【摘要】 新疆西南天山乌恰地区早侏罗世软沉积物变形位于湖相砂岩中;由地震触发的软沉积物变形有三个层位,位于下侏罗统康苏组的顶部。变形主要类型为负载(load)、球-枕(ball-and-pillow)、滴状体(droplet)、锥形体(cusps)、液化均一层(homogeneous layer)和液化不整合(liquefied unconformity)。三个变形层位反映乌恰地区早侏罗世末曾连续发生过三次强地震;变形类型机制不同反映三次地震强度有别。乌恰下侏罗统处于中亚塔拉斯—费尔干纳巨型走滑断裂控制的拉分盆地中,断裂走滑伴随地震直接诱发软沉积物变形;古地震震级为Ms6.5～7。更多还原

【Abstract】 Early Jurassic soft-sediment deformation occuring within lacustrine sandstone is distributed mainly in the Wuqia region,SW Tianshan Mountains,Xinjiang.Triggered by earthquakes,soft-sediment deformation was found to occur in three layers of the Lower Jurassic Kangsu Formation.The main styles of deformation structures contain load cast,ball-and-pillow,droplet,cusps,homogeneous layer,and liquefied unconformity.Three deformation layers reflect that the Wuqia region had undergone three strong earthquakes at the end of Early Jurassic.The differences of deformation mechanisms may represent varying magnitudes of earthquakes.During the Late Jurassic,the Wuqia area was located at the pull-apart basin controlled by significant Talas—Ferghana strike-slip fault in central Asia,accompanied by the soft-sediment deformation induced by the earthquakes.It is suggested in this paper that the magnitudes of the paleoseisms may range from 6.5 to 7.更多还原