塔里木盆地南部塘古孜巴斯坳陷发现晚新生代伸展构造

通过认真、系统的地震资料解释，在塔里木盆地南部的塘古孜巴斯坳陷及周缘首次发现晚新生代正断层。在塘古孜巴斯坳陷内部发现的晚新生代正断层走向为北西-南东向，剖面上组合成地堑或堑-垒构造，与巴楚隆起东北缘所发育的晚新生代正断层相似。塘古孜巴斯坳陷西北缘发现的两条晚新生代正断层走向为北东-南西，剖面组合成一地堑构造，与阿瓦提凹陷西北缘沙井子断裂带上发育的晚新生代张扭性正断层带走向一致，但不具备张扭性变形特征。正断层形成于上新世晚期(约3 Ma)，持续演化至更新世早期(约2 Ma)。正断层的活动时间也与阿瓦提凹陷周缘的晚新生代正断层一致。它们形成于一个区域性弱伸展构造应力场内，代表印度-亚洲碰撞远程效应下，塔里木盆地脉式挤压(-冲断)过程中的一个构造间歇期。

New discovery of Late Cenozoic extensional structures in Tangguzibasi depression，southern Tarim Basin

Late Cemozoic normal faults were discovered for the first time in Tangguzibasi depression of southern Tarim Basin based on systematic seismic interpretation. The Late Cenozoic normal faults discovered in Tangguzibasi depression extend mainly in NW-SE direction. Only 2 Late Cenozoic normal faults on the northwestern boundary of Tangguzibasi depression extend in NE-SW direction. The normal faults combine into graben and horst structures in profile. On the basis of the analysis on the variation of the fault displacement, the normal faulting began in Late Pliocene (～3 Ma), and lasted in Early Pleistocene and ceased at ca. 2 Ma. They were formed in the same time as those on the boundaries of Awati sag, NW Tarim. The 3～2 Ma normal faulting occurred under a regional extensional tectonic background, and represent a tectonic pause in the Late Cenozoic far-field effect of the India-Asia collision.