【摘要】 本文利用野外调查结果、二维地震反射剖面、钻井和测井数据建立了一条横穿库车河地区的南北向构造剖面,将库车冲断褶皱带划分为北部褶皱带、克依构造带、秋立塔格背斜带和亚肯背斜带。作者在库车冲断褶皱带北部发现了渐新世—中新世角度不整合,在库车南部亚肯背斜和东秋立塔格背斜顶部发现了构造生长地层,通过确定构造生长地层的底界,利用库车河地区古近系(下第三系)—第四系磁极柱,判断亚肯背斜和东秋立塔格背斜构造生长地层的沉积时代为5.2±0.2 Ma。上述结果暗示库车冲断褶皱带北部山前带的变形始于渐新世,并且经历了中新世、上新世的构造改造,南部秋立塔格背斜带和亚肯背斜带形成较晚,可能是上新世开始变形,而且变形活动持续至今,由此看来库车冲断褶皱带的变形时代由北向南变新。作者估算东秋立塔格背斜上新世以来(5.2±0.2 Ma)的构造变形量为7.5 km,变形速率为1.5 mm/a。更多还原

【Abstract】 The Tianshan is one of the largest and the most active intracontinental mountain ranges in the world. Ac-tive fold-and-thrust belts flank both sides of the mountain. This paper based on the data of seismic refection profiles, wells, remote sensing, detailed surface structural survey and magnetostrati graphy focuses on the Kuqa thrust system in the central part of the southern Tianshan. In the Kuqa River area, the 60 km wide fold-and-thrust belt is characterized by four east-west-trending folds. Near the mountain front, the Northern fold and the Keyi fold involve Mesozoic and Eogene strata and make two unconformities between the Meocene Jidike Formation and the Eogene Suweiyi Formation and in the Meocene Kangcun Formation. The unconformities im-ply that the beginning of deformation in the Kuqa thrust system is around Oligocene. Toward the Tarim basin, the more recent Miocene to Pleistocene sediment is folded along the Quilitake anticline. Further south, the Yaken anticline is involving the Holocene surface that is folded. The growth strata over the Yaken anticline and the Quilitake anticline are in the lower part of the Pliocene Kuqa Formation. Combining with the magne-tostratigraphic sections on the both sides of the Qiulitake anticline we suggest that the timing of deformation on the Yaken anticline and the Quilitake anticline is the early Pliocene (5. 5 ± 0. 2 Ma), and an average slip rate of 1. 5 mm/a since Pliocene is estimated on the Quilitake anticline.更多还原