东天山东段碱泉子-巴里坤断裂系晚第四纪左旋走滑的地质证据

发布时间：2018-04-26 19:28

本文选题：东天山 + 走滑断裂系　；参考：《地震地质》2016年03期

【摘要】：东天山至阿尔泰一带吸收了约10mm/a的地壳缩短量,占印度-欧亚大陆缩短量(约40mm/a)的~(1/4),其中一部分变形量在阿尔泰一带通过断裂的右旋走滑和块体的逆时针旋转的联合作用吸收,但东天山一带的地壳变形吸收和调节方式目前仍然存在争议。通过近年来在东天山东段碱泉子、巴里坤山和哈尔尼克山进行的野外地质调查工作,发现东天山东段展布1个左旋走滑断裂系。自西向东,碱泉子-托莱泉断裂、巴里坤盆地南缘断裂和哈尔尼克山中央断裂构成该断裂系的主要格架,这个断裂系在东天山晚第四纪乃至新生代以来的造山过程中调节了山脉隆升过程的变形分配。这些断裂的晚第四纪活动随着断裂走向与区域主应力(NE向)夹角大小的变化呈现不同的活动特征。具体来说,近EW向的碱泉子-托莱泉断裂展现出以走滑为主的特征,这种特征一直延伸到EW—NW向巴里坤盆地南缘断裂的雄库尔一带,但自洛包泉以东巴里坤盆地南缘断裂开始发育逆冲分量,在巴里坤县城以东断裂的活动则表现为逆冲伴随走滑,往东NWW—EW向的哈尔尼克山中央断裂则又呈现出以走滑为主的特征。断裂系的活动特征耦合在东天山东段的造山过程之中,调节和吸收了部分地壳变形,造山带根部断层的变形在造山过程中可能并不是唯一起决定性作用的释放方式。
[Abstract]:The eastern Tianshan to Altai area absorbed about 10mm/a 's crustal shortening, accounting for a quarter of a percent of the India-Eurasian shortening. Some of the deformation was absorbed in the Altai area by the combination of the right-hand strike-slip of the fault and the counterclockwise rotation of the block. However, the absorption and adjustment of crustal deformation in the East Tianshan area are still controversial. Based on the field geological survey in recent years in the eastern segment of East Tianshan Mountain, it is found that there is a left-lateral strike-slip fault system in the eastern section of East Tianshan Mountain. From west to east, the main framework of the fault system is the Jiquanzi-Tolaiquan fault, the southern margin fault of the Balikun basin and the central fault of Halnik Mountain. During the late Quaternary and Cenozoic orogeny of East Tianshan, this fault system regulates the deformation distribution of mountain uplift. The late Quaternary activities of these faults show different active characteristics with the variation of the angle between the strike of the fault and the NE direction of the regional principal stress. Specifically, the near EW trending Jiquanzi-Tolaiquan fault shows a strike-slip feature, which extends to the Xiongkur area of the southern margin of the EW-NW to the Barricun Basin. However, thrusting components began to develop in the southern margin of the Balikun basin east of Luobaoquan, and the activity of the faults east of Balikuncheng shows that thrusts accompanied by strike-slip. Towards east NWW-EW, the central fault of Halnick Mountain shows the characteristics of strike-slip. The active characteristics of the fault system are coupled in the orogenic process of the eastern part of the East Tianshan Mountains, which regulates and absorbs some crustal deformation. The deformation of the root fault of the orogenic belt may not be the only decisive releasing mode in the orogenic process.
【作者单位】：中国地震局地质研究所活动构造与火山重点实验室;中国地震局地质研究所地震动力学国家重点实验室;中国地震局地壳应力研究所;
【基金】：财政部项目“中国重点监视防御区活动断层地震危险性评价”(1521044025)资助
【分类号】：P315.2

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