柯坪塔格推覆体的新生代变形与扩展  

CENOZOIC DEFORMATION AND PROPAGATION OF THE KALPINTAG FOLD NAPPE

作　　者：宋方敏[1] 闵伟[1] 韩竹军[1] 徐锡伟[1] 

机构地区：[1]中国地震局地质研究所,北京100029

出　　处：《地震地质》2006年第2期224-233,共10页Seismology and Geology

基　　金：中国地震局"新疆巴楚-伽师6.8级地震应急工作专项计划"项目资助

摘　　要：柯坪塔格推覆体位于天山西南麓。新生代以来，由于印度板块与欧亚板块的碰撞，天山晚古生代褶皱和断裂构造重新复活隆起，并向南北两侧推挤，在前陆盆地中渐进式地形成多排褶皱-逆断裂带。文中讨论了皮羌近SN向断裂带以西推覆体的新生代变形与扩展特征。结果表明，推覆体的新生代变形为波浪式差异性隆起。从天山南侧到塔里木盆地方向，构成推覆体的各排褶皱-逆断裂带的形成顺序有先后之分，早期形成的靠近天山，晚期形成的靠近塔里木盆地，反映推覆体在形成过程中由北向南的扩展，其扩展距离最大约76km。除此之外，各排褶皱-逆断裂带前缘都由多条断裂组成，它们与褶皱伴生，具有不同的形成和新活动时代。早期形成的断裂靠近山地一侧，晚期形成的断裂靠近盆地一侧，反映褶皱-逆断裂带单排前缘断裂也具有由北向南扩展的性质，其扩展距离为100—500m。最后，对推覆体扩展的形成机制进行了讨论。The Kalpintag fold nappe is located at the northwestern foot of the Tianshan Mountains. Since Cenozoic, owing to the Indian-Eurasian collision, the Mesozoic fold structures of Tianshan have been rejuvenated, uplifted and pushed northward and westward. As a result, several rows of fold-reverse fault zones have been progressively formed within the foreland basins. This paper describes in detail the Cenozoic deformation features and propagation of the fold-reverse fault zone on the west of the nearly south-north-trending Piqiang fault zone. The results show that the Cenozoic deformation of the nappe was characterized by wavy differential uplift, and this has caused the successive formation of the fold-reverse fault zone from the southern side of the Tianshan Mountains to the Tarim Basin. Among them, the early-formed folds are close to the Tianshan Mountains, while the latter-formed folds are close to the Tarim Basin, indicating the general tendency of northward propagation of the fold-reverse fault zone during their formation process. The distance of propagation may reach up to 76km. Moreover, the front of individual fold-reverse fault zone consists of several fault strands, which are associated with folds and have different ages of formation and time of recent activity. The early-formed faults are close to the Mountain side and the latter-formed close to the basin, indicating the northward propagation of the frontal faults of the individual fold. The distance of propagation is about 100 - 500m. The mechanism of the propagation of the fold-reverse fault zone is discussed in this paper as well.

关 键 词：柯坪塔格 推覆体 褶皱-逆断裂带 变形与扩展 

分 类 号：P315.2[天文地球—地震学]