and Tianshan extrusion process.